<?php
/*
 * $RCSfile: WebHelper_simple.class,v $
 *
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2005 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.
 */
/**
 * @version $Revision: 1.12 $ $Date: 2005/08/23 03:49:04 $
 * @package GalleryCore
 * @author Bharat Mediratta <bharat@menalto.com>
 */

/**
 * A collection of useful web-page post/get related utilities
 *
 * @package GalleryCore
 * @subpackage Helpers
 * @static
 */
class WebHelper_simple {

    /**
     * Fetch the web page at the given url.  Follow redirects to get the data and
     * upon completion return the http response, headers and the actual URL that we used
     * to get the data.
     *
     * @param string the url
     * @param string the output file
     * @param int the redirect depth (pass in 0 or leave this empty to start)
     * @return array(boolean success, http response, headers, url)
     */
    function fetchWebFile($url, $outputFile, $depth=0) {
	global $gallery;

	/* Convert illegal characters */
	$url = str_replace(' ', '%20', $url);

	$components = parse_url($url);
	$port = empty($components['port']) ? 80 : $components['port'];
	if (empty($components['path'])) {
	    $components['path'] = '/';
	}

	/* Don't redirect too far */
	if ($depth > 5) {
	    $gallery->debug('Too many levels of HTTP redirection!');
	    return array(false, null, null, null);
	}

	$platform = $gallery->getPlatform();
	$fd = @$platform->fsockopen($components['host'], $port, $errno, $errstr, 1);
	if (empty($fd)) {
	    $gallery->debug("Error $errno: '$errstr' retrieving $url");
	    return array(false, null, null, null);
	}

	$get = $components['path'];
	if (!empty($components['query'])) {
	    $get .= '?' . $components['query'];
	}

	/* Unescape ampersands, since if the url comes from form input it will be escaped */
	$get = str_replace('&amp;', '&', $get);

	/* Read the web page into a buffer */
	$platform->fwrite($fd, sprintf("GET %s HTTP/1.0\r\n" .
				       "Host: %s\r\n" .
				       "\r\n",
				       $get,
				       $components['host']));
	$platform->fflush($fd);

	/*
	 * Read the response code. fgets stops after newlines.
	 * The first line contains only the status code (200, 404, etc.).
	 */
	$headers = array();
	$response = trim($platform->fgets($fd, 4096));

	/* Read the headers. */
	while (!$platform->feof($fd)) {
	    $line = trim($platform->fgets($fd, 4096));
	    if (empty($line)) {
		break;
	    }

	    /* Normalize the line endings */
	    $line = str_replace("\r", '', $line);

	    list ($key, $value) = explode(':', $line, 2);
	    if (isset($headers[$key])) {
		if (!is_array($headers[$key])) {
		    $headers[$key] = array($headers[$key]);
		}
		$headers[$key][] = trim($value);
	    } else {
		$headers[$key] = trim($value);
	    }
	}

	if (isset($headers['Location'])) {
	    $redirectUrl = $headers['Location'];
	    if (is_array($redirectUrl)) {
		/* If odd http response has multiple Location headers just pick the first */
		$redirectUrl = array_shift($redirectUrl);
	    }

	    /* The redirect url is supposed to be absolute, but not everybody plays by the rules */
	    $redirectComponents = parse_url($redirectUrl);
	    foreach (array('scheme', 'host') as $key) {
		if (empty($redirectComponents[$key])) {
		    $redirectComponents[$key] = $components[$key];
		}
	    }

	    if (empty($redirectComponents['port'])) {
		if (isset($components['port'])) {
		    $redirectPort = ':' . $components['port'];
		} else {
		    $redirectPort = '';
		}
	    }

	    if (empty($redirectComponents['query'])) {
		$query = '';
	    } else {
		$query = '?' . $redirectComponents['query'];
	    }

	    $redirectUrl = sprintf('%s://%s%s%s%s',
				   $redirectComponents['scheme'],
				   $redirectComponents['host'],
				   $redirectPort,
				   $redirectComponents['path'],
				   $query);

	    /* Returning output directly from fetchWebFile() confuses the CodeAudit */
	    $result = WebHelper_simple::fetchWebFile($redirectUrl, $outputFile, $depth+1);
	    return array($result[0], $result[1], $result[2], $result[3]);
	}

	$success = false;
	$ofd = $platform->fopen($outputFile, 'wb');
	if ($ofd) {
	    /* Read the body */
	    $failed = false;
	    while (!$platform->feof($fd) && !$failed) {
		$buf = $platform->fread($fd, 4096);
		if ($platform->fwrite($ofd, $buf) != strlen($buf)) {
		    $failed = true;
		    break;
		}
	    }
	    $platform->fclose($ofd);
	    if (!$failed) {
		$success = true;
	    }
	}
	$platform->fclose($fd);

	return array($success, $response, $headers, $url);
    }

    /**
     * Fetch the web page at the given url.  Follow redirects to get the data and
     * upon completion return the body, http response, headers and the actual URL that
     * we used to get the data.
     *
     * @param string the url
     * @param array (optional) extra headers to pass to the server
     * @param int the redirect depth (pass in 0 or leave this empty to start)
     * @return array(body, http response, headers, url)
     */
    function fetchWebPage($url, $extraHeaders=array(), $depth=0) {
	global $gallery;

	/* Convert illegal characters */
	$url = str_replace(' ', '%20', $url);

	$components = parse_url($url);
	$port = empty($components['port']) ? 80 : $components['port'];
	if (empty($components['path'])) {
	    $components['path'] = '/';
	}

	/* Don't redirect too far */
	if ($depth > 5) {
	    $gallery->debug('Too many levels of HTTP redirection!');
	    return array(null, null, null, null);
	}

	$platform = $gallery->getPlatform();
	$fd = @$platform->fsockopen($components['host'], $port, $errno, $errstr, 1);
	if (empty($fd)) {
	    $gallery->debug("Error $errno: '$errstr' retrieving $url");
	    return array(null, null, null, null);
	}

	$get = $components['path'];
	if (!empty($components['query'])) {
	    $get .= '?' . $components['query'];
	}

	/* Unescape ampersands, since if the url comes from form input it will be escaped */
	$get = str_replace('&amp;', '&', $get);

	/* Read the web page into a buffer */
	$extraHeaderLines = array();
	foreach ($extraHeaders as $headerKey => $headerValue) {
	    $extraHeaderLines[] = "$headerKey: $headerValue";
	}
	$platform->fwrite($fd, sprintf("GET %s HTTP/1.0\r\n" .
				       "Host: %s\r\n" .
				       "%s" .
				       "\r\n",
				       $get,
				       $components['host'],
				       empty($extraHeaderLines) ? '' : join("\r\n", $extraHeaderLines) . "\r\n"));
	$platform->fflush($fd);

	/*
	 * Read the response code. fgets stops after newlines.
	 * The first line contains only the status code (200, 404, etc.).
	 */
	$headers = array();
	$response = trim($platform->fgets($fd, 4096));

	/* Read the headers. */
	while (!$platform->feof($fd)) {
	    $line = trim($platform->fgets($fd, 4096));
	    if (empty($line)) {
		break;
	    }

	    /* Normalize the line endings */
	    $line = str_replace("\r", '', $line);

	    list ($key, $value) = explode(':', $line, 2);
	    if (isset($headers[$key])) {
		if (!is_array($headers[$key])) {
		    $headers[$key] = array($headers[$key]);
		}
		$headers[$key][] = trim($value);
	    } else {
		$headers[$key] = trim($value);
	    }
	}

	if (isset($headers['Location'])) {
	    $redirectUrl = $headers['Location'];
	    if (is_array($redirectUrl)) {
		/* If odd http response has multiple Location headers just pick the first */
		$redirectUrl = array_shift($redirectUrl);
	    }

	    /* The redirect url is supposed to be absolute, but not everybody plays by the rules */
	    $redirectComponents = parse_url($redirectUrl);
	    foreach (array('scheme', 'host') as $key) {
		if (empty($redirectComponents[$key])) {
		    $redirectComponents[$key] = $components[$key];
		}
	    }

	    if (empty($redirectComponents['port'])) {
		if (isset($components['port'])) {
		    $redirectPort = ':' . $components['port'];
		} else {
		    $redirectPort = '';
		}
	    }

	    if (empty($redirectComponents['query'])) {
		$query = '';
	    } else {
		$query = '?' . $redirectComponents['query'];
	    }

	    $redirectUrl = sprintf('%s://%s%s%s%s',
				   $redirectComponents['scheme'],
				   $redirectComponents['host'],
				   $redirectPort,
				   $redirectComponents['path'],
				   $query);

	    /* Returning output directly from fetchWebPage() confuses the CodeAudit */
	    $result = WebHelper_simple::fetchWebPage($redirectUrl, $extraHeaders, $depth+1);
	    return array($result[0], $result[1], $result[2], $result[3]);
	}

	/* Read the body */
	$body = '';
	while (!$platform->feof($fd)) {
	    $body .= $platform->fread($fd, 4096);
	}
	$platform->fclose($fd);

	return array($body, $response, $headers, $url);
    }

    /**
     * Post form data to a remote url and return the http response, headers and body of the reply
     *
     * @param string the url
     * @param array the key/value post data
     * @param array (optional) extra headers to pass to the server
     * @return array(body, http response, headers)
     */
    function postToWebPage($url, $postDataArray, $extraHeaders=array()) {
	global $gallery;

	$components = parse_url($url);
	$port = empty($components['port']) ? 80 : $components['port'];
	if (empty($components['path'])) {
	    $components['path'] = '/';
	}

	$platform = $gallery->getPlatform();
	$fd = @$platform->fsockopen($components['host'], $port, $errno, $errstr, 1);
	if (empty($fd)) {
	    $gallery->debug("Error $errno: '$errstr' retrieving $url");
	    return array(null, null, null);
	}

	$post = $components['path'];
	if (!empty($components['query'])) {
	    $post .= '?' . $components['query'];
	}

	$postDataRaw = '';
	foreach ($postDataArray as $key => $value) {
	    if (!empty($postDataRaw)) {
		$postDataRaw .= '&';
	    }
	    $postDataRaw .= urlencode($key) . '=' . urlencode($value);
	}

	$extraHeaderLines = array();
	foreach ($extraHeaders as $headerKey => $headerValue) {
	    $extraHeaderLines[] = "$headerKey: $headerValue";
	}
	$postRequest = sprintf("POST %s HTTP/1.0\r\n" .
			       "Host: %s\r\n" .
			       "%s" .
			       "Content-Type: application/x-www-form-urlencoded\r\n" .
			       "Content-Length: %s\r\n" .
			       "\r\n" .
			       "%s\r\n",
			       $post,
			       $components['host'],
			       empty($extraHeaderLines) ? '' : join("\r\n", $extraHeaderLines) . "\r\n",
			       strlen($postDataRaw),
			       $postDataRaw);
	$platform->fwrite($fd, $postRequest);
	$platform->fflush($fd);

	/*
	 * Read the response code. fgets stops after newlines.
	 * The first line contains only the status code (200, 404, etc.).
	 */
	$headers = array();
	$response = trim($platform->fgets($fd, 4096));

	/* Read the headers. */
	while (!$platform->feof($fd)) {
	    $line = trim($platform->fgets($fd, 4096));
	    if (empty($line)) {
		break;
	    }

	    /* Normalize the line endings */
	    $line = str_replace("\r", '', $line);

	    list ($key, $value) = explode(':', $line, 2);
	    if (isset($headers[$key])) {
		if (!is_array($headers[$key])) {
		    $headers[$key] = array($headers[$key]);
		}
		$headers[$key][] = trim($value);
	    } else {
		$headers[$key] = trim($value);
	    }
	}

	/* Now read the body */
	$body = '';
	while (!$platform->feof($fd)) {
	    $body .= $platform->fread($fd, 4096);
	    $platform->fflush($fd);
	}
	$platform->fclose($fd);

	return array($body, $response, $headers);
    }
}
?>