// 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 "ash/wm/power_button_controller.h"

#include "ash/ash_switches.h"
#include "ash/shell.h"
#include "ash/shell_window_ids.h"
#include "ash/wm/root_window_event_filter.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "base/time.h"
#include "third_party/skia/include/core/SkColor.h"
#include "ui/aura/root_window.h"
#include "ui/aura/window.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/compositor/layer.h"
#include "ui/gfx/compositor/layer_animation_element.h"
#include "ui/gfx/compositor/layer_animation_sequence.h"
#include "ui/gfx/compositor/layer_animator.h"
#include "ui/gfx/rect.h"
#include "ui/gfx/size.h"
#include "ui/gfx/transform.h"

namespace ash {

namespace {

// Amount of time that the power button needs to be held before we lock the
// screen.
const int kLockTimeoutMs = 400;

// Amount of time that the power button needs to be held before we shut down.
const int kShutdownTimeoutMs = 400;

// Amount of time to wait for our lock requests to be honored before giving up.
const int kLockFailTimeoutMs = 4000;

// When the button has been held continuously from the unlocked state, amount of
// time that we wait after the screen locker window is shown before starting the
// pre-shutdown animation.
const int kLockToShutdownTimeoutMs = 150;

// Amount of time taken to scale the snapshot of the screen down to a
// slightly-smaller size once the user starts holding the power button.  Used
// for both the pre-lock and pre-shutdown animations.
const int kSlowCloseAnimMs = 400;

// Amount of time taken to scale the snapshot of the screen back to its original
// size when the button is released.
const int kUndoSlowCloseAnimMs = 100;

// Amount of time taken to scale the snapshot down to a point in the center of
// the screen once the screen has been locked or we've been notified that the
// system is shutting down.
const int kFastCloseAnimMs = 150;

// Amount of time taken to make the lock window fade in when the screen is
// locked.
const int kLockFadeInAnimMs = 500;

// Additional time (beyond kFastCloseAnimMs) to wait after starting the
// fast-close shutdown animation before actually requesting shutdown, to give
// the animation time to finish.
const int kShutdownRequestDelayMs = 50;

// Slightly-smaller size that we scale the screen down to for the pre-lock and
// pre-shutdown states.
const float kSlowCloseSizeRatio = 0.95f;

// Containers holding screen locker windows.
const int kScreenLockerContainerIds[] = {
  internal::kShellWindowId_LockScreenContainer,
  internal::kShellWindowId_LockSystemModalContainer,
};

// Containers holding additional windows that should be shown while the screen
// is locked.
const int kRelatedContainerIds[] = {
  internal::kShellWindowId_StatusContainer,
  internal::kShellWindowId_MenuContainer,
  internal::kShellWindowId_DragImageAndTooltipContainer,
  internal::kShellWindowId_SettingBubbleContainer,
  internal::kShellWindowId_OverlayContainer,
};

// Is |window| a container that holds screen locker windows?
bool IsScreenLockerContainer(aura::Window* window) {
  for (size_t i = 0; i < arraysize(kScreenLockerContainerIds); ++i)
    if (window->id() == kScreenLockerContainerIds[i])
      return true;
  return false;
}

// Is |window| a container that holds other windows that should be shown while
// the screen is locked?
bool IsRelatedContainer(aura::Window* window) {
  for (size_t i = 0; i < arraysize(kRelatedContainerIds); ++i)
    if (window->id() == kRelatedContainerIds[i])
      return true;
  return false;
}

// Returns the transform, based on |base_transform|, that should be applied
// to containers for slow-close animation.
ui::Transform GetSlowCloseTransform(const ui::Transform& base_transform) {
  gfx::Size root_size = Shell::GetRootWindow()->bounds().size();
  ui::Transform transform(base_transform);
  transform.ConcatScale(kSlowCloseSizeRatio, kSlowCloseSizeRatio);
  transform.ConcatTranslate(
      floor(0.5 * (1.0 - kSlowCloseSizeRatio) * root_size.width() + 0.5),
      floor(0.5 * (1.0 - kSlowCloseSizeRatio) * root_size.height() + 0.5));
  return transform;
}

// Returns the transform, based on |base_transform|, that should be applied
// to containers for fast-close animation.
ui::Transform GetFastCloseTransform(const ui::Transform& base_transform) {
  gfx::Size root_size = Shell::GetRootWindow()->bounds().size();
  ui::Transform transform(base_transform);
  transform.ConcatScale(0.0, 0.0);
  transform.ConcatTranslate(floor(0.5 * root_size.width() + 0.5),
                            floor(0.5 * root_size.height() + 0.5));
  return transform;
}

// Slowly shrinks |window| to a slightly-smaller size.
void StartSlowCloseAnimationForWindow(aura::Window* window) {
  ui::LayerAnimator* animator = window->layer()->GetAnimator();
  animator->set_preemption_strategy(
      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
  animator->StartAnimation(
      new ui::LayerAnimationSequence(
          ui::LayerAnimationElement::CreateTransformElement(
              GetSlowCloseTransform(window->layer()->GetTargetTransform()),
              base::TimeDelta::FromMilliseconds(kSlowCloseAnimMs))));
}

// Quickly undoes the effects of the slow-close animation on |window|.
void StartUndoSlowCloseAnimationForWindow(aura::Window* window,
                                          const ui::Transform& orig_transform) {
  ui::LayerAnimator* animator = window->layer()->GetAnimator();
  animator->set_preemption_strategy(
      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
  animator->StartAnimation(
      new ui::LayerAnimationSequence(
          ui::LayerAnimationElement::CreateTransformElement(
              orig_transform,
              base::TimeDelta::FromMilliseconds(kUndoSlowCloseAnimMs))));
}

// Quickly shrinks |window| down to a point in the center of the screen and
// fades it out to 0 opacity.
void StartFastCloseAnimationForWindow(aura::Window* window) {
  ui::LayerAnimator* animator = window->layer()->GetAnimator();
  animator->set_preemption_strategy(
      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
  animator->StartAnimation(
      new ui::LayerAnimationSequence(
          ui::LayerAnimationElement::CreateTransformElement(
              GetFastCloseTransform(window->layer()->GetTargetTransform()),
              base::TimeDelta::FromMilliseconds(kFastCloseAnimMs))));
  animator->StartAnimation(
      new ui::LayerAnimationSequence(
          ui::LayerAnimationElement::CreateOpacityElement(
              0.0, base::TimeDelta::FromMilliseconds(kFastCloseAnimMs))));
}

// Fades |window| in to full opacity.
void FadeInWindow(aura::Window* window) {
  ui::LayerAnimator* animator = window->layer()->GetAnimator();
  animator->set_preemption_strategy(
      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
  animator->StartAnimation(
      new ui::LayerAnimationSequence(
          ui::LayerAnimationElement::CreateOpacityElement(
              1.0, base::TimeDelta::FromMilliseconds(kLockFadeInAnimMs))));
}

// Makes |window| fully transparent instantaneously.
void HideWindow(aura::Window* window) {
  window->layer()->SetOpacity(0.0);
}

// Restores |window| to its original position and scale and full opacity
// instantaneously.
void RestoreWindow(aura::Window* window,
                   const ui::Transform& orig_transform) {
  window->layer()->SetTransform(orig_transform);
  window->layer()->SetOpacity(1.0);
}

}  // namespace

bool PowerButtonController::TestApi::ContainerGroupIsAnimated(
    ContainerGroup group, AnimationType type) const {
  aura::Window::Windows containers;
  controller_->GetContainers(group, &containers);
  for (aura::Window::Windows::const_iterator it = containers.begin();
       it != containers.end(); ++it) {
    aura::Window* window = *it;
    ui::Layer* layer = window->layer();

    switch (type) {
      case PowerButtonController::ANIMATION_SLOW_CLOSE:
        if (layer->GetTargetTransform() !=
            GetSlowCloseTransform(
                controller_->RetrieveOriginalTransform(window)))
          return false;
        break;
      case PowerButtonController::ANIMATION_UNDO_SLOW_CLOSE:
        if (layer->GetTargetTransform() !=
            controller_->RetrieveOriginalTransform(window))
        return false;
        break;
      case PowerButtonController::ANIMATION_FAST_CLOSE:
        if (layer->GetTargetTransform() !=
            GetFastCloseTransform(layer->GetTargetTransform()) ||
            layer->GetTargetOpacity() > 0.0001)
          return false;
        break;
      case PowerButtonController::ANIMATION_FADE_IN:
        if (layer->GetTargetOpacity() < 0.9999)
          return false;
        break;
      case PowerButtonController::ANIMATION_HIDE:
        if (layer->GetTargetOpacity() > 0.0001)
          return false;
        break;
      case PowerButtonController::ANIMATION_RESTORE:
        if (layer->opacity() < 0.9999 ||
            layer->transform() !=
            controller_->RetrieveOriginalTransform(window))
          return false;
        break;
      default:
        NOTREACHED() << "Unhandled animation type " << type;
        return false;
    }
  }
  return true;
}

bool PowerButtonController::TestApi::BackgroundLayerIsVisible() const {
  return controller_->background_layer_.get() &&
         controller_->background_layer_->visible();
}

PowerButtonController::PowerButtonController()
    : logged_in_(false),
      is_guest_(false),
      locked_(false),
      power_button_down_(false),
      lock_button_down_(false),
      shutting_down_(false),
      has_legacy_power_button_(
          CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kAuraLegacyPowerButton)) {
}

PowerButtonController::~PowerButtonController() {
}

void PowerButtonController::OnLoginStateChange(bool logged_in, bool is_guest) {
  logged_in_ = logged_in;
  is_guest_ = is_guest;
}

void PowerButtonController::OnExit() {
  // If we hear that Chrome is exiting but didn't request it ourselves, all we
  // can really hope for is that we'll have time to clear the screen.
  if (!shutting_down_) {
    shutting_down_ = true;
    ash::Shell::GetInstance()->root_filter()->
        set_update_cursor_visibility(false);
    Shell::GetRootWindow()->ShowCursor(false);
    ShowBackgroundLayer();
    StartAnimation(ALL_CONTAINERS, ANIMATION_HIDE);
  }
}

void PowerButtonController::OnLockStateChange(bool locked) {
  if (shutting_down_ || locked_ == locked)
    return;

  locked_ = locked;
  if (locked) {
    StartAnimation(SCREEN_LOCKER_CONTAINERS, ANIMATION_FADE_IN);
    lock_timer_.Stop();
    lock_fail_timer_.Stop();

    if (!has_legacy_power_button_ && power_button_down_) {
      lock_to_shutdown_timer_.Stop();
      lock_to_shutdown_timer_.Start(
          FROM_HERE,
          base::TimeDelta::FromMilliseconds(kLockToShutdownTimeoutMs),
          this, &PowerButtonController::OnLockToShutdownTimeout);
    }
  } else {
    StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                   ANIMATION_RESTORE);
    HideBackgroundLayer();
  }
}

void PowerButtonController::OnStartingLock() {
  if (shutting_down_ || locked_)
    return;

  // Ensure that the background layer is visible -- if the screen was locked via
  // the wrench menu, we won't have already shown the background as part of the
  // slow-close animation.
  ShowBackgroundLayer();

  StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                 ANIMATION_FAST_CLOSE);

  // Hide the screen locker containers so we can make them fade in later.
  StartAnimation(SCREEN_LOCKER_CONTAINERS, ANIMATION_HIDE);
}

void PowerButtonController::OnPowerButtonEvent(
    bool down, const base::TimeTicks& timestamp) {
  power_button_down_ = down;

  if (shutting_down_)
    return;

  if (has_legacy_power_button_) {
    // If power button releases won't get reported correctly because we're not
    // running on official hardware, just lock the screen or shut down
    // immediately.
    if (down) {
      ShowBackgroundLayer();
      if (logged_in_as_non_guest() && !locked_) {
        StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                       ANIMATION_SLOW_CLOSE);
        OnLockTimeout();
      } else {
        OnShutdownTimeout();
      }
    }
  } else {  // !has_legacy_power_button_
    if (down) {
      // If we already have a pending request to lock the screen, wait.
      if (lock_fail_timer_.IsRunning())
        return;

      if (logged_in_as_non_guest() && !locked_)
        StartLockTimer();
      else
        StartShutdownTimer();
    } else {  // Button is up.
      if (lock_timer_.IsRunning() || shutdown_timer_.IsRunning())
        StartAnimation(
            locked_ ? SCREEN_LOCKER_AND_RELATED_CONTAINERS : ALL_CONTAINERS,
            ANIMATION_UNDO_SLOW_CLOSE);

      // Drop the background layer after the undo animation finishes.
      if (lock_timer_.IsRunning() ||
          (shutdown_timer_.IsRunning() && !logged_in_as_non_guest())) {
        hide_background_layer_timer_.Stop();
        hide_background_layer_timer_.Start(
            FROM_HERE,
            base::TimeDelta::FromMilliseconds(kUndoSlowCloseAnimMs),
            this, &PowerButtonController::HideBackgroundLayer);
      }

      lock_timer_.Stop();
      shutdown_timer_.Stop();
      lock_to_shutdown_timer_.Stop();
    }
  }
}

void PowerButtonController::OnLockButtonEvent(
    bool down, const base::TimeTicks& timestamp) {
  lock_button_down_ = down;

  if (shutting_down_ || !logged_in_as_non_guest())
    return;

  // Bail if we're already locked or are in the process of locking.  Also give
  // the power button precedence over the lock button (we don't expect both
  // buttons to be present, so this is just making sure that we don't do
  // something completely stupid if that assumption changes later).
  if (locked_ || lock_fail_timer_.IsRunning() || power_button_down_)
    return;

  if (down) {
    StartLockTimer();
  } else {
    if (lock_timer_.IsRunning()) {
      StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                     ANIMATION_UNDO_SLOW_CLOSE);
      hide_background_layer_timer_.Stop();
      hide_background_layer_timer_.Start(
          FROM_HERE,
          base::TimeDelta::FromMilliseconds(kUndoSlowCloseAnimMs),
          this, &PowerButtonController::HideBackgroundLayer);
      lock_timer_.Stop();
    }
  }
}

void PowerButtonController::RequestShutdown() {
  if (!shutting_down_)
    StartShutdownAnimationAndRequestShutdown();
}

// Fills |containers| with the containers described by |group|.
void PowerButtonController::GetContainers(ContainerGroup group,
                                          aura::Window::Windows* containers) {
  containers->clear();

  aura::Window* root = Shell::GetRootWindow();
  for (aura::Window::Windows::const_iterator it = root->children().begin();
       it != root->children().end(); ++it) {
    aura::Window* window = *it;

    bool matched = true;
    if (group != ALL_CONTAINERS) {
      bool is_screen_locker = IsScreenLockerContainer(window);
      bool is_related = IsRelatedContainer(window);

      switch (group) {
        case SCREEN_LOCKER_CONTAINERS:
          matched = is_screen_locker;
          break;
        case SCREEN_LOCKER_AND_RELATED_CONTAINERS:
          matched = is_screen_locker || is_related;
          break;
        case ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS:
          matched = !is_screen_locker && !is_related;
          break;
        default:
          NOTREACHED() << "Unhandled container group " << group;
      }
    }

    if (matched)
      containers->push_back(window);
  }
}

void PowerButtonController::OnRootWindowResized(const gfx::Size& new_size) {
  if (background_layer_.get())
    background_layer_->SetBounds(gfx::Rect(new_size));
}

void PowerButtonController::OnLockTimeout() {
  delegate_->RequestLockScreen();
  lock_fail_timer_.Start(
      FROM_HERE,
      base::TimeDelta::FromMilliseconds(kLockFailTimeoutMs),
      this, &PowerButtonController::OnLockFailTimeout);
}

void PowerButtonController::OnLockFailTimeout() {
  DCHECK(!locked_);
  LOG(ERROR) << "Screen lock request timed out";
  StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                 ANIMATION_RESTORE);
  HideBackgroundLayer();
}

void PowerButtonController::OnLockToShutdownTimeout() {
  DCHECK(locked_);
  StartShutdownTimer();
}

void PowerButtonController::OnShutdownTimeout() {
  if (!shutting_down_)
    StartShutdownAnimationAndRequestShutdown();
}

void PowerButtonController::OnRealShutdownTimeout() {
  DCHECK(shutting_down_);
  delegate_->RequestShutdown();
}

void PowerButtonController::StartLockTimer() {
  ShowBackgroundLayer();
  StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                 ANIMATION_SLOW_CLOSE);
  lock_timer_.Stop();
  lock_timer_.Start(FROM_HERE,
                    base::TimeDelta::FromMilliseconds(kSlowCloseAnimMs),
                    this, &PowerButtonController::OnLockTimeout);
}

void PowerButtonController::StartShutdownTimer() {
  ShowBackgroundLayer();
  StartAnimation(ALL_CONTAINERS, ANIMATION_SLOW_CLOSE);
  shutdown_timer_.Stop();
  shutdown_timer_.Start(
      FROM_HERE,
      base::TimeDelta::FromMilliseconds(kShutdownTimeoutMs),
      this, &PowerButtonController::OnShutdownTimeout);
}

void PowerButtonController::StartShutdownAnimationAndRequestShutdown() {
  DCHECK(!shutting_down_);
  shutting_down_ = true;

  ash::Shell::GetInstance()->root_filter()->set_update_cursor_visibility(false);
  Shell::GetRootWindow()->ShowCursor(false);

  ShowBackgroundLayer();
  if (!logged_in_ || locked_) {
    // Hide the other containers before starting the animation.
    // ANIMATION_FAST_CLOSE will make the screen locker windows partially
    // transparent, and we don't want the other windows to show through.
    StartAnimation(ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
                   ANIMATION_HIDE);
    StartAnimation(SCREEN_LOCKER_AND_RELATED_CONTAINERS, ANIMATION_FAST_CLOSE);
  } else {
    StartAnimation(ALL_CONTAINERS, ANIMATION_FAST_CLOSE);
  }

  real_shutdown_timer_.Start(
      FROM_HERE,
      base::TimeDelta::FromMilliseconds(
          kFastCloseAnimMs + kShutdownRequestDelayMs),
      this, &PowerButtonController::OnRealShutdownTimeout);
}

void PowerButtonController::ShowBackgroundLayer() {
  if (hide_background_layer_timer_.IsRunning())
    hide_background_layer_timer_.Stop();

  if (!background_layer_.get()) {
    background_layer_.reset(new ui::Layer(ui::Layer::LAYER_SOLID_COLOR));
    background_layer_->SetColor(SK_ColorBLACK);

    ui::Layer* root_layer = Shell::GetRootWindow()->layer();
    background_layer_->SetBounds(root_layer->bounds());
    root_layer->Add(background_layer_.get());
    root_layer->StackAtBottom(background_layer_.get());
  }
  background_layer_->SetVisible(true);
}

void PowerButtonController::HideBackgroundLayer() {
  background_layer_.reset();
}

// Apply animation |type| to all containers described by |group|.
void PowerButtonController::StartAnimation(ContainerGroup group,
                                           AnimationType type) {
  aura::Window::Windows containers;
  GetContainers(group, &containers);
  for (aura::Window::Windows::const_iterator it = containers.begin();
       it != containers.end(); ++it) {
    aura::Window* window = *it;

    // Store this away so we can restore.
    if (type != ANIMATION_RESTORE && type != ANIMATION_UNDO_SLOW_CLOSE)
      container_transforms_[window] = window->layer()->GetTargetTransform();

    switch (type) {
      case ANIMATION_SLOW_CLOSE:
        StartSlowCloseAnimationForWindow(window);
        break;
      case ANIMATION_UNDO_SLOW_CLOSE:
        StartUndoSlowCloseAnimationForWindow(
            window,
            RetrieveOriginalTransform(window));
        break;
      case ANIMATION_FAST_CLOSE:
        StartFastCloseAnimationForWindow(window);
        break;
      case ANIMATION_FADE_IN:
        FadeInWindow(window);
        break;
      case ANIMATION_HIDE:
        HideWindow(window);
        break;
      case ANIMATION_RESTORE:
        RestoreWindow(window, RetrieveOriginalTransform(window));
        break;
      default:
        NOTREACHED() << "Unhandled animation type " << type;
    }
  }
}

ui::Transform PowerButtonController::RetrieveOriginalTransform(
    aura::Window* window) {
  WindowTransformsMap::const_iterator it = container_transforms_.find(window);
  if (it != container_transforms_.end())
    return it->second;
  return ui::Transform();
}

}  // namespace ash