# EPrints Services/Shelves
# adds all the EPrintIds of a Search to a Shelf (given a Search cache_id)

use EPrints;

use strict;
use warnings;


our $GLOBAL_ERROR; #set by side-effect!


my $session = EPrints::Session->new();
exit(0) unless( defined $session );

my $user = $session->current_user;
unless( defined $user )
{
	$GLOBAL_ERROR = '<div class=\"epjs_shelves_error\">You must login to use the Shelves</div>';
	terminate_with_error($session);
	return;
}

my $shelfid = $session->param( 'shelfid' );
my $cacheid = $session->param( 'cacheid' );
my $search_url = $session->param( 'searchurl');

my $shelf = get_shelf($session, $user, $shelfid);

unless ( defined $shelf || defined $GLOBAL_ERROR )
{
	terminate_with_error($session);
	return;
}


my $ids;
if (defined $cacheid)
{
	$ids = list_ids_from_cache_id($session, $user, $cacheid);
}
elsif (defined $search_url)
{
	$ids = list_ids_from_search_url($session, $search_url);
}

if ( (!defined $ids) || (defined $GLOBAL_ERROR) )
{
	terminate_with_error($session);
	return;
}

$shelf->add_items( @{$ids} );

$session->terminate;



sub list_ids_from_cache_id
{
	my ($session, $user, $cacheid) = @_;

	# sanity checks first
	my $cachemap = $session->dataset( 'cachemap' )->dataobj( $cacheid );

	unless( defined $cachemap )
	{
		# perhaps it timed-out
		$GLOBAL_ERROR = '<div class=\"epjs_shelves_error\">Search expired. Try starting another search.</div>';
		return;
	}

	my $cache_owner_id = $cachemap->get_value( "userid" );
	my $user_id = $user->get_id;

	unless( "$cache_owner_id" eq "$user_id" )
	{
		$GLOBAL_ERROR = '<div class=\"epjs_shelves_error\">You do not own this Search.</div>';
		return;
	}

	my $list = EPrints::List->new(
		session => $session,
		dataset => $session->dataset( 'eprint' ),
		cache_id => $cacheid
	);

	return $list->ids;
}

sub list_ids_from_search_url
{
	


}


sub get_shelf
{
	my ($session, $user, $shelfid) = @_;

	return unless $shelfid;

	# instanciate shelf, check current user has the perms to write to it

	my $shelf = $session->dataset( 'shelf' )->dataobj( $shelfid );
	unless( defined $shelf )
	{
		$GLOBAL_ERROR = '<div class=\"epjs_shelves_error\">Shelf #'.$shelfid.' does not exist.</div>';
		return;
	}

	unless( $shelf->has_editor( $user ) )
	{
		$GLOBAL_ERROR = '<div class=\"epjs_shelves_error\">You may not modify this Shelf.</div>';
		return;
	}

	return $shelf;
}

sub terminate_with_error
{
	my ($session) = @_;

	if ($GLOBAL_ERROR)
	{
		$session->send_http_header( content_type => "application/json" );
		print STDOUT JSON::encode_json( { error => $GLOBAL_ERROR } );
	}
	$session->terminate;
	return;
}