<?php

/**
 * @file classes/file/FileArchive.inc.php
 *
 * Copyright (c) 2014-2021 Simon Fraser University
 * Copyright (c) 2000-2021 John Willinsky
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class FileArchive
 * @ingroup file
 *
 * @brief Class provides functionality for creating an archive of files.
 */

class FileArchive {

	/**
	 * Assembles an array of filenames into either a tar.gz or a .zip
	 * file, based on what is available.  Returns a string representing
	 * the path to the archive on disk.
	 * @param array $files the files to add, in an associative array of the
	 *  format ('serverPath' => 'clientFilename')
	 * @param string $filesDir a path to the files on disk.
	 * @return string the path to the archive.
	 */
	function create($files, $filesDir) {
		// Create a temporary file.
		$archivePath = tempnam('/tmp', 'sf-');
		if ($archivePath === false) return false;
		unlink($archivePath);

		// attempt to use Zip first, if it is available.  Otherwise
		// fall back to the tar CLI.
		$zipTest = false;
		if (self::zipFunctional()) {
			$zipTest = true;
			$zip = new ZipArchive();
			if ($zip->open($archivePath, ZIPARCHIVE::CREATE) == true) {
				foreach ($files as $serverPath => $clientFilename) {
					$zip->addFile($filesDir . '/' . $serverPath, $clientFilename);
				}
				$zip->close();
			}
		} elseif (self::tarFunctional()) {
			// Create the archive and download the file.
			exec(Config::getVar('cli', 'tar') . ' -c -z ' .
					'-f ' . escapeshellarg($archivePath) . ' ' .
					'-C ' . escapeshellarg($filesDir) . ' ' .
					implode(' ', array_map('escapeshellarg', array_keys($files)))
			);
		} else {
			throw new Exception('No archive tool is available!');
		}

		return $archivePath;
	}

	/**
	 * Return true if the zip extension is loaded.
	 * @return boolean
	 */
	static function zipFunctional() {
		return (extension_loaded('zip'));
	}

	/**
	 * Return true if the tar tools are configured.
	 */
	static function tarFunctional() {
		$tarBinary = Config::getVar('cli', 'tar');
		return !empty($tarBinary) && file_exists($tarBinary);
	}

	static function isFunctional() {
		return self::zipFunctional() || self::tarFunctional();
	}
}