// Copyright 2014 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 "content/browser/renderer_host/browser_compositor_view_mac.h"

#import <Cocoa/Cocoa.h>
#include <stdint.h>
#include <utility>

#include "base/command_line.h"
#include "base/containers/circular_deque.h"
#include "base/lazy_instance.h"
#include "base/trace_event/trace_event.h"
#include "components/viz/common/features.h"
#include "components/viz/common/surfaces/local_surface_id_allocation.h"
#include "content/browser/compositor/image_transport_factory.h"
#include "content/browser/renderer_host/display_util.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/context_factory.h"
#include "ui/accelerated_widget_mac/accelerated_widget_mac.h"
#include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
#include "ui/base/layout.h"
#include "ui/compositor/recyclable_compositor_mac.h"
#include "ui/display/screen.h"
#include "ui/gfx/geometry/dip_util.h"

namespace content {

namespace {

// Weak pointers to all BrowserCompositorMac instances, used to
// - Determine if a spare RecyclableCompositorMac should be kept around (one
//   should be only if there exists at least one BrowserCompositorMac).
// - Force all ui::Compositors to be destroyed at shut-down (because the NSView
//   signals to shut down will come in very late, long after things that the
//   ui::Compositor depend on have been destroyed).
//   https://crbug.com/805726
base::LazyInstance<std::set<BrowserCompositorMac*>>::Leaky
    g_browser_compositors;

}  // namespace

////////////////////////////////////////////////////////////////////////////////
// BrowserCompositorMac

BrowserCompositorMac::BrowserCompositorMac(
    ui::AcceleratedWidgetMacNSView* accelerated_widget_mac_ns_view,
    BrowserCompositorMacClient* client,
    bool render_widget_host_is_hidden,
    const display::Display& initial_display,
    const viz::FrameSinkId& frame_sink_id)
    : client_(client),
      accelerated_widget_mac_ns_view_(accelerated_widget_mac_ns_view),
      dfh_display_(initial_display),
      weak_factory_(this) {
  g_browser_compositors.Get().insert(this);

  root_layer_.reset(new ui::Layer(ui::LAYER_SOLID_COLOR));
  // Ensure that this layer draws nothing when it does not not have delegated
  // content (otherwise this solid color will be flashed during navigation).
  root_layer_->SetColor(SK_ColorTRANSPARENT);
  delegated_frame_host_.reset(new DelegatedFrameHost(
      frame_sink_id, this, true /* should_register_frame_sink_id */));

  SetRenderWidgetHostIsHidden(render_widget_host_is_hidden);
}

BrowserCompositorMac::~BrowserCompositorMac() {
  // Ensure that copy callbacks completed or cancelled during further tear-down
  // do not call back into this.
  weak_factory_.InvalidateWeakPtrs();

  TransitionToState(HasNoCompositor);
  delegated_frame_host_.reset();
  root_layer_.reset();

  size_t num_erased = g_browser_compositors.Get().erase(this);
  DCHECK_EQ(1u, num_erased);
}

DelegatedFrameHost* BrowserCompositorMac::GetDelegatedFrameHost() {
  DCHECK(delegated_frame_host_);
  return delegated_frame_host_.get();
}

bool BrowserCompositorMac::ForceNewSurfaceId() {
  dfh_local_surface_id_allocator_.GenerateId();
  delegated_frame_host_->EmbedSurface(
      dfh_local_surface_id_allocator_.GetCurrentLocalSurfaceIdAllocation()
          .local_surface_id(),
      dfh_size_dip_, cc::DeadlinePolicy::UseExistingDeadline());
  return client_->OnBrowserCompositorSurfaceIdChanged();
}

const gfx::CALayerParams* BrowserCompositorMac::GetLastCALayerParams() const {
  if (!recyclable_compositor_)
    return nullptr;
  return recyclable_compositor_->widget()->GetCALayerParams();
}

viz::FrameSinkId BrowserCompositorMac::GetRootFrameSinkId() {
  if (parent_ui_layer_)
    return parent_ui_layer_->GetCompositor()->frame_sink_id();
  if (recyclable_compositor_)
    return recyclable_compositor_->compositor()->frame_sink_id();
  return viz::FrameSinkId();
}

void BrowserCompositorMac::DidCreateNewRendererCompositorFrameSink(
    viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink) {
  renderer_compositor_frame_sink_ = renderer_compositor_frame_sink;
  delegated_frame_host_->DidCreateNewRendererCompositorFrameSink(
      renderer_compositor_frame_sink_);
}

void BrowserCompositorMac::OnDidNotProduceFrame(const viz::BeginFrameAck& ack) {
  delegated_frame_host_->DidNotProduceFrame(ack);
}

void BrowserCompositorMac::SetBackgroundColor(SkColor background_color) {
  background_color_ = background_color;
  if (recyclable_compositor_)
    recyclable_compositor_->compositor()->SetBackgroundColor(background_color_);
}

bool BrowserCompositorMac::UpdateSurfaceFromNSView(
    const gfx::Size& new_size_dip,
    const display::Display& new_display) {
  if (new_size_dip == dfh_size_dip_ && new_display == dfh_display_)
    return false;

  bool is_resize = !dfh_size_dip_.IsEmpty() && new_size_dip != dfh_size_dip_;

  bool needs_new_surface_id =
      new_size_dip != dfh_size_dip_ ||
      new_display.device_scale_factor() != dfh_display_.device_scale_factor();

  dfh_display_ = new_display;
  dfh_size_dip_ = new_size_dip;
  dfh_size_pixels_ = gfx::ConvertSizeToPixel(dfh_display_.device_scale_factor(),
                                             dfh_size_dip_);
  root_layer_->SetBounds(gfx::Rect(dfh_size_dip_));

  if (needs_new_surface_id) {
    dfh_local_surface_id_allocator_.GenerateId();
    delegated_frame_host_->EmbedSurface(
        dfh_local_surface_id_allocator_.GetCurrentLocalSurfaceIdAllocation()
            .local_surface_id(),
        dfh_size_dip_, GetDeadlinePolicy(is_resize));
  }

  if (recyclable_compositor_) {
    recyclable_compositor_->compositor()->SetDisplayColorSpace(
        dfh_display_.color_space());
    recyclable_compositor_->UpdateSurface(dfh_size_pixels_,
                                          dfh_display_.device_scale_factor());
  }

  return true;
}

void BrowserCompositorMac::UpdateSurfaceFromChild(
    float new_device_scale_factor,
    const gfx::Size& new_size_in_pixels,
    const viz::LocalSurfaceIdAllocation& child_local_surface_id_allocation) {
  if (dfh_local_surface_id_allocator_.UpdateFromChild(
          child_local_surface_id_allocation)) {
    dfh_display_.set_device_scale_factor(new_device_scale_factor);
    dfh_size_dip_ = gfx::ConvertSizeToDIP(dfh_display_.device_scale_factor(),
                                          new_size_in_pixels);
    dfh_size_pixels_ = new_size_in_pixels;
    root_layer_->SetBounds(gfx::Rect(dfh_size_dip_));
    if (recyclable_compositor_) {
      recyclable_compositor_->UpdateSurface(dfh_size_pixels_,
                                            dfh_display_.device_scale_factor());
    }
    delegated_frame_host_->EmbedSurface(
        dfh_local_surface_id_allocator_.GetCurrentLocalSurfaceIdAllocation()
            .local_surface_id(),
        dfh_size_dip_, GetDeadlinePolicy(true /* is_resize */));
  }
  client_->OnBrowserCompositorSurfaceIdChanged();
}

void BrowserCompositorMac::UpdateVSyncParameters(
    const base::TimeTicks& timebase,
    const base::TimeDelta& interval) {
  ui::Compositor* compositor = nullptr;
  if (recyclable_compositor_)
    compositor = recyclable_compositor_->compositor();
  // TODO(ccameron): VSync parameters for a ui::Compositor should be tracked
  // with the owner of that ui::Compositor (which, in the case of MacViews, is
  // BridgedNativeView). For the moment, push the VSync parameters from here to
  // the BridgedNativeView's ui::Compositor because that is a small change and
  // is easy to merge.
  // https://crbug.com/869129
  if (parent_ui_layer_)
    compositor = parent_ui_layer_->GetCompositor();
  if (compositor)
    compositor->SetDisplayVSyncParameters(timebase, interval);
}

void BrowserCompositorMac::SetRenderWidgetHostIsHidden(bool hidden) {
  render_widget_host_is_hidden_ = hidden;
  UpdateState();
}

void BrowserCompositorMac::SetViewVisible(bool visible) {
  root_layer_->SetVisible(visible);
}

void BrowserCompositorMac::UpdateState() {
  // Always use the parent ui::Layer's ui::Compositor if available.
  if (parent_ui_layer_) {
    TransitionToState(UseParentLayerCompositor);
    return;
  }

  // If the host is visible and a compositor is required then create one.
  if (!render_widget_host_is_hidden_) {
    TransitionToState(HasOwnCompositor);
    return;
  }

  // Otherwise put the compositor up for recycling.
  TransitionToState(HasNoCompositor);
}

void BrowserCompositorMac::TransitionToState(State new_state) {
  // Skip if there is no change to make.
  bool is_no_op = false;
  if (state_ == new_state) {
    if (state_ == UseParentLayerCompositor)
      is_no_op = parent_ui_layer_ == root_layer_->parent();
    else
      is_no_op = true;
  }
  if (is_no_op)
    return;

  // First, detach from the current compositor, if there is one.
  delegated_frame_host_->DetachFromCompositor();
  if (state_ == UseParentLayerCompositor) {
    DCHECK(root_layer_->parent());
    state_ = HasNoCompositor;
    root_layer_->parent()->RemoveObserver(this);
    root_layer_->parent()->Remove(root_layer_.get());
  }
  if (state_ == HasOwnCompositor) {
    recyclable_compositor_->widget()->ResetNSView();
    recyclable_compositor_->compositor()->SetRootLayer(nullptr);
    recyclable_compositor_->InvalidateSurface();
    ui::RecyclableCompositorMacFactory::Get()->RecycleCompositor(
        std::move(recyclable_compositor_));
  }

  // The compositor is now detached. If this is the target state, we're done.
  state_ = HasNoCompositor;
  if (new_state == HasNoCompositor) {
    // Don't transiently hide the DelegatedFrameHost because that can cause the
    // current frame to be inappropriately evicted.
    // https://crbug.com/897156
    delegated_frame_host_->WasHidden();
    return;
  }

  // Attach to the new compositor.
  if (new_state == UseParentLayerCompositor) {
    DCHECK(parent_ui_layer_);
    parent_ui_layer_->Add(root_layer_.get());
    parent_ui_layer_->AddObserver(this);
    state_ = UseParentLayerCompositor;
  }
  if (new_state == HasOwnCompositor) {
    recyclable_compositor_ =
        ui::RecyclableCompositorMacFactory::Get()->CreateCompositor(
            content::GetContextFactory(), content::GetContextFactoryPrivate());
    recyclable_compositor_->UpdateSurface(dfh_size_pixels_,
                                          dfh_display_.device_scale_factor());
    recyclable_compositor_->compositor()->SetRootLayer(root_layer_.get());
    recyclable_compositor_->compositor()->SetBackgroundColor(background_color_);
    recyclable_compositor_->compositor()->SetDisplayColorSpace(
        dfh_display_.color_space());
    recyclable_compositor_->widget()->SetNSView(
        accelerated_widget_mac_ns_view_);
    recyclable_compositor_->Unsuspend();
    state_ = HasOwnCompositor;
  }
  DCHECK_EQ(state_, new_state);
  delegated_frame_host_->AttachToCompositor(GetCompositor());
  has_saved_frame_before_state_transition_ =
      delegated_frame_host_->HasSavedFrame();
  delegated_frame_host_->WasShown(
      GetRendererLocalSurfaceIdAllocation().local_surface_id(), dfh_size_dip_,
      false /* record_presentation_time */);
}

// static
void BrowserCompositorMac::DisableRecyclingForShutdown() {
  // Ensure that the client has destroyed its BrowserCompositorViewMac before
  // it dependencies are destroyed.
  // https://crbug.com/805726
  while (!g_browser_compositors.Get().empty()) {
    BrowserCompositorMac* browser_compositor =
        *g_browser_compositors.Get().begin();
    browser_compositor->client_->DestroyCompositorForShutdown();
  }

  ui::RecyclableCompositorMacFactory::Get()->DisableRecyclingForShutdown();
}

void BrowserCompositorMac::SetNeedsBeginFrames(bool needs_begin_frames) {
  delegated_frame_host_->SetNeedsBeginFrames(needs_begin_frames);
}

void BrowserCompositorMac::SetWantsAnimateOnlyBeginFrames() {
  delegated_frame_host_->SetWantsAnimateOnlyBeginFrames();
}

void BrowserCompositorMac::TakeFallbackContentFrom(
    BrowserCompositorMac* other) {
  delegated_frame_host_->TakeFallbackContentFrom(
      other->delegated_frame_host_.get());
}

////////////////////////////////////////////////////////////////////////////////
// DelegatedFrameHost, public:

ui::Layer* BrowserCompositorMac::DelegatedFrameHostGetLayer() const {
  return root_layer_.get();
}

bool BrowserCompositorMac::DelegatedFrameHostIsVisible() const {
  return state_ != HasNoCompositor;
}

SkColor BrowserCompositorMac::DelegatedFrameHostGetGutterColor() const {
  return client_->BrowserCompositorMacGetGutterColor();
}

void BrowserCompositorMac::OnBeginFrame(base::TimeTicks frame_time) {
  client_->BrowserCompositorMacOnBeginFrame(frame_time);
}

void BrowserCompositorMac::OnFrameTokenChanged(uint32_t frame_token) {
  client_->OnFrameTokenChanged(frame_token);
}

float BrowserCompositorMac::GetDeviceScaleFactor() const {
  return dfh_display_.device_scale_factor();
}

void BrowserCompositorMac::InvalidateLocalSurfaceIdOnEviction() {
  dfh_local_surface_id_allocator_.Invalidate();
}

std::vector<viz::SurfaceId>
BrowserCompositorMac::CollectSurfaceIdsForEviction() {
  return client_->CollectSurfaceIdsForEviction();
}

bool BrowserCompositorMac::ShouldShowStaleContentOnEviction() {
  return false;
}

void BrowserCompositorMac::DidNavigate() {
  if (render_widget_host_is_hidden_) {
    // Navigating while hidden should not allocate a new LocalSurfaceID. Once
    // sizes are ready, or we begin to Show, we can then allocate the new
    // LocalSurfaceId.
    dfh_local_surface_id_allocator_.Invalidate();
  } else {
    // The first navigation does not need a new LocalSurfaceID. The renderer can
    // use the ID that was already provided.
    if (!is_first_navigation_) {
      dfh_local_surface_id_allocator_.GenerateId();
    }
    delegated_frame_host_->EmbedSurface(
        dfh_local_surface_id_allocator_.GetCurrentLocalSurfaceIdAllocation()
            .local_surface_id(),
        dfh_size_dip_, cc::DeadlinePolicy::UseExistingDeadline());
    client_->OnBrowserCompositorSurfaceIdChanged();
  }

  delegated_frame_host_->DidNavigate();
  is_first_navigation_ = false;
}

void BrowserCompositorMac::SetParentUiLayer(ui::Layer* new_parent_ui_layer) {
  if (new_parent_ui_layer)
    DCHECK(new_parent_ui_layer->GetCompositor());

  // Set |parent_ui_layer_| to the new value, which potentially not match the
  // value of |root_layer_->parent()|. The call to UpdateState will re-parent
  // |root_layer_|.
  DCHECK_EQ(root_layer_->parent(), parent_ui_layer_);
  parent_ui_layer_ = new_parent_ui_layer;
  UpdateState();
  DCHECK_EQ(root_layer_->parent(), parent_ui_layer_);
}

bool BrowserCompositorMac::ForceNewSurfaceForTesting() {
  display::Display new_display(dfh_display_);
  new_display.set_device_scale_factor(new_display.device_scale_factor() * 2.0f);
  return UpdateSurfaceFromNSView(dfh_size_dip_, new_display);
}

void BrowserCompositorMac::GetRendererScreenInfo(
    ScreenInfo* screen_info) const {
  DisplayUtil::DisplayToScreenInfo(screen_info, dfh_display_);
}

viz::ScopedSurfaceIdAllocator
BrowserCompositorMac::GetScopedRendererSurfaceIdAllocator(
    base::OnceCallback<void()> allocation_task) {
  return viz::ScopedSurfaceIdAllocator(&dfh_local_surface_id_allocator_,
                                       std::move(allocation_task));
}

const viz::LocalSurfaceIdAllocation&
BrowserCompositorMac::GetRendererLocalSurfaceIdAllocation() {
  if (!dfh_local_surface_id_allocator_.HasValidLocalSurfaceIdAllocation())
    dfh_local_surface_id_allocator_.GenerateId();

  return dfh_local_surface_id_allocator_.GetCurrentLocalSurfaceIdAllocation();
}

void BrowserCompositorMac::TransformPointToRootSurface(gfx::PointF* point) {
  gfx::Transform transform_to_root;
  if (parent_ui_layer_)
    parent_ui_layer_->GetTargetTransformRelativeTo(nullptr, &transform_to_root);
  transform_to_root.TransformPoint(point);
}

void BrowserCompositorMac::LayerDestroyed(ui::Layer* layer) {
  DCHECK_EQ(layer, parent_ui_layer_);
  SetParentUiLayer(nullptr);
}

ui::Compositor* BrowserCompositorMac::GetCompositor() const {
  if (parent_ui_layer_)
    return parent_ui_layer_->GetCompositor();
  if (recyclable_compositor_)
    return recyclable_compositor_->compositor();
  return nullptr;
}

cc::DeadlinePolicy BrowserCompositorMac::GetDeadlinePolicy(
    bool is_resize) const {
  // Determined empirically for smoothness. Don't wait for non-resize frames,
  // as it can cause jank at new tab creation.
  // https://crbug.com/855364
  uint32_t frames_to_wait = is_resize ? 8 : 0;

  // When using the RecyclableCompositor, never wait for frames to arrive
  // (surface sync is managed by the Suspend/Unsuspend lock).
  if (recyclable_compositor_)
    frames_to_wait = 0;

  return cc::DeadlinePolicy::UseSpecifiedDeadline(frames_to_wait);
}

}  // namespace content