%# BEGIN BPS TAGGED BLOCK {{{
%#
%# COPYRIGHT:
%#
%# This software is Copyright (c) 1996-2014 Best Practical Solutions, LLC
%#                                          <sales@bestpractical.com>
%#
%# (Except where explicitly superseded by other copyright notices)
%#
%#
%# LICENSE:
%#
%# This work is made available to you under the terms of Version 2 of
%# the GNU General Public License. A copy of that license should have
%# been provided with this software, but in any event can be snarfed
%# from www.gnu.org.
%#
%# This work is distributed in the hope that it will be useful, but
%# WITHOUT ANY WARRANTY; without even the implied warranty of
%# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
%# General Public License for more details.
%#
%# You should have received a copy of the GNU General Public License
%# along with this program; if not, write to the Free Software
%# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
%# 02110-1301 or visit their web page on the internet at
%# http://www.gnu.org/licenses/old-licenses/gpl-2.0.html.
%#
%#
%# CONTRIBUTION SUBMISSION POLICY:
%#
%# (The following paragraph is not intended to limit the rights granted
%# to you to modify and distribute this software under the terms of
%# the GNU General Public License and is only of importance to you if
%# you choose to contribute your changes and enhancements to the
%# community by submitting them to Best Practical Solutions, LLC.)
%#
%# By intentionally submitting any modifications, corrections or
%# derivatives to this work, or any other work intended for use with
%# Request Tracker, to Best Practical Solutions, LLC, you confirm that
%# you are the copyright holder for those contributions and you grant
%# Best Practical Solutions,  LLC a nonexclusive, worldwide, irrevocable,
%# royalty-free, perpetual, license to use, copy, create derivative
%# works based on those contributions, and sublicense and distribute
%# those contributions and any derivatives thereof.
%#
%# END BPS TAGGED BLOCK }}}
%# REST/1.0/Forms/ticket/links
%#
<%ARGS>
$id
$format => 's'
$changes => undef
</%ARGS>
<%INIT>
my @data;
my $ticket = RT::Ticket->new($session{CurrentUser});

$ticket->Load($id);
if (!$ticket->Id) {
    return [ "# Ticket $id does not exist.", [], {}, 1 ];
}

my ($c, $o, $k, $e) = ("", [], {}, 0);
my @fields = qw(DependsOn DependedOnBy RefersTo ReferredToBy Members MemberOf);
my %fields = map { lc $_ => $_ } @fields;

my %lfields = (
    Members      => { Type => 'MemberOf',  Mode => 'Base'   },
    ReferredToBy => { Type => 'RefersTo',  Mode => 'Base'   },
    DependedOnBy => { Type => 'DependsOn', Mode => 'Base'   },
    MemberOf     => { Type => 'MemberOf',  Mode => 'Target' },
    RefersTo     => { Type => 'RefersTo',  Mode => 'Target' },
    DependsOn    => { Type => 'DependsOn', Mode => 'Target' },
);

if ($changes) {
    my ($get, $set, $key, $val, $n, $s);
    my %data = %$changes;
    my @comments;

    foreach $key (keys %data) {
        $val = $data{$key};
        $key = lc $key;
        $n = 1;

        if (exists $fields{$key}) {
            $key = $fields{$key};

            my %old;
            my $field = $lfields{$key}->{Mode};
            while (my $link = $ticket->$key->Next) {
                $old{$link->$field} = 1;
            }

            my %new;
            foreach my $nkey (@{vsplit($val)}) {
                if ($nkey =~ /^\d+$/) {
                    my $uri = RT::URI->new($session{CurrentUser});
                    my $tick = RT::Ticket->new($session{CurrentUser});
                    $tick->Load($nkey);
                    if ($tick->Id) {
                        $uri->FromObject($tick);
                        $nkey = $uri->URI;
                    }
                    else {
                        $n = 0;
                        $s = "Ticket $nkey does not exist.";
                        goto SET;
                    }
                }
                $new{$nkey} = 1;
            }

            foreach my $u (keys %old) {
                if (exists $new{$u}) {
                    delete $new{$u};
                }
                else {
                    my $type = $lfields{$key}->{Type};
                    my $mode = $lfields{$key}->{Mode};
                    ($n, $s) = $ticket->DeleteLink(Type => $type, $mode => $u);
                    goto SET;
                }
            }
            foreach my $u (keys %new) {
                my $type = $lfields{$key}->{Type};
                my $mode = $lfields{$key}->{Mode};
                ($n, $s) = $ticket->AddLink(Type => $type, $mode => $u);
                goto SET;
            }
        }
        elsif ($key ne 'id' && $key ne 'type') {
            $n = 0;
            $s = "Unknown field: $key";
        }

    SET:
        if ($n == 0) {
            $e = 1;
            push @comments, "# $key: $s";
            unless (@$o) {
                @$o = ("id", @fields);
                %$k = %data;
            }
        }
    }

    push(@comments, "# Links for ticket $id updated.") unless @comments;
    $c = join("\n", @comments) if @comments;
}
else {
    my @data;

    push @data, [ id => "ticket/".$ticket->Id."/links" ];
    foreach my $key (@fields) {
        my @val;

        my $field = $lfields{$key}->{Mode};
        while (my $link = $ticket->$key->Next) {
            push @val, $link->$field;
        }
        push(@val, "") if (@val == 0 && defined $format && $format eq 'l');
        push @data, [ $key => [ @val ] ] if @val;
    }

    my %k = map {@$_} @data;
    $o = [ map {$_->[0]} @data ];
    $k = \%k;
}

return [ $c, $o, $k, $e ];
</%INIT>