# --
# Kernel/System/Ticket.pm - all ticket functions
# Copyright (C) 2001-2014 OTRS AG, http://otrs.com/
# --
# This software comes with ABSOLUTELY NO WARRANTY. For details, see
# the enclosed file COPYING for license information (AGPL). If you
# did not receive this file, see http://www.gnu.org/licenses/agpl.txt.
# --

package Kernel::System::Ticket;

use strict;
use warnings;

use File::Path;
use utf8;
use Encode ();

use Kernel::System::EventHandler;
use Kernel::System::Ticket::Article;
use Kernel::System::Ticket::TicketACL;
use Kernel::System::Ticket::TicketSearch;
use Kernel::System::VariableCheck qw(:all);

use vars qw(@ISA);

our @ObjectDependencies = (
    'Kernel::Config',
    'Kernel::System::Cache',
    'Kernel::System::CustomerUser',
    'Kernel::System::DB',
    'Kernel::System::DynamicField',
    'Kernel::System::DynamicField::Backend',
    'Kernel::System::Email',
    'Kernel::System::Group',
    'Kernel::System::HTMLUtils',
    'Kernel::System::LinkObject',
    'Kernel::System::Lock',
    'Kernel::System::Log',
    'Kernel::System::Main',
    'Kernel::System::Notification',
    'Kernel::System::PostMaster::LoopProtection',
    'Kernel::System::Priority',
    'Kernel::System::Queue',
    'Kernel::System::Service',
    'Kernel::System::SLA',
    'Kernel::System::State',
    'Kernel::System::TemplateGenerator',
    'Kernel::System::Time',
    'Kernel::System::Type',
    'Kernel::System::User',
    'Kernel::System::Valid',
);

=head1 NAME

Kernel::System::Ticket - ticket lib

=head1 SYNOPSIS

All ticket functions.

=head1 PUBLIC INTERFACE

=over 4

=cut

=item new()

create an object. Do not use it directly, instead use:

    use Kernel::System::ObjectManager;
    local $Kernel::OM = Kernel::System::ObjectManager->new();
    my $TicketObject = $Kernel::OM->Get('Kernel::System::Ticket');

=cut

sub new {
    my ( $Type, %Param ) = @_;

    # allocate new hash for object
    my $Self = {};
    bless( $Self, $Type );

    # 0=off; 1=on;
    $Self->{Debug} = $Param{Debug} || 0;

    $Self->{CacheType} = 'Ticket';
    $Self->{CacheTTL}  = 60 * 60 * 24 * 20;

    @ISA = qw(
        Kernel::System::Ticket::Article
        Kernel::System::Ticket::TicketACL
        Kernel::System::Ticket::TicketSearch
        Kernel::System::EventHandler
    );

    # init of event handler
    $Self->EventHandlerInit(
        Config => 'Ticket::EventModulePost',
    );

    # get needed objects
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');
    my $MainObject   = $Kernel::OM->Get('Kernel::System::Main');

    # load ticket number generator
    my $GeneratorModule = $ConfigObject->Get('Ticket::NumberGenerator')
        || 'Kernel::System::Ticket::Number::AutoIncrement';
    if ( !$MainObject->RequireBaseClass($GeneratorModule) ) {
        die "Can't load ticket number generator backend module $GeneratorModule! $@";
    }

    # load ticket index generator
    my $GeneratorIndexModule = $ConfigObject->Get('Ticket::IndexModule')
        || 'Kernel::System::Ticket::IndexAccelerator::RuntimeDB';
    if ( !$MainObject->RequireBaseClass($GeneratorIndexModule) ) {
        die "Can't load ticket index backend module $GeneratorIndexModule! $@";
    }

    # load article storage module
    my $StorageModule = $ConfigObject->Get('Ticket::StorageModule')
        || 'Kernel::System::Ticket::ArticleStorageDB';
    if ( !$MainObject->RequireBaseClass($StorageModule) ) {
        die "Can't load ticket storage backend module $StorageModule! $@";
    }

    # do we need to check all backends, or just one?
    $Self->{CheckAllBackends} =
        $ConfigObject->Get('Ticket::StorageModule::CheckAllBackends')
        // 0;

    # load article search index module
    my $SearchIndexModule = $ConfigObject->Get('Ticket::SearchIndexModule')
        || 'Kernel::System::Ticket::ArticleSearchIndex::RuntimeDB';
    if ( !$MainObject->RequireBaseClass($SearchIndexModule) ) {
        die "Can't load ticket search index backend module $SearchIndexModule! $@";
    }

    # load ticket extension modules
    my $CustomModule = $ConfigObject->Get('Ticket::CustomModule');
    if ($CustomModule) {

        my %ModuleList;
        if ( ref $CustomModule eq 'HASH' ) {
            %ModuleList = %{$CustomModule};
        }
        else {
            $ModuleList{Init} = $CustomModule;
        }

        MODULEKEY:
        for my $ModuleKey ( sort keys %ModuleList ) {

            my $Module = $ModuleList{$ModuleKey};

            next MODULEKEY if !$Module;
            next MODULEKEY if !$MainObject->RequireBaseClass($Module);
        }
    }

    # init of article backend
    $Self->ArticleStorageInit();

    return $Self;
}

=item TicketCreateNumber()

creates a new ticket number

    my $TicketNumber = $TicketObject->TicketCreateNumber();

=cut

# use it from Kernel/System/Ticket/Number/*.pm

=item TicketCheckNumber()

checks if ticket number exists, returns ticket id if number exists

    my $TicketID = $TicketObject->TicketCheckNumber(
        Tn => '200404051004575',
    );

=cut

sub TicketCheckNumber {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{Tn} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TN!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL   => 'SELECT id FROM ticket WHERE tn = ?',
        Bind  => [ \$Param{Tn} ],
        Limit => 1,
    );

    my $TicketID;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $TicketID = $Row[0];
    }

    # get main ticket id if ticket has been merged
    return if !$TicketID;

    my %Ticket = $Self->TicketGet(
        TicketID      => $TicketID,
        DynamicFields => 0,
    );

    return $TicketID if $Ticket{StateType} ne 'merged';

    # get ticket history
    my @Lines = $Self->HistoryGet(
        TicketID => $Ticket{TicketID},
        UserID   => 1,
    );

    HISTORYLINE:
    for my $Data ( reverse @Lines ) {
        next HISTORYLINE if $Data->{HistoryType} ne 'Merged';
        if ( $Data->{Name} =~ /^.*\(\d+?\/(\d+?)\)$/ ) {
            return $1;
        }
    }

    return $TicketID;
}

=item TicketCreate()

creates a new ticket

    my $TicketID = $TicketObject->TicketCreate(
        Title        => 'Some Ticket Title',
        Queue        => 'Raw',            # or QueueID => 123,
        Lock         => 'unlock',
        Priority     => '3 normal',       # or PriorityID => 2,
        State        => 'new',            # or StateID => 5,
        CustomerID   => '123465',
        CustomerUser => 'customer@example.com',
        OwnerID      => 123,
        UserID       => 123,
    );

or

    my $TicketID = $TicketObject->TicketCreate(
        TN            => $TicketObject->TicketCreateNumber(), # optional
        Title         => 'Some Ticket Title',
        Queue         => 'Raw',              # or QueueID => 123,
        Lock          => 'unlock',
        Priority      => '3 normal',         # or PriorityID => 2,
        State         => 'new',              # or StateID => 5,
        Type          => 'Incident',         # or TypeID => 1, not required
        Service       => 'Service A',        # or ServiceID => 1, not required
        SLA           => 'SLA A',            # or SLAID => 1, not required
        CustomerID    => '123465',
        CustomerUser  => 'customer@example.com',
        OwnerID       => 123,
        ResponsibleID => 123,                # not required
        ArchiveFlag   => 'y',                # (y|n) not required
        UserID        => 123,
    );

Events:
    TicketCreate

=cut

sub TicketCreate {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(OwnerID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # set default values if no values are specified
    my $Age = $Kernel::OM->Get('Kernel::System::Time')->SystemTime();

    my $ArchiveFlag = 0;
    if ( $Param{ArchiveFlag} && $Param{ArchiveFlag} eq 'y' ) {
        $ArchiveFlag = 1;
    }

    $Param{ResponsibleID} ||= 1;

    if ( !$Param{TypeID} && !$Param{Type} ) {
        $Param{TypeID} = 1;
    }

    # get type object
    my $TypeObject = $Kernel::OM->Get('Kernel::System::Type');

    # TypeID/Type lookup!
    if ( !$Param{TypeID} && $Param{Type} ) {
        $Param{TypeID} = $TypeObject->TypeLookup( Type => $Param{Type} );
    }
    elsif ( $Param{TypeID} && !$Param{Type} ) {
        $Param{Type} = $TypeObject->TypeLookup( TypeID => $Param{TypeID} );
    }
    if ( !$Param{TypeID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "No TypeID for '$Param{Type}'!",
        );
        return;
    }

    # get queue object
    my $QueueObject = $Kernel::OM->Get('Kernel::System::Queue');

    # QueueID/Queue lookup!
    if ( !$Param{QueueID} && $Param{Queue} ) {
        $Param{QueueID} = $QueueObject->QueueLookup( Queue => $Param{Queue} );
    }
    elsif ( !$Param{Queue} ) {
        $Param{Queue} = $QueueObject->QueueLookup( QueueID => $Param{QueueID} );
    }
    if ( !$Param{QueueID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "No QueueID for '$Param{Queue}'!",
        );
        return;
    }

    # get state object
    my $StateObject = $Kernel::OM->Get('Kernel::System::State');

    # StateID/State lookup!
    if ( !$Param{StateID} ) {
        my %State = $StateObject->StateGet( Name => $Param{State} );
        $Param{StateID} = $State{ID};
    }
    elsif ( !$Param{State} ) {
        my %State = $StateObject->StateGet( ID => $Param{StateID} );
        $Param{State} = $State{Name};
    }
    if ( !$Param{StateID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "No StateID for '$Param{State}'!",
        );
        return;
    }

    # LockID lookup!
    if ( !$Param{LockID} && $Param{Lock} ) {

        $Param{LockID} = $Kernel::OM->Get('Kernel::System::Lock')->LockLookup(
            Lock => $Param{Lock},
        );
    }
    if ( !$Param{LockID} && !$Param{Lock} ) {

        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'No LockID and no LockType!',
        );
        return;
    }

    # get priority object
    my $PriorityObject = $Kernel::OM->Get('Kernel::System::Priority');

    # PriorityID/Priority lookup!
    if ( !$Param{PriorityID} && $Param{Priority} ) {
        $Param{PriorityID} = $PriorityObject->PriorityLookup(
            Priority => $Param{Priority},
        );
    }
    elsif ( $Param{PriorityID} && !$Param{Priority} ) {
        $Param{Priority} = $PriorityObject->PriorityLookup(
            PriorityID => $Param{PriorityID},
        );
    }
    if ( !$Param{PriorityID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'No PriorityID (invalid Priority Name?)!',
        );
        return;
    }

    # get service object
    my $ServiceObject = $Kernel::OM->Get('Kernel::System::Service');

    # ServiceID/Service lookup!
    if ( !$Param{ServiceID} && $Param{Service} ) {
        $Param{ServiceID} = $ServiceObject->ServiceLookup(
            Name => $Param{Service},
        );
    }
    elsif ( $Param{ServiceID} && !$Param{Service} ) {
        $Param{Service} = $ServiceObject->ServiceLookup(
            ServiceID => $Param{ServiceID},
        );
    }

    # get sla object
    my $SLAObject = $Kernel::OM->Get('Kernel::System::SLA');

    # SLAID/SLA lookup!
    if ( !$Param{SLAID} && $Param{SLA} ) {
        $Param{SLAID} = $SLAObject->SLALookup( Name => $Param{SLA} );
    }
    elsif ( $Param{SLAID} && !$Param{SLA} ) {
        $Param{SLA} = $SLAObject->SLALookup( SLAID => $Param{SLAID} );
    }

    # create ticket number if none is given
    if ( !$Param{TN} ) {
        $Param{TN} = $Self->TicketCreateNumber();
    }

    # check ticket title
    if ( !defined $Param{Title} ) {
        $Param{Title} = '';
    }

    # substitute title if needed
    else {
        $Param{Title} = substr( $Param{Title}, 0, 255 );
    }

    # check database undef/NULL (set value to undef/NULL to prevent database errors)
    $Param{ServiceID} ||= undef;
    $Param{SLAID}     ||= undef;

    # create db record
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => '
            INSERT INTO ticket (tn, title, create_time_unix, type_id, queue_id, ticket_lock_id,
                user_id, responsible_user_id, ticket_priority_id, ticket_state_id,
                escalation_time, escalation_update_time, escalation_response_time,
                escalation_solution_time, timeout, service_id, sla_id, until_time,
                archive_flag, create_time, create_by, change_time, change_by)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 0, 0, 0, 0, 0, ?, ?, 0, ?,
                current_timestamp, ?, current_timestamp, ?)',
        Bind => [
            \$Param{TN}, \$Param{Title}, \$Age, \$Param{TypeID}, \$Param{QueueID},
            \$Param{LockID},     \$Param{OwnerID}, \$Param{ResponsibleID},
            \$Param{PriorityID}, \$Param{StateID}, \$Param{ServiceID},
            \$Param{SLAID}, \$ArchiveFlag, \$Param{UserID}, \$Param{UserID},
        ],
    );

    # get ticket id
    my $TicketID = $Self->TicketIDLookup(
        TicketNumber => $Param{TN},
        UserID       => $Param{UserID},
    );

    # add history entry
    $Self->HistoryAdd(
        TicketID     => $TicketID,
        QueueID      => $Param{QueueID},
        HistoryType  => 'NewTicket',
        Name         => "\%\%$Param{TN}\%\%$Param{Queue}\%\%$Param{Priority}\%\%$Param{State}\%\%$TicketID",
        CreateUserID => $Param{UserID},
    );

    if ( $Kernel::OM->Get('Kernel::Config')->Get('Ticket::Service') ) {

        # history insert for service so that initial values can be seen
        my $HistoryService   = $Param{Service}   || 'NULL';
        my $HistoryServiceID = $Param{ServiceID} || '';
        $Self->HistoryAdd(
            TicketID     => $TicketID,
            HistoryType  => 'ServiceUpdate',
            Name         => "\%\%$HistoryService\%\%$HistoryServiceID\%\%NULL\%\%",
            CreateUserID => $Param{UserID},
        );

        # history insert for SLA
        my $HistorySLA   = $Param{SLA}   || 'NULL';
        my $HistorySLAID = $Param{SLAID} || '';
        $Self->HistoryAdd(
            TicketID     => $TicketID,
            HistoryType  => 'SLAUpdate',
            Name         => "\%\%$HistorySLA\%\%$HistorySLAID\%\%NULL\%\%",
            CreateUserID => $Param{UserID},
        );
    }

    # set customer data if given
    if ( $Param{CustomerNo} || $Param{CustomerID} || $Param{CustomerUser} ) {
        $Self->TicketCustomerSet(
            TicketID => $TicketID,
            No       => $Param{CustomerNo} || $Param{CustomerID} || '',
            User => $Param{CustomerUser} || '',
            UserID => $Param{UserID},
        );
    }

    # update ticket view index
    $Self->TicketAcceleratorAdd( TicketID => $TicketID );

    # log ticket creation
    $Kernel::OM->Get('Kernel::System::Log')->Log(
        Priority => 'info',
        Message  => "New Ticket [$Param{TN}/" . substr( $Param{Title}, 0, 15 ) . "] created "
            . "(TicketID=$TicketID,Queue=$Param{Queue},Priority=$Param{Priority},State=$Param{State})",
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketCreate',
        Data  => {
            TicketID => $TicketID,
        },
        UserID => $Param{UserID},
    );

    return $TicketID;
}

=item TicketDelete()

deletes a ticket with articles from storage

    my $Success = $TicketObject->TicketDelete(
        TicketID => 123,
        UserID   => 123,
    );

Events:
    TicketDelete

=cut

sub TicketDelete {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # delete ticket links
    $Kernel::OM->Get('Kernel::System::LinkObject')->LinkDeleteAll(
        Object => 'Ticket',
        Key    => $Param{TicketID},
        UserID => $Param{UserID},
    );

    # update ticket index
    return if !$Self->TicketAcceleratorDelete(%Param);

    # update full text index
    return if !$Self->ArticleIndexDeleteTicket(%Param);

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # remove ticket watcher
    return if !$DBObject->Do(
        SQL  => 'DELETE FROM ticket_watcher WHERE ticket_id = ?',
        Bind => [ \$Param{TicketID} ],
    );

    # delete ticket flags
    return if !$DBObject->Do(
        SQL  => 'DELETE FROM ticket_flag WHERE ticket_id = ?',
        Bind => [ \$Param{TicketID} ],
    );

    # delete ticket_history
    return if !$Self->HistoryDelete(
        TicketID => $Param{TicketID},
        UserID   => $Param{UserID},
    );

    # delete article, attachments and plain emails
    my @Articles = $Self->ArticleIndex( TicketID => $Param{TicketID} );
    for my $ArticleID (@Articles) {
        return if !$Self->ArticleDelete(
            ArticleID => $ArticleID,
            %Param,
        );
    }

    # get dynamic field objects
    my $DynamicFieldObject        = $Kernel::OM->Get('Kernel::System::DynamicField');
    my $DynamicFieldBackendObject = $Kernel::OM->Get('Kernel::System::DynamicField::Backend');

    # get all dynamic fields for the object type Ticket
    my $DynamicFieldListTicket = $DynamicFieldObject->DynamicFieldListGet(
        ObjectType => 'Ticket',
        Valid      => 0,
    );

    # delete dynamicfield values for this ticket
    DYNAMICFIELD:
    for my $DynamicFieldConfig ( @{$DynamicFieldListTicket} ) {

        next DYNAMICFIELD if !$DynamicFieldConfig;
        next DYNAMICFIELD if !IsHashRefWithData($DynamicFieldConfig);
        next DYNAMICFIELD if !$DynamicFieldConfig->{Name};
        next DYNAMICFIELD if !IsHashRefWithData( $DynamicFieldConfig->{Config} );

        $DynamicFieldBackendObject->ValueDelete(
            DynamicFieldConfig => $DynamicFieldConfig,
            ObjectID           => $Param{TicketID},
            UserID             => $Param{UserID},
        );
    }

    # delete ticket
    return if !$DBObject->Do(
        SQL  => 'DELETE FROM ticket WHERE id = ?',
        Bind => [ \$Param{TicketID} ],
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketDelete',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketIDLookup()

ticket id lookup by ticket number

    my $TicketID = $TicketObject->TicketIDLookup(
        TicketNumber => '2004040510440485',
        UserID       => 123,
    );

=cut

sub TicketIDLookup {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketNumber} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketNumber!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL   => 'SELECT id FROM ticket WHERE tn = ?',
        Bind  => [ \$Param{TicketNumber} ],
        Limit => 1,
    );

    my $ID;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $ID = $Row[0];
    }

    return $ID;
}

=item TicketNumberLookup()

ticket number lookup by ticket id

    my $TicketNumber = $TicketObject->TicketNumberLookup(
        TicketID => 123,
        UserID   => 123,
    );

=cut

sub TicketNumberLookup {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL   => 'SELECT tn FROM ticket WHERE id = ?',
        Bind  => [ \$Param{TicketID} ],
        Limit => 1,
    );

    my $Number;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Number = $Row[0];
    }

    return $Number;
}

=item TicketSubjectBuild()

rebuild a new ticket subject

This will generate a subject like "RE: [Ticket# 2004040510440485] Some subject"

    my $NewSubject = $TicketObject->TicketSubjectBuild(
        TicketNumber => '2004040510440485',
        Subject      => $OldSubject,
        Action       => 'Reply',
    );

This will generate a subject like  "[Ticket# 2004040510440485] Some subject"
(so without RE: )

    my $NewSubject = $TicketObject->TicketSubjectBuild(
        TicketNumber => '2004040510440485',
        Subject      => $OldSubject,
        Type         => 'New',
        Action       => 'Reply',
    );

This will generate a subject like "FWD: [Ticket# 2004040510440485] Some subject"

    my $NewSubject = $TicketObject->TicketSubjectBuild(
        TicketNumber => '2004040510440485',
        Subject      => $OldSubject,
        Action       => 'Forward', # Possible values are Reply and Forward, Reply is default.
    );

This will generate a subject like "[Ticket# 2004040510440485] Re: Some subject"
(so without clean-up of subject)

    my $NewSubject = $TicketObject->TicketSubjectBuild(
        TicketNumber => '2004040510440485',
        Subject      => $OldSubject,
        Type         => 'New',
        NoCleanup    => 1,
    );

=cut

sub TicketSubjectBuild {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !defined $Param{TicketNumber} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketNumber!"
        );
        return;
    }
    my $Subject = $Param{Subject} || '';
    my $Action  = $Param{Action}  || 'Reply';

    # cleanup of subject, remove existing ticket numbers and reply indentifier
    if ( !$Param{NoCleanup} ) {
        $Subject = $Self->TicketSubjectClean(%Param);
    }

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # get config options
    my $TicketHook          = $ConfigObject->Get('Ticket::Hook');
    my $TicketHookDivider   = $ConfigObject->Get('Ticket::HookDivider');
    my $TicketSubjectRe     = $ConfigObject->Get('Ticket::SubjectRe');
    my $TicketSubjectFwd    = $ConfigObject->Get('Ticket::SubjectFwd');
    my $TicketSubjectFormat = $ConfigObject->Get('Ticket::SubjectFormat') || 'Left';

    # return subject for new tickets
    if ( $Param{Type} && $Param{Type} eq 'New' ) {
        if ( lc $TicketSubjectFormat eq 'right' ) {
            return $Subject . " [$TicketHook$TicketHookDivider$Param{TicketNumber}]";
        }
        if ( lc $TicketSubjectFormat eq 'none' ) {
            return $Subject;
        }
        return "[$TicketHook$TicketHookDivider$Param{TicketNumber}] " . $Subject;
    }

    # return subject for existing tickets
    if ( $Action eq 'Forward' ) {
        if ($TicketSubjectFwd) {
            $TicketSubjectFwd .= ': ';
        }
        if ( lc $TicketSubjectFormat eq 'right' ) {
            return $TicketSubjectFwd . $Subject
                . " [$TicketHook$TicketHookDivider$Param{TicketNumber}]";
        }
        if ( lc $TicketSubjectFormat eq 'none' ) {
            return $TicketSubjectFwd . $Subject;
        }
        return
            $TicketSubjectFwd
            . "[$TicketHook$TicketHookDivider$Param{TicketNumber}] "
            . $Subject;
    }
    else {
        if ($TicketSubjectRe) {
            $TicketSubjectRe .= ': ';
        }
        if ( lc $TicketSubjectFormat eq 'right' ) {
            return $TicketSubjectRe . $Subject
                . " [$TicketHook$TicketHookDivider$Param{TicketNumber}]";
        }
        if ( lc $TicketSubjectFormat eq 'none' ) {
            return $TicketSubjectRe . $Subject;
        }
        return $TicketSubjectRe . "[$TicketHook$TicketHookDivider$Param{TicketNumber}] " . $Subject;
    }
}

=item TicketSubjectClean()

strip/clean up a ticket subject

    my $NewSubject = $TicketObject->TicketSubjectClean(
        TicketNumber => '2004040510440485',
        Subject      => $OldSubject,
        Size         => $SubjectSizeToBeDisplayed   # optional, if 0 do not cut subject
    );

=cut

sub TicketSubjectClean {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !defined $Param{TicketNumber} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketNumber!"
        );
        return;
    }

    my $Subject = $Param{Subject} || '';

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # get config options
    my $TicketHook        = $ConfigObject->Get('Ticket::Hook');
    my $TicketHookDivider = $ConfigObject->Get('Ticket::HookDivider');
    my $TicketSubjectSize = $Param{Size};
    if ( !defined $TicketSubjectSize ) {
        $TicketSubjectSize = $ConfigObject->Get('Ticket::SubjectSize')
            || 120;
    }
    my $TicketSubjectRe  = $ConfigObject->Get('Ticket::SubjectRe');
    my $TicketSubjectFwd = $ConfigObject->Get('Ticket::SubjectFwd');

    # remove all possible ticket hook formats with []
    $Subject =~ s/\[\s*\Q$TicketHook: $Param{TicketNumber}\E\s*\]\s*//g;
    $Subject =~ s/\[\s*\Q$TicketHook:$Param{TicketNumber}\E\s*\]\s*//g;
    $Subject =~ s/\[\s*\Q$TicketHook$TicketHookDivider$Param{TicketNumber}\E\s*\]\s*//g;

    # remove all ticket numbers with []
    if ( $ConfigObject->Get('Ticket::SubjectCleanAllNumbers') ) {
        $Subject =~ s/\[\s*\Q$TicketHook$TicketHookDivider\E\d+?\s*\]\s*//g;
    }

    # remove all possible ticket hook formats without []
    $Subject =~ s/\Q$TicketHook: $Param{TicketNumber}\E\s*//g;
    $Subject =~ s/\Q$TicketHook:$Param{TicketNumber}\E\s*//g;
    $Subject =~ s/\Q$TicketHook$TicketHookDivider$Param{TicketNumber}\E\s*//g;

    # remove all ticket numbers without []
    if ( $ConfigObject->Get('Ticket::SubjectCleanAllNumbers') ) {
        $Subject =~ s/\Q$TicketHook$TicketHookDivider\E\d+?\s*//g;
    }

    # remove leading number with configured "RE:\s" or "RE[\d+]:\s" e. g. "RE: " or "RE[4]: "
    $Subject =~ s/^($TicketSubjectRe(\[\d+\])?:\s)+//i;

    # remove leading number with configured "Fwd:\s" or "Fwd[\d+]:\s" e. g. "Fwd: " or "Fwd[4]: "
    $Subject =~ s/^($TicketSubjectFwd(\[\d+\])?:\s)+//i;

    # trim white space at the beginning or end
    $Subject =~ s/(^\s+|\s+$)//;

    # resize subject based on config
    # do not cut subject, if size parameter was 0
    if ($TicketSubjectSize) {
        $Subject =~ s/^(.{$TicketSubjectSize}).*$/$1 [...]/;
    }

    return $Subject;
}

=item TicketGet()

Get ticket info

    my %Ticket = $TicketObject->TicketGet(
        TicketID      => 123,
        DynamicFields => 0,         # Optional, default 0. To include the dynamic field values for this ticket on the return structure.
        UserID        => 123,
        Silent        => 0,         # Optional, default 0. To suppress the warning if the ticket does not exist.
    );

Returns:

    %Ticket = (
        TicketNumber       => '20101027000001',
        Title              => 'some title',
        TicketID           => 123,
        State              => 'some state',
        StateID            => 123,
        StateType          => 'some state type',
        Priority           => 'some priority',
        PriorityID         => 123,
        Lock               => 'lock',
        LockID             => 123,
        Queue              => 'some queue',
        QueueID            => 123,
        CustomerID         => 'customer_id_123',
        CustomerUserID     => 'customer_user_id_123',
        Owner              => 'some_owner_login',
        OwnerID            => 123,
        Type               => 'some ticket type',
        TypeID             => 123,
        SLA                => 'some sla',
        SLAID              => 123,
        Service            => 'some service',
        ServiceID          => 123,
        Responsible        => 'some_responsible_login',
        ResponsibleID      => 123,
        Age                => 3456,
        Created            => '2010-10-27 20:15:00'
        CreateTimeUnix     => '1231414141',
        CreateBy           => 123,
        Changed            => '2010-10-27 20:15:15',
        ChangeBy           => 123,
        ArchiveFlag        => 'y',

        # If DynamicFields => 1 was passed, you'll get an entry like this for each dynamic field:
        DynamicField_X     => 'value_x',

        # (time stamps of expected escalations)
        EscalationResponseTime           (unix time stamp of response time escalation)
        EscalationUpdateTime             (unix time stamp of update time escalation)
        EscalationSolutionTime           (unix time stamp of solution time escalation)

        # (general escalation info of nearest escalation type)
        EscalationDestinationIn          (escalation in e. g. 1h 4m)
        EscalationDestinationTime        (date of escalation in unix time, e. g. 72193292)
        EscalationDestinationDate        (date of escalation, e. g. "2009-02-14 18:00:00")
        EscalationTimeWorkingTime        (seconds of working/service time till escalation, e. g. "1800")
        EscalationTime                   (seconds total till escalation of nearest escalation time type - response, update or solution time, e. g. "3600")

        # (detailed escalation info about first response, update and solution time)
        FirstResponseTimeEscalation      (if true, ticket is escalated)
        FirstResponseTimeNotification    (if true, notify - x% of escalation has reached)
        FirstResponseTimeDestinationTime (date of escalation in unix time, e. g. 72193292)
        FirstResponseTimeDestinationDate (date of escalation, e. g. "2009-02-14 18:00:00")
        FirstResponseTimeWorkingTime     (seconds of working/service time till escalation, e. g. "1800")
        FirstResponseTime                (seconds total till escalation, e. g. "3600")

        UpdateTimeEscalation             (if true, ticket is escalated)
        UpdateTimeNotification           (if true, notify - x% of escalation has reached)
        UpdateTimeDestinationTime        (date of escalation in unix time, e. g. 72193292)
        UpdateTimeDestinationDate        (date of escalation, e. g. "2009-02-14 18:00:00")
        UpdateTimeWorkingTime            (seconds of working/service time till escalation, e. g. "1800")
        UpdateTime                       (seconds total till escalation, e. g. "3600")

        SolutionTimeEscalation           (if true, ticket is escalated)
        SolutionTimeNotification         (if true, notify - x% of escalation has reached)
        SolutionTimeDestinationTime      (date of escalation in unix time, e. g. 72193292)
        SolutionTimeDestinationDate      (date of escalation, e. g. "2009-02-14 18:00:00")
        SolutionTimeWorkingTime          (seconds of working/service time till escalation, e. g. "1800")
        SolutionTime                     (seconds total till escalation, e. g. "3600")
    );

To get extended ticket attributes, use param Extended:

    my %Ticket = $TicketObject->TicketGet(
        TicketID => 123,
        UserID   => 123,
        Extended => 1,
    );

Additional params are:

    %Ticket = (
        FirstResponse                   (timestamp of first response, first contact with customer)
        FirstResponseInMin              (minutes till first response)
        FirstResponseDiffInMin          (minutes till or over first response)

        SolutionTime                    (timestamp of solution time, also close time)
        SolutionInMin                   (minutes till solution time)
        SolutionDiffInMin               (minutes till or over solution time)

        FirstLock                       (timestamp of first lock)
    );

=cut

sub TicketGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }
    $Param{Extended} ||= '';

    # Caching TicketGet() is a bit more complex than usual.
    #   The full function result will be cached in an in-memory cache to
    #       speed up subsequent operations in one request, but not on disk,
    #       because there are dependencies to other objects such as queue which cannot
    #       easily be tracked.
    #   The SQL for fetching ticket data will be cached on disk as well because this cache
    #       can easily be invalidated on ticket changes.

    # check cache
    my $FetchDynamicFields = $Param{DynamicFields} ? 1 : 0;

    my $CacheKey = 'Cache::GetTicket' . $Param{TicketID};

    # check if result is cached
    if ( $Self->{$CacheKey}->{ $Param{Extended} }->{$FetchDynamicFields} ) {
        return %{ $Self->{$CacheKey}->{ $Param{Extended} }->{$FetchDynamicFields} };
    }

    my %Ticket;

    my $Cached = $Kernel::OM->Get('Kernel::System::Cache')->Get(
        Type => $Self->{CacheType},
        Key  => $CacheKey,
    );

    if ( ref $Cached eq 'HASH' ) {
        %Ticket = %{$Cached};
    }
    else {

        # get database object
        my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

        return if !$DBObject->Prepare(
            SQL => '
                SELECT st.id, st.queue_id, st.ticket_state_id, st.ticket_lock_id, st.ticket_priority_id,
                    st.create_time_unix, st.create_time, st.tn, st.customer_id, st.customer_user_id,
                    st.user_id, st.responsible_user_id, st.until_time, st.change_time, st.title,
                    st.escalation_update_time, st.timeout, st.type_id, st.service_id, st.sla_id,
                    st.escalation_response_time, st.escalation_solution_time, st.escalation_time, st.archive_flag,
                    st.create_by, st.change_by
                FROM ticket st
                WHERE st.id = ?',
            Bind  => [ \$Param{TicketID} ],
            Limit => 1,
        );

        while ( my @Row = $DBObject->FetchrowArray() ) {
            $Ticket{TicketID}   = $Row[0];
            $Ticket{QueueID}    = $Row[1];
            $Ticket{StateID}    = $Row[2];
            $Ticket{LockID}     = $Row[3];
            $Ticket{PriorityID} = $Row[4];

            $Ticket{CreateTimeUnix} = $Row[5];
            $Ticket{TicketNumber}   = $Row[7];
            $Ticket{CustomerID}     = $Row[8];
            $Ticket{CustomerUserID} = $Row[9];

            $Ticket{OwnerID}             = $Row[10];
            $Ticket{ResponsibleID}       = $Row[11] || 1;
            $Ticket{RealTillTimeNotUsed} = $Row[12];
            $Ticket{Changed}             = $Row[13];
            $Ticket{Title}               = $Row[14];

            $Ticket{EscalationUpdateTime} = $Row[15];
            $Ticket{UnlockTimeout}        = $Row[16];
            $Ticket{TypeID}               = $Row[17] || 1;
            $Ticket{ServiceID}            = $Row[18] || '';
            $Ticket{SLAID}                = $Row[19] || '';

            $Ticket{EscalationResponseTime} = $Row[20];
            $Ticket{EscalationSolutionTime} = $Row[21];
            $Ticket{EscalationTime}         = $Row[22];
            $Ticket{ArchiveFlag}            = $Row[23] ? 'y' : 'n';

            $Ticket{CreateBy} = $Row[24];
            $Ticket{ChangeBy} = $Row[25];
        }

        $Kernel::OM->Get('Kernel::System::Cache')->Set(
            Type => $Self->{CacheType},
            TTL  => $Self->{CacheTTL},
            Key  => $CacheKey,

            # make a local copy of the ticket data to avoid it being altered in-memory later
            Value => {%Ticket},
        );
    }

    # check ticket
    if ( !$Ticket{TicketID} ) {
        if ( !$Param{Silent} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "No such TicketID ($Param{TicketID})!",
            );
        }
        return;
    }

    # check if need to return DynamicFields
    if ($FetchDynamicFields) {

        # get dynamic field objects
        my $DynamicFieldObject        = $Kernel::OM->Get('Kernel::System::DynamicField');
        my $DynamicFieldBackendObject = $Kernel::OM->Get('Kernel::System::DynamicField::Backend');

        # get all dynamic fields for the object type Ticket
        my $DynamicFieldList = $DynamicFieldObject->DynamicFieldListGet(
            ObjectType => 'Ticket'
        );

        DYNAMICFIELD:
        for my $DynamicFieldConfig ( @{$DynamicFieldList} ) {

            # validate each dynamic field
            next DYNAMICFIELD if !$DynamicFieldConfig;
            next DYNAMICFIELD if !IsHashRefWithData($DynamicFieldConfig);
            next DYNAMICFIELD if !$DynamicFieldConfig->{Name};
            next DYNAMICFIELD if !IsHashRefWithData( $DynamicFieldConfig->{Config} );

            # get the current value for each dynamic field
            my $Value = $DynamicFieldBackendObject->ValueGet(
                DynamicFieldConfig => $DynamicFieldConfig,
                ObjectID           => $Ticket{TicketID},
            );

            # set the dynamic field name and value into the ticket hash
            $Ticket{ 'DynamicField_' . $DynamicFieldConfig->{Name} } = $Value;
        }
    }

    # get time object
    my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

    $Ticket{Created} = $TimeObject->SystemTime2TimeStamp(
        SystemTime => $Ticket{CreateTimeUnix},
    );

    my %Queue = $Kernel::OM->Get('Kernel::System::Queue')->QueueGet(
        ID => $Ticket{QueueID},
    );

    $Ticket{Queue}   = $Queue{Name};
    $Ticket{GroupID} = $Queue{GroupID};

    # fillup runtime values
    $Ticket{Age} = $TimeObject->SystemTime() - $Ticket{CreateTimeUnix};

    $Ticket{Priority} = $Kernel::OM->Get('Kernel::System::Priority')->PriorityLookup(
        PriorityID => $Ticket{PriorityID},
    );

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # get owner
    $Ticket{Owner} = $UserObject->UserLookup(
        UserID => $Ticket{OwnerID},
    );

    # get responsible
    $Ticket{Responsible} = $UserObject->UserLookup(
        UserID => $Ticket{ResponsibleID},
    );

    # get lock
    $Ticket{Lock} = $Kernel::OM->Get('Kernel::System::Lock')->LockLookup(
        LockID => $Ticket{LockID},
    );

    # get type
    $Ticket{Type} = $Kernel::OM->Get('Kernel::System::Type')->TypeLookup( TypeID => $Ticket{TypeID} );

    # get service
    if ( $Ticket{ServiceID} ) {

        $Ticket{Service} = $Kernel::OM->Get('Kernel::System::Service')->ServiceLookup(
            ServiceID => $Ticket{ServiceID},
        );
    }

    # get sla
    if ( $Ticket{SLAID} ) {
        $Ticket{SLA} = $Kernel::OM->Get('Kernel::System::SLA')->SLALookup(
            SLAID => $Ticket{SLAID},
        );
    }

    # get state info
    my %StateData = $Kernel::OM->Get('Kernel::System::State')->StateGet(
        ID => $Ticket{StateID}
    );

    $Ticket{StateType} = $StateData{TypeName};
    $Ticket{State}     = $StateData{Name};

    if ( !$Ticket{RealTillTimeNotUsed} || lc $StateData{TypeName} eq 'pending' ) {
        $Ticket{UntilTime} = 0;
    }
    else {
        $Ticket{UntilTime} = $Ticket{RealTillTimeNotUsed} - $TimeObject->SystemTime();
    }

    # get escalation attributes
    my %Escalation = $Self->TicketEscalationDateCalculation(
        Ticket => \%Ticket,
        UserID => $Param{UserID} || 1,
    );

    for my $Key ( sort keys %Escalation ) {
        $Ticket{$Key} = $Escalation{$Key};
    }

    # do extended lookups
    if ( $Param{Extended} ) {
        my %TicketExtended = $Self->_TicketGetExtended(
            TicketID => $Param{TicketID},
            Ticket   => \%Ticket,
        );
        for my $Key ( sort keys %TicketExtended ) {
            $Ticket{$Key} = $TicketExtended{$Key};
        }
    }

    # cache user result
    $Self->{$CacheKey}->{ $Param{Extended} }->{$FetchDynamicFields} = \%Ticket;

    return %Ticket;
}

sub _TicketCacheClear {
    my ( $Self, %Param ) = @_;

    for my $Needed (qw(TicketID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # TicketGet()
    my $CacheKey = 'Cache::GetTicket' . $Param{TicketID};
    delete $Self->{$CacheKey};
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => $CacheKey,
    );

    # ArticleIndex()
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => 'ArticleIndex::' . $Param{TicketID} . '::agent'
    );
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => 'ArticleIndex::' . $Param{TicketID} . '::customer'
    );
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => 'ArticleIndex::' . $Param{TicketID} . '::system'
    );
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => 'ArticleIndex::' . $Param{TicketID} . '::ALL'
    );

}

sub _TicketGetExtended {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Ticket)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get extended attributes
    my %FirstResponse   = $Self->_TicketGetFirstResponse(%Param);
    my %FirstLock       = $Self->_TicketGetFirstLock(%Param);
    my %TicketGetClosed = $Self->_TicketGetClosed(%Param);

    # return all as hash
    return ( %TicketGetClosed, %FirstResponse, %FirstLock );
}

sub _TicketGetFirstResponse {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Ticket)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # check if first response is already done
    return if !$DBObject->Prepare(
        SQL => 'SELECT a.create_time,a.id FROM article a, article_sender_type ast, article_type art'
            . ' WHERE a.article_sender_type_id = ast.id AND a.article_type_id = art.id AND'
            . ' a.ticket_id = ? AND ast.name = \'agent\' AND'
            . ' (art.name LIKE \'email-ext%\' OR art.name LIKE \'note-ext%\' OR art.name = \'phone\' OR art.name = \'fax\' OR art.name = \'sms\')'
            . ' ORDER BY a.create_time',
        Bind  => [ \$Param{TicketID} ],
        Limit => 1,
    );

    my %Data;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Data{FirstResponse} = $Row[0];

        # cleanup time stamps (some databases are using e. g. 2008-02-25 22:03:00.000000
        # and 0000-00-00 00:00:00 time stamps)
        $Data{FirstResponse} =~ s/^(\d\d\d\d-\d\d-\d\d\s\d\d:\d\d:\d\d)\..+?$/$1/;
    }

    return if !$Data{FirstResponse};

    # get escalation properties
    my %Escalation = $Self->TicketEscalationPreferences(
        Ticket => $Param{Ticket},
        UserID => $Param{UserID} || 1,
    );

    if ( $Escalation{FirstResponseTime} ) {

        # get time object
        my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

        # get unix time stamps
        my $CreateTime = $TimeObject->TimeStamp2SystemTime(
            String => $Param{Ticket}->{Created},
        );
        my $FirstResponseTime = $TimeObject->TimeStamp2SystemTime(
            String => $Data{FirstResponse},
        );

        # get time between creation and first response
        my $WorkingTime = $TimeObject->WorkingTime(
            StartTime => $CreateTime,
            StopTime  => $FirstResponseTime,
            Calendar  => $Escalation{Calendar},
        );

        $Data{FirstResponseInMin} = int( $WorkingTime / 60 );
        my $EscalationFirstResponseTime = $Escalation{FirstResponseTime} * 60;
        $Data{FirstResponseDiffInMin} = int( ( $EscalationFirstResponseTime - $WorkingTime ) / 60 );
    }

    return %Data;
}

sub _TicketGetClosed {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Ticket)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get close state types
    my @List = $Kernel::OM->Get('Kernel::System::State')->StateGetStatesByType(
        StateType => ['closed'],
        Result    => 'ID',
    );
    return if !@List;

    # Get id for history types
    my @HistoryTypeIDs;
    for my $HistoryType (qw(StateUpdate NewTicket)) {
        push @HistoryTypeIDs, $Self->HistoryTypeLookup( Type => $HistoryType );
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    return if !$DBObject->Prepare(
        SQL => "
            SELECT MAX(create_time)
            FROM ticket_history
            WHERE ticket_id = ?
               AND state_id IN (${\(join ', ', sort @List)})
               AND history_type_id IN  (${\(join ', ', sort @HistoryTypeIDs)})
            ",
        Bind => [ \$Param{TicketID} ],
    );

    my %Data;
    ROW:
    while ( my @Row = $DBObject->FetchrowArray() ) {
        last ROW if !defined $Row[0];
        $Data{Closed} = $Row[0];

        # cleanup time stamps (some databases are using e. g. 2008-02-25 22:03:00.000000
        # and 0000-00-00 00:00:00 time stamps)
        $Data{Closed} =~ s/^(\d\d\d\d-\d\d-\d\d\s\d\d:\d\d:\d\d)\..+?$/$1/;
    }

    return if !$Data{Closed};

    # for compat. wording reasons
    $Data{SolutionTime} = $Data{Closed};

    # get escalation properties
    my %Escalation = $Self->TicketEscalationPreferences(
        Ticket => $Param{Ticket},
        UserID => $Param{UserID} || 1,
    );

    if ( $Escalation{SolutionTime} ) {

        # get time object
        my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

        # get unix time stamps
        my $CreateTime = $TimeObject->TimeStamp2SystemTime(
            String => $Param{Ticket}->{Created},
        );
        my $SolutionTime = $TimeObject->TimeStamp2SystemTime(
            String => $Data{Closed},
        );

        # get time between creation and solution
        my $WorkingTime = $TimeObject->WorkingTime(
            StartTime => $CreateTime,
            StopTime  => $SolutionTime,
            Calendar  => $Escalation{Calendar},
        );

        $Data{SolutionInMin} = int( $WorkingTime / 60 );

        my $EscalationSolutionTime = $Escalation{SolutionTime} * 60;
        $Data{SolutionDiffInMin} = int( ( $EscalationSolutionTime - $WorkingTime ) / 60 );
    }

    return %Data;
}

sub _TicketGetFirstLock {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Ticket)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # first lock
    return if !$DBObject->Prepare(
        SQL => 'SELECT th.name, tht.name, th.create_time '
            . 'FROM ticket_history th, ticket_history_type tht '
            . 'WHERE th.history_type_id = tht.id AND th.ticket_id = ? '
            . 'AND tht.name = \'Lock\' ORDER BY th.create_time, th.id ASC',
        Bind  => [ \$Param{TicketID} ],
        Limit => 100,
    );

    my %Data;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        if ( !$Data{FirstLock} ) {
            $Data{FirstLock} = $Row[2];

            # cleanup time stamps (some databases are using e. g. 2008-02-25 22:03:00.000000
            # and 0000-00-00 00:00:00 time stamps)
            $Data{FirstLock} =~ s/^(\d\d\d\d-\d\d-\d\d\s\d\d:\d\d:\d\d)\..+?$/$1/;
        }
    }

    return %Data;
}

=item TicketTitleUpdate()

update ticket title

    my $Success = $TicketObject->TicketTitleUpdate(
        Title    => 'Some Title',
        TicketID => 123,
        UserID   => 1,
    );

Events:
    TicketTitleUpdate

=cut

sub TicketTitleUpdate {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(Title TicketID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # check if update is needed
    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        UserID        => $Param{UserID},
        DynamicFields => 0,
    );

    return 1 if defined $Ticket{Title} && $Ticket{Title} eq $Param{Title};

    # db access
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET title = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{Title}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # history insert
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        HistoryType  => 'TitleUpdate',
        Name         => "\%\%$Ticket{Title}\%\%$Param{Title}",
        CreateUserID => $Param{UserID},
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketTitleUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketUnlockTimeoutUpdate()

set the ticket unlock time to the passed time

    my $Success = $TicketObject->TicketUnlockTimeoutUpdate(
        UnlockTimeout => $TimeObject->SystemTime(),
        TicketID      => 123,
        UserID        => 143,
    );

Events:
    TicketUnlockTimeoutUpdate

=cut

sub TicketUnlockTimeoutUpdate {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(UnlockTimeout TicketID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # check if update is needed
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    return 1 if $Ticket{UnlockTimeout} eq $Param{UnlockTimeout};

    # reset unlock time
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET timeout = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{UnlockTimeout}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'Misc',
        Name         => 'Reset of unlock time.',
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketUnlockTimeoutUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketQueueID()

get ticket queue id

    my $QueueID = $TicketObject->TicketQueueID(
        TicketID => 123,
    );

=cut

sub TicketQueueID {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    # get ticket data
    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        DynamicFields => 0,
        UserID        => 1,
    );

    return if !%Ticket;

    return $Ticket{QueueID};
}

=item TicketMoveList()

to get the move queue list for a ticket (depends on workflow, if configured)

    my %Queues = $TicketObject->TicketMoveList(
        Type   => 'create',
        UserID => 123,
    );

    my %Queues = $TicketObject->TicketMoveList(
        QueueID => 123,
        UserID  => 123,
    );

    my %Queues = $TicketObject->TicketMoveList(
        TicketID => 123,
        UserID   => 123,
    );

=cut

sub TicketMoveList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID or CustomerUserID!',
        );
        return;
    }

    # check needed stuff
    if ( !$Param{QueueID} && !$Param{TicketID} && !$Param{Type} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID, TicketID or Type!',
        );
        return;
    }

    # get queue object
    my $QueueObject = $Kernel::OM->Get('Kernel::System::Queue');

    my %Queues;
    if ( $Param{UserID} && $Param{UserID} eq 1 ) {
        %Queues = $QueueObject->GetAllQueues();
    }
    else {
        %Queues = $QueueObject->GetAllQueues(%Param);
    }

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'Queue',
        Data          => \%Queues,
    );
    return $Self->TicketAclData() if $ACL;
    return %Queues;
}

=item TicketQueueSet()

to move a ticket (sends notification to agents of selected my queues, if ticket isn't closed)

    my $Success = $TicketObject->TicketQueueSet(
        QueueID  => 123,
        TicketID => 123,
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketQueueSet(
        Queue    => 'Some Queue Name',
        TicketID => 123,
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketQueueSet(
        Queue    => 'Some Queue Name',
        TicketID => 123,
        Comment  => 'some comment', # optional
        ForceNotificationToUserID => [1,43,56], # if you want to force somebody
        UserID   => 123,
    );

Optional attribute:
SendNoNotification disables or enables agent and customer notification for this
action.

For example:

        SendNoNotification => 0, # optional 1|0 (send no agent and customer notification)

Events:
    TicketQueueUpdate

=cut

sub TicketQueueSet {
    my ( $Self, %Param ) = @_;

    # get queue object
    my $QueueObject = $Kernel::OM->Get('Kernel::System::Queue');

    # queue lookup
    if ( $Param{Queue} && !$Param{QueueID} ) {
        $Param{QueueID} = $QueueObject->QueueLookup( Queue => $Param{Queue} );
    }

    # check needed stuff
    for my $Needed (qw(TicketID QueueID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get current ticket
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # move needed?
    if ( $Param{QueueID} == $Ticket{QueueID} && !$Param{Comment} ) {

        # update not needed
        return 1;
    }

    # permission check
    my %MoveList = $Self->MoveList( %Param, Type => 'move_into' );
    if ( !$MoveList{ $Param{QueueID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID}!",
        );
        return;
    }

    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET queue_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{QueueID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # queue lookup
    my $Queue = $QueueObject->QueueLookup( QueueID => $Param{QueueID} );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # history insert
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        QueueID      => $Param{QueueID},
        HistoryType  => 'Move',
        Name         => "\%\%$Queue\%\%$Param{QueueID}\%\%$Ticket{Queue}\%\%$Ticket{QueueID}",
        CreateUserID => $Param{UserID},
    );

    # send move notify to queue subscriber
    if ( !$Param{SendNoNotification} && $Ticket{StateType} ne 'closed' ) {

        my %Used;
        my @UserIDs = $Self->GetSubscribedUserIDsByQueueID( QueueID => $Param{QueueID} );

        if ( $Param{ForceNotificationToUserID} ) {
            push @UserIDs, @{ $Param{ForceNotificationToUserID} };
        }

        # get user object
        my $UserObject = $Kernel::OM->Get('Kernel::System::User');

        USER:
        for my $UserID (@UserIDs) {
            if ( !$Used{$UserID} && $UserID ne $Param{UserID} ) {
                $Used{$UserID} = 1;
                my %UserData = $UserObject->GetUserData(
                    UserID => $UserID,
                    Valid  => 1,
                );
                next USER if !$UserData{UserSendMoveNotification};

                # send agent notification
                $Self->SendAgentNotification(
                    Type                  => 'Move',
                    RecipientID           => $UserID,
                    CustomerMessageParams => {
                        Queue => $Queue,
                        Body  => $Param{Comment} || '',
                    },
                    TicketID => $Param{TicketID},
                    UserID   => $Param{UserID},
                );
            }
        }
    }

    # trigger event, OldTicketData is needed for escalation events
    $Self->EventHandler(
        Event => 'TicketQueueUpdate',
        Data  => {
            TicketID      => $Param{TicketID},
            OldTicketData => \%Ticket,
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketMoveQueueList()

returns a list of used queue ids / names

    my @QueueIDList = $TicketObject->TicketMoveQueueList(
        TicketID => 123,
        Type     => 'ID',
    );

Returns:

    @QueueIDList = ( 1, 2, 3 );

    my @QueueList = $TicketObject->TicketMoveQueueList(
        TicketID => 123,
        Type     => 'Name',
    );

Returns:

    @QueueList = ( 'QueueA', 'QueueB', 'QueueC' );

=cut

sub TicketMoveQueueList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketID!"
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL => 'SELECT sh.name, ht.name, sh.create_by, sh.queue_id FROM '
            . 'ticket_history sh, ticket_history_type ht WHERE '
            . 'sh.ticket_id = ? AND ht.name IN (\'Move\', \'NewTicket\') AND '
            . 'ht.id = sh.history_type_id ORDER BY sh.id',
        Bind => [ \$Param{TicketID} ],
    );

    my @QueueID;
    while ( my @Row = $DBObject->FetchrowArray() ) {

        # store result
        if ( $Row[1] eq 'NewTicket' ) {
            if ( $Row[3] ) {
                push @QueueID, $Row[3];
            }
        }
        elsif ( $Row[1] eq 'Move' ) {
            if ( $Row[0] =~ /^\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)/ ) {
                push @QueueID, $2;
            }
            elsif ( $Row[0] =~ /^Ticket moved to Queue '.+?' \(ID=(.+?)\)/ ) {
                push @QueueID, $1;
            }
        }
    }

    # get queue object
    my $QueueObject = $Kernel::OM->Get('Kernel::System::Queue');

    # queue lookup
    my @QueueName;
    for my $QueueID (@QueueID) {

        my $Queue = $QueueObject->QueueLookup( QueueID => $QueueID );

        push @QueueName, $Queue;
    }

    if ( $Param{Type} && $Param{Type} eq 'Name' ) {
        return @QueueName;
    }
    else {
        return @QueueID;
    }
}

=item TicketTypeList()

to get all possible types for a ticket (depends on workflow, if configured)

    my %Types = $TicketObject->TicketTypeList(
        UserID => 123,
    );

    my %Types = $TicketObject->TicketTypeList(
        QueueID => 123,
        UserID  => 123,
    );

    my %Types = $TicketObject->TicketTypeList(
        TicketID => 123,
        UserID   => 123,
    );

Returns:

    %Types = (
        1 => 'default',
        2 => 'request',
        3 => 'offer',
    );

=cut

sub TicketTypeList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID or CustomerUserID!'
        );
        return;
    }

    my %Types = $Kernel::OM->Get('Kernel::System::Type')->TypeList( Valid => 1 );

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'Type',
        Data          => \%Types,
    );

    return $Self->TicketAclData() if $ACL;
    return %Types;
}

=item TicketTypeSet()

to set a ticket type

    my $Success = $TicketObject->TicketTypeSet(
        TypeID   => 123,
        TicketID => 123,
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketTypeSet(
        Type     => 'normal',
        TicketID => 123,
        UserID   => 123,
    );

Events:
    TicketTypeUpdate

=cut

sub TicketTypeSet {
    my ( $Self, %Param ) = @_;

    # type lookup
    if ( $Param{Type} && !$Param{TypeID} ) {
        $Param{TypeID} = $Kernel::OM->Get('Kernel::System::Type')->TypeLookup( Type => $Param{Type} );
    }

    # check needed stuff
    for my $Needed (qw(TicketID TypeID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get current ticket
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # update needed?
    return 1 if $Param{TypeID} == $Ticket{TypeID};

    # permission check
    my %TypeList = $Self->TicketTypeList(%Param);
    if ( !$TypeList{ $Param{TypeID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID}!",
        );
        return;
    }

    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET type_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{TypeID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # get new ticket data
    my %TicketNew = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );
    $TicketNew{Type} = $TicketNew{Type} || 'NULL';
    $Param{TypeID}   = $Param{TypeID}   || '';
    $Ticket{Type}    = $Ticket{Type}    || 'NULL';
    $Ticket{TypeID}  = $Ticket{TypeID}  || '';

    # history insert
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        HistoryType  => 'TypeUpdate',
        Name         => "\%\%$TicketNew{Type}\%\%$Param{TypeID}\%\%$Ticket{Type}\%\%$Ticket{TypeID}",
        CreateUserID => $Param{UserID},
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketTypeUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketServiceList()

to get all possible services for a ticket (depends on workflow, if configured)

    my %Services = $TicketObject->TicketServiceList(
        QueueID        => 123,
        UserID         => 123,
    );

    my %Services = $TicketObject->TicketServiceList(
        CustomerUserID => 123,
        QueueID        => 123,
    );

    my %Services = $TicketObject->TicketServiceList(
        CustomerUserID => 123,
        TicketID       => 123,
        UserID         => 123,
    );

Returns:

    %Services = (
        1 => 'ServiceA',
        2 => 'ServiceB',
        3 => 'ServiceC',
    );

=cut

sub TicketServiceList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID, CustomerUserID or UserID and CustomerUserID is needed!',
        );
        return;
    }

    # check needed stuff
    if ( !$Param{QueueID} && !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID or TicketID!',
        );
        return;
    }

    # get service object
    my $ServiceObject = $Kernel::OM->Get('Kernel::System::Service');

    my %Services;
    if ( !$Param{CustomerUserID} ) {
        %Services = $ServiceObject->ServiceList(
            UserID => 1,
            KeepChildren =>
                $Kernel::OM->Get('Kernel::Config')->Get('Ticket::Service::KeepChildren'),
        );
    }
    else {
        %Services = $ServiceObject->CustomerUserServiceMemberList(
            Result            => 'HASH',
            CustomerUserLogin => $Param{CustomerUserID},
            UserID            => 1,
        );
    }

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'Service',
        Data          => \%Services,
    );

    return $Self->TicketAclData() if $ACL;
    return %Services;
}

=item TicketServiceSet()

to set a ticket service

    my $Success = $TicketObject->TicketServiceSet(
        ServiceID => 123,
        TicketID  => 123,
        UserID    => 123,
    );

    my $Success = $TicketObject->TicketServiceSet(
        Service  => 'Service A',
        TicketID => 123,
        UserID   => 123,
    );

Events:
    TicketServiceUpdate

=cut

sub TicketServiceSet {
    my ( $Self, %Param ) = @_;

    # service lookup
    if ( $Param{Service} && !$Param{ServiceID} ) {
        $Param{ServiceID} = $Kernel::OM->Get('Kernel::System::Service')->ServiceLookup(
            Name => $Param{Service},
        );
    }

    # check needed stuff
    for my $Needed (qw(TicketID ServiceID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get current ticket
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # update needed?
    return 1 if $Param{ServiceID} eq $Ticket{ServiceID};

    # permission check
    my %ServiceList = $Self->TicketServiceList(%Param);
    if ( $Param{ServiceID} ne '' && !$ServiceList{ $Param{ServiceID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID}!",
        );
        return;
    }

    # check database undef/NULL (set value to undef/NULL to prevent database errors)
    for my $Parameter (qw(ServiceID SLAID)) {
        if ( !$Param{$Parameter} ) {
            $Param{$Parameter} = undef;
        }
    }

    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET service_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{ServiceID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # get new ticket data
    my %TicketNew = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );
    $TicketNew{Service} = $TicketNew{Service} || 'NULL';
    $Param{ServiceID}   = $Param{ServiceID}   || '';
    $Ticket{Service}    = $Ticket{Service}    || 'NULL';
    $Ticket{ServiceID}  = $Ticket{ServiceID}  || '';

    # history insert
    $Self->HistoryAdd(
        TicketID    => $Param{TicketID},
        HistoryType => 'ServiceUpdate',
        Name =>
            "\%\%$TicketNew{Service}\%\%$Param{ServiceID}\%\%$Ticket{Service}\%\%$Ticket{ServiceID}",
        CreateUserID => $Param{UserID},
    );

    # get queue data for this ticket
    my %Queue = $Kernel::OM->Get('Kernel::System::Queue')->QueueGet(
        ID => $Ticket{QueueID},
    );

    # get needed objects
    my $GroupObject = $Kernel::OM->Get('Kernel::System::Group');
    my $UserObject  = $Kernel::OM->Get('Kernel::System::User');

    USERID:
    for my $UserID ( $Self->GetSubscribedUserIDsByServiceID( ServiceID => $Param{ServiceID} ) ) {

        # get the preferences for each user
        my %Preferences = $UserObject->GetPreferences(
            UserID => $UserID,
        );

        next USERID if !%Preferences;
        next USERID if !$Preferences{UserSendServiceUpdateNotification};

        # get groups where user is a member for at least the ro permission
        my %GroupMember = $GroupObject->GroupMemberList(
            UserID => $UserID,
            Type   => 'ro',
            Result => 'HASH',
        );

        # do not send to users without ro permissions on this queue
        next USERID if !$GroupMember{ $Queue{GroupID} };

        # send agent notification
        $Self->SendAgentNotification(
            Type                  => 'ServiceUpdate',
            RecipientID           => $UserID,
            CustomerMessageParams => {},
            TicketID              => $Param{TicketID},
            UserID                => $Param{UserID},
        );
    }

    # trigger event
    $Self->EventHandler(
        Event => 'TicketServiceUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketEscalationPreferences()

get escalation preferences of a ticket (e. g. from SLA or from Queue based settings)

    my %Escalation = $TicketObject->TicketEscalationPreferences(
        Ticket => $Param{Ticket},
        UserID => $Param{UserID},
    );

=cut

sub TicketEscalationPreferences {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(Ticket UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get ticket attributes
    my %Ticket = %{ $Param{Ticket} };

    # get escalation properties
    my %Escalation;
    if ( $Kernel::OM->Get('Kernel::Config')->Get('Ticket::Service') && $Ticket{SLAID} ) {

        %Escalation = $Kernel::OM->Get('Kernel::System::SLA')->SLAGet(
            SLAID  => $Ticket{SLAID},
            UserID => $Param{UserID},
            Cache  => 1,
        );
    }
    else {
        %Escalation = $Kernel::OM->Get('Kernel::System::Queue')->QueueGet(
            ID     => $Ticket{QueueID},
            UserID => $Param{UserID},
            Cache  => 1,
        );
    }

    return %Escalation;
}

=item TicketEscalationDateCalculation()

get escalation properties of a ticket

    my %Escalation = $TicketObject->TicketEscalationDateCalculation(
        Ticket => $Param{Ticket},
        UserID => $Param{UserID},
    );

it returnes

    (general escalation info)
    EscalationDestinationIn          (escalation in e. g. 1h 4m)
    EscalationDestinationTime        (date of escalation in unix time, e. g. 72193292)
    EscalationDestinationDate        (date of escalation, e. g. "2009-02-14 18:00:00")
    EscalationTimeWorkingTime        (seconds of working/service time till escalation, e. g. "1800")
    EscalationTime                   (seconds total till escalation, e. g. "3600")

    (detail escalation info about first response, update and solution time)
    FirstResponseTimeEscalation      (if true, ticket is escalated)
    FirstResponseTimeNotification    (if true, notify - x% of escalation has reached)
    FirstResponseTimeDestinationTime (date of escalation in unix time, e. g. 72193292)
    FirstResponseTimeDestinationDate (date of escalation, e. g. "2009-02-14 18:00:00")
    FirstResponseTimeWorkingTime     (seconds of working/service time till escalation, e. g. "1800")
    FirstResponseTime                (seconds total till escalation, e. g. "3600")

    UpdateTimeEscalation             (if true, ticket is escalated)
    UpdateTimeNotification           (if true, notify - x% of escalation has reached)
    UpdateTimeDestinationTime        (date of escalation in unix time, e. g. 72193292)
    UpdateTimeDestinationDate        (date of escalation, e. g. "2009-02-14 18:00:00")
    UpdateTimeWorkingTime            (seconds of working/service time till escalation, e. g. "1800")
    UpdateTime                       (seconds total till escalation, e. g. "3600")

    SolutionTimeEscalation           (if true, ticket is escalated)
    SolutionTimeNotification         (if true, notify - x% of escalation has reached)
    SolutionTimeDestinationTime      (date of escalation in unix time, e. g. 72193292)
    SolutionTimeDestinationDate      (date of escalation, e. g. "2009-02-14 18:00:00")
    SolutionTimeWorkingTime          (seconds of working/service time till escalation, e. g. "1800")
    SolutionTime                     (seconds total till escalation, e. g. "3600")

=cut

sub TicketEscalationDateCalculation {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(Ticket UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get ticket attributes
    my %Ticket = %{ $Param{Ticket} };

    # do no escalations on (merge|close|remove) tickets
    return if $Ticket{StateType} eq 'merged';
    return if $Ticket{StateType} eq 'closed';
    return if $Ticket{StateType} eq 'removed';

    # get escalation properties
    my %Escalation = $Self->TicketEscalationPreferences(
        Ticket => $Param{Ticket},
        UserID => $Param{UserID} || 1,
    );

    # return if we do not have any escalation attributes
    my %Map = (
        EscalationResponseTime => 'FirstResponse',
        EscalationUpdateTime   => 'Update',
        EscalationSolutionTime => 'Solution',
    );
    my $EscalationAttribute;
    KEY:
    for my $Key ( sort keys %Map ) {
        if ( $Escalation{ $Map{$Key} . 'Time' } ) {
            $EscalationAttribute = 1;
            last KEY;
        }
    }

    return if !$EscalationAttribute;

    # get time object
    my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

    # calculate escalation times based on escalation properties
    my $Time = $TimeObject->SystemTime();
    my %Data;

    TIME:
    for my $Key ( sort keys %Map ) {

        next TIME if !$Ticket{$Key};

        # get time before or over escalation (escalation_destination_unixtime - now)
        my $TimeTillEscalation = $Ticket{$Key} - $Time;

        # ticket is not escalated till now ($TimeTillEscalation > 0)
        my $WorkingTime = 0;
        if ( $TimeTillEscalation > 0 ) {

            $WorkingTime = $TimeObject->WorkingTime(
                StartTime => $Time,
                StopTime  => $Ticket{$Key},
                Calendar  => $Escalation{Calendar},
            );

            # extract needed data
            my $Notify = $Escalation{ $Map{$Key} . 'Notify' };
            my $Time   = $Escalation{ $Map{$Key} . 'Time' };

            # set notification if notify % is reached
            if ( $Notify && $Time ) {

                my $Reached = 100 - ( $WorkingTime / ( $Time * 60 / 100 ) );

                if ( $Reached >= $Notify ) {
                    $Data{ $Map{$Key} . 'TimeNotification' } = 1;
                }
            }
        }

        # ticket is overtime ($TimeTillEscalation < 0)
        else {
            $WorkingTime = $TimeObject->WorkingTime(
                StartTime => $Ticket{$Key},
                StopTime  => $Time,
                Calendar  => $Escalation{Calendar},
            );
            $WorkingTime = "-$WorkingTime";

            # set escalation
            $Data{ $Map{$Key} . 'TimeEscalation' } = 1;
        }
        my $DestinationDate = $TimeObject->SystemTime2TimeStamp(
            SystemTime => $Ticket{$Key},
        );
        $Data{ $Map{$Key} . 'TimeDestinationTime' } = $Ticket{$Key};
        $Data{ $Map{$Key} . 'TimeDestinationDate' } = $DestinationDate;
        $Data{ $Map{$Key} . 'TimeWorkingTime' }     = $WorkingTime;
        $Data{ $Map{$Key} . 'Time' }                = $TimeTillEscalation;

        # set global escalation attributes (set the escalation which is the first in time)
        if (
            !$Data{EscalationDestinationTime}
            || $Data{EscalationDestinationTime} > $Ticket{$Key}
            )
        {
            $Data{EscalationDestinationTime} = $Ticket{$Key};
            $Data{EscalationDestinationDate} = $DestinationDate;
            $Data{EscalationTimeWorkingTime} = $WorkingTime;
            $Data{EscalationTime}            = $TimeTillEscalation;

            # escalation time in readable way
            $Data{EscalationDestinationIn} = '';
            $WorkingTime = abs($WorkingTime);
            if ( $WorkingTime >= 3600 ) {
                $Data{EscalationDestinationIn} .= int( $WorkingTime / 3600 ) . 'h ';
                $WorkingTime = $WorkingTime
                    - ( int( $WorkingTime / 3600 ) * 3600 );    # remove already shown hours
            }
            if ( $WorkingTime <= 3600 || int( $WorkingTime / 60 ) ) {
                $Data{EscalationDestinationIn} .= int( $WorkingTime / 60 ) . 'm';
            }
        }
    }

    return %Data;
}

=item TicketEscalationIndexBuild()

build escalation index of one ticket with current settings (SLA, Queue, Calendar...)

    my $Success = $TicketObject->TicketEscalationIndexBuild(
        TicketID => $Param{TicketID},
        UserID   => $Param{UserID},
    );

=cut

sub TicketEscalationIndexBuild {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        UserID        => $Param{UserID},
        DynamicFields => 0,
    );

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # do no escalations on (merge|close|remove) tickets
    if ( $Ticket{StateType} =~ /^(merge|close|remove)/i ) {

        # update escalation times with 0
        my %EscalationTimes = (
            EscalationTime         => 'escalation_time',
            EscalationResponseTime => 'escalation_response_time',
            EscalationUpdateTime   => 'escalation_update_time',
            EscalationSolutionTime => 'escalation_solution_time',
        );

        TIME:
        for my $Key ( sort keys %EscalationTimes ) {

            # check if table update is needed
            next TIME if !$Ticket{$Key};

            # update ticket table
            $DBObject->Do(
                SQL =>
                    "UPDATE ticket SET $EscalationTimes{$Key} = 0, change_time = current_timestamp, "
                    . " change_by = ? WHERE id = ?",
                Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ],
            );
        }

        # clear ticket cache
        $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

        return 1;
    }

    # get escalation properties
    my %Escalation = $Self->TicketEscalationPreferences(
        Ticket => \%Ticket,
        UserID => $Param{UserID},
    );

    # find escalation times
    my $EscalationTime = 0;

    # update first response (if not responded till now)
    if ( !$Escalation{FirstResponseTime} ) {
        $DBObject->Do(
            SQL =>
                'UPDATE ticket SET escalation_response_time = 0, change_time = current_timestamp, '
                . ' change_by = ? WHERE id = ?',
            Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ]
        );
    }
    else {

        # check if first response is already done
        my %FirstResponseDone = $Self->_TicketGetFirstResponse(
            TicketID => $Ticket{TicketID},
            Ticket   => \%Ticket,
        );

        # update first response time to 0
        if (%FirstResponseDone) {
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_response_time = 0, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ]
            );
        }

        # update first response time to expected escalation destination time
        else {

            # get time object
            my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

            my $DestinationTime = $TimeObject->DestinationTime(
                StartTime => $TimeObject->TimeStamp2SystemTime(
                    String => $Ticket{Created}
                ),
                Time     => $Escalation{FirstResponseTime} * 60,
                Calendar => $Escalation{Calendar},
            );

            # update first response time to $DestinationTime
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_response_time = ?, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$DestinationTime, \$Param{UserID}, \$Ticket{TicketID}, ]
            );

            # remember escalation time
            $EscalationTime = $DestinationTime;
        }
    }

    # update update && do not escalate in "pending auto" for escalation update time
    if ( !$Escalation{UpdateTime} || $Ticket{StateType} =~ /^(pending)/i ) {
        $DBObject->Do(
            SQL => 'UPDATE ticket SET escalation_update_time = 0, change_time = current_timestamp, '
                . ' change_by = ? WHERE id = ?',
            Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ]
        );
    }
    else {

        # check if update escalation should be set
        my @SenderHistory;
        return if !$DBObject->Prepare(
            SQL => 'SELECT article_sender_type_id, article_type_id, create_time FROM '
                . 'article WHERE ticket_id = ? ORDER BY create_time ASC',
            Bind => [ \$Param{TicketID} ],
        );
        while ( my @Row = $DBObject->FetchrowArray() ) {
            push @SenderHistory, {
                SenderTypeID  => $Row[0],
                ArticleTypeID => $Row[1],
                Created       => $Row[2],
            };
        }

        # fill up lookups
        for my $Row (@SenderHistory) {

            # get sender type
            $Row->{SenderType} = $Self->ArticleSenderTypeLookup(
                SenderTypeID => $Row->{SenderTypeID},
            );

            # get article type
            $Row->{ArticleType} = $Self->ArticleTypeLookup(
                ArticleTypeID => $Row->{ArticleTypeID},
            );
        }

        # get latest customer contact time
        my $LastSenderTime;
        my $LastSenderType = '';
        ROW:
        for my $Row ( reverse @SenderHistory ) {

            # fill up latest sender time (as initial value)
            if ( !$LastSenderTime ) {
                $LastSenderTime = $Row->{Created};
            }

            # do not use locked tickets for calculation
            #last ROW if $Ticket{Lock} eq 'lock';

            # do not use /int/ article types for calculation
            next ROW if $Row->{ArticleType} =~ /int/i;

            # only use 'agent' and 'customer' sender types for calculation
            next ROW if $Row->{SenderType} !~ /^(agent|customer)$/;

            # last ROW if latest was customer and the next was not customer
            # otherwise use also next, older customer article as latest
            # customer followup for starting escalation
            if ( $Row->{SenderType} eq 'agent' && $LastSenderType eq 'customer' ) {
                last ROW;
            }

            # start escalation on latest customer article
            if ( $Row->{SenderType} eq 'customer' ) {
                $LastSenderType = 'customer';
                $LastSenderTime = $Row->{Created};
            }

            # start escalation on latest agent article
            if ( $Row->{SenderType} eq 'agent' ) {
                $LastSenderTime = $Row->{Created};
                last ROW;
            }
        }
        if ($LastSenderTime) {

            # get time object
            my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

            my $DestinationTime = $TimeObject->DestinationTime(
                StartTime => $TimeObject->TimeStamp2SystemTime(
                    String => $LastSenderTime,
                ),
                Time     => $Escalation{UpdateTime} * 60,
                Calendar => $Escalation{Calendar},
            );

            # update update time to $DestinationTime
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_update_time = ?, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$DestinationTime, \$Param{UserID}, \$Ticket{TicketID}, ]
            );

            # remember escalation time
            if ( $EscalationTime == 0 || $DestinationTime < $EscalationTime ) {
                $EscalationTime = $DestinationTime;
            }
        }

        # else, no not escalate, because latest sender was agent
        else {
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_update_time = 0, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ]
            );
        }
    }

    # update solution
    if ( !$Escalation{SolutionTime} ) {
        $DBObject->Do(
            SQL =>
                'UPDATE ticket SET escalation_solution_time = 0, change_time = current_timestamp, '
                . ' change_by = ? WHERE id = ?',
            Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ],
        );
    }
    else {

        # find solution time / first close time
        my %SolutionDone = $Self->_TicketGetClosed(
            TicketID => $Ticket{TicketID},
            Ticket   => \%Ticket,
        );

        # update solution time to 0
        if (%SolutionDone) {
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_solution_time = 0, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$Param{UserID}, \$Ticket{TicketID}, ],
            );
        }
        else {

            # get time object
            my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

            my $DestinationTime = $TimeObject->DestinationTime(
                StartTime => $TimeObject->TimeStamp2SystemTime(
                    String => $Ticket{Created}
                ),
                Time     => $Escalation{SolutionTime} * 60,
                Calendar => $Escalation{Calendar},
            );

            # update solution time to $DestinationTime
            $DBObject->Do(
                SQL =>
                    'UPDATE ticket SET escalation_solution_time = ?, change_time = current_timestamp, '
                    . ' change_by = ? WHERE id = ?',
                Bind => [ \$DestinationTime, \$Param{UserID}, \$Ticket{TicketID}, ],
            );

            # remember escalation time
            if ( $EscalationTime == 0 || $DestinationTime < $EscalationTime ) {
                $EscalationTime = $DestinationTime;
            }
        }
    }

    # update escalation time (< escalation time)
    if ( defined $EscalationTime ) {
        $DBObject->Do(
            SQL => 'UPDATE ticket SET escalation_time = ?, change_time = current_timestamp, '
                . ' change_by = ? WHERE id = ?',
            Bind => [ \$EscalationTime, \$Param{UserID}, \$Ticket{TicketID}, ],
        );
    }

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    return 1;
}

=item TicketSLAList()

to get all possible SLAs for a ticket (depends on workflow, if configured)

    my %SLAs = $TicketObject->TicketSLAList(
        ServiceID => 1,
        UserID    => 123,
    );

    my %SLAs = $TicketObject->TicketSLAList(
        QueueID   => 123,
        ServiceID => 1,
        UserID    => 123,
    );

    my %SLAs = $TicketObject->TicketSLAList(
        TicketID  => 123,
        ServiceID => 1,
        UserID    => 123,
    );

Returns:

    %SLAs = (
        1 => 'SLA A',
        2 => 'SLA B',
        3 => 'SLA C',
    );

=cut

sub TicketSLAList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID or CustomerUserID!'
        );
        return;
    }

    # check needed stuff
    if ( !$Param{QueueID} && !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID or TicketID!'
        );
        return;
    }

    # return emty hash, if no service id is given
    if ( !$Param{ServiceID} ) {
        return ();
    }

    # get sla list
    my %SLAs = $Kernel::OM->Get('Kernel::System::SLA')->SLAList(
        ServiceID => $Param{ServiceID},
        UserID    => 1,
    );

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'SLA',
        Data          => \%SLAs,
    );

    return $Self->TicketAclData() if $ACL;
    return %SLAs;
}

=item TicketSLASet()

to set a ticket service level agreement

    my $Success = $TicketObject->TicketSLASet(
        SLAID    => 123,
        TicketID => 123,
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketSLASet(
        SLA      => 'SLA A',
        TicketID => 123,
        UserID   => 123,
    );

Events:
    TicketSLAUpdate

=cut

sub TicketSLASet {
    my ( $Self, %Param ) = @_;

    # sla lookup
    if ( $Param{SLA} && !$Param{SLAID} ) {
        $Param{SLAID} = $Kernel::OM->Get('Kernel::System::SLA')->SLALookup( Name => $Param{SLA} );
    }

    # check needed stuff
    for my $Needed (qw(TicketID SLAID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get current ticket
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # update needed?
    return 1 if ( $Param{SLAID} eq $Ticket{SLAID} );

    # permission check
    my %SLAList = $Self->TicketSLAList(
        %Param,
        ServiceID => $Ticket{ServiceID},
    );

    if ( $Param{UserID} != 1 && $Param{SLAID} ne '' && !$SLAList{ $Param{SLAID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID}!",
        );
        return;
    }

    # check database undef/NULL (set value to undef/NULL to prevent database errors)
    for my $Parameter (qw(ServiceID SLAID)) {
        if ( !$Param{$Parameter} ) {
            $Param{$Parameter} = undef;
        }
    }

    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET sla_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{SLAID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # get new ticket data
    my %TicketNew = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );
    $TicketNew{SLA} = $TicketNew{SLA} || 'NULL';
    $Param{SLAID}   = $Param{SLAID}   || '';
    $Ticket{SLA}    = $Ticket{SLA}    || 'NULL';
    $Ticket{SLAID}  = $Ticket{SLAID}  || '';

    # history insert
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        HistoryType  => 'SLAUpdate',
        Name         => "\%\%$TicketNew{SLA}\%\%$Param{SLAID}\%\%$Ticket{SLA}\%\%$Ticket{SLAID}",
        CreateUserID => $Param{UserID},
    );

    # trigger event, OldTicketData is needed for escalation events
    $Self->EventHandler(
        Event => 'TicketSLAUpdate',
        Data  => {
            TicketID      => $Param{TicketID},
            OldTicketData => \%Ticket,
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketCustomerSet()

Set customer data of ticket. Can set 'No' (CustomerID),
'User' (CustomerUserID), or both.

    my $Success = $TicketObject->TicketCustomerSet(
        No       => 'client123',
        User     => 'client-user-123',
        TicketID => 123,
        UserID   => 23,
    );

Events:
    TicketCustomerUpdate

=cut

sub TicketCustomerSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    if ( !defined $Param{No} && !defined $Param{User} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need User or No for update!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db customer id update
    if ( defined $Param{No} ) {

        my $Ok = $DBObject->Do(
            SQL => 'UPDATE ticket SET customer_id = ?, '
                . ' change_time = current_timestamp, change_by = ? WHERE id = ?',
            Bind => [ \$Param{No}, \$Param{UserID}, \$Param{TicketID} ]
        );

        if ($Ok) {
            $Param{History} = "CustomerID=$Param{No};";
        }
    }

    # db customer user update
    if ( defined $Param{User} ) {

        my $Ok = $DBObject->Do(
            SQL => 'UPDATE ticket SET customer_user_id = ?, '
                . 'change_time = current_timestamp, change_by = ? WHERE id = ?',
            Bind => [ \$Param{User}, \$Param{UserID}, \$Param{TicketID} ],
        );

        if ($Ok) {
            $Param{History} .= "CustomerUser=$Param{User};";
        }
    }

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # if no change
    if ( !$Param{History} ) {
        return;
    }

    # history insert
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        HistoryType  => 'CustomerUpdate',
        Name         => "\%\%" . $Param{History},
        CreateUserID => $Param{UserID},
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketCustomerUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketPermission()

returns whether or not the agent has permission on a ticket

    my $Access = $TicketObject->TicketPermission(
        Type     => 'ro',
        TicketID => 123,
        UserID   => 123,
    );

or without logging, for example for to check if a link/action should be shown

    my $Access = $TicketObject->TicketPermission(
        Type     => 'ro',
        TicketID => 123,
        LogNo    => 1,
        UserID   => 123,
    );

=cut

sub TicketPermission {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(Type TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get needed objects
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');
    my $MainObject   = $Kernel::OM->Get('Kernel::System::Main');

    # run all TicketPermission modules
    if ( ref $ConfigObject->Get('Ticket::Permission') eq 'HASH' ) {
        my %Modules = %{ $ConfigObject->Get('Ticket::Permission') };

        MODULE:
        for my $Module ( sort keys %Modules ) {

            # log try of load module
            if ( $Self->{Debug} > 1 ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'debug',
                    Message  => "Try to load module: $Modules{$Module}->{Module}!",
                );
            }

            # load module
            next MODULE if !$MainObject->Require( $Modules{$Module}->{Module} );

            # create object
            my $ModuleObject = $Modules{$Module}->{Module}->new();

            # execute Run()
            my $AccessOk = $ModuleObject->Run(%Param);

            # check granted option (should I say ok)
            if ( $AccessOk && $Modules{$Module}->{Granted} ) {
                if ( $Self->{Debug} > 0 ) {
                    $Kernel::OM->Get('Kernel::System::Log')->Log(
                        Priority => 'debug',
                        Message  => "Granted access '$Param{Type}' true for "
                            . "TicketID '$Param{TicketID}' "
                            . "through $Modules{$Module}->{Module} (no more checks)!",
                    );
                }

                # access ok
                return 1;
            }

            # return because access is false but it's required
            if ( !$AccessOk && $Modules{$Module}->{Required} ) {
                if ( !$Param{LogNo} ) {
                    $Kernel::OM->Get('Kernel::System::Log')->Log(
                        Priority => 'notice',
                        Message  => "Permission denied because module "
                            . "($Modules{$Module}->{Module}) is required "
                            . "(UserID: $Param{UserID} '$Param{Type}' on "
                            . "TicketID: $Param{TicketID})!",
                    );
                }

                # access not ok
                return;
            }
        }
    }

    # don't grant access to the ticket
    if ( !$Param{LogNo} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied (UserID: $Param{UserID} '$Param{Type}' "
                . "on TicketID: $Param{TicketID})!",
        );
    }

    return;
}

=item TicketCustomerPermission()

returns whether or not a customer has permission to a ticket

    my $Access = $TicketObject->TicketCustomerPermission(
        Type     => 'ro',
        TicketID => 123,
        UserID   => 123,
    );

or without logging, for example for to check if a link/action should be displayed

    my $Access = $TicketObject->TicketCustomerPermission(
        Type     => 'ro',
        TicketID => 123,
        LogNo    => 1,
        UserID   => 123,
    );

=cut

sub TicketCustomerPermission {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(Type TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get main object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');
    my $MainObject   = $Kernel::OM->Get('Kernel::System::Main');

    # run all CustomerTicketPermission modules
    if ( ref $ConfigObject->Get('CustomerTicket::Permission') eq 'HASH' ) {
        my %Modules = %{ $ConfigObject->Get('CustomerTicket::Permission') };

        MODULE:
        for my $Module ( sort keys %Modules ) {

            # log try of load module
            if ( $Self->{Debug} > 1 ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'debug',
                    Message  => "Try to load module: $Modules{$Module}->{Module}!",
                );
            }

            # load module
            next MODULE if !$MainObject->Require( $Modules{$Module}->{Module} );

            # create object
            my $ModuleObject = $Modules{$Module}->{Module}->new();

            # execute Run()
            my $AccessOk = $ModuleObject->Run(%Param);

            # check granted option (should I say ok)
            if ( $AccessOk && $Modules{$Module}->{Granted} ) {
                if ( $Self->{Debug} > 0 ) {
                    $Kernel::OM->Get('Kernel::System::Log')->Log(
                        Priority => 'debug',
                        Message  => "Granted access '$Param{Type}' true for "
                            . "TicketID '$Param{TicketID}' "
                            . "through $Modules{$Module}->{Module} (no more checks)!",
                    );
                }

                # access ok
                return 1;
            }

            # return because access is false but it's required
            if ( !$AccessOk && $Modules{$Module}->{Required} ) {
                if ( !$Param{LogNo} ) {
                    $Kernel::OM->Get('Kernel::System::Log')->Log(
                        Priority => 'notice',
                        Message  => "Permission denied because module "
                            . "($Modules{$Module}->{Module}) is required "
                            . "(UserID: $Param{UserID} '$Param{Type}' on "
                            . "TicketID: $Param{TicketID})!",
                    );
                }

                # access not ok
                return;
            }
        }
    }

    # don't grant access to the ticket
    if ( !$Param{LogNo} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied (UserID: $Param{UserID} '$Param{Type}' on "
                . "TicketID: $Param{TicketID})!",
        );
    }
    return;
}

=item GetSubscribedUserIDsByQueueID()

returns an array of user ids which selected the given queue id as
custom queue.

    my @UserIDs = $TicketObject->GetSubscribedUserIDsByQueueID(
        QueueID => 123,
    );

Returns:

    @UserIDs = ( 1, 2, 3 );

=cut

sub GetSubscribedUserIDsByQueueID {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{QueueID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID!'
        );
        return;
    }

    # get group of queue
    my %Queue = $Kernel::OM->Get('Kernel::System::Queue')->QueueGet( ID => $Param{QueueID} );

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # fetch all queues
    my @UserIDs;
    return if !$DBObject->Prepare(
        SQL  => 'SELECT user_id FROM personal_queues WHERE queue_id = ?',
        Bind => [ \$Param{QueueID} ],
    );
    while ( my @Row = $DBObject->FetchrowArray() ) {
        push @UserIDs, $Row[0];
    }

    # get needed objects
    my $GroupObject = $Kernel::OM->Get('Kernel::System::Group');
    my $UserObject  = $Kernel::OM->Get('Kernel::System::User');

    # check if user is valid and check permissions
    my @CleanUserIDs;

    USER:
    for my $UserID (@UserIDs) {

        my %User = $UserObject->GetUserData(
            UserID => $UserID,
            Valid  => 1
        );

        next USER if !%User;

        # just send emails to permitted agents
        my %GroupMember = $GroupObject->GroupMemberList(
            UserID => $UserID,
            Type   => 'ro',
            Result => 'HASH',
        );

        if ( $GroupMember{ $Queue{GroupID} } ) {
            push @CleanUserIDs, $UserID;
        }
    }

    return @CleanUserIDs;
}

=item GetSubscribedUserIDsByServiceID()

returns an array of user ids which selected the given service id as
custom service.

    my @UserIDs = $TicketObject->GetSubscribedUserIDsByServiceID(
        ServiceID => 123,
    );

Returns:

    @UserIDs = ( 1, 2, 3 );

=cut

sub GetSubscribedUserIDsByServiceID {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{ServiceID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need ServiceID!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # fetch all users
    my @UserIDs;
    return if !$DBObject->Prepare(
        SQL => '
            SELECT user_id
            FROM personal_services
            WHERE service_id = ?',
        Bind => [ \$Param{ServiceID} ],
    );

    while ( my @Row = $DBObject->FetchrowArray() ) {
        push @UserIDs, $Row[0];
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # check if user is valid
    my @CleanUserIDs;
    USER:
    for my $UserID (@UserIDs) {

        my %User = $UserObject->GetUserData(
            UserID => $UserID,
            Valid  => 1,
        );

        next USER if !%User;

        push @CleanUserIDs, $UserID;
    }

    return @CleanUserIDs;
}

=item TicketPendingTimeSet()

set ticket pending time:

    my $Success = $TicketObject->TicketPendingTimeSet(
        Year     => 2003,
        Month    => 08,
        Day      => 14,
        Hour     => 22,
        Minute   => 05,
        TicketID => 123,
        UserID   => 23,
    );

or use a time stamp:

    my $Success = $TicketObject->TicketPendingTimeSet(
        String   => '2003-08-14 22:05:00',
        TicketID => 123,
        UserID   => 23,
    );

or use a diff (set pending time to "now" + diff minutes)

    my $Success = $TicketObject->TicketPendingTimeSet(
        Diff     => ( 7 * 24 * 60 ),  # minutes (here: 10080 minutes - 7 days)
        TicketID => 123,
        UserID   => 23,
    );

If you want to set the pending time to null, just supply zeros:

    my $Success = $TicketObject->TicketPendingTimeSet(
        Year     => 0000,
        Month    => 00,
        Day      => 00,
        Hour     => 00,
        Minute   => 00,
        TicketID => 123,
        UserID   => 23,
    );

or use a time stamp:

    my $Success = $TicketObject->TicketPendingTimeSet(
        String   => '0000-00-00 00:00:00',
        TicketID => 123,
        UserID   => 23,
    );

Events:
    TicketPendingTimeUpdate

=cut

sub TicketPendingTimeSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{String} && !$Param{Diff} ) {
        for my $Needed (qw(Year Month Day Hour Minute TicketID UserID)) {
            if ( !defined $Param{$Needed} ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'error',
                    Message  => "Need $Needed!"
                );
                return;
            }
        }
    }
    elsif (
        !$Param{String} &&
        !( $Param{Year} && $Param{Month} && $Param{Day} && $Param{Hour} && $Param{Minute} )
        )
    {
        for my $Needed (qw(Diff TicketID UserID)) {
            if ( !defined $Param{$Needed} ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'error',
                    Message  => "Need $Needed!"
                );
                return;
            }
        }
    }
    else {
        for my $Needed (qw(String TicketID UserID)) {
            if ( !defined $Param{$Needed} ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'error',
                    Message  => "Need $Needed!"
                );
                return;
            }
        }
    }

    # check if we need to null the PendingTime
    my $PendingTimeNull;
    if ( $Param{String} && $Param{String} eq '0000-00-00 00:00:00' ) {
        $PendingTimeNull = 1;
        $Param{Sec}      = 0;
        $Param{Minute}   = 0;
        $Param{Hour}     = 0;
        $Param{Day}      = 0;
        $Param{Month}    = 0;
        $Param{Year}     = 0;
    }
    elsif (
        !$Param{String}
        && !$Param{Diff}
        && $Param{Minute} == 0
        && $Param{Hour} == 0 && $Param{Day} == 0
        && $Param{Month} == 0
        && $Param{Year} == 0
        )
    {
        $PendingTimeNull = 1;
    }

    # get system time from string/params
    my $Time = 0;
    if ( !$PendingTimeNull ) {

        # get time object
        my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

        if ( $Param{String} ) {
            $Time = $TimeObject->TimeStamp2SystemTime(
                String => $Param{String},
            );
            ( $Param{Sec}, $Param{Minute}, $Param{Hour}, $Param{Day}, $Param{Month}, $Param{Year} )
                = $TimeObject->SystemTime2Date(
                SystemTime => $Time,
                );
        }
        elsif ( $Param{Diff} ) {
            $Time = $TimeObject->SystemTime() + ( $Param{Diff} * 60 );
            ( $Param{Sec}, $Param{Minute}, $Param{Hour}, $Param{Day}, $Param{Month}, $Param{Year} ) =
                $TimeObject->SystemTime2Date(
                SystemTime => $Time,
                );
        }
        else {
            $Time = $TimeObject->TimeStamp2SystemTime(
                String => "$Param{Year}-$Param{Month}-$Param{Day} $Param{Hour}:$Param{Minute}:00",
            );
        }

        # return if no convert is possible
        return if !$Time;
    }

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET until_time = ?, change_time = current_timestamp, change_by = ?'
            . ' WHERE id = ?',
        Bind => [ \$Time, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # history insert
    $Self->HistoryAdd(
        TicketID    => $Param{TicketID},
        HistoryType => 'SetPendingTime',
        Name        => '%%'
            . sprintf( "%02d", $Param{Year} ) . '-'
            . sprintf( "%02d", $Param{Month} ) . '-'
            . sprintf( "%02d", $Param{Day} ) . ' '
            . sprintf( "%02d", $Param{Hour} ) . ':'
            . sprintf( "%02d", $Param{Minute} ) . '',
        CreateUserID => $Param{UserID},
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketPendingTimeUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketLockGet()

check if a ticket is locked or not

    if ($TicketObject->TicketLockGet(TicketID => 123)) {
        print "Ticket is locked!\n";
    }
    else {
        print "Ticket is not locked!\n";
    }

=cut

sub TicketLockGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # check lock state
    return 1 if lc $Ticket{Lock} eq 'lock';

    return;
}

=item TicketLockSet()

to lock or unlock a ticket

    my $Success = $TicketObject->TicketLockSet(
        Lock     => 'lock',
        TicketID => 123,
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketLockSet(
        LockID   => 1,
        TicketID => 123,
        UserID   => 123,
    );

Optional attribute:
SendNoNotification, disable or enable agent and customer notification for this
action. Otherwise a notification will be sent to agent and cusomer.

For example:

        SendNoNotification => 0, # optional 1|0 (send no agent and customer notification)

Events:
    TicketLockUpdate

=cut

sub TicketLockSet {
    my ( $Self, %Param ) = @_;

    # lookup!
    if ( !$Param{LockID} && $Param{Lock} ) {

        $Param{LockID} = $Kernel::OM->Get('Kernel::System::Lock')->LockLookup(
            Lock => $Param{Lock},
        );
    }
    if ( $Param{LockID} && !$Param{Lock} ) {

        $Param{Lock} = $Kernel::OM->Get('Kernel::System::Lock')->LockLookup(
            LockID => $Param{LockID},
        );
    }

    # check needed stuff
    for my $Needed (qw(TicketID UserID LockID Lock)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    if ( !$Param{Lock} && !$Param{LockID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need LockID or Lock!'
        );
        return;
    }

    # check if update is needed
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );
    return 1 if $Ticket{Lock} eq $Param{Lock};

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET ticket_lock_id = ?, '
            . ' change_time = current_timestamp, change_by = ? WHERE id = ?',
        Bind => [ \$Param{LockID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    my $HistoryType = '';
    if ( lc $Param{Lock} eq 'unlock' ) {
        $HistoryType = 'Unlock';
    }
    elsif ( lc $Param{Lock} eq 'lock' ) {
        $HistoryType = 'Lock';
    }
    else {
        $HistoryType = 'Misc';
    }
    if ($HistoryType) {
        $Self->HistoryAdd(
            TicketID     => $Param{TicketID},
            CreateUserID => $Param{UserID},
            HistoryType  => $HistoryType,
            Name         => "\%\%$Param{Lock}",
        );
    }

    # set unlock time it event is 'lock'
    if ( $Param{Lock} eq 'lock' ) {

        # get time object
        my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

        $Self->TicketUnlockTimeoutUpdate(
            UnlockTimeout => $TimeObject->SystemTime(),
            TicketID      => $Param{TicketID},
            UserID        => $Param{UserID},
        );
    }

    # send unlock notify
    if ( lc $Param{Lock} eq 'unlock' ) {

        my %Ticket = $Self->TicketGet(
            %Param,
            DynamicFields => 0,
        );

        # check if the current user is the current owner, if not send a notify
        my $To = '';
        my $Notification = defined $Param{Notification} ? $Param{Notification} : 1;
        if (
            !$Param{SendNoNotification}
            && $Ticket{OwnerID} ne $Param{UserID}
            && $Notification
            )
        {

            # get user data of owner
            my %Preferences = $Kernel::OM->Get('Kernel::System::User')->GetUserData(
                UserID => $Ticket{OwnerID},
                Valid  => 1,
            );

            # send
            if ( $Preferences{UserSendLockTimeoutNotification} ) {
                $Self->SendAgentNotification(
                    Type                  => 'LockTimeout',
                    RecipientID           => $Ticket{OwnerID},
                    CustomerMessageParams => {},
                    TicketID              => $Param{TicketID},
                    UserID                => $Param{UserID},
                );
            }
        }
    }

    # trigger event
    $Self->EventHandler(
        Event => 'TicketLockUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketArchiveFlagSet()

to set the ticket archive flag

    my $Success = $TicketObject->TicketArchiveFlagSet(
        ArchiveFlag => 'y',  # (y|n)
        TicketID    => 123,
        UserID      => 123,
    );

Events:
    TicketArchiveFlagUpdate

=cut

sub TicketArchiveFlagSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID ArchiveFlag)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!",
            );
            return;
        }
    }

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # return if feature is not enabled
    return if !$ConfigObject->Get('Ticket::ArchiveSystem');

    # check given archive flag
    if ( $Param{ArchiveFlag} ne 'y' && $Param{ArchiveFlag} ne 'n' ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "ArchiveFlag is invalid '$Param{ArchiveFlag}'!",
        );
        return;
    }

    # check if update is needed
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # return if no update is needed
    return 1 if $Ticket{ArchiveFlag} && $Ticket{ArchiveFlag} eq $Param{ArchiveFlag};

    # translate archive flag
    my $ArchiveFlag = $Param{ArchiveFlag} eq 'y' ? 1 : 0;

    # set new archive flag
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => '
            UPDATE ticket
            SET archive_flag = ?, change_time = current_timestamp, change_by = ?
            WHERE id = ?',
        Bind => [ \$ArchiveFlag, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # Remove seen flags from ticket and article and ticket watcher data if configured
    #   and if the ticket flag was just set.
    if ($ArchiveFlag) {

        if ( $ConfigObject->Get('Ticket::ArchiveSystem::RemoveSeenFlags') ) {
            $Self->TicketFlagDelete(
                TicketID => $Param{TicketID},
                Key      => 'Seen',
                AllUsers => 1,
            );

            for my $ArticleID ( $Self->ArticleIndex( TicketID => $Param{TicketID} ) ) {
                $Self->ArticleFlagDelete(
                    ArticleID => $ArticleID,
                    Key       => 'Seen',
                    AllUsers  => 1,
                );
            }
        }

        if (
            $ConfigObject->Get('Ticket::ArchiveSystem::RemoveTicketWatchers')
            && $ConfigObject->Get('Ticket::Watcher')
            )
        {
            $Self->TicketWatchUnsubscribe(
                TicketID => $Param{TicketID},
                AllUsers => 1,
                UserID   => $Param{UserID},
            );
        }
    }

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'ArchiveFlagUpdate',
        Name         => "\%\%$Param{ArchiveFlag}",
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketArchiveFlagUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketStateSet()

to set a ticket state

    my $Success = $TicketObject->TicketStateSet(
        State     => 'open',
        TicketID  => 123,
        ArticleID => 123, #optional, for history
        UserID    => 123,
    );

    my $Success = $TicketObject->TicketStateSet(
        StateID  => 3,
        TicketID => 123,
        UserID   => 123,
    );

Optional attribute:
SendNoNotification, disable or enable agent and customer notification for this
action. Otherwise a notification will be sent to agent and cusomer.

For example:

        SendNoNotification => 0, # optional 1|0 (send no agent and customer notification)

Events:
    TicketStateUpdate

=cut

sub TicketStateSet {
    my ( $Self, %Param ) = @_;

    my %State;
    my $ArticleID = $Param{ArticleID} || '';

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    if ( !$Param{State} && !$Param{StateID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need StateID or State!'
        );
        return;
    }

    # get state object
    my $StateObject = $Kernel::OM->Get('Kernel::System::State');

    # state id lookup
    if ( !$Param{StateID} ) {
        %State = $StateObject->StateGet( Name => $Param{State} );
    }

    # state lookup
    if ( !$Param{State} ) {
        %State = $StateObject->StateGet( ID => $Param{StateID} );
    }
    if ( !%State ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need StateID or State!'
        );
        return;
    }

    # check if update is needed
    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        DynamicFields => 0,
    );
    if ( $State{Name} eq $Ticket{State} ) {

        # update is not needed
        return 1;
    }

    # permission check
    my %StateList = $Self->StateList(%Param);
    if ( !$StateList{ $State{ID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID} / StateID: $State{ID}!",
        );
        return;
    }

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET ticket_state_id = ?, '
            . ' change_time = current_timestamp, change_by = ? WHERE id = ?',
        Bind => [ \$State{ID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        ArticleID    => $ArticleID,
        QueueID      => $Ticket{QueueID},
        Name         => "\%\%$Ticket{State}\%\%$State{Name}\%\%",
        HistoryType  => 'StateUpdate',
        CreateUserID => $Param{UserID},
    );

    # trigger event, OldTicketData is needed for escalation events
    $Self->EventHandler(
        Event => 'TicketStateUpdate',
        Data  => {
            TicketID      => $Param{TicketID},
            OldTicketData => \%Ticket,
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketStateList()

to get the state list for a ticket (depends on workflow, if configured)

    my %States = $TicketObject->TicketStateList(
        TicketID => 123,
        UserID   => 123,
    );

    my %States = $TicketObject->TicketStateList(
        QueueID => 123,
        UserID  => 123,
    );

    my %States = $TicketObject->TicketStateList(
        TicketID => 123,
        Type     => 'open',
        UserID   => 123,
    );

Returns:

    %States = (
        1 => 'State A',
        2 => 'State B',
        3 => 'State C',
    );

=cut

sub TicketStateList {
    my ( $Self, %Param ) = @_;

    my %States;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID or CustomerUserID!'
        );
        return;
    }

    # check needed stuff
    if ( !$Param{QueueID} && !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID, TicketID!'
        );
        return;
    }

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # get state object
    my $StateObject = $Kernel::OM->Get('Kernel::System::State');

    # get states by type
    if ( $Param{Type} ) {
        %States = $StateObject->StateGetStatesByType(
            Type   => $Param{Type},
            Result => 'HASH',
        );
    }
    elsif ( $Param{Action} ) {

        if (
            ref $ConfigObject->Get("Ticket::Frontend::$Param{Action}")->{StateType} ne
            'ARRAY'
            )
        {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need config for Ticket::Frontend::$Param{Action}->StateType!"
            );
            return;
        }

        my @StateType = @{ $ConfigObject->Get("Ticket::Frontend::$Param{Action}")->{StateType} };
        %States = $StateObject->StateGetStatesByType(
            StateType => \@StateType,
            Result    => 'HASH',
        );
    }

    # get whole states list
    else {
        %States = $StateObject->StateList(
            UserID => $Param{UserID},
        );
    }

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'State',
        Data          => \%States,
    );

    return $Self->TicketAclData() if $ACL;
    return %States;
}

=item OwnerCheck()

to get the ticket owner

    my ($OwnerID, $Owner) = $TicketObject->OwnerCheck(
        TicketID => 123,
    );

or for access control

    my $AccessOk = $TicketObject->OwnerCheck(
        TicketID => 123,
        OwnerID  => 321,
    );

=cut

sub OwnerCheck {
    my ( $Self, %Param ) = @_;

    my $SQL = '';

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    if ( $Param{OwnerID} ) {

        # create cache key
        my $CacheKey = $Param{TicketID} . '::' . $Param{OwnerID};

        # check cache
        if ( defined $Self->{OwnerCheck}->{$CacheKey} ) {
            return   if !$Self->{OwnerCheck}->{$CacheKey};
            return 1 if $Self->{OwnerCheck}->{$CacheKey};
        }

        # check if user has access
        return if !$DBObject->Prepare(
            SQL => 'SELECT user_id FROM ticket WHERE '
                . ' id = ? AND (user_id = ? OR responsible_user_id = ?)',
            Bind => [ \$Param{TicketID}, \$Param{OwnerID}, \$Param{OwnerID}, ],
        );
        my $Access = 0;
        while ( my @Row = $DBObject->FetchrowArray() ) {
            $Access = 1;
        }

        # fill cache
        $Self->{OwnerCheck}->{$CacheKey} = $Access;
        return   if !$Access;
        return 1 if $Access;
    }

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # search for owner_id and owner
    return if !$DBObject->Prepare(
        SQL => "SELECT st.user_id, su.$ConfigObject->{DatabaseUserTableUser} "
            . " FROM ticket st, $ConfigObject->{DatabaseUserTable} su "
            . " WHERE st.id = ? AND "
            . " st.user_id = su.$ConfigObject->{DatabaseUserTableUserID}",
        Bind => [ \$Param{TicketID}, ],
    );

    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Param{SearchUserID} = $Row[0];
        $Param{SearchUser}   = $Row[1];
    }

    # return if no owner as been found
    return if !$Param{SearchUserID};

    # return owner id and owner
    return $Param{SearchUserID}, $Param{SearchUser};
}

=item TicketOwnerSet()

to set the ticket owner (notification to the new owner will be sent)

by using user id

    my $Success = $TicketObject->TicketOwnerSet(
        TicketID  => 123,
        NewUserID => 555,
        UserID    => 123,
    );

by using user login

    my $Success = $TicketObject->TicketOwnerSet(
        TicketID => 123,
        NewUser  => 'some-user-login',
        UserID   => 123,
    );

Return:
    1 = owner has been set
    2 = this owner is already set, no update needed

Optional attribute:
SendNoNotification, disable or enable agent and customer notification for this
action. Otherwise a notification will be sent to agent and cusomer.

For example:

        SendNoNotification => 0, # optional 1|0 (send no agent and customer notification)

Events:
    TicketOwnerUpdate

=cut

sub TicketOwnerSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    if ( !$Param{NewUserID} && !$Param{NewUser} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need NewUserID or NewUser!'
        );
        return;
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # lookup if no NewUserID is given
    if ( !$Param{NewUserID} ) {

        $Param{NewUserID} = $UserObject->UserLookup(
            UserLogin => $Param{NewUser},
        );
    }

    # lookup if no NewUser is given
    if ( !$Param{NewUser} ) {

        $Param{NewUser} = $UserObject->UserLookup(
            UserID => $Param{NewUserID},
        );
    }

    # check if update is needed!
    my ( $OwnerID, $Owner ) = $Self->OwnerCheck( TicketID => $Param{TicketID} );
    if ( $OwnerID eq $Param{NewUserID} ) {

        # update is "not" needed!
        return 2;
    }

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET '
            . ' user_id = ?, change_time = current_timestamp, change_by = ? WHERE id = ?',
        Bind => [ \$Param{NewUserID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'OwnerUpdate',
        Name         => "\%\%$Param{NewUser}\%\%$Param{NewUserID}",
    );

    # send agent notify
    if ( !$Param{SendNoNotification} ) {
        if (
            $Param{UserID} ne $Param{NewUserID}
            && $Param{NewUserID} ne $Kernel::OM->Get('Kernel::Config')->Get('PostmasterUserID')
            )
        {

            # send agent notification
            $Self->SendAgentNotification(
                Type                  => 'OwnerUpdate',
                RecipientID           => $Param{NewUserID},
                CustomerMessageParams => {
                    %Param,
                    Body => $Param{Comment} || '',
                },
                TicketID => $Param{TicketID},
                UserID   => $Param{UserID},
            );
        }
    }

    # trigger event
    $Self->EventHandler(
        Event => 'TicketOwnerUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketOwnerList()

returns the owner in the past as array with hash ref of the owner data
(name, email, ...)

    my @Owner = $TicketObject->TicketOwnerList(
        TicketID => 123,
    );

Returns:

    @Owner = (
        {
            UserFirstname => 'SomeName',
            UserLastname  => 'SomeName',
            UserEmail     => 'some@example.com',
            # custom attributes
        },
        {
            UserFirstname => 'SomeName',
            UserLastname  => 'SomeName',
            UserEmail     => 'some@example.com',
            # custom attributes
        },
    );

=cut

sub TicketOwnerList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketID!"
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL => 'SELECT sh.owner_id FROM ticket_history sh, ticket_history_type ht WHERE '
            . ' sh.ticket_id = ? AND ht.name IN (\'OwnerUpdate\', \'NewTicket\') AND '
            . ' ht.id = sh.history_type_id ORDER BY sh.id',
        Bind => [ \$Param{TicketID} ],
    );
    my @UserID;

    USER:
    while ( my @Row = $DBObject->FetchrowArray() ) {
        next USER if !$Row[0];
        next USER if $Row[0] eq 1;
        push @UserID, $Row[0];
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    my @UserInfo;
    USER:
    for my $UserID (@UserID) {

        my %User = $UserObject->GetUserData(
            UserID => $UserID,
            Cache  => 1,
            Valid  => 1,
        );

        next USER if !%User;

        push @UserInfo, \%User;
    }

    return @UserInfo;
}

=item TicketResponsibleSet()

to set the ticket responsible (notification to the new responsible will be sent)

by using user id

    my $Success = $TicketObject->TicketResponsibleSet(
        TicketID  => 123,
        NewUserID => 555,
        UserID    => 213,
    );

by using user login

    my $Success = $TicketObject->TicketResponsibleSet(
        TicketID  => 123,
        NewUser   => 'some-user-login',
        UserID    => 213,
    );

Return:
    1 = responsible has been set
    2 = this responsible is already set, no update needed

Optional attribute:
SendNoNotification, disable or enable agent and customer notification for this
action. Otherwise a notification will be sent to agent and cusomer.

For example:

        SendNoNotification => 0, # optional 1|0 (send no agent and customer notification)

Events:
    TicketResponsibleUpdate

=cut

sub TicketResponsibleSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    if ( !$Param{NewUserID} && !$Param{NewUser} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need NewUserID or NewUser!'
        );
        return;
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # lookup if no NewUserID is given
    if ( !$Param{NewUserID} ) {
        $Param{NewUserID} = $UserObject->UserLookup( UserLogin => $Param{NewUser} );
    }

    # lookup if no NewUser is given
    if ( !$Param{NewUser} ) {
        $Param{NewUser} = $UserObject->UserLookup( UserID => $Param{NewUserID} );
    }

    # check if update is needed!
    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        UserID        => $Param{NewUserID},
        DynamicFields => 0,
    );
    if ( $Ticket{ResponsibleID} eq $Param{NewUserID} ) {

        # update is "not" needed!
        return 2;
    }

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET responsible_user_id = ?, '
            . ' change_time = current_timestamp, change_by = ? '
            . ' WHERE id = ?',
        Bind => [ \$Param{NewUserID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'ResponsibleUpdate',
        Name         => "\%\%$Param{NewUser}\%\%$Param{NewUserID}",
    );

    # send agent notify
    if ( !$Param{SendNoNotification} ) {
        if (
            $Param{UserID} ne $Param{NewUserID}
            && $Param{NewUserID} ne $Kernel::OM->Get('Kernel::Config')->Get('PostmasterUserID')
            )
        {
            if ( !$Param{Comment} ) {
                $Param{Comment} = '';
            }

            # send agent notification
            $Self->SendAgentNotification(
                Type                  => 'ResponsibleUpdate',
                RecipientID           => $Param{NewUserID},
                CustomerMessageParams => \%Param,
                TicketID              => $Param{TicketID},
                UserID                => $Param{UserID},
            );
        }
    }

    # trigger event
    $Self->EventHandler(
        Event => 'TicketResponsibleUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketResponsibleList()

returns the responsible in the past as array with hash ref of the owner data
(name, email, ...)

    my @Responsible = $TicketObject->TicketResponsibleList(
        TicketID => 123,
    );

Returns:

    @Responsible = (
        {
            UserFirstname => 'SomeName',
            UserLastname  => 'SomeName',
            UserEmail     => 'some@example.com',
            # custom attributes
        },
        {
            UserFirstname => 'SomeName',
            UserLastname  => 'SomeName',
            UserEmail     => 'some@example.com',
            # custom attributes
        },
    );

=cut

sub TicketResponsibleList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketID!"
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    my @User;
    my $LastResponsible = 1;
    return if !$DBObject->Prepare(
        SQL => 'SELECT sh.name, ht.name, sh.create_by FROM '
            . ' ticket_history sh, ticket_history_type ht WHERE '
            . ' sh.ticket_id = ? AND '
            . ' ht.name IN (\'ResponsibleUpdate\', \'NewTicket\') AND '
            . ' ht.id = sh.history_type_id ORDER BY sh.id',
        Bind => [ \$Param{TicketID} ],
    );

    while ( my @Row = $DBObject->FetchrowArray() ) {

        # store result
        if ( $Row[1] eq 'NewTicket' && $Row[2] ne '1' && $LastResponsible ne $Row[2] ) {
            $LastResponsible = $Row[2];
            push @User, $Row[2];
        }
        elsif ( $Row[1] eq 'ResponsibleUpdate' ) {
            if (
                $Row[0] =~ /^New Responsible is '(.+?)' \(ID=(.+?)\)/
                || $Row[0] =~ /^\%\%(.+?)\%\%(.+?)$/
                )
            {
                $LastResponsible = $2;
                push @User, $2;
            }
        }
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    my @UserInfo;
    for my $SingleUser (@User) {

        my %User = $UserObject->GetUserData(
            UserID => $SingleUser,
            Cache  => 1
        );
        push @UserInfo, \%User;
    }

    return @UserInfo;
}

=item TicketInvolvedAgentsList()

returns an array with hash ref of agents which have been involved with a ticket.
It is guaranteed that no agent is returned twice.

    my @InvolvedAgents = $TicketObject->TicketInvolvedAgentsList(
        TicketID => 123,
    );

Returns:

    @InvolvedAgents = (
        {
            UserFirstname => 'SomeName',
            UserLastname  => 'SomeName',
            UserEmail     => 'some@example.com',
            # custom attributes
        },
        {
            UserFirstname => 'AnotherName',
            UserLastname  => 'AnotherName',
            UserEmail     => 'another@example.com',
            # custom attributes
        },
    );

=cut

sub TicketInvolvedAgentsList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query, only entries with a known history_id are retrieved
    my @User;
    my %UsedOwner;
    return if !$DBObject->Prepare(
        SQL => ''
            . 'SELECT sh.create_by'
            . ' FROM ticket_history sh, ticket_history_type ht'
            . ' WHERE sh.ticket_id = ?'
            . ' AND ht.id = sh.history_type_id'
            . ' ORDER BY sh.id',
        Bind => [ \$Param{TicketID} ],
    );

    while ( my @Row = $DBObject->FetchrowArray() ) {

        # store result, skip the
        if ( $Row[0] ne 1 && !$UsedOwner{ $Row[0] } ) {
            $UsedOwner{ $Row[0] } = $Row[0];
            push @User, $Row[0];
        }
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # collect agent information
    my @UserInfo;
    USER:
    for my $SingleUser (@User) {

        my %User = $UserObject->GetUserData(
            UserID => $SingleUser,
            Valid  => 1,
            Cache  => 1,
        );

        next USER if !%User;

        push @UserInfo, \%User;
    }

    return @UserInfo;
}

=item TicketPrioritySet()

to set the ticket priority

    my $Success = $TicketObject->TicketPrioritySet(
        TicketID => 123,
        Priority => 'low',
        UserID   => 213,
    );

    my $Success = $TicketObject->TicketPrioritySet(
        TicketID   => 123,
        PriorityID => 2,
        UserID     => 213,
    );

Events:
    TicketPriorityUpdate

=cut

sub TicketPrioritySet {
    my ( $Self, %Param ) = @_;

    # get priority object
    my $PriorityObject = $Kernel::OM->Get('Kernel::System::Priority');

    # lookup!
    if ( !$Param{PriorityID} && $Param{Priority} ) {
        $Param{PriorityID} = $PriorityObject->PriorityLookup(
            Priority => $Param{Priority},
        );
    }
    if ( $Param{PriorityID} && !$Param{Priority} ) {
        $Param{Priority} = $PriorityObject->PriorityLookup(
            PriorityID => $Param{PriorityID},
        );
    }

    # check needed stuff
    for my $Needed (qw(TicketID UserID PriorityID Priority)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    my %Ticket = $Self->TicketGet(
        %Param,
        DynamicFields => 0,
    );

    # check if update is needed
    if ( $Ticket{Priority} eq $Param{Priority} ) {

        # update not needed
        return 1;
    }

    # permission check
    my %PriorityList = $Self->PriorityList(%Param);
    if ( !$PriorityList{ $Param{PriorityID} } ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "Permission denied on TicketID: $Param{TicketID}!",
        );
        return;
    }

    # db update
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'UPDATE ticket SET ticket_priority_id = ?, '
            . ' change_time = current_timestamp, change_by = ?'
            . ' WHERE id = ?',
        Bind => [ \$Param{PriorityID}, \$Param{UserID}, \$Param{TicketID} ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        QueueID      => $Ticket{QueueID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'PriorityUpdate',
        Name         => "\%\%$Ticket{Priority}\%\%$Ticket{PriorityID}"
            . "\%\%$Param{Priority}\%\%$Param{PriorityID}",
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketPriorityUpdate',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketPriorityList()

to get the priority list for a ticket (depends on workflow, if configured)

    my %Priorities = $TicketObject->TicketPriorityList(
        TicketID => 123,
        UserID   => 123,
    );

    my %Priorities = $TicketObject->TicketPriorityList(
        QueueID => 123,
        UserID  => 123,
    );

Returns:

    %Priorities = (
        1 => 'Priority A',
        2 => 'Priority B',
        3 => 'Priority C',
    );

=cut

sub TicketPriorityList {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{UserID} && !$Param{CustomerUserID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need UserID or CustomerUserID!'
        );
        return;
    }

    my %Data = $Kernel::OM->Get('Kernel::System::Priority')->PriorityList(%Param);

    # workflow
    my $ACL = $Self->TicketAcl(
        %Param,
        ReturnType    => 'Ticket',
        ReturnSubType => 'Priority',
        Data          => \%Data,
    );

    return $Self->TicketAclData() if $ACL;
    return %Data;
}

=item HistoryTicketStatusGet()

get a hash with ticket id as key and a hash ref (result of HistoryTicketGet)
of all affected tickets in this time area.

    my %Tickets = $TicketObject->HistoryTicketStatusGet(
        StartDay   => 12,
        StartMonth => 1,
        StartYear  => 2006,
        StopDay    => 18,
        StopMonth  => 1,
        StopYear   => 2006,
        Force      => 0,
    );

=cut

sub HistoryTicketStatusGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(StopYear StopMonth StopDay StartYear StartMonth StartDay)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # format month and day params
    for my $DateParameter (qw(StopMonth StopDay StartMonth StartDay)) {
        $Param{$DateParameter} = sprintf( "%02d", $Param{$DateParameter} );
    }

    my $SQLExt = '';
    for my $HistoryTypeData (
        qw(NewTicket FollowUp OwnerUpdate PriorityUpdate CustomerUpdate StateUpdate
        PhoneCallCustomer Forward Bounce SendAnswer EmailCustomer
        PhoneCallAgent WebRequestCustomer TicketDynamicFieldUpdate)
        )
    {
        my $ID = $Self->HistoryTypeLookup( Type => $HistoryTypeData );
        if ( !$SQLExt ) {
            $SQLExt = "AND history_type_id IN ($ID";
        }
        else {
            $SQLExt .= ",$ID";
        }
    }

    if ($SQLExt) {
        $SQLExt .= ')';
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    return if !$DBObject->Prepare(
        SQL => "
            SELECT DISTINCT(th.ticket_id), th.create_time
            FROM ticket_history th
            WHERE th.create_time <= '$Param{StopYear}-$Param{StopMonth}-$Param{StopDay} 23:59:59'
                AND th.create_time >= '$Param{StartYear}-$Param{StartMonth}-$Param{StartDay} 00:00:01'
                $SQLExt
            ORDER BY th.create_time DESC",
        Limit => 150000,
    );

    my %Ticket;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Ticket{ $Row[0] } = 1;
    }

    for my $TicketID ( sort keys %Ticket ) {

        my %TicketData = $Self->HistoryTicketGet(
            TicketID  => $TicketID,
            StopYear  => $Param{StopYear},
            StopMonth => $Param{StopMonth},
            StopDay   => $Param{StopDay},
            Force     => $Param{Force} || 0,
        );

        if (%TicketData) {
            $Ticket{$TicketID} = \%TicketData;
        }
        else {
            $Ticket{$TicketID} = {};
        }
    }

    return %Ticket;
}

=item HistoryTicketGet()

returns a hash of some of the ticket data
calculated based on ticket history info at the given date.

    my %HistoryData = $TicketObject->HistoryTicketGet(
        StopYear   => 2003,
        StopMonth  => 12,
        StopDay    => 24,
        StopHour   => 10, (optional, default 23)
        StopMinute => 0,  (optional, default 59)
        StopSecond => 0,  (optional, default 59)
        TicketID   => 123,
        Force      => 0,     # 1: don't use cache
    );

returns

    TicketNumber
    TicketID
    Type
    TypeID
    Queue
    QueueID
    Priority
    PriorityID
    State
    StateID
    Owner
    OwnerID
    CreateUserID
    CreateTime (timestamp)
    CreateOwnerID
    CreatePriority
    CreatePriorityID
    CreateState
    CreateStateID
    CreateQueue
    CreateQueueID
    LockFirst (timestamp)
    LockLast (timestamp)
    UnlockFirst (timestamp)
    UnlockLast (timestamp)

=cut

sub HistoryTicketGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID StopYear StopMonth StopDay)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }
    $Param{StopHour}   = defined $Param{StopHour}   ? $Param{StopHour}   : '23';
    $Param{StopMinute} = defined $Param{StopMinute} ? $Param{StopMinute} : '59';
    $Param{StopSecond} = defined $Param{StopSecond} ? $Param{StopSecond} : '59';

    # format month and day params
    for my $DateParameter (qw(StopMonth StopDay)) {
        $Param{$DateParameter} = sprintf( "%02d", $Param{$DateParameter} );
    }

    my $CacheKey = 'HistoryTicketGet::'
        . join( '::', map { ( $_ || 0 ) . "::$Param{$_}" } sort keys %Param );

    my $Cached = $Kernel::OM->Get('Kernel::System::Cache')->Get(
        Type => $Self->{CacheType},
        Key  => $CacheKey,
    );
    if ( ref $Cached eq 'HASH' && !$Param{Force} ) {
        return %{$Cached};
    }

    my $Time
        = "$Param{StopYear}-$Param{StopMonth}-$Param{StopDay} $Param{StopHour}:$Param{StopMinute}:$Param{StopSecond}";

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    return if !$DBObject->Prepare(
        SQL => '
            SELECT th.name, tht.name, th.create_time, th.create_by, th.ticket_id,
                th.article_id, th.queue_id, th.state_id, th.priority_id, th.owner_id, th.type_id
            FROM ticket_history th, ticket_history_type tht
            WHERE th.history_type_id = tht.id
                AND th.ticket_id = ?
                AND th.create_time <= ?
            ORDER BY th.create_time, th.id ASC',
        Bind  => [ \$Param{TicketID}, \$Time ],
        Limit => 3000,
    );

    my %Ticket;
    while ( my @Row = $DBObject->FetchrowArray() ) {

        if ( $Row[1] eq 'NewTicket' ) {
            if (
                $Row[0] =~ /^\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)$/
                || $Row[0] =~ /Ticket=\[(.+?)\],.+?Q\=(.+?);P\=(.+?);S\=(.+?)/
                )
            {
                $Ticket{TicketNumber}   = $1;
                $Ticket{Queue}          = $2;
                $Ticket{CreateQueue}    = $2;
                $Ticket{Priority}       = $3;
                $Ticket{CreatePriority} = $3;
                $Ticket{State}          = $4;
                $Ticket{CreateState}    = $4;
                $Ticket{TicketID}       = $Row[4];
                $Ticket{Owner}          = 'root';
                $Ticket{CreateUserID}   = $Row[3];
                $Ticket{CreateTime}     = $Row[2];
            }
            else {

                # COMPAT: compat to 1.1
                # NewTicket
                $Ticket{TicketVersion} = '1.1';
                $Ticket{TicketID}      = $Row[4];
                $Ticket{CreateUserID}  = $Row[3];
                $Ticket{CreateTime}    = $Row[2];
            }
            $Ticket{CreateOwnerID}    = $Row[9] || '';
            $Ticket{CreatePriorityID} = $Row[8] || '';
            $Ticket{CreateStateID}    = $Row[7] || '';
            $Ticket{CreateQueueID}    = $Row[6] || '';
        }

        # COMPAT: compat to 1.1
        elsif ( $Row[1] eq 'PhoneCallCustomer' ) {
            $Ticket{TicketVersion} = '1.1';
            $Ticket{TicketID}      = $Row[4];
            $Ticket{CreateUserID}  = $Row[3];
            $Ticket{CreateTime}    = $Row[2];
        }
        elsif ( $Row[1] eq 'Move' ) {
            if (
                $Row[0] =~ /^\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)/
                || $Row[0] =~ /^Ticket moved to Queue '(.+?)'/
                )
            {
                $Ticket{Queue} = $1;
            }
        }
        elsif (
            $Row[1] eq 'StateUpdate'
            || $Row[1] eq 'Close successful'
            || $Row[1] eq 'Close unsuccessful'
            || $Row[1] eq 'Open'
            || $Row[1] eq 'Misc'
            )
        {
            if (
                $Row[0] =~ /^\%\%(.+?)\%\%(.+?)(\%\%|)$/
                || $Row[0] =~ /^Old: '(.+?)' New: '(.+?)'/
                || $Row[0] =~ /^Changed Ticket State from '(.+?)' to '(.+?)'/
                )
            {
                $Ticket{State}     = $2;
                $Ticket{StateTime} = $Row[2];
            }
        }
        elsif ( $Row[1] eq 'TicketFreeTextUpdate' ) {
            if ( $Row[0] =~ /^\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)$/ ) {
                $Ticket{ 'Ticket' . $1 } = $2;
                $Ticket{ 'Ticket' . $3 } = $4;
                $Ticket{$1}              = $2;
                $Ticket{$3}              = $4;
            }
        }
        elsif ( $Row[1] eq 'TicketDynamicFieldUpdate' ) {

            # take care about different values between 3.3 and 4
            # 3.x: %%FieldName%%test%%Value%%TestValue1
            # 4.x: %%FieldName%%test%%Value%%TestValue1%%OldValue%%OldTestValue1
            if ( $Row[0] =~ /^\%\%FieldName\%\%(.+?)\%\%Value\%\%(.*?)(?:\%\%|$)/ ) {

                my $FieldName = $1;
                my $Value = $2 || '';
                $Ticket{$FieldName} = $Value;

                # Backward compatibility for TicketFreeText and TicketFreeTime
                if ( $FieldName =~ /^Ticket(Free(?:Text|Key)(?:[?:1[0-6]|[1-9]))$/ ) {

                    # Remove the leading Ticket on field name
                    my $FreeFieldName = $1;
                    $Ticket{$FreeFieldName} = $Value;
                }
            }
        }
        elsif ( $Row[1] eq 'PriorityUpdate' ) {
            if ( $Row[0] =~ /^\%\%(.+?)\%\%(.+?)\%\%(.+?)\%\%(.+?)/ ) {
                $Ticket{Priority} = $3;
            }
        }
        elsif ( $Row[1] eq 'OwnerUpdate' ) {
            if ( $Row[0] =~ /^\%\%(.+?)\%\%(.+?)/ || $Row[0] =~ /^New Owner is '(.+?)'/ ) {
                $Ticket{Owner} = $1;
            }
        }
        elsif ( $Row[1] eq 'Lock' ) {
            if ( !$Ticket{LockFirst} ) {
                $Ticket{LockFirst} = $Row[2];
            }
            $Ticket{LockLast} = $Row[2];
        }
        elsif ( $Row[1] eq 'Unlock' ) {
            if ( !$Ticket{UnlockFirst} ) {
                $Ticket{UnlockFirst} = $Row[2];
            }
            $Ticket{UnlockLast} = $Row[2];
        }

        # get default options
        $Ticket{TypeID}     = $Row[10] || '';
        $Ticket{OwnerID}    = $Row[9]  || '';
        $Ticket{PriorityID} = $Row[8]  || '';
        $Ticket{StateID}    = $Row[7]  || '';
        $Ticket{QueueID}    = $Row[6]  || '';
    }
    if ( !%Ticket ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'notice',
            Message  => "No such TicketID in ticket history till "
                . "'$Param{StopYear}-$Param{StopMonth}-$Param{StopDay} $Param{StopHour}:$Param{StopMinute}:$Param{StopSecond}' ($Param{TicketID})!",
        );
        return;
    }

    # update old ticket info
    my %CurrentTicketData = $Self->TicketGet(
        TicketID      => $Ticket{TicketID},
        DynamicFields => 0,
    );
    for my $TicketAttribute (qw(State Priority Queue TicketNumber)) {
        if ( !$Ticket{$TicketAttribute} ) {
            $Ticket{$TicketAttribute} = $CurrentTicketData{$TicketAttribute};
        }
        if ( !$Ticket{"Create$TicketAttribute"} ) {
            $Ticket{"Create$TicketAttribute"} = $CurrentTicketData{$TicketAttribute};
        }
    }

    # get time object
    my $TimeObject = $Kernel::OM->Get('Kernel::System::Time');

    # check if we should cache this ticket data
    my ( $Sec, $Min, $Hour, $Day, $Month, $Year, $WDay ) = $TimeObject->SystemTime2Date(
        SystemTime => $TimeObject->SystemTime(),
    );

    # if the request is for the last month or older, cache it
    if ( "$Year-$Month" gt "$Param{StopYear}-$Param{StopMonth}" ) {
        $Kernel::OM->Get('Kernel::System::Cache')->Set(
            Type  => $Self->{CacheType},
            TTL   => $Self->{CacheTTL},
            Key   => $CacheKey,
            Value => \%Ticket,
        );
    }

    return %Ticket;
}

=item HistoryTypeLookup()

returns the id of the requested history type.

    my $ID = $TicketObject->HistoryTypeLookup( Type => 'Move' );

=cut

sub HistoryTypeLookup {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{Type} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need Type!'
        );
        return;
    }

    # check if we ask the same request?
    my $CacheKey = 'Ticket::History::HistoryTypeLookup::' . $Param{Type};
    if ( $Self->{$CacheKey} ) {
        return $Self->{$CacheKey};
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL  => 'SELECT id FROM ticket_history_type WHERE name = ?',
        Bind => [ \$Param{Type} ],
    );
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Self->{$CacheKey} = $Row[0];
    }

    # check if data exists
    if ( !$Self->{$CacheKey} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "No TypeID for $Param{Type} found!",
        );
        return;
    }

    return $Self->{$CacheKey};
}

=item HistoryAdd()

add a history entry to an ticket

    my $Success = $TicketObject->HistoryAdd(
        Name         => 'Some Comment',
        HistoryType  => 'Move', # see system tables
        TicketID     => 123,
        ArticleID    => 1234, # not required!
        QueueID      => 123, # not required!
        TypeID       => 123, # not required!
        CreateUserID => 123,
    );

Events:
    HistoryAdd

=cut

sub HistoryAdd {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{Name} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need Name!'
        );
        return;
    }

    # lookup!
    if ( !$Param{HistoryTypeID} && $Param{HistoryType} ) {
        $Param{HistoryTypeID} = $Self->HistoryTypeLookup( Type => $Param{HistoryType} );
    }

    # check needed stuff
    for my $Needed (qw(TicketID CreateUserID HistoryTypeID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get QueueID
    if ( !$Param{QueueID} ) {
        $Param{QueueID} = $Self->TicketQueueID( TicketID => $Param{TicketID} );
    }

    # get type
    if ( !$Param{TypeID} ) {
        my %Ticket = $Self->TicketGet(
            %Param,
            DynamicFields => 0,
        );
        $Param{TypeID} = $Ticket{TypeID};
    }

    # get owner
    if ( !$Param{OwnerID} ) {
        my %Ticket = $Self->TicketGet(
            %Param,
            DynamicFields => 0,
        );
        $Param{OwnerID} = $Ticket{OwnerID};
    }

    # get priority
    if ( !$Param{PriorityID} ) {
        my %Ticket = $Self->TicketGet(
            %Param,
            DynamicFields => 0,
        );
        $Param{PriorityID} = $Ticket{PriorityID};
    }

    # get state
    if ( !$Param{StateID} ) {
        my %Ticket = $Self->TicketGet(
            %Param,
            DynamicFields => 0,
        );
        $Param{StateID} = $Ticket{StateID};
    }

    # limit name to 200 chars
    if ( $Param{Name} ) {
        $Param{Name} = substr( $Param{Name}, 0, 200 );
    }

    # db quote
    if ( !$Param{ArticleID} ) {
        $Param{ArticleID} = undef;
    }

    # db insert
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL => 'INSERT INTO ticket_history '
            . ' (name, history_type_id, ticket_id, article_id, queue_id, owner_id, '
            . ' priority_id, state_id, type_id, '
            . ' create_time, create_by, change_time, change_by) '
            . 'VALUES '
            . '(?, ?, ?, ?, ?, ?, ?, ?, ?, current_timestamp, ?, current_timestamp, ?)',
        Bind => [
            \$Param{Name},    \$Param{HistoryTypeID}, \$Param{TicketID},   \$Param{ArticleID},
            \$Param{QueueID}, \$Param{OwnerID},       \$Param{PriorityID}, \$Param{StateID},
            \$Param{TypeID},  \$Param{CreateUserID},  \$Param{CreateUserID},
        ],
    );

    # trigger event
    $Self->EventHandler(
        Event => 'HistoryAdd',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{CreateUserID},
    );

    return 1;
}

=item HistoryGet()

get ticket history as array with hashes
(TicketID, ArticleID, Name, CreateBy, CreateTime, HistoryType, QueueID,
OwnerID, PriorityID, StateID, HistoryTypeID and TypeID)

    my @HistoryLines = $TicketObject->HistoryGet(
        TicketID => 123,
        UserID   => 123,
    );

=cut

sub HistoryGet {
    my ( $Self, %Param ) = @_;

    my @Lines;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    return if !$DBObject->Prepare(
        SQL => 'SELECT sh.name, sh.article_id, sh.create_time, sh.create_by, ht.name, '
            . ' sh.queue_id, sh.owner_id, sh.priority_id, sh.state_id, sh.history_type_id, sh.type_id '
            . ' FROM ticket_history sh, ticket_history_type ht WHERE '
            . ' sh.ticket_id = ? AND ht.id = sh.history_type_id'
            . ' ORDER BY sh.create_time, sh.id',
        Bind => [ \$Param{TicketID} ],
    );

    while ( my @Row = $DBObject->FetchrowArray() ) {
        my %Data;
        $Data{TicketID}      = $Param{TicketID};
        $Data{ArticleID}     = $Row[1] || 0;
        $Data{Name}          = $Row[0];
        $Data{CreateBy}      = $Row[3];
        $Data{CreateTime}    = $Row[2];
        $Data{HistoryType}   = $Row[4];
        $Data{QueueID}       = $Row[5];
        $Data{OwnerID}       = $Row[6];
        $Data{PriorityID}    = $Row[7];
        $Data{StateID}       = $Row[8];
        $Data{HistoryTypeID} = $Row[9];
        $Data{TypeID}        = $Row[10];
        push @Lines, \%Data;
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    # get user data
    for my $Data (@Lines) {

        my %UserInfo = $UserObject->GetUserData(
            UserID => $Data->{CreateBy},
        );

        # merge result, put %Data last so that it "wins"
        %{$Data} = ( %UserInfo, %{$Data} );
    }

    return @Lines;
}

=item HistoryDelete()

delete a ticket history (from storage)

    my $Success = $TicketObject->HistoryDelete(
        TicketID => 123,
        UserID   => 123,
    );

Events:
    HistoryDelete

=cut

sub HistoryDelete {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # delete ticket history entries from db
    return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
        SQL =>
            'DELETE FROM ticket_history WHERE ticket_id = ? AND (article_id IS NULL OR article_id = 0)',
        Bind => [ \$Param{TicketID} ],
    );

    # trigger event
    $Self->EventHandler(
        Event => 'HistoryDelete',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketAccountedTimeGet()

returns the accounted time of a ticket.

    my $AccountedTime = $TicketObject->TicketAccountedTimeGet(TicketID => 1234);

=cut

sub TicketAccountedTimeGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!'
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db query
    return if !$DBObject->Prepare(
        SQL  => 'SELECT time_unit FROM time_accounting WHERE ticket_id = ?',
        Bind => [ \$Param{TicketID} ],
    );

    my $AccountedTime = 0;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Row[0] =~ s/,/./g;
        $AccountedTime = $AccountedTime + $Row[0];
    }

    return $AccountedTime;
}

=item TicketAccountTime()

account time to a ticket.

    my $Success = $TicketObject->TicketAccountTime(
        TicketID  => 1234,
        ArticleID => 23542,
        TimeUnit  => '4.5',
        UserID    => 1,
    );

Events:
    TicketAccountTime

=cut

sub TicketAccountTime {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID ArticleID TimeUnit UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # check some wrong formats
    $Param{TimeUnit} =~ s/,/\./g;
    $Param{TimeUnit} =~ s/ //g;
    $Param{TimeUnit} =~ s/^(\d{1,10}\.\d\d).+?$/$1/g;
    chomp $Param{TimeUnit};

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # update change time
    return if !$DBObject->Do(
        SQL => 'UPDATE ticket SET change_time = current_timestamp, '
            . ' change_by = ? WHERE id = ?',
        Bind => [ \$Param{UserID}, \$Param{TicketID} ],
    );

    # db quote
    $Param{TimeUnit} = $DBObject->Quote( $Param{TimeUnit}, 'Number' );

    # db update
    return if !$DBObject->Do(
        SQL => "INSERT INTO time_accounting "
            . " (ticket_id, article_id, time_unit, create_time, create_by, change_time, change_by) "
            . " VALUES (?, ?, $Param{TimeUnit}, current_timestamp, ?, current_timestamp, ?)",
        Bind => [
            \$Param{TicketID}, \$Param{ArticleID}, \$Param{UserID}, \$Param{UserID},
        ],
    );

    # clear ticket cache
    $Self->_TicketCacheClear( TicketID => $Param{TicketID} );

    # add history
    my $AccountedTime = $Self->TicketAccountedTimeGet( TicketID => $Param{TicketID} );
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        ArticleID    => $Param{ArticleID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'TimeAccounting',
        Name         => "\%\%$Param{TimeUnit}\%\%$AccountedTime",
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketAccountTime',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketMerge()

merge two tickets

    my $Success = $TicketObject->TicketMerge(
        MainTicketID  => 412,
        MergeTicketID => 123,
        UserID        => 123,
    );

Events:
    TicketMerge

=cut

sub TicketMerge {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(MainTicketID MergeTicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # change ticket id of merge ticket to main ticket
    return if !$DBObject->Do(
        SQL => 'UPDATE article SET ticket_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE ticket_id = ?',
        Bind => [ \$Param{MainTicketID}, \$Param{UserID}, \$Param{MergeTicketID} ],
    );

    # bug 9635
    # do the same with article_search (harmless if not used)
    return if !$DBObject->Do(
        SQL  => 'UPDATE article_search SET ticket_id = ? WHERE ticket_id = ?',
        Bind => [ \$Param{MainTicketID}, \$Param{MergeTicketID} ],
    );

    # reassign article history
    return if !$DBObject->Do(
        SQL => 'UPDATE ticket_history SET ticket_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE ticket_id = ?
            AND (article_id IS NOT NULL OR article_id != 0)',
        Bind => [ \$Param{MainTicketID}, \$Param{UserID}, \$Param{MergeTicketID} ],
    );

    # update the accounted time of the main ticket
    return if !$DBObject->Do(
        SQL => 'UPDATE time_accounting SET ticket_id = ?, change_time = current_timestamp, '
            . ' change_by = ? WHERE ticket_id = ?',
        Bind => [ \$Param{MainTicketID}, \$Param{UserID}, \$Param{MergeTicketID} ],
    );

    my %MainTicket = $Self->TicketGet(
        TicketID      => $Param{MainTicketID},
        DynamicFields => 0,
    );
    my %MergeTicket = $Self->TicketGet(
        TicketID      => $Param{MergeTicketID},
        DynamicFields => 0,
    );

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    my $Body = $ConfigObject->Get('Ticket::Frontend::AutomaticMergeText');
    $Body =~ s{<OTRS_TICKET>}{$MergeTicket{TicketNumber}}xms;
    $Body =~ s{<OTRS_MERGE_TO_TICKET>}{$MainTicket{TicketNumber}}xms;

    # add merge article to merge ticket
    $Self->ArticleCreate(
        TicketID       => $Param{MergeTicketID},
        SenderType     => 'agent',
        ArticleType    => 'note-external',
        ContentType    => "text/plain; charset=ascii",
        UserID         => $Param{UserID},
        HistoryType    => 'AddNote',
        HistoryComment => '%%Note',
        Subject        => $ConfigObject->Get('Ticket::Frontend::AutomaticMergeSubject')
            || 'Ticket Merged',
        Body          => $Body,
        NoAgentNotify => 1,
    );

    # add merge history to merge ticket
    $Self->HistoryAdd(
        TicketID    => $Param{MergeTicketID},
        HistoryType => 'Merged',
        Name =>
            "Merged Ticket ($MergeTicket{TicketNumber}/$Param{MergeTicketID}) to ($MainTicket{TicketNumber}/$Param{MainTicketID})",
        CreateUserID => $Param{UserID},
    );

    # add merge history to main ticket
    $Self->HistoryAdd(
        TicketID    => $Param{MainTicketID},
        HistoryType => 'Merged',
        Name =>
            "Merged Ticket ($MergeTicket{TicketNumber}/$Param{MergeTicketID}) to ($MainTicket{TicketNumber}/$Param{MainTicketID})",
        CreateUserID => $Param{UserID},
    );

    # tranfer watchers - only those that were not already watching the main ticket
    # delete all watchers from the merge ticket that are already watching the main ticket
    my %MainWatchers = $Self->TicketWatchGet(
        TicketID => $Param{MainTicketID},
    );

    my %MergeWatchers = $Self->TicketWatchGet(
        TicketID => $Param{MergeTicketID},
    );

    WATCHER:
    for my $WatcherID ( sort keys %MergeWatchers ) {

        next WATCHER if !$MainWatchers{$WatcherID};
        return if !$DBObject->Do(
            SQL => '
                DELETE FROM ticket_watcher
                    WHERE user_id = ?
                    AND ticket_id = ?
                ',
            Bind => [ \$WatcherID, \$Param{MergeTicketID} ],
        );
    }

    # transfer remaining watchers to new ticket
    return if !$DBObject->Do(
        SQL => '
            UPDATE ticket_watcher
                SET ticket_id = ?
                WHERE ticket_id = ?
            ',
        Bind => [ \$Param{MainTicketID}, \$Param{MergeTicketID} ],
    );

    # link tickets
    $Kernel::OM->Get('Kernel::System::LinkObject')->LinkAdd(
        SourceObject => 'Ticket',
        SourceKey    => $Param{MainTicketID},
        TargetObject => 'Ticket',
        TargetKey    => $Param{MergeTicketID},
        Type         => 'ParentChild',
        State        => 'Valid',
        UserID       => $Param{UserID},
    );

    # set new state of merge ticket
    $Self->StateSet(
        State    => 'merged',
        TicketID => $Param{MergeTicketID},
        UserID   => $Param{UserID},
    );

    # unlock ticket
    $Self->LockSet(
        Lock     => 'unlock',
        TicketID => $Param{MergeTicketID},
        UserID   => $Param{UserID},
    );

    # remove seen flag for all users on the main ticket
    my $Success = $Self->TicketFlagDelete(
        TicketID => $Param{MainTicketID},
        Key      => 'Seen',
        AllUsers => 1,
    );

    $Self->TicketMergeDynamicFields(
        MergeTicketID => $Param{MergeTicketID},
        MainTicketID  => $Param{MainTicketID},
        UserID        => $Param{UserID},
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketMerge',
        Data  => {
            TicketID     => $Param{MergeTicketID},
            MainTicketID => $Param{MainTicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketMergeDynamicFields()

merge dynamic fields from one ticket into another, that is, copy
them from the merge ticket to the main ticket if the value is empty
in the main ticket.

    my $Success = $TicketObject->TicketMergeDynamicFields(
        MainTicketID  => 123,
        MergeTicketID => 42,
        UserID        => 1,
        DynamicFields => ['DynamicField_TicketFreeText1'], # optional
    );

If DynamicFields is not present, it is taken from the Ticket::MergeDynamicFields
configuration.

=cut

sub TicketMergeDynamicFields {
    my ( $Self, %Param ) = @_;

    for my $Needed (qw(MainTicketID MergeTicketID UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    my $DynamicFields = $Param{DynamicFields};

    if ( !$DynamicFields ) {
        $DynamicFields = $Kernel::OM->Get('Kernel::Config')->Get('Ticket::MergeDynamicFields');
    }

    return 1 if !IsArrayRefWithData($DynamicFields);

    my %MainTicket = $Self->TicketGet(
        TicketID      => $Param{MainTicketID},
        UserID        => $Param{UserID},
        DynamicFields => 1,
    );
    my %MergeTicket = $Self->TicketGet(
        TicketID      => $Param{MergeTicketID},
        UserID        => $Param{UserID},
        DynamicFields => 1,
    );

    # get dynamic field objects
    my $DynamicFieldObject        = $Kernel::OM->Get('Kernel::System::DynamicField');
    my $DynamicFieldBackendObject = $Kernel::OM->Get('Kernel::System::DynamicField::Backend');

    FIELDS:
    for my $DynamicFieldName ( @{$DynamicFields} ) {

        my $Key = "DynamicField_$DynamicFieldName";

        if (
            defined $MergeTicket{$Key}
            && length $MergeTicket{$Key}
            && !( defined $MainTicket{$Key} && length $MainTicket{$Key} )
            )
        {

            my $DynamicFieldConfig = $DynamicFieldObject->DynamicFieldGet(
                Name => $DynamicFieldName,
            );

            if ( !$DynamicFieldConfig ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'Error',
                    Message  => qq[No such dynamic field "$DynamicFieldName"],
                );
                return;
            }

            $DynamicFieldBackendObject->ValueSet(
                DynamicFieldConfig => $DynamicFieldConfig,
                ObjectID           => $Param{MainTicketID},
                UserID             => $Param{UserID},
                Value              => $MergeTicket{$Key},
            );
        }
    }

    return 1;
}

=item TicketWatchGet()

to get all user ids and additional attributes of an watched ticket

    my %Watch = $TicketObject->TicketWatchGet(
        TicketID => 123,
    );

get list of users to notify

    my %Watch = $TicketObject->TicketWatchGet(
        TicketID => 123,
        Notify   => 1,
    );

get list of users as array

    my @Watch = $TicketObject->TicketWatchGet(
        TicketID => 123,
        Result   => 'ARRAY',
    );

=cut

sub TicketWatchGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketID!"
        );
        return;
    }

    # check if feature is enabled
    return if !$Kernel::OM->Get('Kernel::Config')->Get('Ticket::Watcher');

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # get all attributes of an watched ticket
    return if !$DBObject->Prepare(
        SQL => '
            SELECT user_id, create_time, create_by, change_time, change_by
            FROM ticket_watcher
            WHERE ticket_id = ?',
        Bind => [ \$Param{TicketID} ],
    );

    # fetch the result
    my %Data;
    while ( my @Row = $DBObject->FetchrowArray() ) {
        $Data{ $Row[0] } = {
            CreateTime => $Row[1],
            CreateBy   => $Row[2],
            ChangeTime => $Row[3],
            ChangeBy   => $Row[4],
        };
    }

    if ( $Param{Notify} ) {

        for my $UserID ( sort keys %Data ) {

            # get user object
            my $UserObject = $Kernel::OM->Get('Kernel::System::User');

            my %UserData = $UserObject->GetUserData(
                UserID => $UserID,
                Valid  => 1,
            );

            if ( !$UserData{UserSendWatcherNotification} ) {
                delete $Data{$UserID};
            }
        }
    }

    # check result
    if ( $Param{Result} && $Param{Result} eq 'ARRAY' ) {

        my @UserIDs;

        for my $UserID ( sort keys %Data ) {
            push @UserIDs, $UserID;
        }

        return @UserIDs;
    }

    return %Data;
}

=item TicketWatchSubscribe()

to subscribe a ticket to watch it

    my $Success = $TicketObject->TicketWatchSubscribe(
        TicketID    => 111,
        WatchUserID => 123,
        UserID      => 123,
    );

Events:
    TicketSubscribe

=cut

sub TicketWatchSubscribe {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID WatchUserID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # db access
    return if !$DBObject->Do(
        SQL => '
            DELETE FROM ticket_watcher
            WHERE ticket_id = ?
                AND user_id = ?',
        Bind => [ \$Param{TicketID}, \$Param{WatchUserID} ],
    );
    return if !$DBObject->Do(
        SQL => '
            INSERT INTO ticket_watcher (ticket_id, user_id, create_time, create_by, change_time, change_by)
            VALUES (?, ?, current_timestamp, ?, current_timestamp, ?)',
        Bind => [ \$Param{TicketID}, \$Param{WatchUserID}, \$Param{UserID}, \$Param{UserID} ],
    );

    # get user data
    my %User = $Kernel::OM->Get('Kernel::System::User')->GetUserData(
        UserID => $Param{WatchUserID},
    );

    # add history
    $Self->HistoryAdd(
        TicketID     => $Param{TicketID},
        CreateUserID => $Param{UserID},
        HistoryType  => 'Subscribe',
        Name         => "\%\%$User{UserFirstname} $User{UserLastname} ($User{UserLogin})",
    );

    # trigger event
    $Self->EventHandler(
        Event => 'TicketSubscribe',
        Data  => {
            TicketID => $Param{TicketID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketWatchUnsubscribe()

to remove a subscribtion of a ticket

    my $Success = $TicketObject->TicketWatchUnsubscribe(
        TicketID    => 111,
        WatchUserID => 123,
        UserID      => 123,
    );

Events:
    TicketUnsubscribe

=cut

sub TicketWatchUnsubscribe {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # only one of these parameters is needed
    if ( !$Param{WatchUserID} && !$Param{AllUsers} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need WatchUserID or AllUsers param!"
        );
        return;
    }

    # get user object
    my $UserObject = $Kernel::OM->Get('Kernel::System::User');

    if ( $Param{AllUsers} ) {
        my @WatchUsers = $Self->TicketWatchGet(
            TicketID => $Param{TicketID},
            Result   => 'ARRAY',
        );

        return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
            SQL  => 'DELETE FROM ticket_watcher WHERE ticket_id = ?',
            Bind => [ \$Param{TicketID} ],
        );

        for my $WatchUser (@WatchUsers) {

            my %User = $UserObject->GetUserData(
                UserID => $WatchUser,
            );

            $Self->HistoryAdd(
                TicketID     => $Param{TicketID},
                CreateUserID => $Param{UserID},
                HistoryType  => 'Unsubscribe',
                Name         => "\%\%$User{UserFirstname} $User{UserLastname} ($User{UserLogin})",
            );

            $Self->EventHandler(
                Event => 'TicketUnsubscribe',
                Data  => {
                    TicketID => $Param{TicketID},
                },
                UserID => $Param{UserID},
            );
        }

    }
    else {
        return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
            SQL  => 'DELETE FROM ticket_watcher WHERE ticket_id = ? AND user_id = ?',
            Bind => [ \$Param{TicketID}, \$Param{WatchUserID} ],
        );

        my %User = $UserObject->GetUserData(
            UserID => $Param{WatchUserID},
        );

        $Self->HistoryAdd(
            TicketID     => $Param{TicketID},
            CreateUserID => $Param{UserID},
            HistoryType  => 'Unsubscribe',
            Name         => "\%\%$User{UserFirstname} $User{UserLastname} ($User{UserLogin})",
        );

        $Self->EventHandler(
            Event => 'TicketUnsubscribe',
            Data  => {
                TicketID => $Param{TicketID},
            },
            UserID => $Param{UserID},
        );
    }

    return 1;
}

=item TicketFlagSet()

set ticket flags

    my $Success = $TicketObject->TicketFlagSet(
        TicketID => 123,
        Key      => 'Seen',
        Value    => 1,
        UserID   => 123, # apply to this user
    );

Events:
    TicketFlagSet

=cut

sub TicketFlagSet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Key Value UserID)) {
        if ( !defined $Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    my %Flag = $Self->TicketFlagGet(%Param);

    # check if set is needed
    return 1 if defined $Flag{ $Param{Key} } && $Flag{ $Param{Key} } eq $Param{Value};

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    # set flag
    return if !$DBObject->Do(
        SQL => '
            DELETE FROM ticket_flag
            WHERE ticket_id = ?
                AND ticket_key = ?
                AND create_by = ?',
        Bind => [ \$Param{TicketID}, \$Param{Key}, \$Param{UserID} ],
    );
    return if !$DBObject->Do(
        SQL => '
            INSERT INTO ticket_flag
            (ticket_id, ticket_key, ticket_value, create_time, create_by)
            VALUES (?, ?, ?, current_timestamp, ?)',
        Bind => [ \$Param{TicketID}, \$Param{Key}, \$Param{Value}, \$Param{UserID} ],
    );

    # delete cache
    my $CacheKey = 'TicketFlagGet::' . $Param{TicketID} . '::' . $Param{UserID};
    $Kernel::OM->Get('Kernel::System::Cache')->Delete(
        Type => $Self->{CacheType},
        Key  => $CacheKey,
    );

    # event
    $Self->EventHandler(
        Event => 'TicketFlagSet',
        Data  => {
            TicketID => $Param{TicketID},
            Key      => $Param{Key},
            Value    => $Param{Value},
            UserID   => $Param{UserID},
        },
        UserID => $Param{UserID},
    );

    return 1;
}

=item TicketFlagDelete()

delete ticket flag

    my $Success = $TicketObject->TicketFlagDelete(
        TicketID => 123,
        Key      => 'Seen',
        UserID   => 123,
    );

    my $Success = $TicketObject->TicketFlagDelete(
        TicketID => 123,
        Key      => 'Seen',
        AllUsers => 1,
    );

Events:
    TicketFlagDelete

=cut

sub TicketFlagDelete {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Key)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # only one of these parameters is needed
    if ( !$Param{UserID} && !$Param{AllUsers} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need UserID or AllUsers param!"
        );
        return;
    }

    # if all users parameter was given
    if ( $Param{AllUsers} ) {

        # check all affected users
        my @AllTicketFlags = $Self->TicketFlagGet(
            TicketID => $Param{TicketID},
            AllUsers => 1,
        );

        # do db insert
        return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
            SQL => '
                DELETE FROM ticket_flag
                WHERE ticket_id = ?
                    AND ticket_key = ?',
            Bind => [ \$Param{TicketID}, \$Param{Key} ],
        );

        # clean the cache
        for my $Record (@AllTicketFlags) {
            my $CacheKey = 'TicketFlagGet::' . $Param{TicketID} . '::' . $Record->{UserID};

            # delete cache
            $Kernel::OM->Get('Kernel::System::Cache')->Delete(
                Type => $Self->{CacheType},
                Key  => $CacheKey,
            );

            $Self->EventHandler(
                Event => 'TicketFlagDelete',
                Data  => {
                    TicketID => $Param{TicketID},
                    Key      => $Param{Key},
                    UserID   => $Record->{UserID},
                },
                UserID => $Record->{UserID},
            );
        }
    }
    else {

        # do db insert
        return if !$Kernel::OM->Get('Kernel::System::DB')->Do(
            SQL => '
                DELETE FROM ticket_flag
                WHERE ticket_id = ?
                    AND create_by = ?
                    AND ticket_key = ?',
            Bind => [ \$Param{TicketID}, \$Param{UserID}, \$Param{Key} ],
        );

        # delete cache
        my $CacheKey = 'TicketFlagGet::' . $Param{TicketID} . '::' . $Param{UserID};
        $Kernel::OM->Get('Kernel::System::Cache')->Delete(
            Type => $Self->{CacheType},
            Key  => $CacheKey,
        );

        $Self->EventHandler(
            Event => 'TicketFlagDelete',
            Data  => {
                TicketID => $Param{TicketID},
                Key      => $Param{Key},
                UserID   => $Param{UserID},
            },
            UserID => $Param{UserID},
        );
    }

    return 1;
}

=item TicketFlagGet()

get ticket flags

    my %Flags = $TicketObject->TicketFlagGet(
        TicketID => 123,
        UserID   => 123, # to get flags one user
    );

    my @Flags = $TicketObject->TicketFlagGet(
        TicketID => 123,
        AllUsers   => 1, # to get flags all users
    );

=cut

sub TicketFlagGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need TicketID!"
        );
        return;
    }

    # check optional
    if ( !$Param{UserID} && !$Param{AllUsers} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => "Need UserID or AllUsers param!"
        );
        return;
    }

    # get database object
    my $DBObject = $Kernel::OM->Get('Kernel::System::DB');

    if ( $Param{UserID} ) {

        # check cache
        my $CacheKey = 'TicketFlagGet::' . $Param{TicketID} . '::' . $Param{UserID};
        my $Cache    = $Kernel::OM->Get('Kernel::System::Cache')->Get(
            Type => $Self->{CacheType},
            Key  => $CacheKey,
        );
        return %{$Cache} if $Cache;

        my %Flag;

        # sql query
        return if !$DBObject->Prepare(
            SQL => '
                SELECT ticket_key, ticket_value
                FROM ticket_flag
                WHERE ticket_id = ?
                    AND create_by = ?',
            Bind  => [ \$Param{TicketID}, \$Param{UserID} ],
            Limit => 1500,
        );

        while ( my @Row = $DBObject->FetchrowArray() ) {
            $Flag{ $Row[0] } = $Row[1];
        }

        # set cache
        $Kernel::OM->Get('Kernel::System::Cache')->Set(
            Type  => $Self->{CacheType},
            TTL   => $Self->{CacheTTL},
            Key   => $CacheKey,
            Value => \%Flag,
        );

        return %Flag;

    }

    # all users flags from ticket
    else {

        # sql query
        return if !$DBObject->Prepare(
            SQL => '
                SELECT ticket_key, ticket_value, create_by
                FROM ticket_flag
                WHERE ticket_id = ?',
            Bind  => [ \$Param{TicketID} ],
            Limit => 1500,
        );

        my @FlagAllUsers;
        while ( my @Row = $DBObject->FetchrowArray() ) {
            push @FlagAllUsers, {
                Key    => $Row[0],
                Value  => $Row[1],
                UserID => $Row[2],
            };
        }

        return @FlagAllUsers;
    }

    return;
}

=item TicketArticleStorageSwitch()

move article storage from one backend to other backend

    my $Success = $TicketObject->TicketArticleStorageSwitch(
        TicketID    => 123,
        Source      => 'ArticleStorageDB',
        Destination => 'ArticleStorageFS',
        UserID      => 1,
    );

=cut

sub TicketArticleStorageSwitch {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    for my $Needed (qw(TicketID Source Destination UserID)) {
        if ( !$Param{$Needed} ) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Need $Needed!"
            );
            return;
        }
    }

    # check source vs. destination
    return 1 if $Param{Source} eq $Param{Destination};

    # get config object
    my $ConfigObject = $Kernel::OM->Get('Kernel::Config');

    # reset events and remember
    my $EventConfig = $ConfigObject->Get('Ticket::EventModulePost');
    $ConfigObject->{'Ticket::EventModulePost'} = {};

    # make sure that CheckAllBackends is set for the duration of this method
    $Self->{CheckAllBackends} = 1;

    # get articles
    my @ArticleIndex = $Self->ArticleIndex(
        TicketID => $Param{TicketID},
        UserID   => $Param{UserID},
    );

    # get main object
    my $MainObject = $Kernel::OM->Get('Kernel::System::Main');

    # create source object
    $ConfigObject->Set(
        Key   => 'Ticket::StorageModule',
        Value => 'Kernel::System::Ticket::' . $Param{Source},
    );

    my $TicketObjectSource = Kernel::System::Ticket->new();

    return if !$TicketObjectSource;

    # create target object
    $ConfigObject->Set(
        Key   => 'Ticket::StorageModule',
        Value => 'Kernel::System::Ticket::' . $Param{Destination},
    );

    my $TicketObjectDestination = Kernel::System::Ticket->new();

    return if !$TicketObjectDestination;

    ARTICLEID:
    for my $ArticleID (@ArticleIndex) {

        # read source attachments
        my %Index = $TicketObjectSource->ArticleAttachmentIndex(
            ArticleID     => $ArticleID,
            UserID        => $Param{UserID},
            OnlyMyBackend => 1,
        );

        # read source plain
        my $Plain = $TicketObjectSource->ArticlePlain(
            ArticleID     => $ArticleID,
            OnlyMyBackend => 1,
        );
        my $PlainMD5Sum = '';
        if ($Plain) {
            my $PlainMD5 = $Plain;
            $PlainMD5Sum = $MainObject->MD5sum(
                String => \$PlainMD5,
            );
        }

        # read source attachments
        my @Attachments;
        my %MD5Sums;
        for my $FileID ( sort keys %Index ) {
            my %Attachment = $TicketObjectSource->ArticleAttachment(
                ArticleID     => $ArticleID,
                FileID        => $FileID,
                UserID        => $Param{UserID},
                OnlyMyBackend => 1,
                Force         => 1,
            );
            push @Attachments, \%Attachment;
            my $MD5Sum = $MainObject->MD5sum(
                String => $Attachment{Content},
            );
            $MD5Sums{$MD5Sum}++;
        }

        # nothing to transfer
        next ARTICLEID if !@Attachments && !$Plain;

        # read destination attachments
        %Index = $TicketObjectDestination->ArticleAttachmentIndex(
            ArticleID     => $ArticleID,
            UserID        => $Param{UserID},
            OnlyMyBackend => 1,
        );

        # read source attachments
        if (%Index) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message =>
                    "Attachments of TicketID:$Param{TicketID}/ArticleID:$ArticleID already in $Param{Destination}!"
            );
        }
        else {

            # write attachments to destination
            for my $Attachment (@Attachments) {

                # Check UTF8 string for validity and replace any wrongly encoded characters with _
                if (
                    utf8::is_utf8( $Attachment->{Filename} )
                    && !eval { Encode::is_utf8( $Attachment->{Filename}, 1 ) }
                    )
                {

                    Encode::_utf8_off( $Attachment->{Filename} );

                    # replace invalid characters with � (U+FFFD, Unicode replacement character)
                    # If it runs on good UTF-8 input, output should be identical to input
                    $Attachment->{Filename} = eval {
                        Encode::decode( 'UTF-8', $Attachment->{Filename} );
                    };

                    # Replace wrong characters with "_".
                    $Attachment->{Filename} =~ s{[\x{FFFD}]}{_}xms;
                }

                $TicketObjectDestination->ArticleWriteAttachment(
                    %{$Attachment},
                    ArticleID => $ArticleID,
                    UserID    => $Param{UserID},
                    Force     => 1,
                );
            }

            # write destination plain
            if ($Plain) {
                $TicketObjectDestination->ArticleWritePlain(
                    Email     => $Plain,
                    ArticleID => $ArticleID,
                    UserID    => $Param{UserID},
                );
            }

            # verify destination attachments
            %Index = $TicketObjectDestination->ArticleAttachmentIndex(
                ArticleID     => $ArticleID,
                UserID        => $Param{UserID},
                OnlyMyBackend => 1,
            );
        }

        for my $FileID ( sort keys %Index ) {
            my %Attachment = $TicketObjectDestination->ArticleAttachment(
                ArticleID     => $ArticleID,
                FileID        => $FileID,
                UserID        => $Param{UserID},
                OnlyMyBackend => 1,
                Force         => 1,
            );
            my $MD5Sum = $MainObject->MD5sum(
                String => \$Attachment{Content},
            );
            if ( $MD5Sums{$MD5Sum} ) {
                $MD5Sums{$MD5Sum}--;
                if ( !$MD5Sums{$MD5Sum} ) {
                    delete $MD5Sums{$MD5Sum};
                }
            }
            else {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'error',
                    Message =>
                        "Corrupt file: $Attachment{Filename} (TicketID:$Param{TicketID}/ArticleID:$ArticleID)!",
                );

                # delete corrupt attachments from destination
                $TicketObjectDestination->ArticleDeleteAttachment(
                    ArticleID     => $ArticleID,
                    UserID        => 1,
                    OnlyMyBackend => 1,
                );

                # set events
                $ConfigObject->{'Ticket::EventModulePost'} = $EventConfig;
                return;
            }
        }

        # check if all files are moved
        if (%MD5Sums) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message =>
                    "Not all files are moved! (TicketID:$Param{TicketID}/ArticleID:$ArticleID)!",
            );

            # delete incomplete attachments from destination
            $TicketObjectDestination->ArticleDeleteAttachment(
                ArticleID     => $ArticleID,
                UserID        => 1,
                OnlyMyBackend => 1,
            );

            # set events
            $ConfigObject->{'Ticket::EventModulePost'} = $EventConfig;
            return;
        }

        # verify destination plain if exists in source backend
        if ($Plain) {
            my $PlainVerify = $TicketObjectDestination->ArticlePlain(
                ArticleID     => $ArticleID,
                OnlyMyBackend => 1,
            );
            my $PlainMD5SumVerify = '';
            if ($PlainVerify) {
                $PlainMD5SumVerify = $MainObject->MD5sum(
                    String => \$PlainVerify,
                );
            }
            if ( $PlainMD5Sum ne $PlainMD5SumVerify ) {
                $Kernel::OM->Get('Kernel::System::Log')->Log(
                    Priority => 'error',
                    Message =>
                        "Corrupt plain file: ArticleID: $ArticleID ($PlainMD5Sum/$PlainMD5SumVerify)",
                );

                # delete corrupt plain file from destination
                $TicketObjectDestination->ArticleDeletePlain(
                    ArticleID     => $ArticleID,
                    UserID        => 1,
                    OnlyMyBackend => 1,
                );

                # set events
                $ConfigObject->{'Ticket::EventModulePost'} = $EventConfig;
                return;
            }
        }

        # remove source attachments
        $ConfigObject->Set(
            Key   => 'Ticket::StorageModule',
            Value => 'Kernel::System::Ticket::' . $Param{Source},
        );

        $TicketObjectSource->ArticleDeleteAttachment(
            ArticleID     => $ArticleID,
            UserID        => 1,
            OnlyMyBackend => 1,
        );

        # remove source plain
        $TicketObjectSource->ArticleDeletePlain(
            ArticleID     => $ArticleID,
            UserID        => 1,
            OnlyMyBackend => 1,
        );

        # read source attachments
        %Index = $TicketObjectSource->ArticleAttachmentIndex(
            ArticleID     => $ArticleID,
            UserID        => $Param{UserID},
            OnlyMyBackend => 1,
        );

        # read source attachments
        if (%Index) {
            $Kernel::OM->Get('Kernel::System::Log')->Log(
                Priority => 'error',
                Message  => "Attachments still in $Param{Source}!"
            );
            return;
        }
    }

    # set events
    $ConfigObject->{'Ticket::EventModulePost'} = $EventConfig;

    # restore previous behaviour
    $Self->{CheckAllBackends} =
        $ConfigObject->Get('Ticket::StorageModule::CheckAllBackends')
        // 0;

    return 1;
}

# ProcessManagement functions

=item TicketCheckForProcessType()

    checks wether or not the ticket is of a process type.

    $TicketObject->TicketCheckForProcessType(
        TicketID => 123,
    );

=cut

sub TicketCheckForProcessType {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{TicketID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need TicketID!',
        );
        return;
    }

    my $DynamicFieldName = $Kernel::OM->Get('Kernel::Config')->Get('Process::DynamicFieldProcessManagementProcessID');

    return if !$DynamicFieldName;
    $DynamicFieldName = 'DynamicField_' . $DynamicFieldName;

    # get ticket attributes
    my %Ticket = $Self->TicketGet(
        TicketID      => $Param{TicketID},
        DynamicFields => 1,
    );

    # return 1 if we got process ticket
    return 1 if $Ticket{$DynamicFieldName};
}

=item TicketCalendarGet()

checks calendar to be used for ticket based on sla and queue

    my $Calendar = $TicketObject->TicketCalendarGet(
        QueueID => 1,
        SLAID   => 1,   # optional
    );

returns calendar number or empty string for default calendar

=cut

sub TicketCalendarGet {
    my ( $Self, %Param ) = @_;

    # check needed stuff
    if ( !$Param{QueueID} ) {
        $Kernel::OM->Get('Kernel::System::Log')->Log(
            Priority => 'error',
            Message  => 'Need QueueID!'
        );
        return;
    }

    # check if SLAID was passed and if sla has a specific calendar
    if ( $Param{SLAID} ) {

        my %SLAData = $Kernel::OM->Get('Kernel::System::SLA')->SLAGet(
            SLAID  => $Param{SLAID},
            UserID => 1,
        );

        # if SLA has a defined calendar, return it
        return $SLAData{Calendar} if $SLAData{Calendar};
    }

    # if no calendar was determined by SLA, check if queue has a specific calendar
    my %QueueData = $Kernel::OM->Get('Kernel::System::Queue')->QueueGet(
        ID => $Param{QueueID},
    );

    # if queue has a defined calendar, return it
    return $QueueData{Calendar} if $QueueData{Calendar};

    # use default calendar
    return '';
}

sub DESTROY {
    my $Self = shift;

    # execute all transaction events
    $Self->EventHandlerTransaction();

    return 1;
}

# COMPAT: to OTRS 1.x and 2.x (can be removed later)

sub CustomerPermission {
    my $Self = shift;

    return $Self->TicketCustomerPermission(@_);
}

sub InvolvedAgents {
    my $Self = shift;

    return $Self->TicketInvolvedAgentsList(@_);
}

sub LockIsTicketLocked {
    my $Self = shift;

    return $Self->TicketLockGet(@_);
}

sub LockSet {
    my $Self = shift;

    return $Self->TicketLockSet(@_);
}

sub MoveList {
    my $Self = shift;

    return $Self->TicketMoveList(@_);
}

sub MoveTicket {
    my $Self = shift;

    return $Self->TicketQueueSet(@_);
}

sub MoveQueueList {
    my $Self = shift;

    return $Self->TicketMoveQueueList(@_);
}

sub OwnerList {
    my $Self = shift;

    return $Self->TicketOwnerList(@_);
}

sub OwnerSet {
    my $Self = shift;

    return $Self->TicketOwnerSet(@_);
}

sub Permission {
    my $Self = shift;

    return $Self->TicketPermission(@_);
}

sub PriorityList {
    my $Self = shift;

    return $Self->TicketPriorityList(@_);
}

sub PrioritySet {
    my $Self = shift;

    return $Self->TicketPrioritySet(@_);
}

sub ResponsibleList {
    my $Self = shift;

    return $Self->TicketResponsibleList(@_);
}

sub ResponsibleSet {
    my $Self = shift;

    return $Self->TicketResponsibleSet(@_);
}

sub SetCustomerData {
    my $Self = shift;

    return $Self->TicketCustomerSet(@_);
}

sub StateList {
    my $Self = shift;

    return $Self->TicketStateList(@_);
}

sub StateSet {
    my $Self = shift;

    return $Self->TicketStateSet(@_);
}

1;

=back

=head1 TERMS AND CONDITIONS

This software is part of the OTRS project (L<http://otrs.org/>).

This software comes with ABSOLUTELY NO WARRANTY. For details, see
the enclosed file COPYING for license information (AGPL). If you
did not receive this file, see L<http://www.gnu.org/licenses/agpl.txt>.

=cut
