/*
 * Copyright 2012 Google Inc.
 *
 * Licensed 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.
 */

// Author: mmohabey@google.com (Megha Mohabey)

#include "net/instaweb/rewriter/public/deterministic_js_filter.h"

#include "net/instaweb/rewriter/public/rewrite_driver.h"
#include "net/instaweb/rewriter/public/server_context.h"
#include "net/instaweb/rewriter/public/static_asset_manager.h"
#include "pagespeed/kernel/base/string_util.h"
#include "pagespeed/kernel/html/html_element.h"
#include "pagespeed/kernel/html/html_name.h"

namespace net_instaweb {

DeterministicJsFilter::DeterministicJsFilter(RewriteDriver* driver)
    : CommonFilter(driver),
      found_head_(false) {
}

DeterministicJsFilter::~DeterministicJsFilter() {}

void DeterministicJsFilter::StartDocumentImpl() {
  found_head_ = false;
}

void DeterministicJsFilter::StartElementImpl(HtmlElement* element) {
  if (!found_head_ && element->keyword() == HtmlName::kHead) {
    found_head_ = true;
    HtmlElement* script = driver()->NewElement(element, HtmlName::kScript);
    driver()->InsertNodeAfterCurrent(script);
    StaticAssetManager* static_asset_manager =
        driver()->server_context()->static_asset_manager();
    StringPiece deterministic_js =
        static_asset_manager->GetAsset(
            StaticAssetEnum::DETERMINISTIC_JS, driver()->options());
    AddJsToElement(deterministic_js, script);
    driver()->AddAttribute(script, HtmlName::kDataPagespeedNoDefer, NULL);
  }
}

}  // namespace net_instaweb