<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

namespace tool_brickfield\local\htmlchecker\common\checks;

use tool_brickfield\local\htmlchecker\common\brickfield_accessibility_test;

/**
 * Brickfield accessibility HTML checker library.
 *
 *  Anchor should not open new window without warning.
 *  a (anchor) element must not contain a target attribute unless the target attribute value is either _self, _top, or _parent.
 *
 * @package    tool_brickfield
 * @copyright  2020 onward: Brickfield Education Labs, www.brickfield.ie
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class a_links_dont_open_new_window extends brickfield_accessibility_test {
    /** @var int $defaultseverity The default severity code for this test. */
    public $defaultseverity = \tool_brickfield\local\htmlchecker\brickfield_accessibility::BA_TEST_SEVERE;

    /** @var string[] A list of targets allowed that don't open a new window. */
    public $allowedtargets = array('_self', '_parent', '_top', '');

    /**
     * The main check function. This is called by the parent class to actually check content.
     */
    public function check(): void {

        // Need to process all enabled lang versions of newwindowphrases.
        $text = brickfield_accessibility_test::get_all_newwindowphrases();

        foreach ($this->get_all_elements('a') as $a) {
            if ($a->hasAttribute('target') && !in_array($a->getAttribute('target'), $this->allowedtargets)) {
                $phrasefound = false;
                foreach ($text as $phrase) {
                    // Sanity check for readable text.
                    if (!brickfield_accessibility_test::is_text_readable($phrase)) {
                        break;
                    }
                    $pos = stripos($a->nodeValue, $phrase);
                    if ($pos !== false) {
                        $phrasefound = true;
                        break;
                    }
                }
                if (!$phrasefound) {
                    $this->add_report($a);
                }
            }
        }
    }
}
