// Copyright 2015 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.

#ifndef CC_TREES_PROXY_IMPL_H_
#define CC_TREES_PROXY_IMPL_H_

#include <memory>

#include "base/macros.h"
#include "cc/base/completion_event.h"
#include "cc/base/delayed_unique_notifier.h"
#include "cc/input/top_controls_state.h"
#include "cc/scheduler/scheduler.h"
#include "cc/trees/channel_impl.h"
#include "cc/trees/layer_tree_host_impl.h"

namespace cc {

// This class aggregates all the interactions that the main side of the
// compositor needs to have with the impl side. It is created and owned by the
// ChannelImpl implementation. The class lives entirely on the impl thread.
class CC_EXPORT ProxyImpl : public NON_EXPORTED_BASE(LayerTreeHostImplClient),
                            public NON_EXPORTED_BASE(SchedulerClient) {
 public:
  static std::unique_ptr<ProxyImpl> Create(
      ChannelImpl* channel_impl,
      LayerTreeHost* layer_tree_host,
      TaskRunnerProvider* task_runner_provider,
      std::unique_ptr<BeginFrameSource> external_begin_frame_source);

  ~ProxyImpl() override;

  // Virtual for testing.
  virtual void UpdateTopControlsStateOnImpl(TopControlsState constraints,
                                            TopControlsState current,
                                            bool animate);
  virtual void InitializeOutputSurfaceOnImpl(OutputSurface* output_surface);
  virtual void InitializeMutatorOnImpl(
      std::unique_ptr<LayerTreeMutator> mutator);
  virtual void MainThreadHasStoppedFlingingOnImpl();
  virtual void SetInputThrottledUntilCommitOnImpl(bool is_throttled);
  virtual void SetDeferCommitsOnImpl(bool defer_commits) const;
  virtual void SetNeedsRedrawOnImpl(const gfx::Rect& damage_rect);
  virtual void SetNeedsCommitOnImpl();
  virtual void BeginMainFrameAbortedOnImpl(
      CommitEarlyOutReason reason,
      base::TimeTicks main_thread_start_time);
  virtual void FinishAllRenderingOnImpl(CompletionEvent* completion);
  virtual void SetVisibleOnImpl(bool visible);
  virtual void ReleaseOutputSurfaceOnImpl(CompletionEvent* completion);
  virtual void FinishGLOnImpl(CompletionEvent* completion);
  virtual void StartCommitOnImpl(CompletionEvent* completion,
                                 LayerTreeHost* layer_tree_host,
                                 base::TimeTicks main_thread_start_time,
                                 bool hold_commit_for_activation);

  void MainFrameWillHappenOnImplForTesting(CompletionEvent* completion,
                                           bool* main_frame_will_happen);
  void BlockNotifyReadyToActivateForTesting(bool block);
  CompletionEvent* ActivationCompletionEventForTesting();

 protected:
  // protected for testing.
  ProxyImpl(ChannelImpl* channel_impl,
            LayerTreeHost* layer_tree_host,
            TaskRunnerProvider* task_runner_provider,
            std::unique_ptr<BeginFrameSource> external_begin_frame_source);

 private:
  // The members of this struct should be accessed on the impl thread only when
  // the main thread is blocked for a commit.
  struct BlockedMainCommitOnly {
    BlockedMainCommitOnly();
    ~BlockedMainCommitOnly();
    LayerTreeHost* layer_tree_host;
  };

  friend class ProxyImplForTest;

  // LayerTreeHostImplClient implementation
  void UpdateRendererCapabilitiesOnImplThread() override;
  void DidLoseOutputSurfaceOnImplThread() override;
  void CommitVSyncParameters(base::TimeTicks timebase,
                             base::TimeDelta interval) override;
  void SetBeginFrameSource(BeginFrameSource* source) override;
  void SetEstimatedParentDrawTime(base::TimeDelta draw_time) override;
  void DidSwapBuffersOnImplThread() override;
  void DidSwapBuffersCompleteOnImplThread() override;
  void OnCanDrawStateChanged(bool can_draw) override;
  void NotifyReadyToActivate() override;
  void NotifyReadyToDraw() override;
  // Please call these 3 functions through
  // LayerTreeHostImpl's SetNeedsRedraw(), SetNeedsRedrawRect() and
  // SetNeedsOneBeginImplFrame().
  void SetNeedsRedrawOnImplThread() override;
  void SetNeedsRedrawRectOnImplThread(const gfx::Rect& dirty_rect) override;
  void SetNeedsOneBeginImplFrameOnImplThread() override;
  void SetNeedsPrepareTilesOnImplThread() override;
  void SetNeedsCommitOnImplThread() override;
  void SetVideoNeedsBeginFrames(bool needs_begin_frames) override;
  void PostAnimationEventsToMainThreadOnImplThread(
      std::unique_ptr<AnimationEvents> events) override;
  bool IsInsideDraw() override;
  void RenewTreePriority() override;
  void PostDelayedAnimationTaskOnImplThread(const base::Closure& task,
                                            base::TimeDelta delay) override;
  void DidActivateSyncTree() override;
  void WillPrepareTiles() override;
  void DidPrepareTiles() override;
  void DidCompletePageScaleAnimationOnImplThread() override;
  void OnDrawForOutputSurface(bool resourceless_software_draw) override;

  // SchedulerClient implementation
  void WillBeginImplFrame(const BeginFrameArgs& args) override;
  void DidFinishImplFrame() override;
  void ScheduledActionSendBeginMainFrame(const BeginFrameArgs& args) override;
  DrawResult ScheduledActionDrawAndSwapIfPossible() override;
  DrawResult ScheduledActionDrawAndSwapForced() override;
  void ScheduledActionCommit() override;
  void ScheduledActionActivateSyncTree() override;
  void ScheduledActionBeginOutputSurfaceCreation() override;
  void ScheduledActionPrepareTiles() override;
  void ScheduledActionInvalidateOutputSurface() override;
  void SendBeginMainFrameNotExpectedSoon() override;

  DrawResult DrawAndSwapInternal(bool forced_draw);

  bool IsImplThread() const;
  bool IsMainThreadBlocked() const;

  const int layer_tree_host_id_;

  std::unique_ptr<Scheduler> scheduler_;

  // Set when the main thread is waiting on a pending tree activation.
  bool commit_completion_waits_for_activation_;

  // Set when the main thread is waiting on a commit to complete.
  CompletionEvent* commit_completion_event_;

  // Set when the main thread is waiting for activation to complete.
  CompletionEvent* activation_completion_event_;

  // Set when the next draw should post DidCommitAndDrawFrame to the main
  // thread.
  bool next_frame_is_newly_committed_frame_;

  bool inside_draw_;
  bool input_throttled_until_commit_;

  TaskRunnerProvider* task_runner_provider_;

  DelayedUniqueNotifier smoothness_priority_expiration_notifier_;

  std::unique_ptr<BeginFrameSource> external_begin_frame_source_;
  std::unique_ptr<BeginFrameSource> unthrottled_begin_frame_source_;
  std::unique_ptr<SyntheticBeginFrameSource> synthetic_begin_frame_source_;

  RenderingStatsInstrumentation* rendering_stats_instrumentation_;

  std::unique_ptr<LayerTreeHostImpl> layer_tree_host_impl_;

  ChannelImpl* channel_impl_;

  // Use accessors instead of this variable directly.
  BlockedMainCommitOnly main_thread_blocked_commit_vars_unsafe_;
  BlockedMainCommitOnly& blocked_main_commit();

  DISALLOW_COPY_AND_ASSIGN(ProxyImpl);
};

}  // namespace cc

#endif  // CC_TREES_PROXY_IMPL_H_