// 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.

#ifndef CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_
#define CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_

#include <stddef.h>

#include <memory>

#include "base/cancelable_callback.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/time/time.h"
#include "cc/trees/element_id.h"
#include "cc/trees/layer_tree_host_client.h"
#include "cc/trees/layer_tree_host_single_thread_client.h"
#include "components/viz/common/frame_sinks/begin_frame_source.h"
#include "components/viz/common/surfaces/frame_sink_id.h"
#include "components/viz/common/surfaces/local_surface_id.h"
#include "components/viz/common/surfaces/local_surface_id_allocation.h"
#include "components/viz/host/host_frame_sink_client.h"
#include "content/common/content_export.h"
#include "content/public/browser/android/compositor.h"
#include "gpu/command_buffer/common/capabilities.h"
#include "gpu/ipc/common/surface_handle.h"
#include "services/viz/privileged/interfaces/compositing/display_private.mojom.h"
#include "services/ws/public/cpp/gpu/context_provider_command_buffer.h"
#include "third_party/khronos/GLES2/gl2.h"
#include "ui/android/resources/resource_manager_impl.h"
#include "ui/android/resources/ui_resource_provider.h"
#include "ui/android/window_android_compositor.h"
#include "ui/compositor/compositor_lock.h"
#include "ui/compositor/external_begin_frame_client.h"
#include "ui/display/display_observer.h"

struct ANativeWindow;

namespace cc {
class AnimationHost;
class Layer;
class LayerTreeHost;
}

namespace ui {
class ExternalBeginFrameControllerClientImpl;
}

namespace viz {
class Display;
class FrameSinkId;
class FrameSinkManagerImpl;
class HostDisplayClient;
class HostFrameSinkManager;
class OutputSurface;
}

namespace content {
class CompositorClient;

// -----------------------------------------------------------------------------
// Browser-side compositor that manages a tree of content and UI layers.
// -----------------------------------------------------------------------------
class CONTENT_EXPORT CompositorImpl
    : public Compositor,
      public cc::LayerTreeHostClient,
      public cc::LayerTreeHostSingleThreadClient,
      public ui::UIResourceProvider,
      public ui::WindowAndroidCompositor,
      public viz::HostFrameSinkClient,
      public display::DisplayObserver {
 public:
  CompositorImpl(CompositorClient* client, gfx::NativeWindow root_window);
  ~CompositorImpl() override;

  static bool IsInitialized();

  static viz::FrameSinkManagerImpl* GetFrameSinkManager();
  static viz::HostFrameSinkManager* GetHostFrameSinkManager();
  static viz::FrameSinkId AllocateFrameSinkId();

  // ui::ResourceProvider implementation.
  cc::UIResourceId CreateUIResource(cc::UIResourceClient* client) override;
  void DeleteUIResource(cc::UIResourceId resource_id) override;
  bool SupportsETC1NonPowerOfTwo() const override;

  // Test functions:
  bool IsLockedForTesting() const { return lock_manager_.IsLocked(); }
  void SetVisibleForTesting(bool visible) { SetVisible(visible); }
  void SetSwapCompletedWithSizeCallbackForTesting(
      base::RepeatingCallback<void(const gfx::Size&)> cb) {
    swap_completed_with_size_for_testing_ = std::move(cb);
  }

 private:
  // Compositor implementation.
  void SetRootWindow(gfx::NativeWindow root_window) override;
  void SetRootLayer(scoped_refptr<cc::Layer> root) override;
  void SetSurface(jobject surface) override;
  void SetBackgroundColor(int color) override;
  void SetWindowBounds(const gfx::Size& size) override;
  void SetRequiresAlphaChannel(bool flag) override;
  void SetNeedsComposite() override;
  ui::UIResourceProvider& GetUIResourceProvider() override;
  ui::ResourceManager& GetResourceManager() override;

  // LayerTreeHostClient implementation.
  void WillBeginMainFrame() override {}
  void DidBeginMainFrame() override {}
  void BeginMainFrame(const viz::BeginFrameArgs& args) override {}
  void BeginMainFrameNotExpectedSoon() override {}
  void BeginMainFrameNotExpectedUntil(base::TimeTicks time) override {}
  void UpdateLayerTreeHost(bool record_main_frame_metrics) override;
  void ApplyViewportChanges(const cc::ApplyViewportChangesArgs& args) override {
  }
  void RecordWheelAndTouchScrollingCount(bool has_scrolled_by_wheel,
                                         bool has_scrolled_by_touch) override {}
  void SendOverscrollEventFromImplSide(
      const gfx::Vector2dF& overscroll_delta,
      cc::ElementId scroll_latched_element_id) override {}
  void SendScrollEndEventFromImplSide(
      cc::ElementId scroll_latched_element_id) override {}
  void RequestNewLayerTreeFrameSink() override;
  void DidInitializeLayerTreeFrameSink() override;
  void DidFailToInitializeLayerTreeFrameSink() override;
  void WillCommit() override {}
  void DidCommit() override;
  void DidCommitAndDrawFrame() override {}
  void DidReceiveCompositorFrameAck() override;
  void DidCompletePageScaleAnimation() override {}
  void DidPresentCompositorFrame(
      uint32_t frame_token,
      const gfx::PresentationFeedback& feedback) override {}
  void RecordEndOfFrameMetrics(base::TimeTicks frame_begin_time) override {}
  void DidGenerateLocalSurfaceIdAllocation(
      const viz::LocalSurfaceIdAllocation& allocation) override {}

  // LayerTreeHostSingleThreadClient implementation.
  void DidSubmitCompositorFrame() override;
  void DidLoseLayerTreeFrameSink() override;

  // WindowAndroidCompositor implementation.
  void AttachLayerForReadback(scoped_refptr<cc::Layer> layer) override;
  void RequestCopyOfOutputOnRootLayer(
      std::unique_ptr<viz::CopyOutputRequest> request) override;
  void SetNeedsAnimate() override;
  viz::FrameSinkId GetFrameSinkId() override;
  void AddChildFrameSink(const viz::FrameSinkId& frame_sink_id) override;
  void RemoveChildFrameSink(const viz::FrameSinkId& frame_sink_id) override;
  std::unique_ptr<ui::CompositorLock> GetCompositorLock(
      ui::CompositorLockClient* client,
      base::TimeDelta timeout) override;
  bool IsDrawingFirstVisibleFrame() const override;
  void SetVSyncPaused(bool paused) override;

  // viz::HostFrameSinkClient implementation.
  void OnFirstSurfaceActivation(const viz::SurfaceInfo& surface_info) override;
  void OnFrameTokenChanged(uint32_t frame_token) override {}

  // display::DisplayObserver implementation.
  void OnDisplayMetricsChanged(const display::Display& display,
                               uint32_t changed_metrics) override;

  void SetVisible(bool visible);
  void CreateLayerTreeHost();

  void HandlePendingLayerTreeFrameSinkRequest();

  void OnGpuChannelEstablished(
      scoped_refptr<gpu::GpuChannelHost> gpu_channel_host);
  void InitializeDisplay(
      std::unique_ptr<viz::OutputSurface> display_output_surface,
      scoped_refptr<viz::ContextProvider> context_provider);
  void DidSwapBuffers(const gfx::Size& swap_size);

  bool HavePendingReadbacks();

  void DetachRootWindow();

  // Helper functions to perform delayed cleanup after the compositor is no
  // longer visible on low-end devices.
  void EnqueueLowEndBackgroundCleanup();
  void DoLowEndBackgroundCleanup();

  // Returns a new surface ID when in surface-synchronization mode. Otherwise
  // returns an empty surface.
  viz::LocalSurfaceIdAllocation GenerateLocalSurfaceId() const;

  // Tears down the display for both Viz and non-Viz, unregistering the root
  // frame sink ID in the process.
  void TearDownDisplayAndUnregisterRootFrameSink();

  // Registers the root frame sink ID.
  void RegisterRootFrameSink();

  // Called when we fail to create the context for the root frame sink.
  void OnFatalOrSurfaceContextCreationFailure(
      gpu::ContextResult context_result);

  // Viz specific functions:
  void InitializeVizLayerTreeFrameSink(
      scoped_refptr<ws::ContextProviderCommandBuffer> context_provider);

  viz::FrameSinkId frame_sink_id_;

  // root_layer_ is the persistent internal root layer, while subroot_layer_
  // is the one attached by the compositor client.
  scoped_refptr<cc::Layer> subroot_layer_;

  // Subtree for hidden layers with CopyOutputRequests on them.
  scoped_refptr<cc::Layer> readback_layer_tree_;

  // Destruction order matters here:
  std::unique_ptr<cc::AnimationHost> animation_host_;
  std::unique_ptr<cc::LayerTreeHost> host_;
  ui::ResourceManagerImpl resource_manager_;

  std::unique_ptr<viz::Display> display_;

  gfx::ColorSpace display_color_space_;
  gfx::Size size_;
  bool requires_alpha_channel_ = false;

  ANativeWindow* window_;
  gpu::SurfaceHandle surface_handle_;

  CompositorClient* client_;

  gfx::NativeWindow root_window_ = nullptr;

  // Whether we need to update animations on the next composite.
  bool needs_animate_;

  // The number of SubmitFrame calls that have not returned and ACK'd from
  // the GPU thread.
  unsigned int pending_frames_;

  // Whether there is a LayerTreeFrameSink request pending from the current
  // |host_|. Becomes |true| if RequestNewLayerTreeFrameSink is called, and
  // |false| if |host_| is deleted or we succeed in creating *and* initializing
  // a LayerTreeFrameSink (which is essentially the contract with cc).
  bool layer_tree_frame_sink_request_pending_;

  gpu::Capabilities gpu_capabilities_;
  bool has_layer_tree_frame_sink_ = false;
  std::unordered_set<viz::FrameSinkId, viz::FrameSinkIdHash>
      pending_child_frame_sink_ids_;
  ui::CompositorLockManager lock_manager_;
  bool has_submitted_frame_since_became_visible_ = false;

  // If true, we are using surface synchronization.
  const bool enable_surface_synchronization_;

  // If true, we are using a Viz process.
  const bool enable_viz_;

  // Viz-specific members for communicating with the display.
  viz::mojom::DisplayPrivateAssociatedPtr display_private_;
  std::unique_ptr<viz::HostDisplayClient> display_client_;
  bool vsync_paused_ = false;

  // Test-only. Called when we are notified of a swap.
  base::RepeatingCallback<void(const gfx::Size&)>
      swap_completed_with_size_for_testing_;

  base::WeakPtrFactory<CompositorImpl> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(CompositorImpl);
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_