<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2007 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.
 */

/**
 * ISAPI_Rewrite helper.
 * @package Rewrite
 * @subpackage Parsers
 * @author Douglas Cau <douglas@cau.se>
 * @version $Revision: 15990 $
 */
class IsapiRewriteHelper {

    /**
     * @see RewriteParser::saveActiveRules
     */
    function saveActiveRules($parser, $activeRules=null, $upgradeModule=null) {
	list ($ret, $code) = IsapiRewriteHelper::checkFile();
	if ($ret) {
	    return array($ret, null, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, $code, null);
	}

	/* By default we use the rules we've already got */
	if (is_null($activeRules)) {
	    list($ret, $activeRules) = GalleryCoreApi::getPluginParameter(
		'module', 'rewrite', 'activeRules');
	    if ($ret) {
		return array($ret, null, null);
	    }
	    $activeRules = unserialize($activeRules);
	}

	$regexRules = array();
	$shortUrls = array();
	$flags = array('default' => array('QSA', 'N', 'L'), 'mandatory' => array());
	if (!empty($activeRules)) {
	    list ($ret, $code, $regexRules, $shortUrls, $errorId) = RewriteHelper::parseActiveRules(
		$activeRules, $parser, $upgradeModule, $flags);
	    if ($ret) {
		return array($ret, null, null);
	    }
	    if ($code != REWRITE_STATUS_OK) {
		return array(null, $code, $errorId);
	    }
	}

	list ($ret, $code) = IsapiRewriteHelper::writeFile($regexRules);
	if ($ret) {
	    return array($ret, null, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, $code, null);
	}

	/* Finally, save the new rules */
	$ret = GalleryCoreApi::setPluginParameter(
	    'module', 'rewrite', 'shortUrls', serialize($shortUrls));
	if ($ret) {
	    return array($ret, null, null);
	}

	$ret = GalleryCoreApi::setPluginParameter(
	    'module', 'rewrite', 'activeRules', serialize($activeRules));
	if ($ret) {
	    return array($ret, null, null);
	}

	return array(null, REWRITE_STATUS_OK, null);
    }

    /**
     * @see RewriteParser::saveAccessList
     */
    function saveAccessList($accessList, $allowEmptyReferer) {
	list ($ret, $code) = IsapiRewriteHelper::checkFile();
	if ($ret) {
	    return array($ret, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, $code);
	}

	$ret = GalleryCoreApi::setPluginParameter(
	    'module', 'rewrite', 'accessList', serialize($accessList));
	if ($ret) {
	    return array($ret, null);
	}

	$ret = GalleryCoreApi::setPluginParameter(
	    'module', 'rewrite', 'allowEmptyReferer', $allowEmptyReferer ? '1' : '0');
	if ($ret) {
	    return array($ret, null);
	}

	/* Save the new httpd.ini */
	list ($ret, $code) = $this->saveActiveRules();
	if ($ret) {
	    return array($ret, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, $code);
	}

	return array(null, REWRITE_STATUS_OK);
    }

    /**
     * @see RewriteParser::needsConfiguration
     */
    function needsConfiguration($parser) {
	global $gallery;
	$urlGenerator =& $gallery->getUrlGenerator();

	if (strpos($urlGenerator->getCurrentUrlDir(true), 'install/index.php') !== false
		&& $gallery->getConfig('galleryBaseUrl')) {
	    /*
	     * We can't autoconfigure from installer in a multisite install because the current URL
	     * is for the primary site, not the site being installed.
	     */
	    return array(null, true);
	}

	$baseUrlComponents = parse_url(preg_replace('{(install|upgrade)/index\.php.*}', '',
						    $urlGenerator->getCurrentUrlDir(true)));
	$ret = GalleryCoreApi::setPluginParameter(
	    'module', 'rewrite', 'isapirewrite.galleryLocation', $baseUrlComponents['path']);
	if ($ret) {
	    return array($ret, null);
	}

	list ($ret, $code) = IsapiRewriteHelper::checkIsapiRewrite();
	if ($ret) {
	    return array($ret, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, true);
	}

	list ($ret, $code) = IsapiRewriteHelper::checkFile();
	if ($ret) {
	    return array($ret, null);
	}
	if ($code != REWRITE_STATUS_OK) {
	    return array(null, true);
	}

	if (GalleryUtilities::isEmbedded()) {
	    list ($ret, $status) = $parser->needsEmbedConfig();
	    if ($ret) {
		return array($ret, null);
	    }

	    return array(null, $status);
	}

	return array(null, false);
    }

    /**
     * Return the httpd.ini content given a set of rewrite rules.
     * @param array $regexRules regular expression rules with settings
     * @param boolean $embedded (optional) true if embedded httpd.ini content is wanted
     * @return array object GalleryStatus a status code
     *               string the gallery .htaccess section
     */
    function getHttpdiniContent($regexRules, $embedded=false) {
	global $gallery;
	$urlGenerator =& $gallery->getUrlGenerator();

	$Httpdini = array();
	$Httpdini['galleryId'] = GALLERY_CONFIG_DIR;

	list ($ret, $Httpdini['galleryDirectory']) = GalleryCoreApi::getPluginParameter(
	    'module', 'rewrite', 'isapirewrite.galleryLocation');
	if ($ret) {
	    return array($ret, null);
	}

	$Httpdini['directory'] = $Httpdini['galleryDirectory'];
	$Httpdini['rewriteBase'] = $Httpdini['galleryDirectory'];
	$Httpdini['baseFile'] = GALLERY_MAIN_PHP;
	$Httpdini['host'] = preg_quote(GalleryUtilities::getServerVar('SERVER_NAME'));
	if ($embedded) {
	    $Httpdini['baseFile'] = $urlGenerator->_file[false];
	    list ($ret, $Httpdini['directory']) = GalleryCoreApi::getPluginParameter(
		'module', 'rewrite', 'isapirewrite.embeddedLocation');
	    if ($ret) {
		return array($ret, null);
	    }

	    $Httpdini['rewriteBase'] = $Httpdini['directory'];
	}

	/* Substitute with what the Gallery URL generator would generate */
	$galleryUrlGenerator = new GalleryUrlGenerator();
	$galleryUrlGenerator->init($Httpdini['directory'] . $Httpdini['baseFile'],
				   $Httpdini['galleryDirectory'] . GALLERY_MAIN_PHP);

	foreach ($regexRules as $ruleId => $regexRule) {
	    /* Conditions */
	    if (!empty($regexRule['conditions'])) {
		foreach ($regexRule['conditions'] as $conditionId => $condition) {
		    /*
		     * Apache mod_rewrite and ISAPI_Rewrite share the concepts of strings which
		     * start with, end with, or contain a pattern, however they represent these
		     * patterns differently (using ungreedy wildcards):
		     *
		     *             | Apache mod_rewrite | ISAPI_Rewrite 
		     * ------------------------------------------------
		     * Starts with | ^blah              | blah.*?
		     * ------------------------------------------------
		     *   Ends with | blah$              | .*?blah
		     * ------------------------------------------------
		     *    Contains | blah               | .*?blah.*?
		     *
		     * Apache mod_rewrite and ISAPI_Rewrite also share the concept of a negative
		     * pattern:
		     *
		     *             | Apache mod_rewrite | ISAPI_Rewrite 
		     * ------------------------------------------------
		     *    Negative | !blah              | (?!.*?blah).*?
		     *
		     * http://www.isapirewrite.com/docs/#RewriteCond
		     */
		    $isNegative = false;

		    /* Condition pattern starts with '!' */
		    if (substr($condition['pattern'], 0, 1) == '!') {
			$condition['pattern'] = substr($condition['pattern'], 1);
			$isNegative = true;
		    }

		    /* Condition pattern starts with '^' */
		    if (substr($condition['pattern'], 0, 1) == '^') {
			$condition['pattern'] = substr($condition['pattern'], 1);
		    } else {
			$condition['pattern'] = '.*?' . $condition['pattern'];
		    }

		    /*
		     * ISAPI_Rewrite supports only certain test verbs:
		     * http://www.isapirewrite.com/docs/#RewriteCond
		     */
		    switch ($condition['test']) {

		    /*
		     * The ISAPI_Rewrite URL test verb is actually the concatenation of the Apache
		     * mod_rewrite REQUEST_URI and QUERY_STRING variables, but by adding a '\\?' to
		     * the pattern, we can test the correct part of the URL.
		     */
		    case 'REQUEST_URI':
			$condition['test'] = 'URL';
			break;

		    case 'QUERY_STRING':
			$condition['test'] = 'URL';
			$condition['pattern'] = '.*\\?' . $condition['pattern'];
			break;

		    case 'REQUEST_METHOD':
			$condition['test'] = 'METHOD';
			break;

		    default:
			if (strncmp($condition['test'], 'HTTP:', 5) === 0) {
			    $condition['test'] = substr($condition['test'], 5) . ':';
			}
		    }

		    /* Condition pattern ends with unescaped '$' */
		    if (substr($condition['pattern'], -1) == '$'
			    && substr($condition['pattern'], -2) != '\\$') {
			$condition['pattern'] = substr($condition['pattern'], 0, -1);
			if ($isNegative) {
			    $condition['pattern'] = '(?!' . $condition['pattern'] . ')';
			}
			if ($condition['pattern'] == '(?!)') {
			    /* Avoid pattern (?!) (isapi_rewrite logs a parse error). */
			    $condition['pattern'] = '(?!.{0})';
			}
		    } else {
			if ($isNegative) {
			    $condition['pattern'] = '(?!' . $condition['pattern'] . ')';
			}
			$condition['pattern'] = $condition['pattern'] . '.*?';
		    }

		    /*
		     * ISAPI_Rewrite supports only certain flags:
		     * http://www.isapirewrite.com/docs/#RewriteCond
		     */
		    if (!empty($condition['flags'])) {
			$condition['flags'] = array_intersect($condition['flags'],
			    array('O'));
		    }

		    $regexRule['conditions'][$conditionId] = $condition;
		}
	    }

	    $regexRule['conditions'][] = array(
		'test' => 'Host:',
		'pattern' => $Httpdini['host']);

	    /* Pattern */
	    if (!empty($regexRule['pattern'])) {
		$regexRule['conditions'][] = array(
		    'test' => 'URL',
		    'pattern' => $Httpdini['rewriteBase'] . $regexRule['pattern'] . '(?:\\?.*)?');
	    }

	    /* Substitution */
	    $params = $regexRule['queryString'];
	    foreach ($regexRule['keywords'] as $reference => $name) {
		if (empty($name)) {
		    continue;
		}

		$params[$name] = '$' . $reference;
	    }

	    $regexRule['substitution'] = $galleryUrlGenerator->generateUrl(
		$params, $regexRule['options']);

	    /* Convert references from mod_rewrite style to isapi_rewrite style */
	    $regexRule['substitution'] =
		    preg_replace('/%(\d+)/', '$\1', $regexRule['substitution']);

	    /*
	     * ISAPI_Rewrite doesn't support the %{QUERY_STRING} or %{REQUEST_URI} variables but
	     * the last sub-expression, count($regexRules['keywords'] + 1, matches %{QUERY_STRING}
	     * and the second last sub-expression, count($regexRules['keywords']), matches
	     * %{REQUEST_URI}
	     */
	    $regexRule['substitution'] = str_replace('%{REQUEST_URI}',
		'$' . count($regexRule['keywords']), $regexRule['substitution']);
	    $regexRule['substitution'] = str_replace('%{QUERY_STRING}',
		'$' . (count($regexRule['keywords']) + 1), $regexRule['substitution']);

	    /* Flags */
	    if (!empty($regexRule['flags'])) {
		/*
		 * ISAPI_Rewrite doesn't support the 'QSA' flag but we can append the query string
		 * with the last sub-expression, count($regexRules['keywords'] + 1
		 */
		if (in_array('QSA', $regexRule['flags'])) {
		    $regexRule['substitution'] .= (strpos($regexRule['substitution'], '?') === false
			? '?' : '&') . '$' . (count($regexRule['keywords']) + 1);
		}

		/*
		 * ISAPI_Rewrite supports only certain flags:
		 * http://www.isapirewrite.com/docs/#RewriteRule
		 */
		$regexRule['flags'] = array_intersect($regexRule['flags'],
		    array('I', 'F', 'L', 'N', 'NS', 'P', 'R', 'RP', 'U', 'O', 'CL', 'CU'));
	    }

	    $regexRules[$ruleId] = $regexRule;
	}
	$Httpdini['rules'] = $regexRules;

	/* Render template */
	GalleryCoreApi::requireOnce('modules/core/classes/GalleryTemplate.class');
	$template = new GalleryTemplate(dirname(__FILE__) . '/../../../templates', true, false);
	$template->setVariable('Httpdini', $Httpdini);
	$template->setVariable('l10Domain', 'modules_rewrite');
	list ($ret, $content) = $template->fetch('Httpdini.tpl');
	if ($ret) {
	    return array($ret, null);
	}

	return array(null, $content);
    }

    /**
     * Return the absolute path to the httpd.ini file.
     * @return array object GalleryStatus a status code
     *               string httpd.ini file path
     */
    function getHttpdiniPath() {
	list ($ret, $path) =
	    GalleryCoreApi::getPluginParameter('module', 'rewrite', 'isapirewrite.httpdini');
	if ($ret) {
	    return array($ret, null);
	}

	return array(null, $path . '\httpd.ini');
    }

    /**
     * Check if the httpd.ini file is writeable.
     * @return array object GalleryStatus a status code
     *               int rewrite status code (REWRITE_STATUS_OK on success)
     */
    function checkFile() {
	global $gallery;
	$platform =& $gallery->getPlatform();

	list ($ret, $file) = IsapiRewriteHelper::getHttpdiniPath();
	if ($ret) {
	    return array($ret, null);
	}
	if ($file == '\httpd.ini') {
	    return array(null, REWRITE_STATUS_HTTPDINI_MISSING);
	}

	if ($platform->file_exists($file)) {
	    if (!$platform->is_readable($file)) {
		return array(null, REWRITE_STATUS_HTTPDINI_CANT_READ);
	    }

	    if (!$platform->is_writeable($file)) {
		return array(null, REWRITE_STATUS_HTTPDINI_CANT_WRITE);
	    }
	} else {
	    return array(null, REWRITE_STATUS_HTTPDINI_MISSING);
	}
	return array(null, REWRITE_STATUS_OK);
    }

    /**
     * Return one of the following codes:
     *     REWRITE_STATUS_OK                  everything is fine
     *     REWRITE_STATUS_NO_ISAPI_REWRITE    no ISAPI_Rewrite support
     *
     * @return array object GalleryStatus a status code
     *               int rewrite status code (REWRITE_STATUS_OK on success)
     *               int true rewrite status code (REWRITE_STATUS_OK on success)
     */
    function checkIsapiRewrite() {
	global $gallery;
	$urlGenerator =& $gallery->getUrlGenerator();

	list ($ret, $forced) = GalleryCoreApi::getPluginParameter('module', 'rewrite',
	    'isapirewrite.forced');
	if ($ret) {
	    return array($ret, null, null);
	}

	$fetch = $urlGenerator->generateUrl(
	    array('href' => 'modules/rewrite/data/isapi_rewrite/Rewrite.txt'),
	    array('forceFullUrl' => true));
	list ($success, $body) = GalleryCoreAPI::fetchWebPage($fetch);

	if ($success && $body == 'PASS_ISAPI_REWRITE') {
	    return array(null, REWRITE_STATUS_OK, REWRITE_STATUS_OK);
	}

	return array(null,
		     ($forced) ? REWRITE_STATUS_OK : REWRITE_STATUS_NO_ISAPI_REWRITE,
		     REWRITE_STATUS_NO_ISAPI_REWRITE);
    }


    /**
     * Write Gallery data to the httpd.ini file.
     * @param array $regexRules regular expression rules with settings
     * @return array object GalleryStatus a status code
     *               int rewrite status code
     */
    function writeFile($regexRules) {
	global $gallery;
	$platform =& $gallery->getPlatform();
	$galleryId = preg_quote(GALLERY_CONFIG_DIR, '/');

	list ($ret, $file) = IsapiRewriteHelper::getHttpdiniPath();
	if ($ret) {
	    return array($ret, null);
	}

	$htaccess = '#{gallerySection}';
	if (!empty($regexRules)) {
	    list ($ret, $htaccess) = IsapiRewriteHelper::getHttpdiniContent($regexRules);
	    if ($ret) {
		return array($ret, null);
	    }

	    if (GalleryUtilities::isEmbedded()) {
		list ($ret, $embedded) = IsapiRewriteHelper::getHttpdiniContent($regexRules, true);
		if ($ret) {
		    return array($ret, null);
		}

		$htaccess .= "\r\n" . $embedded;
	    }
	}

	if ($platform->file_exists($file)) {
	    if (!$platform->is_readable($file)) {
		return array(null, REWRITE_STATUS_HTTPDINI_CANT_READ);
	    }

	    $oldHtaccess = implode('', $platform->file($file));
	    $newHtaccess = preg_replace(
		'/\# BEGIN Gallery 2 Url Rewrite section \(GalleryID: ' . $galleryId .
			'\)(.+)\# END Url Rewrite section(\r\n|\n|\r)/s',
		'#{gallerySection}', $oldHtaccess);

	    if (strpos($newHtaccess, '#{gallerySection}') !== false) {
		$newHtaccess = str_replace('#{gallerySection}', $htaccess . "\r\n", $newHtaccess);
	    } else {
		if (strpos($oldHtaccess, '[ISAPI_Rewrite]') !== false) {
		    $newHtaccess = str_replace('[ISAPI_Rewrite]', "[ISAPI_Rewrite]\r\n" .
			$htaccess, $newHtaccess);
		} else {
		    $newHtaccess = $newHtaccess . "[ISAPI_Rewrite]\r\n" . $htaccess . "\r\n";
		}
	    }
	} else {
	    $newHtaccess = "[ISAPI_Rewrite]\r\n" . $htaccess . "\r\n";
	}

	/* Write the new file */
	if ($fd = @$platform->fopen($file, 'w')) {
	    $platform->fwrite($fd, $newHtaccess);
	    $platform->fclose($fd);
	} else {
	    return array(null, REWRITE_STATUS_HTTPDINI_CANT_WRITE);
	}

	return array(null, REWRITE_STATUS_OK);
    }

    /**
     * @see RewriteParser::loadTestResultsTemplate
     */
    function loadTestResultsTemplate(&$template, &$form) {
	global $gallery;
	$urlGenerator =& $gallery->getUrlGenerator();

	list ($ret, $TestResults['isapiInfo'], $TestResults['trueIsapiInfo']) =
	    IsapiRewriteHelper::checkIsapiRewrite();
	if ($ret) {
	    return $ret;
	}

	list ($ret, $TestResults['httpdini']) = IsapiRewriteHelper::checkFile();
	if ($ret) {
	    return $ret;
	}

	if ($TestResults['isapiInfo'] != REWRITE_STATUS_OK) {
	    $TestResults['hrefTest'] = $urlGenerator->generateUrl(array(
		'href' => 'modules/rewrite/data/isapi_rewrite/Rewrite.txt'));

	    list ($ret, $TestResults['contents']) = IsapiRewriteHelper::getHttpdiniContent(array());
	    if ($ret) {
		return $ret;
	    }

	    $TestResults['action'] = 1;
	}

	if ($TestResults['isapiInfo'] != REWRITE_STATUS_OK ||
		$TestResults['httpdini'] != REWRITE_STATUS_OK) {
	    $TestResults['refresh'] = 1;
	}

	$TestResults['template'] = 'modules/rewrite/templates/IsapiRewriteTestResults.tpl';
	$template->setVariable('TestResults', $TestResults);

	return null;
    }

    /**
     * @see RewriteParser::loadAdminParserTemplate
     */
    function loadAdminRewriteTemplate(&$template, &$form) {
	global $gallery;
	$urlGenerator =& $gallery->getUrlGenerator();
	$AdminParser = array();

	if (empty($form['formName'])) {
	    list ($ret, $form['httpdini']) =
		GalleryCoreApi::getPluginParameter('module', 'rewrite',
		    'isapirewrite.httpdini');
	    if ($ret) {
		return $ret;
	    }

	    if (GalleryUtilities::isEmbedded()) {
		$AdminParser['isEmbedded'] = 1;
		$AdminParser['host'] = substr($urlGenerator->makeUrl('/'), 0, -1);
		list ($ret, $form['embeddedLocation']) =
		    GalleryCoreApi::getPluginParameter('module', 'rewrite',
			'isapirewrite.embeddedLocation');
		if ($ret) {
		    return $ret;
		}
	    }
	}

	$AdminParser['action'] = 1;
	$AdminParser['template'] = 'modules/rewrite/templates/IsapiRewriteAdminParser.tpl';

	$template->setVariable('AdminParser', $AdminParser);
	return null;
    }

    /**
     * @param array $param config values
     * @param object IsapiRewriteParser $parser
     * @param boolean $saveActiveRules true if we want to write the httpd.ini
     */
    function saveEmbedConfig($param, $parser, $saveActiveRules) {
	$code = REWRITE_STATUS_OK;

	if (empty($param['embeddedLocation'])) {
	    $code = REWRITE_STATUS_EMPTY_VALUE;
	}

	if ($code == REWRITE_STATUS_OK) {
	    $embeddedLocation = '/' . trim($param['embeddedLocation'], '/');
	    if ($embeddedLocation{strlen($embeddedLocation)-1} != '/') {
		$embeddedLocation .= '/';
	    }

	    $ret = GalleryCoreApi::setPluginParameter('module', 'rewrite',
		'isapirewrite.embeddedLocation', $embeddedLocation);
	    if ($ret) {
		return array($ret, null);
	    }

	    if ($saveActiveRules) {
		list($ret, $code) = $parser->saveActiveRules();
		if ($ret) {
		    return array($ret, null);
		}
	    }
	}

	return array(null, $code);
    }
}
?>