<?php
/**
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OCA\DAV\Connector\Sabre;

use Sabre\Xml\Element;
use Sabre\Xml\Reader;
use Sabre\Xml\Writer;

/**
 * TagList property
 *
 * This property contains multiple "tag" elements, each containing a tag name.
 */
class TagList implements Element {
	public const NS_OWNCLOUD = 'http://owncloud.org/ns';

	/**
	 * tags
	 *
	 * @var array
	 */
	private $tags;

	/**
	 * @param array $tags
	 */
	public function __construct(array $tags) {
		$this->tags = $tags;
	}

	/**
	 * Returns the tags
	 *
	 * @return array
	 */
	public function getTags() {
		return $this->tags;
	}

	/**
	 * The deserialize method is called during xml parsing.
	 *
	 * This method is called statically, this is because in theory this method
	 * may be used as a type of constructor, or factory method.
	 *
	 * Often you want to return an instance of the current class, but you are
	 * free to return other data as well.
	 *
	 * You are responsible for advancing the reader to the next element. Not
	 * doing anything will result in a never-ending loop.
	 *
	 * If you just want to skip parsing for this element altogether, you can
	 * just call $reader->next();
	 *
	 * $reader->parseInnerTree() will parse the entire sub-tree, and advance to
	 * the next element.
	 *
	 * @param Reader $reader
	 * @return mixed
	 */
	public static function xmlDeserialize(Reader $reader) {
		$tags = [];

		$tree = $reader->parseInnerTree();
		if ($tree === null) {
			return null;
		}
		foreach ($tree as $elem) {
			if ($elem['name'] === '{' . self::NS_OWNCLOUD . '}tag') {
				$tags[] = $elem['value'];
			}
		}
		return new self($tags);
	}

	/**
	 * The xmlSerialize metod is called during xml writing.
	 *
	 * Use the $writer argument to write its own xml serialization.
	 *
	 * An important note: do _not_ create a parent element. Any element
	 * implementing XmlSerializable should only ever write what's considered
	 * its 'inner xml'.
	 *
	 * The parent of the current element is responsible for writing a
	 * containing element.
	 *
	 * This allows serializers to be re-used for different element names.
	 *
	 * If you are opening new elements, you must also close them again.
	 *
	 * @param Writer $writer
	 * @return void
	 */
	public function xmlSerialize(Writer $writer) {
		foreach ($this->tags as $tag) {
			$writer->writeElement('{' . self::NS_OWNCLOUD . '}tag', $tag);
		}
	}
}
