// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/modules/csspaint/paint_worklet_proxy_client.h"

#include <memory>
#include <utility>

#include "base/task/single_thread_task_runner.h"
#include "third_party/blink/renderer/core/css/cssom/cross_thread_color_value.h"
#include "third_party/blink/renderer/core/css/cssom/cross_thread_unit_value.h"
#include "third_party/blink/renderer/core/css/cssom/css_paint_worklet_input.h"
#include "third_party/blink/renderer/core/css/cssom/css_style_value.h"
#include "third_party/blink/renderer/core/frame/local_dom_window.h"
#include "third_party/blink/renderer/core/frame/web_frame_widget_impl.h"
#include "third_party/blink/renderer/core/frame/web_local_frame_impl.h"
#include "third_party/blink/renderer/core/workers/worker_backing_thread.h"
#include "third_party/blink/renderer/core/workers/worker_thread.h"
#include "third_party/blink/renderer/modules/csspaint/css_paint_definition.h"
#include "third_party/blink/renderer/modules/csspaint/nativepaint/background_color_paint_definition.h"
#include "third_party/blink/renderer/modules/csspaint/nativepaint/native_paint_definition.h"
#include "third_party/blink/renderer/modules/csspaint/paint_worklet.h"
#include "third_party/blink/renderer/platform/graphics/image.h"
#include "third_party/blink/renderer/platform/graphics/paint_worklet_paint_dispatcher.h"
#include "third_party/blink/renderer/platform/scheduler/public/main_thread.h"
#include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"
#include "third_party/blink/renderer/platform/wtf/casting.h"
#include "third_party/blink/renderer/platform/wtf/cross_thread_copier_base.h"
#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"

namespace blink {

const char PaintWorkletProxyClient::kSupplementName[] =
    "PaintWorkletProxyClient";

// static
PaintWorkletProxyClient* PaintWorkletProxyClient::From(WorkerClients* clients) {
  return Supplement<WorkerClients>::From<PaintWorkletProxyClient>(clients);
}

// static
PaintWorkletProxyClient* PaintWorkletProxyClient::Create(LocalDOMWindow* window,
                                                         int worklet_id) {
  PaintWorklet* paint_worklet = PaintWorklet::From(*window);
  scoped_refptr<base::SingleThreadTaskRunner> compositor_host_queue;
  base::WeakPtr<PaintWorkletPaintDispatcher> compositor_paint_dispatcher;
  if (Thread::CompositorThread()) {
    if (WebLocalFrameImpl* local_frame =
            WebLocalFrameImpl::FromFrame(window->GetFrame())) {
      compositor_paint_dispatcher =
          local_frame->LocalRootFrameWidget()->EnsureCompositorPaintDispatcher(
              &compositor_host_queue);
    }
  }
  return MakeGarbageCollected<PaintWorkletProxyClient>(
      worklet_id, paint_worklet,
      window->GetTaskRunner(TaskType::kInternalDefault),
      std::move(compositor_paint_dispatcher), std::move(compositor_host_queue));
}

PaintWorkletProxyClient::PaintWorkletProxyClient(
    int worklet_id,
    PaintWorklet* paint_worklet,
    scoped_refptr<base::SingleThreadTaskRunner> main_thread_runner,
    base::WeakPtr<PaintWorkletPaintDispatcher> paint_dispatcher,
    scoped_refptr<base::SingleThreadTaskRunner> compositor_host_queue)
    : Supplement(nullptr),
      paint_dispatcher_(std::move(paint_dispatcher)),
      compositor_host_queue_(std::move(compositor_host_queue)),
      worklet_id_(worklet_id),
      state_(RunState::kUninitialized),
      main_thread_runner_(std::move(main_thread_runner)),
      paint_worklet_(MakeCrossThreadWeakHandle<PaintWorklet>(paint_worklet)) {
  DCHECK(IsMainThread());
}

void PaintWorkletProxyClient::AddGlobalScope(WorkletGlobalScope* global_scope) {
  DCHECK(global_scope);
  DCHECK(global_scope->IsContextThread());
  if (state_ == RunState::kDisposed)
    return;
  DCHECK(state_ == RunState::kUninitialized);

  global_scopes_.push_back(To<PaintWorkletGlobalScope>(global_scope));

  // Wait for all global scopes to be set before registering.
  if (global_scopes_.size() < PaintWorklet::kNumGlobalScopesPerThread) {
    return;
  }

  // All the global scopes that share a single PaintWorkletProxyClient run on
  // the same thread with the same scheduler. As such we can just grab a task
  // runner from the last one to register.
  scoped_refptr<base::SingleThreadTaskRunner> global_scope_runner =
      global_scope->GetThread()->GetTaskRunner(TaskType::kMiscPlatformAPI);
  state_ = RunState::kWorking;

  PostCrossThreadTask(
      *compositor_host_queue_, FROM_HERE,
      CrossThreadBindOnce(
          &PaintWorkletPaintDispatcher::RegisterPaintWorkletPainter,
          paint_dispatcher_, WrapCrossThreadPersistent(this),
          global_scope_runner));
}

void PaintWorkletProxyClient::RegisterCSSPaintDefinition(
    const String& name,
    CSSPaintDefinition* definition,
    ExceptionState& exception_state) {
  if (document_definition_map_.Contains(name)) {
    DocumentPaintDefinition* document_definition =
        document_definition_map_.at(name);
    if (!document_definition)
      return;
    if (!document_definition->RegisterAdditionalPaintDefinition(*definition)) {
      document_definition_map_.Set(name, nullptr);
      exception_state.ThrowDOMException(
          DOMExceptionCode::kNotSupportedError,
          StrCat({"A class with name:'", name,
                  "' was registered with a different definition."}));
      return;
    }
  } else {
    auto document_definition = std::make_unique<DocumentPaintDefinition>(
        definition->NativeInvalidationProperties(),
        definition->CustomInvalidationProperties(),
        definition->InputArgumentTypes(),
        definition->GetPaintRenderingContext2DSettings()->alpha());
    document_definition_map_.insert(name, std::move(document_definition));
  }

  DocumentPaintDefinition* document_definition =
      document_definition_map_.at(name);
  // Notify the main thread only once all global scopes have registered the same
  // named paint definition (with the same definition as well).
  if (document_definition->GetRegisteredDefinitionCount() ==
      PaintWorklet::kNumGlobalScopesPerThread) {
    PostCrossThreadTask(
        *main_thread_runner_, FROM_HERE,
        CrossThreadBindOnce(
            &PaintWorklet::RegisterMainThreadDocumentPaintDefinition,
            MakeUnwrappingCrossThreadWeakHandle(paint_worklet_), name,
            definition->NativeInvalidationProperties(),
            definition->CustomInvalidationProperties(),
            definition->InputArgumentTypes(),
            definition->GetPaintRenderingContext2DSettings()->alpha()));
  }
}

void PaintWorkletProxyClient::Dispose() {
  if (state_ == RunState::kWorking) {
    PostCrossThreadTask(
        *compositor_host_queue_, FROM_HERE,
        CrossThreadBindOnce(
            &PaintWorkletPaintDispatcher::UnregisterPaintWorkletPainter,
            paint_dispatcher_, worklet_id_));
  }
  paint_dispatcher_ = nullptr;

  state_ = RunState::kDisposed;

  // At worklet scope termination break the reference cycle between
  // PaintWorkletGlobalScope and PaintWorkletProxyClient.
  global_scopes_.clear();
}

void PaintWorkletProxyClient::Trace(Visitor* visitor) const {
  Supplement<WorkerClients>::Trace(visitor);
  PaintWorkletPainter::Trace(visitor);
}

PaintRecord PaintWorkletProxyClient::Paint(
    const CompositorPaintWorkletInput* compositor_input,
    const CompositorPaintWorkletJob::AnimatedPropertyValues&
        animated_property_values) {
  const PaintWorkletInput* worklet_input =
      To<PaintWorkletInput>(compositor_input);
  PaintDefinition* definition;
  if (worklet_input->GetType() !=
      PaintWorkletInput::PaintWorkletInputType::kCSS) {
    definition = native_definitions_.at(worklet_input->GetType());
    return definition->Paint(compositor_input, animated_property_values);
  }
  // TODO: Can this happen? We don't register till all are here.
  if (global_scopes_.empty())
    return PaintRecord();

  // PaintWorklets are stateless by spec. There are two ways script might try to
  // inject state:
  //   * From one PaintWorklet to another, in the same frame.
  //   * Inside the same PaintWorklet, across frames.
  //
  // To discourage both of these, we randomize selection of the global scope.
  // TODO(smcgruer): Once we are passing bundles of PaintWorklets here, we
  // should shuffle the bundle randomly and then assign half to the first global
  // scope, and half to the rest.
  DCHECK_EQ(global_scopes_.size(), PaintWorklet::kNumGlobalScopesPerThread);
  PaintWorkletGlobalScope* global_scope = global_scopes_[base::RandIntInclusive(
      0, (PaintWorklet::kNumGlobalScopesPerThread)-1)];

  const CSSPaintWorkletInput* input =
      To<CSSPaintWorkletInput>(compositor_input);
  device_pixel_ratio_ = input->EffectiveZoom();
  definition = global_scope->FindDefinition(input->NameCopy());
  return definition->Paint(compositor_input, animated_property_values);
}

void PaintWorkletProxyClient::RegisterForNativePaintWorklet(
    WorkerBackingThread* thread,
    NativePaintDefinition* definition,
    PaintWorkletInput::PaintWorkletInputType type) {
  DCHECK(!native_definitions_.Contains(type));
  native_definitions_.insert(type, definition);
  scoped_refptr<base::SingleThreadTaskRunner> task_runner =
      thread ? thread->BackingThread().GetTaskRunner() : nullptr;
  // At this moment, we are in the paint phase which is before commit, we queue
  // a task to the compositor thread to register the |paint_dispatcher_|. When
  // compositor schedules the actual paint job (PaintWorkletPainter::Paint),
  // which is after commit, the |paint_dispatcher_| should have been registerted
  // and ready to use.
  if (compositor_host_queue_) {
    PostCrossThreadTask(
        *compositor_host_queue_, FROM_HERE,
        CrossThreadBindOnce(
            &PaintWorkletPaintDispatcher::RegisterPaintWorkletPainter,
            paint_dispatcher_, WrapCrossThreadPersistent(this), task_runner));
  }
}

void PaintWorkletProxyClient::UnregisterForNativePaintWorklet() {
  if (compositor_host_queue_) {
    PostCrossThreadTask(
        *compositor_host_queue_, FROM_HERE,
        CrossThreadBindOnce(
            &PaintWorkletPaintDispatcher::UnregisterPaintWorkletPainter,
            paint_dispatcher_, worklet_id_));
  }
  paint_dispatcher_ = nullptr;
}

void ProvidePaintWorkletProxyClientTo(WorkerClients* clients,
                                      PaintWorkletProxyClient* client) {
  clients->ProvideSupplement(client);
}

}  // namespace blink