// Copyright 2020 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 "components/exo/ui_lock_controller.h"

#include "ash/public/cpp/app_types.h"
#include "ash/wm/window_state.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "chromeos/ui/base/window_properties.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 "ui/aura/client/aura_constants.h"
#include "ui/aura/window.h"
#include "ui/events/event_constants.h"
#include "ui/events/keycodes/dom/dom_code.h"
#include "ui/views/widget/widget.h"

namespace exo {

constexpr auto kLongPressEscapeDuration = base::TimeDelta::FromSeconds(2);
constexpr auto kExcludedFlags = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
                                ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN |
                                ui::EF_ALTGR_DOWN | ui::EF_IS_REPEAT;

UILockController::UILockController(Seat* seat) : seat_(seat) {
  WMHelper::GetInstance()->AddPreTargetHandler(this);
  seat_->AddObserver(this);
}

UILockController::~UILockController() {
  seat_->RemoveObserver(this);
  WMHelper::GetInstance()->RemovePreTargetHandler(this);
}

void UILockController::OnKeyEvent(ui::KeyEvent* event) {
  // If the event target is not an exo::Surface, let another handler process the
  // event.
  if (!GetShellMainSurface(static_cast<aura::Window*>(event->target())) &&
      !Surface::AsSurface(static_cast<aura::Window*>(event->target()))) {
    return;
  }

  if (event->code() == ui::DomCode::ESCAPE &&
      (event->flags() & kExcludedFlags) == 0) {
    OnEscapeKey(event->type() == ui::ET_KEY_PRESSED);
  }
}

void UILockController::OnSurfaceFocused(Surface* gained_focus) {
  if (gained_focus != focused_surface_to_unlock_)
    StopTimer();
}

namespace {
bool FocusedWindowIsNonImmersiveFullscreen(Seat* seat) {
  auto* surface = seat->GetFocusedSurface();
  if (!surface)
    return false;

  auto* widget =
      views::Widget::GetTopLevelWidgetForNativeView(surface->window());
  if (!widget)
    return false;

  aura::Window* window = widget->GetNativeWindow();
  if (!window || window->GetProperty(chromeos::kImmersiveImpliedByFullscreen))
    return false;

  // TODO(b/165865831): Add the Borealis AppType if/when we add one.
  if (window->GetProperty(aura::client::kAppType) !=
      static_cast<int>(ash::AppType::CROSTINI_APP)) {
    return false;
  }

  auto* window_state = ash::WindowState::Get(window);
  return window_state && window_state->IsFullscreen();
}
}  // namespace

void UILockController::OnEscapeKey(bool pressed) {
  if (pressed) {
    if (FocusedWindowIsNonImmersiveFullscreen(seat_) &&
        !exit_fullscreen_timer_.IsRunning()) {
      focused_surface_to_unlock_ = seat_->GetFocusedSurface();
      exit_fullscreen_timer_.Start(
          FROM_HERE, kLongPressEscapeDuration,
          base::BindOnce(&UILockController::OnEscapeHeld,
                         base::Unretained(this)));
    }
  } else {
    StopTimer();
  }
}

void UILockController::OnEscapeHeld() {
  auto* surface = seat_->GetFocusedSurface();
  if (!surface || surface != focused_surface_to_unlock_) {
    focused_surface_to_unlock_ = nullptr;
    return;
  }

  focused_surface_to_unlock_ = nullptr;

  auto* widget =
      views::Widget::GetTopLevelWidgetForNativeView(surface->window());
  auto* window_state =
      ash::WindowState::Get(widget ? widget->GetNativeWindow() : nullptr);
  if (window_state)
    window_state->Minimize();
}

void UILockController::StopTimer() {
  if (exit_fullscreen_timer_.IsRunning()) {
    exit_fullscreen_timer_.Stop();
    focused_surface_to_unlock_ = nullptr;
  }
}

}  // namespace exo