<?php
namespace W3TCL\Minify;

/**
 * Class Minify
 * @package Minify
 */

/**
 * Minify - Combines, minifies, and caches JavaScript and CSS files on demand.
 *
 * See README for usage instructions (for now).
 *
 * This library was inspired by {@link mailto:flashkot@mail.ru jscsscomp by Maxim Martynyuk}
 * and by the article {@link http://www.hunlock.com/blogs/Supercharged_Javascript "Supercharged JavaScript" by Patrick Hunlock}.
 *
 * Requires PHP 5.1.0.
 * Tested on PHP 5.1.6.
 *
 * @package Minify
 * @author Ryan Grove <ryan@wonko.com>
 * @author Stephen Clay <steve@mrclay.org>
 * @copyright 2008 Ryan Grove, Stephen Clay. All rights reserved.
 * @license http://opensource.org/licenses/bsd-license.php  New BSD License
 * @link http://code.google.com/p/minify/
 */
class Minify {

	const VERSION = '2.1.7';
	const TYPE_CSS = 'text/css';
	const TYPE_HTML = 'text/html';
	// there is some debate over the ideal JS Content-Type, but this is the
	// Apache default and what Yahoo! uses..
	const TYPE_JS = 'application/x-javascript';
	const URL_DEBUG = 'http://code.google.com/p/minify/wiki/Debugging';

	/**
	 * How many hours behind are the file modification times of uploaded files?
	 *
	 * If you upload files from Windows to a non-Windows server, Windows may report
	 * incorrect mtimes for the files. Immediately after modifying and uploading a
	 * file, use the touch command to update the mtime on the server. If the mtime
	 * jumps ahead by a number of hours, set this variable to that number. If the mtime
	 * moves back, this should not be needed.
	 *
	 * @var int $uploaderHoursBehind
	 */
	public static $uploaderHoursBehind = 0;

	/**
	 * If this string is not empty AND the serve() option 'bubbleCssImports' is
	 * NOT set, then serve() will check CSS files for @import declarations that
	 * appear too late in the combined stylesheet. If found, serve() will prepend
	 * the output with this warning.
	 *
	 * @var string $importWarning
	 */
	public static $importWarning = "/* See http://code.google.com/p/minify/wiki/CommonProblems#@imports_can_appear_in_invalid_locations_in_combined_CSS_files */\n";

	/**
	 * Has the DOCUMENT_ROOT been set in user code?
	 *
	 * @var bool
	 */
	public static $isDocRootSet = false;

	/**
	 * Cache ID
	 * @var string
	 */
	protected static $_cacheId = null;

	/**
	 * Specify a cache object (with identical interface as Minify_Cache_File) or
	 * a path to use with Minify_Cache_File.
	 *
	 * If not called, Minify will not use a cache and, for each 200 response, will
	 * need to recombine files, minify and encode the output.
	 *
	 * @param mixed $cache object with identical interface as Minify_Cache_File or
	 * a directory path, or null to disable caching. (default = '')
	 *
	 * @param bool $fileLocking (default = true) This only applies if the first
	 * parameter is a string.
	 *
	 * @return null
	 */
	public static function setCache($cache = '', $fileLocking = true)
	{
		if (is_string($cache)) {
			self::$_cache = new Minify_Cache_File($cache, $fileLocking);
		} else {
			self::$_cache = $cache;
		}
	}

	/**
	 * Serve a request for a minified file.
	 *
	 * Here are the available options and defaults in the base controller:
	 *
	 * 'isPublic' : send "public" instead of "private" in Cache-Control
	 * headers, allowing shared caches to cache the output. (default true)
	 *
	 * 'quiet' : set to true to have serve() return an array rather than sending
	 * any headers/output (default false)
	 *
	 * 'encodeOutput' : set to false to disable content encoding, and not send
	 * the Vary header (default true)
	 *
	 * 'encodeMethod' : generally you should let this be determined by
	 * HTTP_Encoder (leave null), but you can force a particular encoding
	 * to be returned, by setting this to 'gzip' or '' (no encoding)
	 *
	 * 'encodeLevel' : level of encoding compression (0 to 9, default 9)
	 *
	 * 'contentTypeCharset' : appended to the Content-Type header sent. Set to a falsey
	 * value to remove. (default 'utf-8')
	 *
	 * 'maxAge' : set this to the number of seconds the client should use its cache
	 * before revalidating with the server. This sets Cache-Control: max-age and the
	 * Expires header. Unlike the old 'setExpires' setting, this setting will NOT
	 * prevent conditional GETs. Note this has nothing to do with server-side caching.
	 *
	 * 'rewriteCssUris' : If true, serve() will automatically set the 'currentDir'
	 * minifier option to enable URI rewriting in CSS files (default true)
	 *
	 * 'bubbleCssImports' : If true, all @import declarations in combined CSS
	 * files will be move to the top. Note this may alter effective CSS values
	 * due to a change in order. (default false)
	 *
	 * 'debug' : set to true to minify all sources with the 'Lines' controller, which
	 * eases the debugging of combined files. This also prevents 304 responses.
	 * @see Minify_Lines::minify()
	 *
	 * 'minifiers' : to override Minify's default choice of minifier function for
	 * a particular content-type, specify your callback under the key of the
	 * content-type:
	 * <code>
	 * // call customCssMinifier($css) for all CSS minification
	 * $options['minifiers'][Minify::TYPE_CSS] = 'customCssMinifier';
	 *
	 * // don't minify Javascript at all
	 * $options['minifiers'][Minify::TYPE_JS] = '';
	 * </code>
	 *
	 * 'minifierOptions' : to send options to the minifier function, specify your options
	 * under the key of the content-type. E.g. To send the CSS minifier an option:
	 * <code>
	 * // give CSS minifier array('optionName' => 'optionValue') as 2nd argument
	 * $options['minifierOptions'][Minify::TYPE_CSS]['optionName'] = 'optionValue';
	 * </code>
	 *
	 * 'contentType' : (optional) this is only needed if your file extension is not
	 * js/css/html. The given content-type will be sent regardless of source file
	 * extension, so this should not be used in a Groups config with other
	 * Javascript/CSS files.
	 *
	 * Any controller options are documented in that controller's setupSources() method.
	 *
	 * @param mixed $controller instance of subclass of Minify_Controller_Base or string
	 * name of controller. E.g. 'Files'
	 *
	 * @param array $options controller/serve options
	 *
	 * @return null|array if the 'quiet' option is set to true, an array
	 * with keys "success" (bool), "statusCode" (int), "content" (string), and
	 * "headers" (array).
	 *
	 * @throws Exception
	 */
	public static function serve($controller, $options = array())
	{
		if (! self::$isDocRootSet && 0 === stripos(PHP_OS, 'win')) {
			self::setDocRoot();
		}

		if (is_string($controller)) {
			// make $controller into object
			$class = '\W3TCL\Minify\Minify_Controller_' . $controller;
			$controller = new $class();
			/* @var Minify_Controller_Base $controller */
		}

		// set up controller sources and mix remaining options with
		// controller defaults
		$options = $controller->setupSources($options);
		$options = $controller->analyzeSources($options);
		self::$_options = $controller->mixInDefaultOptions($options);

		// check request validity
		if (! $controller->sources) {
			// invalid request!
			if (! self::$_options['quiet']) {
				self::_errorExit(self::$_options['badRequestHeader'], self::URL_DEBUG);
			} else {
				list(,$statusCode) = explode(' ', self::$_options['badRequestHeader']);
				return array(
					'success' => false
					,'statusCode' => (int)$statusCode
					,'content' => ''
					,'headers' => array()
				);
			}
		}

		self::$_controller = $controller;

		if (self::$_options['debug']) {
			self::_setupDebug($controller->sources);
			self::$_options['maxAge'] = 0;
		}

		// determine encoding
		if (self::$_options['encodeOutput']) {
			$sendVary = true;
			if (self::$_options['encodeMethod'] !== null) {
				// controller specifically requested this
				$contentEncoding = self::$_options['encodeMethod'];
			} else {
				// sniff request header
				// depending on what the client accepts, $contentEncoding may be
				// 'x-gzip' while our internal encodeMethod is 'gzip'. Calling
				// getAcceptedEncoding(false, false) leaves out compress and deflate as options.
				list(self::$_options['encodeMethod'], $contentEncoding) = HTTP_Encoder::getAcceptedEncoding(false, false);
				$sendVary = ! HTTP_Encoder::isBuggyIe();
			}
		} else {
			self::$_options['encodeMethod'] = ''; // identity (no encoding)
		}

		// check client cache
		$cgOptions = array(
			'lastModifiedTime' => self::$_options['lastModifiedTime']
			,'cacheHeaders' => self::$_options['cacheHeaders']
			,'isPublic' => self::$_options['isPublic']
			,'encoding' => self::$_options['encodeMethod']
		);
		if (self::$_options['maxAge'] > 0) {
			$cgOptions['maxAge'] = self::$_options['maxAge'];
		} elseif (self::$_options['debug']) {
			$cgOptions['invalidate'] = true;
		}

		$cg = new HTTP_ConditionalGet($cgOptions);
		if ( $cg->cacheIsValid && !self::$_options['disable_304'] &&
			!defined( 'W3TC_MINIFY_CONDITIONAL_OFF' ) ) {
			// client's cache is valid
			if (! self::$_options['quiet']) {
				self::$lastServed = array(
					'fullCacheId' =>self::_getCacheId() .
					(self::$_options['encodeMethod']
						? '.' . self::$_options['encodeMethod']
						: '')
				);
				$cg->sendHeaders();
				return;
			} else {
				return array(
					'success' => true
					,'statusCode' => 304
					,'content' => ''
					,'headers' => $cg->getHeaders()
				);
			}
		} else {
			// client will need output
			$headers = $cg->getHeaders();
			unset($cg);
		}

		if (self::$_options['contentType'] === self::TYPE_CSS
			&& self::$_options['rewriteCssUris']) {
			foreach($controller->sources as $key => $source) {
				if (self::$_options['rewriteCssUris']
					&& $source->filepath
					&& !isset($source->minifyOptions['currentDir'])
					&& !isset($source->minifyOptions['prependRelativePath'])
				) {
					$source->minifyOptions['currentDir'] = dirname($source->filepath);
				}

				$source->minifyOptions['processCssImports'] = self::$_options['processCssImports'];
			}
		}

		// check server cache
		$content = array();
		if (null !== self::$_cache && ! self::$_options['debug']) {
			// using cache
			// the goal is to use only the cache methods to sniff the length and
			// output the content, as they do not require ever loading the file into
			// memory.
			$cacheId = self::_getCacheId();
			$fullCacheId = (self::$_options['encodeMethod'])
				? $cacheId . '.' . self::$_options['encodeMethod']
				: $cacheId;
			// check cache for valid entry
			$cacheIsReady = self::$_cache->isValid($fullCacheId, self::$_options['lastModifiedTime']);
			if ($cacheIsReady) {
				$cacheContentLength = self::$_cache->getSize($fullCacheId);
			} else {
				// generate & cache content
				try {
					$content = self::_combineMinify();
				} catch (\Exception $e) {
					self::$_controller->log($e->getMessage());
					if (! self::$_options['quiet']) {
						self::_errorExit(self::$_options['errorHeader'], self::URL_DEBUG);
					}
					throw $e;
				}
				self::$_cache->store($cacheId, $content);
				if (function_exists('brotli_compress') && self::$_options['encodeMethod'] === 'br' && self::$_options['encodeOutput']) {
					$compressed = $content;
					$compressed['content'] = brotli_compress($content['content']);

					self::$_cache->store($cacheId . '_' . self::$_options['encodeMethod'],
						$compressed);
				}
				if (function_exists('gzencode') && self::$_options['encodeMethod'] && self::$_options['encodeMethod'] !== 'br' && self::$_options['encodeOutput']) {
					$compressed = $content;
					$compressed['content'] = gzencode($content['content'],
						self::$_options['encodeLevel']);

					self::$_cache->store($cacheId . '_' . self::$_options['encodeMethod'],
						$compressed);
				}
			}
		} else {
			// no cache
			$cacheIsReady = false;
			try {
				$content = self::_combineMinify();
			} catch (\Exception $e) {
				self::$_controller->log($e->getMessage());
				if (! self::$_options['quiet']) {
					self::_errorExit(self::$_options['errorHeader'], self::URL_DEBUG);
				}
				throw $e;
			}
		}
		if (! $cacheIsReady && self::$_options['encodeMethod']) {
			switch (self::$_options['encodeMethod']) {
				case 'gzip':
					$content['content'] = gzencode($content['content'], self::$_options['encodeLevel']);
					break;

				case 'deflate':
					$content['content'] = gzdeflate($content['content'], self::$_options['encodeLevel']);
					break;

				case 'br':
					$content['content'] = brotli_compress($content['content']);
					break;
			}
			// still need to encode
		}

		// add headers
		if ( !defined( 'W3TC_MINIFY_CONTENT_LENGTH_OFF' ) ) {
			$headers['Content-Length'] = $cacheIsReady
				? $cacheContentLength
				: ((function_exists('mb_strlen') && ((int)ini_get('mbstring.func_overload') & 2))
					? mb_strlen($content['content'], '8bit')
					: strlen($content['content'])
				);
		}

		$headers['Content-Type'] = self::$_options['contentTypeCharset']
			? self::$_options['contentType'] . '; charset=' . self::$_options['contentTypeCharset']
			: self::$_options['contentType'];
		if (self::$_options['encodeMethod'] !== '') {
			$headers['Content-Encoding'] = $contentEncoding;
		}
		if (self::$_options['encodeOutput'] && $sendVary) {
			$headers['Vary'] = 'Accept-Encoding';
		}

		self::$lastServed = $content;

		if (! self::$_options['quiet']) {
			// output headers & content
			foreach ($headers as $name => $val) {
				header($name . ': ' . $val);
			}
			if ($cacheIsReady) {
				self::$lastServed['fullCacheId'] = $fullCacheId;
				self::$_cache->display($fullCacheId);
			} else {
				echo $content['content'];
			}
		} else {
			if ($cacheIsReady)
				$content = self::$_cache->fetch($fullCacheId);

			return array(
				'success' => true
				,'statusCode' => 200
				,'content' => $content['content']
				,'headers' => $headers
			);
		}
	}

	private static $lastServed = array();

	public static function getUsageStatistics() {
		if (isset(self::$lastServed['fullCacheId']))
			self::$lastServed = self::$_cache->fetch(self::$lastServed['fullCacheId']);

		if (isset(self::$lastServed['content']) &&
				isset(self::$lastServed['originalLength'])) {
			return array(
				'content_type' => self::$_options['contentType'],
				'content_original_length' => self::$lastServed['originalLength'],
				'content_output_length' => strlen(self::$lastServed['content'])
			);
		}

		return array();
	}

	/**
	 * Return combined minified content for a set of sources
	 *
	 * No internal caching will be used and the content will not be HTTP encoded.
	 *
	 * @param array $sources array of filepaths and/or Minify_Source objects
	 *
	 * @param array $options (optional) array of options for serve. By default
	 * these are already set: quiet = true, encodeMethod = '', lastModifiedTime = 0.
	 *
	 * @return string
	 */
	public static function combine($sources, $options = array())
	{
		$cache = self::$_cache;
		self::$_cache = null;
		$options = array_merge(array(
			'files' => (array)$sources
			,'quiet' => true
			,'encodeMethod' => ''
			,'lastModifiedTime' => 0
		), $options);
		$out = self::serve('Files', $options);
		self::$_cache = $cache;
		return $out['content'];
	}

	/**
	 * Set $_SERVER['DOCUMENT_ROOT']. On IIS, the value is created from SCRIPT_FILENAME and SCRIPT_NAME.
	 *
	 * @param string $docRoot value to use for DOCUMENT_ROOT
	 */
	public static function setDocRoot($docRoot = '')
	{
		self::$isDocRootSet = true;
		if ($docRoot) {
			$_SERVER['DOCUMENT_ROOT'] = $docRoot;
		} elseif (isset($_SERVER['SERVER_SOFTWARE'])
				  && 0 === strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/')) {
			$_SERVER['DOCUMENT_ROOT'] = substr(
				$_SERVER['SCRIPT_FILENAME']
				,0
				,strlen($_SERVER['SCRIPT_FILENAME']) - strlen($_SERVER['SCRIPT_NAME']));
			$_SERVER['DOCUMENT_ROOT'] = rtrim($_SERVER['DOCUMENT_ROOT'], '\\');
		}
	}

	public static $recoverableError = null;

	/**
	 * Any Minify_Cache_* object or null (i.e. no server cache is used)
	 *
	 * @var Minify_Cache_File
	 */
	private static $_cache = null;

	/**
	 * Active controller for current request
	 *
	 * @var Minify_Controller_Base
	 */
	protected static $_controller = null;

	/**
	 * Options for current request
	 *
	 * @var array
	 */
	protected static $_options = null;

	/**
	 * @param string $header
	 *
	 * @param string $url
	 */
	protected static function _errorExit($header, $url)
	{
		$url = htmlspecialchars($url, ENT_QUOTES);
		list(,$h1) = explode(' ', $header, 2);
		$h1 = htmlspecialchars($h1);
		// FastCGI environments require 3rd arg to header() to be set
		list(, $code) = explode(' ', $header, 3);
		header($header, true, $code);
		header('Content-Type: text/html; charset=utf-8');
		echo "<h1>$h1</h1>";
		echo "<p>Please see <a href='$url'>$url</a>.</p>";
		exit();
	}

	/**
	 * Set up sources to use Minify_Lines
	 *
	 * @param Minify_Source[] $sources Minify_Source instances
	 */
	protected static function _setupDebug($sources)
	{
		foreach ($sources as $source) {
			$source->minifier = array('\W3TCL\Minify\Minify_Lines', 'minify');
			$id = $source->getId();
			$source->minifyOptions = array(
				'id' => (is_file($id) ? basename($id) : $id)
			);
		}
	}

	/**
	 * Combines sources and minifies the result.
	 *
	 * @return string
	 *
	 * @throws Exception
	 */
	protected static function _combineMinify()
	{
		$type = self::$_options['contentType']; // ease readability

		// when combining scripts, make sure all statements separated and
		// trailing single line comment is terminated
		$implodeSeparator = ($type === self::TYPE_JS)
			? "\n;"
			: '';
		// allow the user to pass a particular array of options to each
		// minifier (designated by type). source objects may still override
		// these
		$defaultOptions = isset(self::$_options['minifierOptions'][$type])
			? self::$_options['minifierOptions'][$type]
			: array();
		// if minifier not set, default is no minification. source objects
		// may still override this
		$defaultMinifier = isset(self::$_options['minifiers'][$type])
			? self::$_options['minifiers'][$type]
			: false;

		// process groups of sources with identical minifiers/options
		$content = array();
		$originalLength = 0;
		$i = 0;
		$l = count(self::$_controller->sources);
		$groupToProcessTogether = array();
		$lastMinifier = null;
		$lastOptions = null;
		do {
			// get next source
			$source = null;
			if ($i < $l) {
				$source = self::$_controller->sources[$i];
				/* @var Minify_Source $source */
				$sourceContent = $source->getContent();
				$originalLength += strlen($sourceContent);

				// allow the source to override our minifier and options
				$minifier = (null !== $source->minifier)
					? $source->minifier
					: $defaultMinifier;
				$options = (null !== $source->minifyOptions)
					? array_merge($defaultOptions, $source->minifyOptions)
					: $defaultOptions;
			}
			// do we need to process our group right now?
			if ($i > 0                               // yes, we have at least the first group populated
				&& (
					! $source                        // yes, we ran out of sources
					|| $type === self::TYPE_CSS      // yes, to process CSS individually (avoiding PCRE bugs/limits)
					|| $minifier !== $lastMinifier   // yes, minifier changed
					|| $options !== $lastOptions)    // yes, options changed
				)
			{
				// minify previous sources with last settings
				$imploded = implode($implodeSeparator, $groupToProcessTogether);
				$groupToProcessTogether = array();
				if ($lastMinifier) {
					try {
						$content[] = call_user_func($lastMinifier, $imploded, $lastOptions);
					} catch (\Exception $e) {
						throw new \Exception("Exception in minifier: " . $e->getMessage());
					}
				} else {
					$content[] = $imploded;
				}
			}
			// add content to the group
			if ($source) {
				$groupToProcessTogether[] = $sourceContent;
				$lastMinifier = $minifier;
				$lastOptions = $options;
			}
			$i++;
		} while ($source);

		$content = implode($implodeSeparator, $content);

		if ($type === self::TYPE_CSS && false !== strpos($content, '@import')) {
			$content = self::_handleCssImports($content);
		}
		if ( $type === self::TYPE_CSS ) {
			$content = apply_filters( 'w3tc_minify_css_content', $content, null, null );
		}
	if ( $type === self::TYPE_JS ) {
		$content = apply_filters( 'w3tc_minify_js_content', $content, null, null );
	}

		// do any post-processing (esp. for editing build URIs)
		if (self::$_options['postprocessorRequire']) {
			require_once self::$_options['postprocessorRequire'];
		}
		if (self::$_options['postprocessor']) {
			$content = call_user_func(self::$_options['postprocessor'], $content, $type);
		}
		return array(
			'originalLength' => $originalLength,
			'content' => $content
		);
	}

	/**
	 * Sets cache ID
	 * @param string $cacheId
	 */
	public static function setCacheId($cacheId = null)
	{
		self::$_cacheId = $cacheId;
	}

	/**
	 * Returns cache ID
	 */
	public static function getCacheId()
	{
		return self::$_cacheId;
	}

	/**
	 * Make a unique cache id for for this request.
	 *
	 * Any settings that could affect output are taken into consideration
	 *
	 * @param string $prefix
	 *
	 * @return string
	 */
	protected static function _getCacheId($prefix = 'minify')
	{
		return (self::$_cacheId ? self::$_cacheId : md5(serialize(array(
			Minify_Source::getDigest(self::$_controller->sources)
			,self::$_options['minifiers']
			,self::$_options['minifierOptions']
			,self::$_options['postprocessor']
			,self::$_options['bubbleCssImports']
			,self::$_options['processCssImports']
		))));
	}

	/**
	 * Bubble CSS @imports to the top or prepend a warning if an import is detected not at the top.
	 *
	 * @param string $css
	 *
	 * @return string
	 */
	protected static function _handleCssImports($css)
	{
		if (self::$_options['bubbleCssImports']) {
			// bubble CSS imports
			preg_match_all('/@import.*?;/', $css, $imports);
			$css = implode('', $imports[0]) . preg_replace('/@import.*?;/', '', $css);
		} else if ('' !== self::$importWarning) {
			// remove comments so we don't mistake { in a comment as a block
			$noCommentCss = preg_replace('@/\\*[\\s\\S]*?\\*/@', '', $css);
			$lastImportPos = strrpos($noCommentCss, '@import');
			$firstBlockPos = strpos($noCommentCss, '{');
			if (false !== $lastImportPos
				&& false !== $firstBlockPos
				&& $firstBlockPos < $lastImportPos
			) {
				// { appears before @import : prepend warning
				$css = self::$importWarning . $css;
			}
		}
		return $css;
	}
}
