<?php
/*****************************************************************************
 * PhotoAlbum.php
 * Contains key class PhotoAlbum.
 *
 * Kabuki CMS (C) 2013-2015, Aaron van Geffen
 *****************************************************************************/

class PhotoAlbum extends Tag
{
	public static function getHierarchy($order, $direction)
	{
		$db = Registry::get('db');
		$res = $db->query('
			SELECT *
			FROM tags
			WHERE kind = {string:album}
			ORDER BY id_parent, {raw:order}',
			[
				'order' => $order . ($direction == 'up' ? ' ASC' : ' DESC'),
				'album' => 'Album',
			]);

		$albums_by_parent = [];
		while ($row = $db->fetch_assoc($res))
		{
			if (!isset($albums_by_parent[$row['id_parent']]))
				$albums_by_parent[$row['id_parent']] = [];

			$albums_by_parent[$row['id_parent']][] = $row + ['children' => []];
		}

		$albums = self::getChildrenRecursively(0, 0, $albums_by_parent);
		$rows = self::flattenChildrenRecursively($albums);

		return $rows;
	}

	private static function getChildrenRecursively($id_parent, $level, &$albums_by_parent)
	{
		$children = [];
		if (!isset($albums_by_parent[$id_parent]))
			return $children;

		foreach ($albums_by_parent[$id_parent] as $child)
		{
			if (isset($albums_by_parent[$child['id_tag']]))
				$child['children'] = self::getChildrenRecursively($child['id_tag'], $level + 1, $albums_by_parent);

			$child['tag'] = ($level ? str_repeat('—', $level * 2) . ' ' : '') . $child['tag'];
			$children[] = $child;
		}

		return $children;
	}

	private static function flattenChildrenRecursively($albums)
	{
		if (empty($albums))
			return [];

		$rows = [];
		foreach ($albums as $album)
		{
			$rows[] = array_intersect_key($album, array_flip(['id_tag', 'tag', 'slug', 'count']));
			if (!empty($album['children']))
			{
				$children = self::flattenChildrenRecursively($album['children']);
				foreach ($children as $child)
					$rows[] = array_intersect_key($child, array_flip(['id_tag', 'tag', 'slug', 'count']));
			}
		}

		return $rows;
	}
}