// 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.

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

#include <string>
#include <vector>

#include "base/metrics/histogram.h"
#include "base/string_number_conversions.h"
#include "base/string_split.h"
#include "base/string_util.h"
#include "base/utf_string_conversions.h"
#include "base/values.h"
#include "chrome/browser/dom_ui/shown_sections_handler.h"
#include "chrome/browser/extensions/default_apps.h"
#include "chrome/browser/extensions/extension_prefs.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/platform_util.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/tab_contents/tab_contents.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_list.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/common/extensions/extension.h"
#include "chrome/common/extensions/extension_constants.h"
#include "chrome/common/extensions/extension_icon_set.h"
#include "chrome/common/extensions/extension_resource.h"
#include "chrome/common/notification_service.h"
#include "chrome/common/notification_type.h"
#include "chrome/common/url_constants.h"
#include "grit/browser_resources.h"
#include "grit/generated_resources.h"
#include "ui/base/animation/animation.h"
#include "ui/gfx/rect.h"

namespace {

// The URL prefixes used by the NTP to signal when the web store or an app
// has launched. These are used for histogram purposes.
const char* kLaunchAppPingURL = "record-app-launch";
const char* kLaunchWebStorePingURL = "record-webstore-launch";

// This extracts an int from a ListValue at the given |index|.
bool ExtractInt(const ListValue* list, size_t index, int* out_int) {
  std::string string_value;

  if (list->GetString(index, &string_value)) {
    base::StringToInt(string_value, out_int);
    return true;
  }

  return false;
}

std::string GetIconURL(const Extension* extension, Extension::Icons icon,
                       const std::string& default_val) {
  GURL url = extension->GetIconURL(icon, ExtensionIconSet::MATCH_EXACTLY);
  if (!url.is_empty())
    return url.spec();
  else
    return default_val;
}

// Extracts the promo parameter from the |path| generated by a ping on the NTP.
bool IsPromoActive(const std::string& path) {
  std::vector<std::string> params;
  base::SplitString(path, '+', &params);

  CHECK(params.size() == 2);

  return params.at(1) == "true";
}

}  // namespace

AppLauncherHandler::AppLauncherHandler(ExtensionService* extension_service)
    : extensions_service_(extension_service),
      promo_active_(false),
      ignore_changes_(false) {
}

AppLauncherHandler::~AppLauncherHandler() {}

// static
void AppLauncherHandler::CreateAppInfo(const Extension* extension,
                                       ExtensionPrefs* extension_prefs,
                                       DictionaryValue* value) {
  value->Clear();
  value->SetString("id", extension->id());
  value->SetString("name", extension->name());
  value->SetString("description", extension->description());
  value->SetString("launch_url", extension->GetFullLaunchURL().spec());
  value->SetString("options_url", extension->options_url().spec());
  value->SetString("icon_big", GetIconURL(
      extension, Extension::EXTENSION_ICON_LARGE,
      "chrome://theme/IDR_APP_DEFAULT_ICON"));
  value->SetString("icon_small", GetIconURL(
      extension, Extension::EXTENSION_ICON_BITTY,
      std::string("chrome://favicon/") + extension->GetFullLaunchURL().spec()));
  value->SetInteger("launch_container", extension->launch_container());
  value->SetInteger("launch_type",
      extension_prefs->GetLaunchType(extension->id(),
                                     ExtensionPrefs::LAUNCH_REGULAR));

  int app_launch_index = extension_prefs->GetAppLaunchIndex(extension->id());
  if (app_launch_index == -1) {
    // Make sure every app has a launch index (some predate the launch index).
    app_launch_index = extension_prefs->GetNextAppLaunchIndex();
    extension_prefs->SetAppLaunchIndex(extension->id(), app_launch_index);
  }
  value->SetInteger("app_launch_index", app_launch_index);
}

// static
bool AppLauncherHandler::HandlePing(Profile* profile, const std::string& path) {
  bool is_web_store_ping =
      path.find(kLaunchWebStorePingURL) != std::string::npos;
  bool is_app_launch_ping =
      path.find(kLaunchAppPingURL) != std::string::npos;

  // We get called for every URL in chrome://newtab/. Return false if it isn't
  // one we handle.
  if (!is_web_store_ping && !is_app_launch_ping)
    return false;

  bool is_promo_active = IsPromoActive(path);

  if (is_web_store_ping)
    RecordWebStoreLaunch(is_promo_active);
  else
    RecordAppLaunch(is_promo_active);

  if (is_promo_active)
    profile->GetExtensionService()->default_apps()->SetPromoHidden();

  return true;
}

DOMMessageHandler* AppLauncherHandler::Attach(DOMUI* dom_ui) {
  // TODO(arv): Add initialization code to the Apps store etc.
  return DOMMessageHandler::Attach(dom_ui);
}

void AppLauncherHandler::RegisterMessages() {
  dom_ui_->RegisterMessageCallback("getApps",
      NewCallback(this, &AppLauncherHandler::HandleGetApps));
  dom_ui_->RegisterMessageCallback("launchApp",
      NewCallback(this, &AppLauncherHandler::HandleLaunchApp));
  dom_ui_->RegisterMessageCallback("setLaunchType",
      NewCallback(this, &AppLauncherHandler::HandleSetLaunchType));
  dom_ui_->RegisterMessageCallback("uninstallApp",
      NewCallback(this, &AppLauncherHandler::HandleUninstallApp));
  dom_ui_->RegisterMessageCallback("hideAppsPromo",
      NewCallback(this, &AppLauncherHandler::HandleHideAppsPromo));
  dom_ui_->RegisterMessageCallback("createAppShortcut",
      NewCallback(this, &AppLauncherHandler::HandleCreateAppShortcut));
  dom_ui_->RegisterMessageCallback("reorderApps",
      NewCallback(this, &AppLauncherHandler::HandleReorderApps));
}

void AppLauncherHandler::Observe(NotificationType type,
                                 const NotificationSource& source,
                                 const NotificationDetails& details) {
  if (ignore_changes_)
    return;

  switch (type.value) {
    case NotificationType::EXTENSION_LOADED:
    case NotificationType::EXTENSION_UNLOADED:
    case NotificationType::EXTENSION_LAUNCHER_REORDERED:
      if (dom_ui_->tab_contents())
        HandleGetApps(NULL);
      break;
    case NotificationType::PREF_CHANGED: {
      if (!dom_ui_->tab_contents())
        break;

      DictionaryValue dictionary;
      FillAppDictionary(&dictionary);
      dom_ui_->CallJavascriptFunction(L"appsPrefChangeCallback", dictionary);
      break;
    }
    default:
      NOTREACHED();
  }
}

void AppLauncherHandler::FillAppDictionary(DictionaryValue* dictionary) {
  ListValue* list = new ListValue();
  const ExtensionList* extensions = extensions_service_->extensions();
  for (ExtensionList::const_iterator it = extensions->begin();
       it != extensions->end(); ++it) {
    // Don't include the WebStore and other component apps.
    // The WebStore launcher gets special treatment in ntp/apps.js.
    if ((*it)->is_app() && (*it)->location() != Extension::COMPONENT) {
      DictionaryValue* app_info = new DictionaryValue();
      CreateAppInfo(*it, extensions_service_->extension_prefs(), app_info);
      list->Append(app_info);
    }
  }
  dictionary->Set("apps", list);

#if defined(OS_MACOSX)
  // App windows are not yet implemented on mac.
  dictionary->SetBoolean("disableAppWindowLaunch", true);
  dictionary->SetBoolean("disableCreateAppShortcut", true);
#endif

#if defined(OS_CHROMEOS)
  // Making shortcut does not make sense on ChromeOS because it does not have
  // a desktop.
  dictionary->SetBoolean("disableCreateAppShortcut", true);
#endif

  dictionary->SetBoolean(
      "showLauncher",
      extensions_service_->default_apps()->ShouldShowAppLauncher(
          extensions_service_->GetAppIds()));
}

void AppLauncherHandler::HandleGetApps(const ListValue* args) {
  DictionaryValue dictionary;

  // Tell the client whether to show the promo for this view. We don't do this
  // in the case of PREF_CHANGED because:
  //
  // a) At that point in time, depending on the pref that changed, it can look
  //    like the set of apps installed has changed, and we will mark the promo
  //    expired.
  // b) Conceptually, it doesn't really make sense to count a
  //    prefchange-triggered refresh as a promo 'view'.
  DefaultApps* default_apps = extensions_service_->default_apps();
  bool promo_just_expired = false;
  if (default_apps->ShouldShowPromo(extensions_service_->GetAppIds(),
                                    &promo_just_expired)) {
    dictionary.SetBoolean("showPromo", true);
    promo_active_ = true;
  } else {
    if (promo_just_expired) {
      ignore_changes_ = true;
      UninstallDefaultApps();
      ignore_changes_ = false;
      ShownSectionsHandler::SetShownSection(dom_ui_->GetProfile()->GetPrefs(),
                                            THUMB);
    }
    dictionary.SetBoolean("showPromo", false);
    promo_active_ = false;
  }

  FillAppDictionary(&dictionary);
  dom_ui_->CallJavascriptFunction(L"getAppsCallback", dictionary);

  // First time we get here we set up the observer so that we can tell update
  // the apps as they change.
  if (registrar_.IsEmpty()) {
    registrar_.Add(this, NotificationType::EXTENSION_LOADED,
        NotificationService::AllSources());
    registrar_.Add(this, NotificationType::EXTENSION_UNLOADED,
        NotificationService::AllSources());
    registrar_.Add(this, NotificationType::EXTENSION_LAUNCHER_REORDERED,
        NotificationService::AllSources());
  }
  if (pref_change_registrar_.IsEmpty()) {
    pref_change_registrar_.Init(
        extensions_service_->extension_prefs()->pref_service());
    pref_change_registrar_.Add(ExtensionPrefs::kExtensionsPref, this);
  }
}

void AppLauncherHandler::HandleLaunchApp(const ListValue* args) {
  std::string extension_id;
  int left = 0;
  int top = 0;
  int width = 0;
  int height = 0;

  if (!args->GetString(0, &extension_id) ||
      !ExtractInt(args, 1, &left) ||
      !ExtractInt(args, 2, &top) ||
      !ExtractInt(args, 3, &width) ||
      !ExtractInt(args, 4, &height)) {
    NOTREACHED();
    return;
  }

  // The rect we get from the client is relative to the browser client viewport.
  // Offset the rect by the tab contents bounds.
  gfx::Rect rect(left, top, width, height);
  gfx::Rect tab_contents_bounds;
  dom_ui_->tab_contents()->GetContainerBounds(&tab_contents_bounds);
  rect.Offset(tab_contents_bounds.origin());

  const Extension* extension =
      extensions_service_->GetExtensionById(extension_id, false);
  DCHECK(extension);
  Profile* profile = extensions_service_->profile();

  // To give a more "launchy" experience when using the NTP launcher, we close
  // it automatically.
  Browser* browser = BrowserList::GetLastActive();
  TabContents* old_contents = NULL;
  if (browser)
    old_contents = browser->GetSelectedTabContents();

  // Look at preference to find the right launch container.  If no preference
  // is set, launch as a regular tab.
  extension_misc::LaunchContainer launch_container =
      extensions_service_->extension_prefs()->GetLaunchContainer(
          extension, ExtensionPrefs::LAUNCH_REGULAR);

  TabContents* new_contents = Browser::OpenApplication(
      profile, extension, launch_container, old_contents);

  if (new_contents != old_contents && browser->tab_count() > 1)
    browser->CloseTabContents(old_contents);

  if (extension_id != extension_misc::kWebStoreAppId) {
    RecordAppLaunch(promo_active_);
    extensions_service_->default_apps()->SetPromoHidden();
  }
}

void AppLauncherHandler::HandleSetLaunchType(const ListValue* args) {
  std::string extension_id;
  int launch_type;
  if (!args->GetString(0, &extension_id) ||
      !ExtractInt(args, 1, &launch_type)) {
    NOTREACHED();
    return;
  }

  const Extension* extension =
      extensions_service_->GetExtensionById(extension_id, false);
  DCHECK(extension);

  extensions_service_->extension_prefs()->SetLaunchType(
      extension_id,
      static_cast<ExtensionPrefs::LaunchType>(launch_type));
}

void AppLauncherHandler::HandleUninstallApp(const ListValue* args) {
  std::string extension_id = WideToUTF8(ExtractStringValue(args));
  const Extension* extension = extensions_service_->GetExtensionById(
      extension_id, false);
  if (!extension)
    return;

  if (!extension_id_prompting_.empty())
    return;  // Only one prompt at a time.

  extension_id_prompting_ = extension_id;
  GetExtensionInstallUI()->ConfirmUninstall(this, extension);
}

void AppLauncherHandler::HandleHideAppsPromo(const ListValue* args) {
  // If the user has intentionally hidden the promotion, we'll uninstall all the
  // default apps (we know the user hasn't installed any apps on their own at
  // this point, or the promotion wouldn't have been shown).
  UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
                            extension_misc::PROMO_CLOSE,
                            extension_misc::PROMO_BUCKET_BOUNDARY);

  ShownSectionsHandler::SetShownSection(dom_ui_->GetProfile()->GetPrefs(),
                                        THUMB);
  ignore_changes_ = true;
  UninstallDefaultApps();
  extensions_service_->default_apps()->SetPromoHidden();
  ignore_changes_ = false;
  HandleGetApps(NULL);
}

void AppLauncherHandler::HandleCreateAppShortcut(const ListValue* args) {
  std::string extension_id;
  if (!args->GetString(0, &extension_id)) {
    NOTREACHED();
    return;
  }

  const Extension* extension =
      extensions_service_->GetExtensionById(extension_id, false);
  CHECK(extension);

  Browser* browser = BrowserList::GetLastActive();
  if (!browser)
    return;
  browser->window()->ShowCreateChromeAppShortcutsDialog(
      browser->profile(), extension);
}

void AppLauncherHandler::HandleReorderApps(const ListValue* args) {
  std::vector<std::string> extension_ids;
  for (size_t i = 0; i < args->GetSize(); ++i) {
    std::string value;
    if (args->GetString(i, &value))
      extension_ids.push_back(value);
  }

  extensions_service_->extension_prefs()->SetAppLauncherOrder(extension_ids);
}

// static
void AppLauncherHandler::RecordWebStoreLaunch(bool promo_active) {
  if (!promo_active) return;

  UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
                            extension_misc::PROMO_LAUNCH_WEB_STORE,
                            extension_misc::PROMO_BUCKET_BOUNDARY);
}

// static
void AppLauncherHandler::RecordAppLaunch(bool promo_active) {
  // TODO(jstritar): record app launches that occur when the promo is not
  // active using a different histogram.

  if (!promo_active) return;

  UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
                            extension_misc::PROMO_LAUNCH_APP,
                            extension_misc::PROMO_BUCKET_BOUNDARY);
}

void AppLauncherHandler::InstallUIProceed() {
  DCHECK(!extension_id_prompting_.empty());

  // The extension can be uninstalled in another window while the UI was
  // showing. Do nothing in that case.
  const Extension* extension =
      extensions_service_->GetExtensionById(extension_id_prompting_, true);
  if (!extension)
    return;

  extensions_service_->UninstallExtension(extension_id_prompting_,
                                          false /* external_uninstall */);
  extension_id_prompting_ = "";
}

void AppLauncherHandler::InstallUIAbort() {
  extension_id_prompting_ = "";
}

ExtensionInstallUI* AppLauncherHandler::GetExtensionInstallUI() {
  if (!install_ui_.get())
    install_ui_.reset(new ExtensionInstallUI(dom_ui_->GetProfile()));
  return install_ui_.get();
}

void AppLauncherHandler::UninstallDefaultApps() {
  DefaultApps* default_apps = extensions_service_->default_apps();
  const ExtensionIdSet& app_ids = default_apps->default_apps();
  for (ExtensionIdSet::const_iterator iter = app_ids.begin();
       iter != app_ids.end(); ++iter) {
    if (extensions_service_->GetExtensionById(*iter, true))
      extensions_service_->UninstallExtension(*iter, false);
  }
}