// Copyright (c) 2012 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/notifications/desktop_notification_service.h"

#include "base/bind.h"
#include "base/metrics/histogram.h"
#include "base/prefs/scoped_user_pref_update.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/thread.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/notifications/desktop_notification_profile_util.h"
#include "chrome/browser/notifications/desktop_notification_service_factory.h"
#include "chrome/browser/notifications/notification.h"
#include "chrome/browser/notifications/notification_object_proxy.h"
#include "chrome/browser/notifications/notification_ui_manager.h"
#include "chrome/browser/notifications/sync_notifier/chrome_notifier_service.h"
#include "chrome/browser/notifications/sync_notifier/chrome_notifier_service_factory.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/url_constants.h"
#include "components/pref_registry/pref_registry_syncable.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/desktop_notification_delegate.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/show_desktop_notification_params.h"
#include "ui/base/webui/web_ui_util.h"
#include "ui/message_center/notifier_settings.h"

#if defined(ENABLE_EXTENSIONS)
#include "chrome/browser/extensions/api/notifications/notifications_api.h"
#include "chrome/browser/extensions/extension_service.h"
#include "extensions/browser/event_router.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_system.h"
#include "extensions/browser/extension_util.h"
#include "extensions/browser/info_map.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_set.h"
#endif

using blink::WebTextDirection;
using content::BrowserThread;
using content::RenderViewHost;
using content::WebContents;
using message_center::NotifierId;

namespace {

void CancelNotification(const std::string& id) {
  g_browser_process->notification_ui_manager()->CancelById(id);
}

}  // namespace

// DesktopNotificationService -------------------------------------------------

// static
void DesktopNotificationService::RegisterProfilePrefs(
    user_prefs::PrefRegistrySyncable* registry) {
  registry->RegisterListPref(
      prefs::kMessageCenterDisabledExtensionIds,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(
      prefs::kMessageCenterDisabledSystemComponentIds,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
}

// static
std::string DesktopNotificationService::AddIconNotification(
    const GURL& origin_url,
    const base::string16& title,
    const base::string16& message,
    const gfx::Image& icon,
    const base::string16& replace_id,
    NotificationDelegate* delegate,
    Profile* profile) {
  Notification notification(message_center::NOTIFICATION_TYPE_SIMPLE,
                            origin_url,
                            title,
                            message,
                            icon,
                            blink::WebTextDirectionDefault,
                            message_center::NotifierId(origin_url),
                            base::string16(),
                            replace_id,
                            message_center::RichNotificationData(),
                            delegate);
  g_browser_process->notification_ui_manager()->Add(notification, profile);
  return notification.delegate_id();
}

DesktopNotificationService::DesktopNotificationService(Profile* profile)
    : PermissionContextBase(profile, CONTENT_SETTINGS_TYPE_NOTIFICATIONS),
      profile_(profile),
#if defined(ENABLE_EXTENSIONS)
      extension_registry_observer_(this),
#endif
      weak_factory_(this) {
  OnStringListPrefChanged(
      prefs::kMessageCenterDisabledExtensionIds, &disabled_extension_ids_);
  OnStringListPrefChanged(
      prefs::kMessageCenterDisabledSystemComponentIds,
      &disabled_system_component_ids_);
  disabled_extension_id_pref_.Init(
      prefs::kMessageCenterDisabledExtensionIds,
      profile_->GetPrefs(),
      base::Bind(
          &DesktopNotificationService::OnStringListPrefChanged,
          base::Unretained(this),
          base::Unretained(prefs::kMessageCenterDisabledExtensionIds),
          base::Unretained(&disabled_extension_ids_)));
  disabled_system_component_id_pref_.Init(
      prefs::kMessageCenterDisabledSystemComponentIds,
      profile_->GetPrefs(),
      base::Bind(
          &DesktopNotificationService::OnStringListPrefChanged,
          base::Unretained(this),
          base::Unretained(prefs::kMessageCenterDisabledSystemComponentIds),
          base::Unretained(&disabled_system_component_ids_)));
#if defined(ENABLE_EXTENSIONS)
  extension_registry_observer_.Add(
      extensions::ExtensionRegistry::Get(profile_));
#endif
}

DesktopNotificationService::~DesktopNotificationService() {
}

void DesktopNotificationService::RequestNotificationPermission(
    content::WebContents* web_contents,
    const PermissionRequestID& request_id,
    const GURL& requesting_frame,
    bool user_gesture,
    const NotificationPermissionCallback& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  RequestPermission(
      web_contents,
      request_id,
      requesting_frame,
      user_gesture,
      base::Bind(&DesktopNotificationService::OnNotificationPermissionRequested,
                 weak_factory_.GetWeakPtr(),
                 callback));
}

void DesktopNotificationService::ShowDesktopNotification(
    const content::ShowDesktopNotificationHostMsgParams& params,
    content::RenderFrameHost* render_frame_host,
    scoped_ptr<content::DesktopNotificationDelegate> delegate,
    base::Closure* cancel_callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  const GURL& origin = params.origin;
  NotificationObjectProxy* proxy =
      new NotificationObjectProxy(render_frame_host, delegate.Pass());

  base::string16 display_source = DisplayNameForOriginInProcessId(
      origin, render_frame_host->GetProcess()->GetID());
  Notification notification(origin, params.icon_url, params.title,
      params.body, params.direction, display_source, params.replace_id,
      proxy);

  // The webkit notification doesn't timeout.
  notification.set_never_timeout(true);

  g_browser_process->notification_ui_manager()->Add(notification, profile_);
  if (cancel_callback)
    *cancel_callback = base::Bind(&CancelNotification, proxy->id());

  DesktopNotificationProfileUtil::UsePermission(profile_, origin);
}

base::string16 DesktopNotificationService::DisplayNameForOriginInProcessId(
    const GURL& origin, int process_id) {
#if defined(ENABLE_EXTENSIONS)
  // If the source is an extension, lookup the display name.
  if (origin.SchemeIs(extensions::kExtensionScheme)) {
    extensions::InfoMap* extension_info_map =
        extensions::ExtensionSystem::Get(profile_)->info_map();
    if (extension_info_map) {
      extensions::ExtensionSet extensions;
      extension_info_map->GetExtensionsWithAPIPermissionForSecurityOrigin(
          origin,
          process_id,
          extensions::APIPermission::kNotifications,
          &extensions);
      for (extensions::ExtensionSet::const_iterator iter = extensions.begin();
           iter != extensions.end(); ++iter) {
        NotifierId notifier_id(NotifierId::APPLICATION, (*iter)->id());
        if (IsNotifierEnabled(notifier_id))
          return base::UTF8ToUTF16((*iter)->name());
      }
    }
  }
#endif

  return base::UTF8ToUTF16(origin.host());
}

bool DesktopNotificationService::IsNotifierEnabled(
    const NotifierId& notifier_id) {
  switch (notifier_id.type) {
    case NotifierId::APPLICATION:
      return disabled_extension_ids_.find(notifier_id.id) ==
          disabled_extension_ids_.end();
    case NotifierId::WEB_PAGE:
      return DesktopNotificationProfileUtil::GetContentSetting(
          profile_, notifier_id.url) == CONTENT_SETTING_ALLOW;
    case NotifierId::SYSTEM_COMPONENT:
#if defined(OS_CHROMEOS)
      return disabled_system_component_ids_.find(notifier_id.id) ==
          disabled_system_component_ids_.end();
#else
      // We do not disable system component notifications.
      return true;
#endif
  }

  NOTREACHED();
  return false;
}

void DesktopNotificationService::SetNotifierEnabled(
    const NotifierId& notifier_id,
    bool enabled) {
  DCHECK_NE(NotifierId::WEB_PAGE, notifier_id.type);

  bool add_new_item = false;
  const char* pref_name = NULL;
  scoped_ptr<base::StringValue> id;
  switch (notifier_id.type) {
    case NotifierId::APPLICATION:
      pref_name = prefs::kMessageCenterDisabledExtensionIds;
      add_new_item = !enabled;
      id.reset(new base::StringValue(notifier_id.id));
      FirePermissionLevelChangedEvent(notifier_id, enabled);
      break;
    case NotifierId::SYSTEM_COMPONENT:
#if defined(OS_CHROMEOS)
      pref_name = prefs::kMessageCenterDisabledSystemComponentIds;
      add_new_item = !enabled;
      id.reset(new base::StringValue(notifier_id.id));
#else
      return;
#endif
      break;
    default:
      NOTREACHED();
  }
  DCHECK(pref_name != NULL);

  ListPrefUpdate update(profile_->GetPrefs(), pref_name);
  base::ListValue* const list = update.Get();
  if (add_new_item) {
    // AppendIfNotPresent will delete |adding_value| when the same value
    // already exists.
    list->AppendIfNotPresent(id.release());
  } else {
    list->Remove(*id, NULL);
  }
}

void DesktopNotificationService::OnStringListPrefChanged(
    const char* pref_name, std::set<std::string>* ids_field) {
  ids_field->clear();
  // Separate GetPrefs()->GetList() to analyze the crash. See crbug.com/322320
  const PrefService* pref_service = profile_->GetPrefs();
  CHECK(pref_service);
  const base::ListValue* pref_list = pref_service->GetList(pref_name);
  for (size_t i = 0; i < pref_list->GetSize(); ++i) {
    std::string element;
    if (pref_list->GetString(i, &element) && !element.empty())
      ids_field->insert(element);
    else
      LOG(WARNING) << i << "-th element is not a string for " << pref_name;
  }
}

#if defined(ENABLE_EXTENSIONS)
void DesktopNotificationService::OnExtensionUninstalled(
    content::BrowserContext* browser_context,
    const extensions::Extension* extension,
    extensions::UninstallReason reason) {
  NotifierId notifier_id(NotifierId::APPLICATION, extension->id());
  if (IsNotifierEnabled(notifier_id))
    return;

  // The settings for ephemeral apps will be persisted across cache evictions.
  if (extensions::util::IsEphemeralApp(extension->id(), profile_))
    return;

  SetNotifierEnabled(notifier_id, true);
}
#endif

// Unlike other permission types, granting a notification for a given origin
// will not take into account the |embedder_origin|, it will only be based
// on the requesting iframe origin.
// TODO(mukai) Consider why notifications behave differently than
// other permissions. crbug.com/416894
void DesktopNotificationService::UpdateContentSetting(
    const GURL& requesting_origin,
    const GURL& embedder_origin,
    bool allowed) {
  if (allowed) {
    DesktopNotificationProfileUtil::GrantPermission(
        profile_, requesting_origin);
  } else {
    DesktopNotificationProfileUtil::DenyPermission(profile_, requesting_origin);
  }
}

void DesktopNotificationService::OnNotificationPermissionRequested(
    const NotificationPermissionCallback& callback, bool allowed) {
  blink::WebNotificationPermission permission = allowed ?
      blink::WebNotificationPermissionAllowed :
      blink::WebNotificationPermissionDenied;

  callback.Run(permission);
}

void DesktopNotificationService::FirePermissionLevelChangedEvent(
    const NotifierId& notifier_id, bool enabled) {
#if defined(ENABLE_EXTENSIONS)
  DCHECK_EQ(NotifierId::APPLICATION, notifier_id.type);
  extensions::api::notifications::PermissionLevel permission =
      enabled ? extensions::api::notifications::PERMISSION_LEVEL_GRANTED
              : extensions::api::notifications::PERMISSION_LEVEL_DENIED;
  scoped_ptr<base::ListValue> args(new base::ListValue());
  args->Append(new base::StringValue(
      extensions::api::notifications::ToString(permission)));
  scoped_ptr<extensions::Event> event(new extensions::Event(
      extensions::api::notifications::OnPermissionLevelChanged::kEventName,
      args.Pass()));
  extensions::EventRouter::Get(profile_)
      ->DispatchEventToExtension(notifier_id.id, event.Pass());

  // Tell the IO thread that this extension's permission for notifications
  // has changed.
  extensions::InfoMap* extension_info_map =
      extensions::ExtensionSystem::Get(profile_)->info_map();
  BrowserThread::PostTask(
      BrowserThread::IO, FROM_HERE,
      base::Bind(&extensions::InfoMap::SetNotificationsDisabled,
                 extension_info_map, notifier_id.id, !enabled));
#endif
}