<?php
namespace apache\shindig\gadgets\servlet;
use apache\shindig\gadgets\GadgetFeatureRegistry;
use apache\shindig\common\HttpServlet;
use apache\shindig\common\Config;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * This event handler deals with the /js/core:caja:etc.js request which content type=url gadgets can use
 * to retrieve our features javascript code, or used to make the most frequently used part of the feature
 * library external, and hence cachable by the browser.
 */
class JsServlet extends HttpServlet {

  public function doGet() {
    $this->noHeaders = true;
    if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
      header("HTTP/1.1 304 Not Modified");
      header('Content-Length: 0');
      ob_end_clean();
      die();
    }
    $uri = strtolower($_SERVER["REQUEST_URI"]);
    $uri = substr($uri, strrpos($uri, '/') + 1);
    // remove any params that would confuse our parser
    if (strpos($uri, '?')) {
      $uri = substr($uri, 0, strpos($uri, '?'));
    }
    if (strpos($uri, '.js') !== false) {
      $uri = substr($uri, 0, strlen($uri) - 3);
    }
    $needed = array();
    if (strpos($uri, ':')) {
      $needed = explode(':', $uri);
    } else {
      $needed[] = $uri;
    }
    $found = array();
    $missing = array();
    $contextClass = Config::get('gadget_context_class');
    $context = new $contextClass('GADGET');
    $registry = new GadgetFeatureRegistry(Config::get('features_path'));
    if ($registry->resolveFeatures($needed, $found, $missing)) {
      $isGadgetContext = !isset($_GET["c"]) || $_GET['c'] == 0 ? true : false;
      $jsData = '';
      foreach ($found as $feature) {
        $jsData .= $registry->getFeatureContent($feature, $context, $isGadgetContext);
      }
      if (! strlen($jsData)) {
        header("HTTP/1.0 404 Not Found", true);
        die();
      }
      $this->setCachingHeaders();
      header("Content-Type: text/javascript");
      echo $jsData;
    } else {
      header("HTTP/1.0 404 Not Found", true);
    }
    die();
  }

  private function setCachingHeaders() {
    // Expires far into the future
    header("Expires: Tue, 01 Jan 2030 00:00:01 GMT");
    // IE seems to need this (10 years should be enough).
    header("Cache-Control: public,max-age=315360000");
    // Firefox requires this for certain cases.
    header("Last-Modified: " . gmdate('D, d M Y H:i:s', time()));
  }
}