// Copyright (c) 2010 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.

#include "chrome/browser/chromeos/login/language_switch_menu.h"

#include "app/l10n_util.h"
#include "app/resource_bundle.h"
#include "base/utf_string_conversions.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chromeos/input_method/input_method_util.h"
#include "chrome/browser/chromeos/language_preferences.h"
#include "chrome/browser/chromeos/login/screen_observer.h"
#include "chrome/browser/pref_service.h"
#include "chrome/common/pref_names.h"
#include "grit/generated_resources.h"
#include "views/widget/widget_gtk.h"

namespace {

const int kLanguageMainMenuSize = 5;
// TODO(glotov): need to specify the list as a part of the image customization.
const char kLanguagesTopped[] = "es,it,de,fr,en-US";
const int kMoreLanguagesSubMenu = 200;

}  // namespace

namespace chromeos {

LanguageSwitchMenu::LanguageSwitchMenu()
    : ALLOW_THIS_IN_INITIALIZER_LIST(menu_model_(this)),
      ALLOW_THIS_IN_INITIALIZER_LIST(menu_model_submenu_(this)),
      delta_x_(0),
      delta_y_(0) {
}

void LanguageSwitchMenu::InitLanguageMenu() {
  // Update LanguageList to contain entries in current locale.
  language_list_.reset(new LanguageList);
  language_list_->CopySpecifiedLanguagesUp(kLanguagesTopped);

  // Clear older menu items.
  menu_model_.Clear();
  menu_model_submenu_.Clear();

  // Fill menu items with updated items.
  for (int line = 0; line != kLanguageMainMenuSize; line++) {
    menu_model_.AddItem(
        line, WideToUTF16(language_list_->GetLanguageNameAt(line)));
  }
  menu_model_.AddSeparator();
  menu_model_.AddSubMenuWithStringId(kMoreLanguagesSubMenu,
                                     IDS_LANGUAGES_MORE,
                                     &menu_model_submenu_);
  for (int line = kLanguageMainMenuSize;
       line != language_list_->get_languages_count(); line++) {
    menu_model_submenu_.AddItem(
        line, WideToUTF16(language_list_->GetLanguageNameAt(line)));
  }

  // Initialize menu here so it appears fast when called.
  menu_.reset(new views::Menu2(&menu_model_));
}

std::wstring LanguageSwitchMenu::GetCurrentLocaleName() const {
  DCHECK(g_browser_process);
  const std::string locale = g_browser_process->GetApplicationLocale();
  return language_list_->GetLanguageNameAt(
      language_list_->GetIndexFromLocale(locale));
};

// Currently, views::Menu is implemented directly with the Gtk
// widgets. So we use native gtk callbacks to get its future size.
int LanguageSwitchMenu::GetFirstLevelMenuWidth() const {
  DCHECK(menu_ != NULL);
  GtkRequisition box_size;
  gtk_widget_size_request(menu_->GetNativeMenu(), &box_size);
  return box_size.width;
}

void LanguageSwitchMenu::SetFirstLevelMenuWidth(int width) {
  DCHECK(menu_ != NULL);
  gtk_widget_set_size_request(menu_->GetNativeMenu(), width, -1);
}

// static
void LanguageSwitchMenu::SwitchLanguage(const std::string& locale) {
  // Save new locale.
  DCHECK(g_browser_process);
  PrefService* prefs = g_browser_process->local_state();
  prefs->SetString(prefs::kApplicationLocale, locale);
  prefs->SavePersistentPrefs();

  // Switch the locale.
  ResourceBundle::ReloadSharedInstance(UTF8ToWide(locale));

  // Enable the keyboard layouts that are necessary for the new locale.
  chromeos::input_method::EnableInputMethods(
      locale, chromeos::input_method::kKeyboardLayoutsOnly,
      kHardwareKeyboardLayout);

  // The following line does not seem to affect locale anyhow. Maybe in future..
  g_browser_process->SetApplicationLocale(locale);
}

////////////////////////////////////////////////////////////////////////////////
// views::ViewMenuDelegate implementation.

void LanguageSwitchMenu::RunMenu(views::View* source, const gfx::Point& pt) {
  DCHECK(menu_ != NULL);
  gfx::Point point(pt);
  point.Offset(delta_x_, delta_y_);
  menu_->RunMenuAt(point, views::Menu2::ALIGN_TOPRIGHT);
}

////////////////////////////////////////////////////////////////////////////////
// menus::SimpleMenuModel::Delegate implementation.

bool LanguageSwitchMenu::IsCommandIdChecked(int command_id) const {
  return false;
}

bool LanguageSwitchMenu::IsCommandIdEnabled(int command_id) const {
  return true;
}

bool LanguageSwitchMenu::GetAcceleratorForCommandId(
    int command_id, menus::Accelerator* accelerator) {
  return false;
}

void LanguageSwitchMenu::ExecuteCommand(int command_id) {
  const std::string locale = language_list_->GetLocaleFromIndex(command_id);
  SwitchLanguage(locale);
  InitLanguageMenu();

  // Update all view hierarchies that the locale has changed.
  views::Widget::NotifyLocaleChanged();
}

}  // namespace chromeos