<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2008 Bharat Mediratta
 *
 * This program 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 2 of the License, or (at
 * your option) any later version.
 *
 * 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

GalleryCoreApi::requireOnce('modules/core/classes/GalleryUrlGenerator.class');

/**
 * Generic rewrite URL generator.
 * @package Rewrite
 * @subpackage Classes
 * @author Douglas Cau <douglas@cau.se>
 * @version $Revision: 17580 $
 */
class RewriteUrlGenerator extends GalleryUrlGenerator {

    /**
     * If there's an error, use parent GalleryUrlGenerator functions.
     * @var bool has an error occured?
     * @access private
     */
    var $_error = false;

    /**
     * Short URL map.
     * @var array of view => short URL pattern
     * @access private
     */
    var $_shortUrls = array();

    /**
     * Return first short URL to match URL params.
     * @param array $params URL params
     * @return array first short URL to match URL params
     */
    function _getShortUrl($params) {
	foreach ($this->_shortUrls as $shortUrl) {
	    foreach ($shortUrl['match'] as $key => $value) {
		if (!isset($params[$key]) || $params[$key] != $value) {
		    continue(2);
		}
	    }

	    /* $shortUrl['match'] is subset of $params */
	    return $shortUrl;
	}
    }

    /**
     * @see GalleryUrlGenerator::init
     */
    function init($baseUri=null, $g2Uri=null, $embedSessionString=null) {
	$ret = parent::init($baseUri, $g2Uri, $embedSessionString);
	if ($ret) {
	    return $ret;
	}

	list ($ret, $this->_shortUrls) = GalleryCoreApi::getPluginParameter(
	    'module', 'rewrite', 'shortUrls');
	if ($ret) {
	    return $ret;
	}
	$this->_shortUrls = empty($this->_shortUrls) ? array() : unserialize($this->_shortUrls);

	return null;
    }

    /**
     * This function is called at the end of URL generator initialization.  If an onLoad function is
     * specified for the current view it loads the needed file and calls the function which should
     * parse any request params that wasn't parsed by the rewrite parser (e.g. %path% to itemId).
     * @return GalleryStatus a status code
     * @private
     */
    function _onLoad() {
	$variables = GalleryUtilities::getAllRequestVariables();

	/* Make sure the onLoad function is called even if the default view is omitted */
	if (empty($variables['controller']) && empty($variables['view'])) {
	    $variables['view'] = GALLERY_DEFAULT_VIEW;
	}

	$shortUrl = $this->_getShortUrl($variables);

	if (!empty($shortUrl['onLoad'])) {
	    GalleryCoreApi::requireOnce('modules/' . $shortUrl['onLoad'][0]
		. '/classes/' . $shortUrl['onLoad'][1] . '.class');
	    $ret = call_user_func(array($shortUrl['onLoad'][1], $shortUrl['onLoad'][2]));
	    if ($ret) {
		return $ret;
	    }
	}

	return null;
    }

    /**
     * @see GalleryUrlGenerator::generateUrl
     */
    function generateUrl($params=array(), $options=array()) {
	if ($this->_error || !empty($params['href'])) {
	    return parent::generateUrl($params, $options);
	}

	/* Build the short style URL */
	$shortUrl = $this->_getShortUrl($params);

	if (empty($shortUrl)) {
	    return parent::generateUrl($params, $options);
	}

	/* Check if we are forced to append the session id in embedded */
	if (!isset($options['forceSessionId']) && $this->embedForceSessionId($params)) {
	    $options['forceSessionId'] = true;
	}

	/* Check if we are forced to append the auth token */
	if (!isset($options['useAuthToken']) && !empty($params['controller'])) {
	    $options['useAuthToken'] = true;
	}

	$trueParams = $params;

	/* Parse and replace all keywords */
	$url = $shortUrl['pattern'];
	$functions = array();
	if (isset($shortUrl['functions'])) {
	    $functions = $shortUrl['functions'];
	}
	if (!$this->_parseShortUrl($url, $params, $options, $functions)) {
	    return parent::generateUrl($trueParams, $options);
	}

	$forceDirect = !empty($options['forceDirect'])
	    || (isset($trueParams['view']) && $trueParams['view'] == 'core.DownloadItem');
	$options['baseUrl'] = $this->_getBaseUrl($forceDirect)
	    . ltrim($url, '/') . $this->_getBaseParamString($forceDirect);

	foreach ($shortUrl['match'] as $key => $value) {
	    unset($params[$key]);
	}

	return parent::generateUrl($params, $options);
    }

    /**
     * Substitute all keywords with values from URL params or custom functions.
     * @param string $url URL to be parsed
     * @param array $params of URL parameters
     * @param array $options of generation options
     * @param array $functions of custom functions
     * @return boolean true on success
     * @access private
     */
    function _parseShortUrl(&$url, &$params, $options, $functions) {
	$entity = null;

	preg_match_all('/%([a-zA-Z]+)%/', $url, $regs);
	foreach ($regs[1] as $arg) {
	    if (isset($functions[$arg])) {
		GalleryCoreApi::requireOnce('modules/' . $functions[$arg][0]
		    . '/classes/' . $functions[$arg][1] . '.class');

		$ret = call_user_func_array(
		    array($functions[$arg][1], $functions[$arg][2]),
		    array(&$url, &$params, &$entity));
		if (!$ret) {
		    return $ret;
		}
	    } else if (!empty($params[$arg])) {
		$value = $params[$arg];
		if (!empty($options['urlEncode']) || !isset($options['urlEncode'])) {
		    $value = urlencode($value);
		}

		$url = str_replace('%' . $arg . '%', $value, $url);

		/* We can't unset the itemId until we have replaced all keywords */
		if ($arg != 'itemId') {
		    unset($params[$arg]);
		} else {
		    $unsetItemId = true;
		}
	    } else {
		return false;
	    }
	}

	if (isset($unsetItemId)) {
	    unset($params['itemId']);
	}

	return true;
    }

    /**
     * Load entity.
     * @param int $itemId itemId of the entity to load
     * @return GalleryEntity or null on failure
     */
    function loadEntity(&$itemId) {
	/* Assume rootAlbum if itemId not specified */
	if (empty($itemId)) {
	    list ($ret, $itemId) = GalleryCoreApi::getDefaultAlbumId();
	    if ($ret) {
		return null;
	    }
	}

	list ($ret, $entity) = GalleryCoreApi::loadEntitiesById($itemId, 'GalleryEntity');
	if ($ret) {
	    return null;
	}

	return $entity;
    }

    /**
     * Return the base URL for all generated short URLs.
     * @param boolean $forceDirect (optional) if true, return Gallery base URL
     *        (different when embedded)
     * @return string the base URL
     * @access private
     */
    function _getBaseUrl($forceDirect=false) {
	return $this->getCurrentUrlDir($forceDirect);
    }

    /**
     * Return the base URL parameters for all generated short URLs, e.g. '?module=gallery'.
     * @param boolean $forceDirect (optional) if true, return Gallery base URL
     *        (different when embedded)
     * @return string the base URL parameters
     * @access private
     */
    function _getBaseParamString($forceDirect=false) {
	return '';
    }
}
?>