// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_UI_WEBUI_NTP_NEW_TAB_PAGE_HANDLER_H_
#define CHROME_BROWSER_UI_WEBUI_NTP_NEW_TAB_PAGE_HANDLER_H_

#include "base/values.h"
#include "content/browser/webui/web_ui.h"

class PrefService;
class Profile;

// Handler for general New Tab Page functionality that does not belong in a
// more specialized handler.
class NewTabPageHandler : public WebUIMessageHandler {
 public:
  NewTabPageHandler() {}
  virtual ~NewTabPageHandler() {}

  // WebUIMessageHandler implementation.
  virtual WebUIMessageHandler* Attach(WebUI* web_ui) OVERRIDE;
  virtual void RegisterMessages() OVERRIDE;

  // Callback for "closeNotificationPromo".
  void HandleCloseNotificationPromo(const ListValue* args);

  // Callback for "notificationPromoViewed".
  void HandleNotificationPromoViewed(const ListValue* args);

  // Callback for "pageSelected".
  void HandlePageSelected(const ListValue* args);

  // Callback for "introMessageDismissed". This is called when the close button
  // on the ntp4 bubble is clicked or when a NavDot is clicked.
  void HandleIntroMessageDismissed(const ListValue* args);

  // Callback for "handleIntroMessageSeen". No arguments. Called when the intro
  // message is displayed.
  void HandleIntroMessageSeen(const ListValue* args);

  // Register NTP preferences.
  static void RegisterUserPrefs(PrefService* prefs);

  // Registers values (strings etc.) for the page.
  static void GetLocalizedValues(Profile* profile, DictionaryValue* values);

  // Permanently dismiss the ntp4 bubble for new users.
  static void DismissIntroMessage(PrefService* prefs);

 private:
  // The purpose of this enum is to track which page on the NTP is showing.
  // The lower 10 bits of kNTPShownPage are used for the index within the page
  // group, and the rest of the bits are used for the page group ID (defined
  // here).
  static const int kPageIdOffset = 10;
  enum {
    INDEX_MASK = (1 << kPageIdOffset) - 1,
    MOST_VISITED_PAGE_ID = 1 << kPageIdOffset,
    APPS_PAGE_ID = 2 << kPageIdOffset,
    BOOKMARKS_PAGE_ID = 3 << kPageIdOffset,
    LAST_PAGE_ID = BOOKMARKS_PAGE_ID
  };
  static const int kHistogramEnumerationMax =
      (LAST_PAGE_ID >> kPageIdOffset) + 1;

  // Helper to send out promo resource change notification.
  void NotifyPromoResourceChanged();

  DISALLOW_COPY_AND_ASSIGN(NewTabPageHandler);
};

#endif  // CHROME_BROWSER_UI_WEBUI_NTP_NEW_TAB_PAGE_HANDLER_H_