// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/ash/login/user_adding_screen.h"

#include "base/functional/bind.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/singleton.h"
#include "base/observer_list.h"
#include "chrome/browser/ash/login/screens/user_selection_screen.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/browser_process_platform_part.h"
#include "chrome/browser/global_features.h"
#include "chrome/browser/ui/ash/login/login_display_host.h"
#include "chrome/browser/ui/ash/login/login_display_host_mojo.h"
#include "chrome/browser/ui/ash/login/user_adding_screen_input_methods_controller.h"
#include "chrome/browser/ui/ash/wallpaper/wallpaper_controller_client_impl.h"
#include "components/session_manager/core/session_manager.h"
#include "components/session_manager/session_manager_types.h"
#include "components/user_manager/user_manager.h"

namespace ash {
namespace {

class UserAddingScreenImpl : public UserAddingScreen {
 public:
  void Start() override;
  void Cancel() override;
  bool IsRunning() override;

  void AddObserver(UserAddingScreen::Observer* observer) override;
  void RemoveObserver(UserAddingScreen::Observer* observer) override;

  static UserAddingScreenImpl* GetInstance();

 private:
  friend struct base::DefaultSingletonTraits<UserAddingScreenImpl>;

  void OnDisplayHostCompletion();

  UserAddingScreenImpl();
  ~UserAddingScreenImpl() override;

  base::ObserverList<UserAddingScreen::Observer>::UncheckedAndDanglingUntriaged
      observers_;
  raw_ptr<LoginDisplayHost, DanglingUntriaged> display_host_;

  UserAddingScreenInputMethodsController im_controller_;
};

void UserAddingScreenImpl::Start() {
  // TODO(crbug.com/403154552): Avoid g_browser_process.
  PrefService* local_state = g_browser_process->local_state();
  ApplicationLocaleStorage* application_locale_storage =
      g_browser_process->GetFeatures()->application_locale_storage();
  scoped_refptr<network::SharedURLLoaderFactory> shared_url_loader_factory =
      g_browser_process->shared_url_loader_factory();
  policy::BrowserPolicyConnectorAsh* browser_policy_connector_ash =
      g_browser_process->platform_part()->browser_policy_connector_ash();

  CHECK(!IsRunning());
  display_host_ = new LoginDisplayHostMojo(
      local_state, application_locale_storage, shared_url_loader_factory,
      browser_policy_connector_ash, DisplayedScreen::USER_ADDING_SCREEN,
      /*update_geolocation_usage_allowed=*/false);

  // This triggers input method manager to filter login screen methods. This
  // should happen before setting user input method, which happens when focusing
  // user pod (triggered by SetSessionState)"
  for (auto& observer : observers_) {
    observer.OnBeforeUserAddingScreenStarted();
  }

  session_manager::SessionManager::Get()->SetSessionState(
      session_manager::SessionState::LOGIN_SECONDARY);
  display_host_->StartUserAdding(base::BindOnce(
      &UserAddingScreenImpl::OnDisplayHostCompletion, base::Unretained(this)));
}

void UserAddingScreenImpl::Cancel() {
  CHECK(IsRunning());

  display_host_->CancelUserAdding();

  // Reset wallpaper if cancel adding user from multiple user sign in page.
  if (user_manager::UserManager::Get()->IsUserLoggedIn()) {
    WallpaperControllerClientImpl::Get()->ShowUserWallpaper(
        user_manager::UserManager::Get()->GetActiveUser()->GetAccountId());
  }
}

bool UserAddingScreenImpl::IsRunning() {
  return display_host_ != nullptr;
}

void UserAddingScreenImpl::AddObserver(UserAddingScreen::Observer* observer) {
  observers_.AddObserver(observer);
}

void UserAddingScreenImpl::RemoveObserver(
    UserAddingScreen::Observer* observer) {
  observers_.RemoveObserver(observer);
}

void UserAddingScreenImpl::OnDisplayHostCompletion() {
  CHECK(IsRunning());
  display_host_ = nullptr;

  session_manager::SessionManager::Get()->SetSessionState(
      session_manager::SessionState::ACTIVE);
  for (auto& observer : observers_) {
    observer.OnUserAddingFinished();
  }
}

// static
UserAddingScreenImpl* UserAddingScreenImpl::GetInstance() {
  return base::Singleton<UserAddingScreenImpl>::get();
}

UserAddingScreenImpl::UserAddingScreenImpl()
    : display_host_(nullptr), im_controller_(this) {}

UserAddingScreenImpl::~UserAddingScreenImpl() = default;

}  // anonymous namespace

UserAddingScreen::UserAddingScreen() = default;
UserAddingScreen::~UserAddingScreen() = default;

UserAddingScreen* UserAddingScreen::Get() {
  return UserAddingScreenImpl::GetInstance();
}

}  // namespace ash