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use strict;
use warnings;

package RT::SearchBuilder::Role::Roles;
use Role::Basic;
use Scalar::Util qw(blessed);

=head1 NAME

RT::Record::Role::Roles - Common methods for records which "watchers" or "roles"

=head1 REQUIRES

=head2 L<RT::SearchBuilder::Role>

=cut

with 'RT::SearchBuilder::Role';

require RT::System;
require RT::Principal;
require RT::Group;
require RT::User;

require RT::EmailParser;

=head1 PROVIDES

=head2 _RoleGroupClass

Returns the class name on which role searches should be based.  This relates to
the internal L<RT::Group/Domain> and distinguishes between roles on the objects
being searched and their counterpart roles on containing classes.  For example,
limiting on L<RT::Queue> roles while searching for L<RT::Ticket>s.

The default implementation is:

    $self->RecordClass

which is the class that this collection object searches and instatiates objects
for.  If you're doing something hinky, you may need to override this method.

=cut

sub _RoleGroupClass {
    my $self = shift;
    return $self->RecordClass;
}

sub _RoleGroupsJoin {
    my $self = shift;
    my %args = (New => 0, Class => '', Name => '', @_);

    $args{'Class'} ||= $self->_RoleGroupClass;

    my $name = $args{'Name'};

    return $self->{'_sql_role_group_aliases'}{ $args{'Class'} .'-'. $name }
        if $self->{'_sql_role_group_aliases'}{ $args{'Class'} .'-'. $name }
           && !$args{'New'};

    # If we're looking at a role group on a class that "contains" this record
    # (i.e. roles on queues for tickets), then we assume that the current
    # record has a column named after the containing class (i.e.
    # Tickets.Queue).
    my $instance = $self->_RoleGroupClass eq $args{Class} ? "id" : $args{Class};
       $instance =~ s/^RT:://;

    # Watcher groups are no longer always created for each record, so we now use left join.
    # Previously (before 4.4) this used an inner join.
    my $groups = $self->Join(
        TYPE            => 'left',
        ALIAS1          => 'main',
        FIELD1          => $instance,
        TABLE2          => 'Groups',
        FIELD2          => 'Instance',
        ENTRYAGGREGATOR => 'AND',
        DISTINCT        => !!$args{'Type'},
    );
    $self->Limit(
        LEFTJOIN        => $groups,
        ALIAS           => $groups,
        FIELD           => 'Domain',
        VALUE           => $args{'Class'} .'-Role',
        CASESENSITIVE   => 0,
    );
    $self->Limit(
        LEFTJOIN        => $groups,
        ALIAS           => $groups,
        FIELD           => 'Name',
        VALUE           => $name,
        CASESENSITIVE   => 0,
    ) if $name;

    $self->{'_sql_role_group_aliases'}{ $args{'Class'} .'-'. $name } = $groups
        unless $args{'New'};

    return $groups;
}

sub _GroupMembersJoin {
    my $self = shift;
    my %args = (New => 1, GroupsAlias => undef, Left => 1, @_);

    return $self->{'_sql_group_members_aliases'}{ $args{'GroupsAlias'} }
        if $self->{'_sql_group_members_aliases'}{ $args{'GroupsAlias'} }
            && !$args{'New'};

    my $alias = $self->Join(
        $args{'Left'} ? (TYPE            => 'LEFT') : (),
        ALIAS1          => $args{'GroupsAlias'},
        FIELD1          => 'id',
        TABLE2          => 'CachedGroupMembers',
        FIELD2          => 'GroupId',
        ENTRYAGGREGATOR => 'AND',
    );
    $self->Limit(
        LEFTJOIN => $alias,
        ALIAS => $alias,
        FIELD => 'Disabled',
        VALUE => 0,
    );

    $self->{'_sql_group_members_aliases'}{ $args{'GroupsAlias'} } = $alias
        unless $args{'New'};

    return $alias;
}

=head2 _WatcherJoin

Helper function which provides joins to a watchers table both for limits
and for ordering.

=cut

sub _WatcherJoin {
    my $self = shift;

    my $groups = $self->_RoleGroupsJoin(@_);
    my $group_members = $self->_GroupMembersJoin( GroupsAlias => $groups );
    # XXX: work around, we must hide groups that
    # are members of the role group we search in,
    # otherwise them result in wrong NULLs in Users
    # table and break ordering. Now, we know that
    # RT doesn't allow to add groups as members of the
    # ticket roles, so we just hide entries in CGM table
    # with MemberId == GroupId from results
    $self->Limit(
        LEFTJOIN   => $group_members,
        FIELD      => 'GroupId',
        OPERATOR   => '!=',
        VALUE      => "$group_members.MemberId",
        QUOTEVALUE => 0,
    );
    my $users = $self->Join(
        TYPE            => 'LEFT',
        ALIAS1          => $group_members,
        FIELD1          => 'MemberId',
        TABLE2          => 'Users',
        FIELD2          => 'id',
    );
    return ($groups, $group_members, $users);
}


sub RoleLimit {
    my $self = shift;
    my %args = (
        TYPE => '',
        CLASS => '',
        FIELD => undef,
        OPERATOR => '=',
        VALUE => undef,
        @_
    );

    my $class = $args{CLASS} || $self->_RoleGroupClass;

    $args{FIELD} ||= 'id' if $args{VALUE} =~ /^\d+$/;

    my $type = delete $args{TYPE};
    if ($type and not $class->HasRole($type)) {
        RT->Logger->warn("RoleLimit called with invalid role $type for $class");
        return;
    }

    my $column = $type ? $class->Role($type)->{Column} : undef;

    # if it's equality op and search by Email or Name then we can preload user
    # we do it to help some DBs better estimate number of rows and get better plans
    if ( $args{OPERATOR} =~ /^!?=$/
             && (!$args{FIELD} || $args{FIELD} eq 'Name' || $args{FIELD} eq 'EmailAddress') ) {
        my $o = RT::User->new( $self->CurrentUser );
        my $method =
            !$args{FIELD}
            ? ($column ? 'Load' : 'LoadByEmail')
            : $args{FIELD} eq 'EmailAddress' ? 'LoadByEmail': 'Load';
        $o->$method( $args{VALUE} );
        $args{FIELD} = 'id';
        $args{VALUE} = $o->id || 0;
    }

    if ( $column and $args{FIELD} and $args{FIELD} eq 'id' ) {
        $self->Limit(
            %args,
            FIELD => $column,
        );
        return;
    }

    $args{FIELD} ||= 'EmailAddress';

    my ($groups, $group_members, $users);
    if ( $args{'BUNDLE'} and @{$args{'BUNDLE'}}) {
        ($groups, $group_members, $users) = @{ $args{'BUNDLE'} };
    } else {
        $groups = $self->_RoleGroupsJoin( Name => $type, Class => $class, New => !$type );
    }

    $self->_OpenParen( $args{SUBCLAUSE} ) if $args{SUBCLAUSE};
    if ( $args{OPERATOR} =~ /^IS(?: NOT)?$/i ) {
        # is [not] empty case

        $group_members ||= $self->_GroupMembersJoin( GroupsAlias => $groups );
        # to avoid joining the table Users into the query, we just join GM
        # and make sure we don't match records where group is member of itself
        $self->Limit(
            LEFTJOIN   => $group_members,
            FIELD      => 'GroupId',
            OPERATOR   => '!=',
            VALUE      => "$group_members.MemberId",
            QUOTEVALUE => 0,
        );
        $self->Limit(
            %args,
            ALIAS         => $group_members,
            FIELD         => 'GroupId',
            OPERATOR      => $args{OPERATOR},
            VALUE         => $args{VALUE},
        );
    }
    elsif ( $args{OPERATOR} =~ /^!=$|^NOT\s+/i ) {
        # negative condition case

        # reverse op
        $args{OPERATOR} =~ s/!|NOT\s+//i;

        # XXX: we have no way to build correct "Watcher.X != 'Y'" when condition
        # "X = 'Y'" matches more then one user so we try to fetch two records and
        # do the right thing when there is only one exist and semi-working solution
        # otherwise.
        my $users_obj = RT::Users->new( $self->CurrentUser );
        $users_obj->Limit(
            FIELD         => $args{FIELD},
            OPERATOR      => $args{OPERATOR},
            VALUE         => $args{VALUE},
        );
        $users_obj->OrderBy;
        $users_obj->RowsPerPage(2);
        my @users = @{ $users_obj->ItemsArrayRef };

        $group_members ||= $self->_GroupMembersJoin( GroupsAlias => $groups );
        if ( @users <= 1 ) {
            my $uid = 0;
            $uid = $users[0]->id if @users;
            $self->Limit(
                LEFTJOIN      => $group_members,
                ALIAS         => $group_members,
                FIELD         => 'MemberId',
                VALUE         => $uid,
            );
            $self->Limit(
                %args,
                ALIAS           => $group_members,
                FIELD           => 'id',
                OPERATOR        => 'IS',
                VALUE           => 'NULL',
            );
        } else {
            $self->Limit(
                LEFTJOIN   => $group_members,
                FIELD      => 'GroupId',
                OPERATOR   => '!=',
                VALUE      => "$group_members.MemberId",
                QUOTEVALUE => 0,
            );
            $users ||= $self->Join(
                TYPE            => 'LEFT',
                ALIAS1          => $group_members,
                FIELD1          => 'MemberId',
                TABLE2          => 'Users',
                FIELD2          => 'id',
            );
            $self->Limit(
                LEFTJOIN      => $users,
                ALIAS         => $users,
                FIELD         => $args{FIELD},
                OPERATOR      => $args{OPERATOR},
                VALUE         => $args{VALUE},
                CASESENSITIVE => 0,
            );
            $self->Limit(
                %args,
                ALIAS         => $users,
                FIELD         => 'id',
                OPERATOR      => 'IS',
                VALUE         => 'NULL',
            );
        }
    } else {
        # positive condition case

        $group_members ||= $self->_GroupMembersJoin(
            GroupsAlias => $groups, New => 1, Left => 0
        );
        if ($args{FIELD} eq "id") {
            # Save a left join to Users, if possible
            $self->Limit(
                %args,
                ALIAS           => $group_members,
                FIELD           => "MemberId",
                OPERATOR        => $args{OPERATOR},
                VALUE           => $args{VALUE},
                CASESENSITIVE   => 0,
            );
        } else {
            $users ||= $self->Join(
                TYPE            => 'LEFT',
                ALIAS1          => $group_members,
                FIELD1          => 'MemberId',
                TABLE2          => 'Users',
                FIELD2          => 'id',
            );
            $self->Limit(
                %args,
                ALIAS           => $users,
                FIELD           => $args{FIELD},
                OPERATOR        => $args{OPERATOR},
                VALUE           => $args{VALUE},
                CASESENSITIVE   => 0,
            );
        }
    }
    $self->_CloseParen( $args{SUBCLAUSE} ) if $args{SUBCLAUSE};
    if ($args{BUNDLE} and not @{$args{BUNDLE}}) {
        @{$args{BUNDLE}} = ($groups, $group_members, $users);
    }
    return ($groups, $group_members, $users);
}

1;
