// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/exo/ui_lock_controller.h"

#include <memory>

#include "ash/bluetooth_devices_observer.h"
#include "ash/constants/ash_features.h"
#include "ash/public/cpp/keyboard/keyboard_controller.h"
#include "ash/public/cpp/session/session_controller.h"
#include "ash/resources/vector_icons/vector_icons.h"
#include "ash/wm/window_state.h"
#include "ash/wm/window_state_observer.h"
#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "base/memory/raw_ptr.h"
#include "base/scoped_observation.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "chromeos/ui/base/window_properties.h"
#include "components/exo/pointer.h"
#include "components/exo/seat.h"
#include "components/exo/shell_surface_util.h"
#include "components/exo/surface.h"
#include "components/exo/wm_helper.h"
#include "components/fullscreen_control/subtle_notification_view.h"
#include "components/strings/grit/components_strings.h"
#include "ui/aura/client/aura_constants.h"
#include "ui/aura/window.h"
#include "ui/aura/window_observer.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/user_activity/user_activity_detector.h"
#include "ui/base/user_activity/user_activity_observer.h"
#include "ui/events/devices/device_data_manager.h"
#include "ui/gfx/paint_vector_icon.h"
#include "ui/strings/grit/ui_strings.h"
#include "ui/views/widget/widget.h"

namespace {

// Fullscreen and pointer-lock notifications hide after a timeout and are shown
// again when the relevant state is entered again.

// Duration to show notifications.
constexpr auto kNotificationDuration = base::Seconds(4);
// Position of Esc notification from top of screen.
const int kEscNotificationTopPx = 45;

// Once the pointer capture notification has finished showing without
// being interrupted, don't show it again until this long has passed.
constexpr auto kPointerCaptureNotificationCooldown = base::Minutes(5);

constexpr auto kReshowNotificationsWhenIdleFor = base::Minutes(5);

constexpr int kUILockControllerSeatObserverPriority = 1;
static_assert(
    exo::Seat::IsValidObserverPriority(kUILockControllerSeatObserverPriority),
    "kUILockCOntrollerSeatObserverPriority is not in the valid range");

bool IsUILockControllerEnabled(aura::Window* window) {
  if (!window)
    return false;

  if (window->GetProperty(chromeos::kUseOverviewToExitFullscreen) ||
      window->GetProperty(chromeos::kUseOverviewToExitPointerLock)) {
    return true;
  }
  return false;
}

// Return true if an external keyboard is attached to the device.
//
// Note: May mistakenly return true when certain non-keyboard devices are
// attached; see crbug/882410, crbug/884096.
//
// Copied from ash/keyboard/virtual_keyboard_controller.cc.
// TODO(cpelling): Refactor to avoid duplicating this logic.
bool HasExternalKeyboard() {
  ui::DeviceDataManager* device_data_manager =
      ui::DeviceDataManager::GetInstance();

  ash::BluetoothDevicesObserver bluetooth(base::DoNothing());

  for (const ui::InputDevice& device :
       device_data_manager->GetKeyboardDevices()) {
    ui::InputDeviceType type = device.type;
    if (type == ui::InputDeviceType::INPUT_DEVICE_USB ||
        (type == ui::InputDeviceType::INPUT_DEVICE_BLUETOOTH &&
         bluetooth.IsConnectedBluetoothDevice(device))) {
      return true;
    }
  }
  return false;
}

// Creates the separator view between bubble views of modifiers and key.
std::unique_ptr<views::View> CreateIconView(const gfx::VectorIcon& icon) {
  constexpr int kIconSize = 28;

  std::unique_ptr<views::ImageView> view = std::make_unique<views::ImageView>();
  gfx::ImageSkia image = gfx::CreateVectorIcon(icon, SK_ColorWHITE);
  view->SetImage(ui::ImageModel::FromImageSkia(image));
  view->SetImageSize(gfx::Size(kIconSize, kIconSize));
  return view;
}

// Create and position Esc notification.
views::Widget* CreateEscNotification(
    aura::Window* parent,
    int message_id,
    std::initializer_list<int> key_message_ids) {
  auto content_view = std::make_unique<SubtleNotificationView>();

  std::vector<std::u16string> key_names;
  std::vector<std::unique_ptr<views::View>> icons;
  for (int key_message_id : key_message_ids) {
    key_names.push_back(l10n_util::GetStringUTF16(key_message_id));

    if (key_message_id == IDS_APP_OVERVIEW_KEY) {
      icons.push_back(CreateIconView(ash::kKsvOverviewIcon));
    } else {
      icons.push_back(nullptr);
    }
  }
  content_view->UpdateContent(
      l10n_util::GetStringFUTF16(message_id, key_names, nullptr),
      std::move(icons));

  gfx::Size size = content_view->GetPreferredSize({});
  views::Widget* popup = SubtleNotificationView::CreatePopupWidget(
      parent, std::move(content_view));
  popup->SetZOrderLevel(ui::ZOrderLevel::kSecuritySurface);
  gfx::Rect bounds = parent->GetBoundsInScreen();
  int y = bounds.y() + kEscNotificationTopPx;
  bounds.ClampToCenteredSize(size);
  bounds.set_y(y);
  popup->SetBounds(bounds);
  return popup;
}

// Owns the widgets for messages prompting to exit fullscreen or pointer lock.
// Owned as a window property.
class ExitNotifier : public exo::UILockController::Notifier,
                     public aura::WindowObserver,
                     public ash::WindowStateObserver {
 public:
  explicit ExitNotifier(exo::UILockController* controller, aura::Window* window)
      : window_(window) {
    controller_observation_.Observe(controller);
    window_observation_.Observe(window);

    ash::WindowState* window_state = ash::WindowState::Get(window);
    window_state_observation_.Observe(window_state);
    if (window_state->IsFullscreen())
      OnFullscreen();
  }

  ExitNotifier(const ExitNotifier&) = delete;
  ExitNotifier& operator=(const ExitNotifier&) = delete;

  ~ExitNotifier() override {
    want_pointer_capture_notification_ = false;
    OnExitFullscreen();
    ClosePointerCaptureNotification();
  }

  void OnPointerCaptureEnabled() {
    pointer_is_captured_ = true;
    MaybeShowPointerCaptureNotification();
  }

  void OnPointerCaptureDisabled() { pointer_is_captured_ = false; }

  // If this window is currently in a state that would have triggered a
  // notification when entered, re-show that notification as a reminder.
  void NotifyAgain() override {
    // Always reset the notification cooldown, to ensure notifications show in
    // the case where pointer lock is not currently active but will be soon.
    next_pointer_notify_time_ = base::TimeTicks::Now();

    ash::WindowState* window_state = ash::WindowState::Get(window_);
    if (window_state->IsFullscreen()) {
      OnFullscreen();
    } else if (pointer_is_captured_) {
      MaybeShowPointerCaptureNotification();
    }
  }

  // Notify again but this only notifies again the fullscreen notifier.
  void NotifyAgainForFullscreen() {
    ash::WindowState* window_state = ash::WindowState::Get(window_);
    if (window_state->IsFullscreen()) {
      OnFullscreen();
    }
  }

  void OnWindowDestroying(aura::Window* window) override {
    window_observation_.Reset();
    window_state_observation_.Reset();
  }

  void OnUILockControllerDestroying() override {
    controller_observation_.Reset();
  }

  views::Widget* fullscreen_esc_notification() {
    return fullscreen_esc_notification_;
  }

  views::Widget* pointer_capture_notification() {
    return pointer_capture_notification_;
  }

 private:
  void MaybeShowPointerCaptureNotification() {
    // Respect cooldown.
    if (base::TimeTicks::Now() < next_pointer_notify_time_)
      return;

    want_pointer_capture_notification_ = true;

    // Don't show in fullscreen; the fullscreen notification will show and is
    // prioritized.
    ash::WindowState* window_state = ash::WindowState::Get(window_);
    if (window_state->IsFullscreen())
      return;

    if (pointer_capture_notification_) {
      pointer_capture_notification_->CloseWithReason(
          views::Widget::ClosedReason::kUnspecified);
    }

    if (HasExternalKeyboard()) {
      if (ash::KeyboardController::Get()->AreTopRowKeysFunctionKeys()) {
        pointer_capture_notification_ =
            CreateEscNotification(window_, IDS_PRESS_TO_EXIT_MOUSELOCK_TWO_KEYS,
                                  {IDS_APP_META_KEY, IDS_APP_F5_KEY});
      } else {
        pointer_capture_notification_ = CreateEscNotification(
            window_, IDS_PRESS_TO_EXIT_MOUSELOCK, {IDS_APP_F5_KEY});
      }
    } else {
      if (ash::KeyboardController::Get()->AreTopRowKeysFunctionKeys()) {
        pointer_capture_notification_ =
            CreateEscNotification(window_, IDS_PRESS_TO_EXIT_MOUSELOCK_TWO_KEYS,
                                  {IDS_APP_SEARCH_KEY, IDS_APP_OVERVIEW_KEY});
      } else {
        pointer_capture_notification_ = CreateEscNotification(
            window_, IDS_PRESS_TO_EXIT_MOUSELOCK, {IDS_APP_OVERVIEW_KEY});
      }
    }

    pointer_capture_notification_->Show();

    // Close Esc notification after 4s.
    pointer_capture_notify_timer_.Start(
        FROM_HERE, kNotificationDuration,
        base::BindOnce(&ExitNotifier::OnPointerCaptureNotifyTimerFinished,
                       base::Unretained(this)));
  }

  void ClosePointerCaptureNotification() {
    pointer_capture_notify_timer_.Stop();
    if (pointer_capture_notification_) {
      pointer_capture_notification_->CloseWithReason(
          views::Widget::ClosedReason::kUnspecified);
      pointer_capture_notification_ = nullptr;
    }
  }

  void OnPointerCaptureNotifyTimerFinished() {
    // Start the cooldown when the timer successfully elapses, to ensure the
    // notification was shown for a sufficiently long time.
    next_pointer_notify_time_ =
        base::TimeTicks::Now() + kPointerCaptureNotificationCooldown;
    ClosePointerCaptureNotification();
    want_pointer_capture_notification_ = false;
  }

  // Overridden from ash::WindowStateObserver:
  void OnPostWindowStateTypeChange(
      ash::WindowState* window_state,
      chromeos::WindowStateType old_type) override {
    DCHECK_EQ(window_, window_state->window());
    if (window_state->IsFullscreen()) {
      OnFullscreen();
    } else {
      OnExitFullscreen();
    }
  }

  void OnFullscreen() {
    if (!window_->GetProperty(chromeos::kUseOverviewToExitFullscreen)) {
      return;
    }

    // Only show Esc notification when window is active.
    if (window_ != exo::WMHelper::GetInstance()->GetActiveWindow())
      return;

    // Fullscreen notifications override pointer capture notifications.
    ClosePointerCaptureNotification();

    if (fullscreen_esc_notification_) {
      fullscreen_esc_notification_->CloseWithReason(
          views::Widget::ClosedReason::kUnspecified);
    }

    if (HasExternalKeyboard()) {
      if (ash::KeyboardController::Get()->AreTopRowKeysFunctionKeys()) {
        fullscreen_esc_notification_ = CreateEscNotification(
            window_, IDS_FULLSCREEN_PRESS_TO_EXIT_FULLSCREEN_TWO_KEYS,
            {IDS_APP_META_KEY, IDS_APP_F5_KEY});
      } else {
        fullscreen_esc_notification_ = CreateEscNotification(
            window_, IDS_FULLSCREEN_PRESS_TO_EXIT_FULLSCREEN, {IDS_APP_F5_KEY});
      }
    } else {
      if (ash::KeyboardController::Get()->AreTopRowKeysFunctionKeys()) {
        fullscreen_esc_notification_ = CreateEscNotification(
            window_, IDS_FULLSCREEN_PRESS_TO_EXIT_FULLSCREEN_TWO_KEYS,
            {IDS_APP_SEARCH_KEY, IDS_APP_OVERVIEW_KEY});
      } else {
        fullscreen_esc_notification_ = CreateEscNotification(
            window_, IDS_FULLSCREEN_PRESS_TO_EXIT_FULLSCREEN,
            {IDS_APP_OVERVIEW_KEY});
      }
    }

    fullscreen_esc_notification_->Show();

    // Close Esc notification after 4s.
    fullscreen_notify_timer_.Start(
        FROM_HERE, kNotificationDuration,
        base::BindOnce(&ExitNotifier::CloseFullscreenEscNotification,
                       base::Unretained(this)));
  }

  void OnExitFullscreen() {
    CloseFullscreenEscNotification();
  }

  void CloseFullscreenEscNotification() {
    if (!fullscreen_esc_notification_)
      return;
    fullscreen_esc_notification_->CloseWithReason(
        views::Widget::ClosedReason::kUnspecified);
    fullscreen_esc_notification_ = nullptr;

    // If a pointer capture notification was previously requested and didn't
    // show (or didn't complete its timer), show it now.
    //
    // This is to prevent the following scenario:
    //   1. App goes fullscreen
    //   2. App immediately requests pointer capture; no notification is shown,
    //      since the fullscreen notification is already visible.
    //   3. App immediately unfullscreens; the fullscreen notification closes.
    //
    // Without this check, the app would have gained pointer capture without
    // any notification showing.
    if (want_pointer_capture_notification_)
      MaybeShowPointerCaptureNotification();
  }

  const raw_ptr<aura::Window> window_;
  raw_ptr<views::Widget> fullscreen_esc_notification_ = nullptr;
  raw_ptr<views::Widget> pointer_capture_notification_ = nullptr;
  bool want_pointer_capture_notification_ = false;
  bool pointer_is_captured_ = false;
  base::OneShotTimer fullscreen_notify_timer_;
  base::OneShotTimer pointer_capture_notify_timer_;
  base::TimeTicks next_pointer_notify_time_;
  base::ScopedObservation<aura::Window, aura::WindowObserver>
      window_observation_{this};
  base::ScopedObservation<ash::WindowState, ash::WindowStateObserver>
      window_state_observation_{this};
  base::ScopedObservation<exo::UILockController,
                          exo::UILockController::Notifier>
      controller_observation_{this};
};

}  // namespace

DEFINE_UI_CLASS_PROPERTY_TYPE(ExitNotifier*)

namespace exo {
namespace {
DEFINE_OWNED_UI_CLASS_PROPERTY_KEY(ExitNotifier, kExitNotifierKey)

ExitNotifier* GetExitNotifier(UILockController* controller,
                              aura::Window* window,
                              bool create) {
  if (!window)
    return nullptr;

  aura::Window* toplevel = window->GetToplevelWindow();
  if (!IsUILockControllerEnabled(toplevel))
    return nullptr;

  ExitNotifier* notifier = toplevel->GetProperty(kExitNotifierKey);
  if (!notifier && create) {
    // Object is owned as a window property.
    notifier = toplevel->SetProperty(
        kExitNotifierKey, std::make_unique<ExitNotifier>(controller, toplevel));
  }

  return notifier;
}

}  // namespace

UILockController::UILockController(Seat* seat) : seat_(seat) {
  last_activity_time_ = base::TimeTicks::Now();
  seat_->AddObserver(this, kUILockControllerSeatObserverPriority);

  WMHelper::GetInstance()->AddPowerObserver(this);

  auto* session_controller = ash::SessionController::Get();
  if (session_controller)
    session_controller->AddObserver(this);

  ui::UserActivityDetector::Get()->AddObserver(this);
}

UILockController::~UILockController() {
  ui::UserActivityDetector::Get()->RemoveObserver(this);

  auto* session_controller = ash::SessionController::Get();
  if (session_controller)
    session_controller->RemoveObserver(this);

  WMHelper::GetInstance()->RemovePowerObserver(this);

  seat_->RemoveObserver(this);

  for (Notifier& notifier : notifiers_)
    notifier.OnUILockControllerDestroying();
}

void UILockController::SuspendDone() {
  ReshowAllNotifications();
}

void UILockController::ScreenBrightnessChanged(double percent) {
  // Show alert when the device returns from low (epsilon) brightness which
  // covers three cases.
  // 1. The device returns from sleep.
  // 2. The device lid is opened (with sleep on).
  // 3. The device returns from low display brightness.
  double epsilon = std::numeric_limits<double>::epsilon();
  if (percent <= epsilon) {
    device_in_dark_ = true;
  } else {
    if (device_in_dark_)
      ReshowAllNotifications();
    device_in_dark_ = false;
  }
}

void UILockController::LidEventReceived(bool opened) {
  // Show alert when the lid is opened. This also covers the case when the user
  // turns off "Sleep when cover is closed".
  if (opened)
    ReshowAllNotifications();
}

void UILockController::OnLockStateChanged(bool locked) {
  if (!locked)
    ReshowAllNotifications();
}

void UILockController::OnSurfaceFocused(Surface* gained_focus,
                                        Surface* lost_focus,
                                        bool has_focused_surface) {
  if (gained_focus) {
    ExitNotifier* exit_notifier =
        GetExitNotifier(this, gained_focus->window(), true);
    if (exit_notifier) {
      exit_notifier->NotifyAgainForFullscreen();
    }
  }
}

void UILockController::OnPointerCaptureEnabled(Pointer* pointer,
                                               aura::Window* window) {
  aura::Window* toplevel = window ? window->GetToplevelWindow() : nullptr;
  if (!toplevel ||
      !toplevel->GetProperty(chromeos::kUseOverviewToExitPointerLock))
    return;

  captured_pointers_.insert(pointer);
  ExitNotifier* notifier = GetExitNotifier(this, window, false);
  if (notifier)
    notifier->OnPointerCaptureEnabled();
}

void UILockController::OnPointerCaptureDisabled(Pointer* pointer,
                                                aura::Window* window) {
  if (captured_pointers_.empty())
    return;

  captured_pointers_.erase(pointer);
  if (captured_pointers_.empty()) {
    ExitNotifier* notifier = GetExitNotifier(this, window, false);
    if (notifier)
      notifier->OnPointerCaptureDisabled();
  }
}

void UILockController::OnUserActivity(const ui::Event* event) {
  base::TimeTicks now = base::TimeTicks::Now();
  if (now - last_activity_time_ >= kReshowNotificationsWhenIdleFor) {
    ReshowAllNotifications();
  }
  last_activity_time_ = now;
}

views::Widget* UILockController::GetPointerCaptureNotificationForTesting(
    aura::Window* window) {
  return window->GetProperty(kExitNotifierKey)->pointer_capture_notification();
}

views::Widget* UILockController::GetEscNotificationForTesting(
    aura::Window* window) {
  return window->GetProperty(kExitNotifierKey)->fullscreen_esc_notification();
}

void UILockController::AddObserver(UILockController::Notifier* notifier) {
  notifiers_.AddObserver(notifier);
}

void UILockController::RemoveObserver(UILockController::Notifier* notifier) {
  notifiers_.RemoveObserver(notifier);
}

void UILockController::ReshowAllNotifications() {
  VLOG(1) << "ReshowAllNotifications";
  for (Notifier& notifier : notifiers_)
    notifier.NotifyAgain();
}

}  // namespace exo