<?php
/**
 * Class Minify_JS_ClosureCompiler
 * @package Minify
 */

/**
 * Minify Javascript using Google's Closure Compiler API
 *
 * @link http://code.google.com/closure/compiler/
 * @package Minify
 * @author Stephen Clay <steve@mrclay.org>
 *
 * @todo can use a stream wrapper to unit test this?
 */
class Minify_JS_ClosureCompiler {
 const URL = 'http://closure-compiler.appspot.com/compile';

 /**
 * Minify Javascript code via HTTP request to the Closure Compiler API
 *
 * @param string $js input code
 * @param array $options unused at this point
 * @return string
 */
 public static function minify($js, array $options = array())
 {
 $obj = new self($options);
 return $obj->min($js);
 }

 /**
 *
 * @param array $options
 *
 * fallbackFunc : default array($this, 'fallback');
 */
 public function __construct(array $options = array())
 {
 $this->_fallbackFunc = isset($options['fallbackMinifier'])
 ? $options['fallbackMinifier']
 : array($this, '_fallback');
 }

 public function min($js)
 {
 $postBody = $this->_buildPostBody($js);
 $bytes = (function_exists('mb_strlen') && ((int)ini_get('mbstring.func_overload') & 2))
 ? mb_strlen($postBody, '8bit')
 : strlen($postBody);
 if ($bytes > 200000) {
 throw new Minify_JS_ClosureCompiler_Exception(
 'POST content larger than 200000 bytes'
 );
 }
 $response = $this->_getResponse($postBody);
 if (preg_match('/^Error\(\d\d?\):/', $response)) {
 if (is_callable($this->_fallbackFunc)) {
 $response = "/* Received errors from Closure Compiler API:\n$response"
 . "\n(Using fallback minifier)\n*/\n";
 $response .= call_user_func($this->_fallbackFunc, $js);
 } else {
 throw new Minify_JS_ClosureCompiler_Exception($response);
 }
 }
 if ($response === '') {
 $errors = $this->_getResponse($this->_buildPostBody($js, true));
 throw new Minify_JS_ClosureCompiler_Exception($errors);
 }
 return $response;
 }

 protected $_fallbackFunc = null;

 protected function _getResponse($postBody)
 {
 $allowUrlFopen = preg_match('/1|yes|on|true/i', ini_get('allow_url_fopen'));
 if ($allowUrlFopen) {
 $contents = file_get_contents(self::URL, false, stream_context_create(array(
 'http' => array(
 'method' => 'POST',
 'header' => "Content-type: application/x-www-form-urlencoded\r\nConnection: close\r\n",
 'content' => $postBody,
 'max_redirects' => 0,
 'timeout' => 15,
 )
 )));
 } elseif (defined('CURLOPT_POST')) {
 $ch = curl_init(self::URL);
 curl_setopt($ch, CURLOPT_POST, true);
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: application/x-www-form-urlencoded'));
 curl_setopt($ch, CURLOPT_POSTFIELDS, $postBody);
 curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
 curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 15);
 $contents = curl_exec($ch);
 curl_close($ch);
 } else {
 throw new Minify_JS_ClosureCompiler_Exception(
 "Could not make HTTP request: allow_url_open is false and cURL not available"
 );
 }
 if (false === $contents) {
 throw new Minify_JS_ClosureCompiler_Exception(
 "No HTTP response from server"
 );
 }
 return trim($contents);
 }

 protected function _buildPostBody($js, $returnErrors = false)
 {
 return http_build_query(array(
 'js_code' => $js,
 'output_info' => ($returnErrors ? 'errors' : 'compiled_code'),
 'output_format' => 'text',
 'compilation_level' => 'SIMPLE_OPTIMIZATIONS'
 ), null, '&');
 }

 /**
 * Default fallback function if CC API fails
 * @param string $js
 * @return string
 */
 protected function _fallback($js)
 {
 return JSMin::minify($js);
 }
}

class Minify_JS_ClosureCompiler_Exception extends Exception {}