<?php
// WebSVN - Subversion repository viewing via the web using PHP
// Copyright (C) 2004-2006 Tim Armes
//
// 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// --
//
// dl.php
//
// Allow for file and directory downloads, creating zip/tar/gz files if needed.

require_once 'include/setup.php';
require_once 'include/svnlook.php';
require_once 'include/utils.php';

ini_set('include_path', $locwebsvnreal.'/lib/pear'.$config->pathSeparator.ini_get('include_path'));
@include_once 'Archive/Tar.php';

function setDirectoryTimestamp($dir, $timestamp) {
	global $config;
	// Changing the timestamp of a directory in Windows is only supported in PHP 5.3.0+
	if (!$config->serverIsWindows || version_compare(PHP_VERSION, '5.3.0alpha') !== -1) {
		touch($dir, $timestamp);
		if (is_dir($dir)) {
			// Set timestamp for all contents, recursing into subdirectories
			$handle = opendir($dir);
			if ($handle) {
				while (($file = readdir($handle)) !== false) {
					if ($file == '.' || $file == '..') {
						continue;
					}
					$f = $dir.DIRECTORY_SEPARATOR.$file;
					if (is_dir($f)) {
						setDirectoryTimestamp($f, $timestamp);
					}
				}
				closedir($handle);
			}
		}
	}
}

function removeDirectory($dir) {
	if (is_dir($dir)) {
		$dir = rtrim($dir, '/');
		$handle = dir($dir);
		while (($file = $handle->read()) !== false) {
			if ($file == '.' || $file == '..') {
				continue;
			}
			$f = $dir.DIRECTORY_SEPARATOR.$file;
			if (!is_link($f) && is_dir($f)) {
				removeDirectory($f);
			} else {
				@unlink($f);
			}
		}
		$handle->close();
		@rmdir($dir);
		return true;
	}
	return false;
}

// Make sure that downloading the specified file/directory is permitted

if (!$rep->isDownloadAllowed($path)) {
	header('HTTP/1.x 403 Forbidden', true, 403);
	error_log('Unable to download resource at path: '.$path);
	print 'Unable to download resource at path: '.xml_entities($path);
	exit;
}

if ($rep) {
	$svnrep = new SVNRepository($rep);

	// Fetch information about a revision (if unspecified, the latest) for this path
	if (empty($rev)) {
		$history = $svnrep->getLog($path, 'HEAD', '', true, 1, $peg);
	} else if ($rev == $peg) {
		$history = $svnrep->getLog($path, '', 1, true, 1, $peg);
	} else {
		$history = $svnrep->getLog($path, $rev, $rev - 1, true, 1, $peg);
	}
	$logEntry = ($history) ? $history->entries[0] : null;

	if (empty($rev)) {
		$rev = $logEntry->rev;
	}

	// Create a temporary filename to be used for a directory to archive a download.
	// Here we have an unavoidable but highly unlikely to occur race condition.
	$tempDir = tempnam($config->getTempDir(), 'websvn');

	if ($tempDir == false) {
		header('HTTP/1.x 500 Internal Server Error', true, 500);
		error_log('Unable to create a temporary directory.');
		print 'Unable to create a temporary directory.';
		exit(0);

	} else {
		@unlink($tempDir);
		mkdir($tempDir);
		// Create the name of the directory being archived
		$archiveName = $path;
		$isDir = (substr($archiveName, -1) == '/');
		if ($isDir) {
			$archiveName = substr($archiveName, 0, -1);
		}
		$archiveName = basename($archiveName);
		if ($archiveName == '') {
			$archiveName = $rep->name;
		}
		$plainfilename = $archiveName;
		$archiveName .= '.r'.$rev;

		// Export the requested path from SVN repository to the temp directory
		$svnExportResult = $svnrep->exportRepositoryPath($path, $tempDir.DIRECTORY_SEPARATOR.$archiveName, $rev, $peg);
		if ($svnExportResult != 0) {
			header('HTTP/1.x 500 Internal Server Error', true, 500);
			error_log('svn export failed for: '.$archiveName);
			print 'svn export failed for "'.xml_entities($archiveName).'".';
			removeDirectory($tempDir);
			exit(0);
		}

		// Set timestamp of exported directory (and subdirectories) to timestamp of
		// the revision so every archive of a given revision has the same timestamp.
		$revDate = $logEntry->date;
		$timestamp = mktime(substr($revDate, 11, 2), // hour
												substr($revDate, 14, 2), // minute
												substr($revDate, 17, 2), // second
												substr($revDate, 5, 2), // month
												substr($revDate, 8, 2), // day
												substr($revDate, 0, 4)); // year
		setDirectoryTimestamp($tempDir, $timestamp);

		// Change to temp directory so that only relative paths are stored in archive.
		$oldcwd = getcwd();
		chdir($tempDir);

		if ($isDir) {
			$downloadMode = $config->getDefaultFolderDlMode();
		} else {
			$downloadMode = $config->getDefaultFileDlMode();
		}

		// $_REQUEST parameter can override dlmode
		if (!empty($_REQUEST['dlmode'])) {
			$downloadMode = $_REQUEST['dlmode'];
			if (substr($logEntry->path, -1) == '/') {
				if (!in_array($downloadMode, $config->validFolderDlModes)) {
					$downloadMode = $config->getDefaultFolderDlMode();
				}
			} else {
				if (!in_array($downloadMode, $config->validFileDlModes)) {
					$downloadMode = $config->getDefaultFileDlMode();
				}
			}
		}

		$downloadArchive = $archiveName;
		if ($downloadMode == 'plain') {
			$downloadMimeType = 'application/octetstream';

		} else if ($downloadMode == 'zip') {
			$downloadMimeType = 'application/x-zip';
			$downloadArchive .= '.zip';
			// Create zip file
			$cmd = $config->zip.' -r '.quote($downloadArchive).' '.quote($archiveName);
			execCommand($cmd, $retcode);
			if ($retcode != 0) {
				error_log('Unable to call zip command: '.$cmd);
				print 'Unable to call zip command. See webserver error log for details.';
			}

		} else {
			$downloadMimeType = 'application/x-gzip';
			$downloadArchive .= '.tar.gz';
			$tarArchive = $archiveName.'.tar';

			// Create the tar file
			$retcode = 0;
			if (class_exists('Archive_Tar')) {
				$tar = new Archive_Tar($tarArchive);
				$created = $tar->create($archiveName);
				if (!$created) {
					$retcode = 1;
					header('HTTP/1.x 500 Internal Server Error', true, 500);
					print 'Unable to create tar archive.';
				}

			} else {
				$cmd = $config->tar.' -cf '.quote($tarArchive).' '.quote($archiveName);
				execCommand($cmd, $retcode);
				if ($retcode != 0) {
					header('HTTP/1.x 500 Internal Server Error', true, 500);
					error_log('Unable to call tar command: '.$cmd);
					print 'Unable to call tar command. See webserver error log for details.';
				}
			}
			if ($retcode != 0) {
				chdir($oldcwd);
				removeDirectory($tempDir);
				exit(0);
			}

			// Set timestamp of tar file to timestamp of revision
			touch($tarArchive, $timestamp);

			// GZIP it up
			if (function_exists('gzopen')) {
				$srcHandle = fopen($tarArchive, 'rb');
				$dstHandle = gzopen($downloadArchive, 'wb');
				if (!$srcHandle || !$dstHandle) {
					header('HTTP/1.x 500 Internal Server Error', true, 500);
					print 'Unable to open file for gz-compression.';
					chdir($oldcwd);
					removeDirectory($tempDir);
					exit(0);
				}
				while (!feof($srcHandle)) {
					gzwrite($dstHandle, fread($srcHandle, 1024 * 512));
				}
				fclose($srcHandle);
				gzclose($dstHandle);

			} else {
				$cmd = $config->gzip.' '.quote($tarArchive);
				$retcode = 0;
				execCommand($cmd, $retcode);
				if ($retcode != 0) {
					header('HTTP/1.x 500 Internal Server Error', true, 500);
					error_log('Unable to call gzip command: '.$cmd);
					print 'Unable to call gzip command. See webserver error log for details.';
					chdir($oldcwd);
					removeDirectory($tempDir);
					exit(0);
				}
			}
		}

		// Give the file to the browser
		if (is_readable($downloadArchive)) {
			if ($downloadMode == 'plain') {
				$downloadFilename = $plainfilename;
			} else {
				$downloadFilename = $rep->name.'-'.$downloadArchive;
			}
			header('Content-Type: '.$downloadMimeType);
			header('Content-Length: '.filesize($downloadArchive));
			header('Content-Disposition: attachment; filename="'. $downloadFilename .'"');
			readfile($downloadArchive);
		} else {
			header('HTTP/1.x 404 Not Found', true, 404);
			print 'Unable to open file: '.xml_entities($downloadArchive);
		}
	}

	chdir($oldcwd);
	removeDirectory($tempDir);

} else {
	header('HTTP/1.x 404 Not Found', true, 404);
}