// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//    * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//    * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "chrome/browser/dom_ui/dom_ui_host.h"

#include "base/json_reader.h"
#include "base/json_writer.h"
#include "chrome/browser/browser.h"
#include "chrome/browser/navigation_entry.h"
#include "chrome/browser/tab_contents_type.h"
#include "chrome/browser/render_view_host.h"

DOMUIHost::DOMUIHost(Profile* profile,
                     SiteInstance* instance,
                     RenderViewHostFactory* render_view_factory)
    : WebContents(profile,
                  instance,
                  render_view_factory,
                  MSG_ROUTING_NONE,
                  NULL) {
  // Implementors of this class will have a specific tab contents type.
  type_ = TAB_CONTENTS_UNKNOWN_TYPE;
}

DOMUIHost::~DOMUIHost() {
  STLDeleteContainerPairSecondPointers(message_callbacks_.begin(),
                                       message_callbacks_.end());
  STLDeleteContainerPointers(handlers_.begin(), handlers_.end());
}

bool DOMUIHost::CreateRenderView(RenderViewHost* render_view_host) {
  // Be sure to enable DOM UI bindings on the RenderViewHost before
  // CreateRenderView is called.  Since a cross-site transition may be
  // involved, this may or may not be the same RenderViewHost that we had when
  // we were created.
  render_view_host->AllowDOMUIBindings();
  return WebContents::CreateRenderView(render_view_host);
}

void DOMUIHost::AddMessageHandler(DOMMessageHandler* handler) {
  handlers_.push_back(handler);
}

void DOMUIHost::RegisterMessageCallback(const std::string& name,
                                        MessageCallback* callback) {
  message_callbacks_.insert(std::make_pair(name, callback));
}


void DOMUIHost::CallJavascriptFunction(const std::wstring& function_name,
                                       const Value& arg) {
  std::string json;
  JSONWriter::Write(&arg, false, &json);
  std::wstring javascript = function_name + L"(" + UTF8ToWide(json) + L");";

  ExecuteJavascript(javascript);
}

void DOMUIHost::CallJavascriptFunction(
    const std::wstring& function_name,
    const Value& arg1, const Value& arg2) {
  std::string json;
  JSONWriter::Write(&arg1, false, &json);
  std::wstring javascript = function_name + L"(" + UTF8ToWide(json);
  JSONWriter::Write(&arg2, false, &json);
  javascript += L"," + UTF8ToWide(json) + L");";

  ExecuteJavascript(javascript);
}

void DOMUIHost::ProcessDOMUIMessage(const std::string& message,
                                    const std::string& content) {
  // Look up the callback for this message.
  MessageCallbackMap::const_iterator callback = message_callbacks_.find(message);
  if (callback == message_callbacks_.end())
    return;

  // Convert the content JSON into a Value.
  Value* value = NULL;
  if (!content.empty()) {
    if (!JSONReader::Read(content, &value, false)) {
      // The page sent us something that we didn't understand.
      // This probably indicates a programming error.
      NOTREACHED();
      return;
    }
  }

  // Forward this message and content on.
  callback->second->Run(value);
  delete value;
}

WebPreferences DOMUIHost::GetWebkitPrefs() {
  // Get the users preferences then force image loading to always be on.
  WebPreferences web_prefs = WebContents::GetWebkitPrefs();
  web_prefs.loads_images_automatically = true;

  return web_prefs;
}

void DOMUIHost::ExecuteJavascript(const std::wstring& javascript) {
  // We're taking a string and making a javascript URL out of it. This means
  // that escaping will follow the rules of a URL. Yet, the JSON text may have
  // stuff in it that would be interpreted as escaped characters in a URL, but
  // we want to preserve them literally.
  //
  // We just escape all the percents to avoid this, since when this javascript
  // URL is interpreted, it will be unescaped.
  std::wstring escaped_js(javascript);
  ReplaceSubstringsAfterOffset(&escaped_js, 0, L"%", L"%25");
  ExecuteJavascriptInWebFrame(L"", L"javascript:" + escaped_js);
}