<?php

// (c) Copyright by authors of the Tiki Wiki CMS Groupware Project
//
// All Rights Reserved. See copyright.txt for details and a complete list of authors.
// Licensed under the GNU LESSER GENERAL PUBLIC LICENSE. See license.txt for details.
// $Id$

class Tiki_Formula_Function_RelationPresent extends Math_Formula_Function
{
    public function evaluate($element)
    {
        $default = 0;
        $allowed = ['qualifier', 'from', 'to'];

        if ($extra = $element->getExtraValues($allowed)) {
            $this->error(tr('Unexpected values: %0', implode(', ', $extra)));
        }

        $from = $element->from;
        $to = $element->to;
        $qualifier = $element->qualifier;

        if (! $qualifier || count($qualifier) != 1) {
            $this->error(tra('Qualifier must be provided and contain one argument: type'));
        }

        if (! $from || count($from) != 2) {
            $this->error(tra('From must be provided and contain two arguments: type, object-id'));
        }

        if (! $to || count($to) != 2) {
            $this->error(tra('To must be provided and contain two arguments: type, object-id'));
        }

        $qualifier = $this->evaluateChild($qualifier[0]);
        $typeFrom = $this->evaluateChild($from[0]);
        $objectFrom = $this->evaluateChild($from[1]);
        $typeTo = $this->evaluateChild($to[0]);
        $objectTo = $this->evaluateChild($to[1]);

        $lib = TikiLib::lib('relation');
        $id = $lib->get_relation_id($qualifier, $typeFrom, $objectFrom, $typeTo, $objectTo);

        return $id ? 1 : 0;
    }
}