// 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.

#include "third_party/blink/renderer/core/workers/dedicated_worker_messaging_proxy.h"

#include <memory>
#include "services/network/public/mojom/fetch_api.mojom-blink.h"
#include "third_party/blink/public/platform/task_type.h"
#include "third_party/blink/renderer/bindings/core/v8/sanitize_script_errors.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_cache_options.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/events/error_event.h"
#include "third_party/blink/renderer/core/events/message_event.h"
#include "third_party/blink/renderer/core/fetch/request.h"
#include "third_party/blink/renderer/core/frame/csp/content_security_policy.h"
#include "third_party/blink/renderer/core/inspector/thread_debugger.h"
#include "third_party/blink/renderer/core/loader/worker_resource_timing_notifier_impl.h"
#include "third_party/blink/renderer/core/messaging/blink_transferable_message.h"
#include "third_party/blink/renderer/core/workers/dedicated_worker.h"
#include "third_party/blink/renderer/core/workers/dedicated_worker_object_proxy.h"
#include "third_party/blink/renderer/core/workers/dedicated_worker_thread.h"
#include "third_party/blink/renderer/core/workers/worker_options.h"
#include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"
#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"
#include "third_party/blink/renderer/platform/wtf/wtf.h"

namespace blink {

DedicatedWorkerMessagingProxy::DedicatedWorkerMessagingProxy(
    ExecutionContext* execution_context,
    DedicatedWorker* worker_object)
    : ThreadedMessagingProxyBase(execution_context),
      worker_object_(worker_object) {
  worker_object_proxy_ = std::make_unique<DedicatedWorkerObjectProxy>(
      this, GetParentExecutionContextTaskRunners());
}

DedicatedWorkerMessagingProxy::~DedicatedWorkerMessagingProxy() = default;

void DedicatedWorkerMessagingProxy::StartWorkerGlobalScope(
    std::unique_ptr<GlobalScopeCreationParams> creation_params,
    const WorkerOptions* options,
    const KURL& script_url,
    const FetchClientSettingsObjectSnapshot& outside_settings_object,
    const v8_inspector::V8StackTraceId& stack_id,
    const String& source_code) {
  DCHECK(IsParentContextThread());
  if (AskedToTerminate()) {
    // Worker.terminate() could be called from JS before the thread was
    // created.
    return;
  }

  OffMainThreadWorkerScriptFetchOption off_main_thread_fetch_option =
      creation_params->off_main_thread_fetch_option;

  InitializeWorkerThread(
      std::move(creation_params),
      CreateBackingThreadStartupData(GetExecutionContext()->GetIsolate()));

  // Step 13: "Obtain script by switching on the value of options's type
  // member:"
  if (options->type() == "classic") {
    // "classic: Fetch a classic worker script given url, outside settings,
    // destination, and inside settings."
    switch (off_main_thread_fetch_option) {
      case OffMainThreadWorkerScriptFetchOption::kEnabled: {
        auto* resource_timing_notifier =
            WorkerResourceTimingNotifierImpl::CreateForOutsideResourceFetcher(
                *GetExecutionContext());
        GetWorkerThread()->FetchAndRunClassicScript(
            script_url, outside_settings_object, *resource_timing_notifier,
            stack_id);
        break;
      }
      case OffMainThreadWorkerScriptFetchOption::kDisabled:
        // Legacy code path (to be deprecated, see https://crbug.com/835717):
        GetWorkerThread()->EvaluateClassicScript(
            script_url, source_code, nullptr /* cached_meta_data */, stack_id);
        break;
    }
  } else if (options->type() == "module") {
    DCHECK_EQ(off_main_thread_fetch_option,
              OffMainThreadWorkerScriptFetchOption::kEnabled);
    // "module: Fetch a module worker script graph given url, outside settings,
    // destination, the value of the credentials member of options, and inside
    // settings."
    network::mojom::CredentialsMode credentials_mode;
    bool result = Request::ParseCredentialsMode(options->credentials(),
                                                &credentials_mode);
    DCHECK(result);
    auto* resource_timing_notifier =
        WorkerResourceTimingNotifierImpl::CreateForOutsideResourceFetcher(
            *GetExecutionContext());
    GetWorkerThread()->FetchAndRunModuleScript(
        script_url, outside_settings_object, *resource_timing_notifier,
        credentials_mode);
  } else {
    NOTREACHED();
  }
}

void DedicatedWorkerMessagingProxy::PostMessageToWorkerGlobalScope(
    BlinkTransferableMessage message) {
  DCHECK(IsParentContextThread());
  if (AskedToTerminate())
    return;
  if (!was_script_evaluated_) {
    queued_early_tasks_.push_back(std::move(message));
    return;
  }
  PostCrossThreadTask(
      *GetWorkerThread()->GetTaskRunner(TaskType::kPostedMessage), FROM_HERE,
      CrossThreadBindOnce(
          &DedicatedWorkerObjectProxy::ProcessMessageFromWorkerObject,
          CrossThreadUnretained(&WorkerObjectProxy()),
          WTF::Passed(std::move(message)),
          CrossThreadUnretained(GetWorkerThread())));
}

bool DedicatedWorkerMessagingProxy::HasPendingActivity() const {
  DCHECK(IsParentContextThread());
  return !AskedToTerminate();
}

void DedicatedWorkerMessagingProxy::DidFailToFetchScript() {
  DCHECK(IsParentContextThread());
  if (!worker_object_ || AskedToTerminate())
    return;
  worker_object_->DispatchErrorEventForScriptFetchFailure();
}

void DedicatedWorkerMessagingProxy::Freeze() {
  DCHECK(IsParentContextThread());
  auto* worker_thread = GetWorkerThread();
  if (AskedToTerminate() || !worker_thread)
    return;
  worker_thread->Freeze();
}

void DedicatedWorkerMessagingProxy::Resume() {
  DCHECK(IsParentContextThread());
  auto* worker_thread = GetWorkerThread();
  if (AskedToTerminate() || !worker_thread)
    return;
  worker_thread->Resume();
}

void DedicatedWorkerMessagingProxy::DidEvaluateScript(bool success) {
  DCHECK(IsParentContextThread());
  was_script_evaluated_ = true;

  Vector<BlinkTransferableMessage> tasks;
  queued_early_tasks_.swap(tasks);

  // The worker thread can already be terminated.
  if (!GetWorkerThread()) {
    DCHECK(AskedToTerminate());
    return;
  }

  // Post all queued tasks to the worker.
  // TODO(nhiroki): Consider whether to post the queued tasks to the worker when
  // |success| is false.
  for (auto& task : tasks) {
    PostCrossThreadTask(
        *GetWorkerThread()->GetTaskRunner(TaskType::kPostedMessage), FROM_HERE,
        CrossThreadBindOnce(
            &DedicatedWorkerObjectProxy::ProcessMessageFromWorkerObject,
            CrossThreadUnretained(&WorkerObjectProxy()),
            WTF::Passed(std::move(task)),
            CrossThreadUnretained(GetWorkerThread())));
  }
}

void DedicatedWorkerMessagingProxy::PostMessageToWorkerObject(
    BlinkTransferableMessage message) {
  DCHECK(IsParentContextThread());
  if (!worker_object_ || AskedToTerminate())
    return;

  ThreadDebugger* debugger =
      ThreadDebugger::From(GetExecutionContext()->GetIsolate());
  MessagePortArray* ports = MessagePort::EntanglePorts(
      *GetExecutionContext(), std::move(message.ports));
  debugger->ExternalAsyncTaskStarted(message.sender_stack_trace_id);
  worker_object_->DispatchEvent(
      *MessageEvent::Create(ports, std::move(message.message)));
  debugger->ExternalAsyncTaskFinished(message.sender_stack_trace_id);
}

void DedicatedWorkerMessagingProxy::DispatchErrorEvent(
    const String& error_message,
    std::unique_ptr<SourceLocation> location,
    int exception_id) {
  DCHECK(IsParentContextThread());
  if (!worker_object_)
    return;

  // We don't bother checking the AskedToTerminate() flag for dispatching the
  // event on the owner context, because exceptions should *always* be reported
  // even if the thread is terminated as the spec says:
  //
  // "Thus, error reports propagate up to the chain of dedicated workers up to
  // the original Document, even if some of the workers along this chain have
  // been terminated and garbage collected."
  // https://html.spec.whatwg.org/C/#runtime-script-errors-2
  ErrorEvent* event =
      ErrorEvent::Create(error_message, location->Clone(), nullptr);
  if (worker_object_->DispatchEvent(*event) !=
      DispatchEventResult::kNotCanceled)
    return;

  // The worker thread can already be terminated.
  if (!GetWorkerThread()) {
    DCHECK(AskedToTerminate());
    return;
  }

  // The HTML spec requires to queue an error event using the DOM manipulation
  // task source.
  // https://html.spec.whatwg.org/C/#runtime-script-errors-2
  PostCrossThreadTask(
      *GetWorkerThread()->GetTaskRunner(TaskType::kDOMManipulation), FROM_HERE,
      CrossThreadBindOnce(
          &DedicatedWorkerObjectProxy::ProcessUnhandledException,
          CrossThreadUnretained(worker_object_proxy_.get()), exception_id,
          CrossThreadUnretained(GetWorkerThread())));

  // Propagate an unhandled error to the parent context.
  const auto mute_script_errors = SanitizeScriptErrors::kDoNotSanitize;
  GetExecutionContext()->DispatchErrorEvent(event, mute_script_errors);
}

void DedicatedWorkerMessagingProxy::Trace(blink::Visitor* visitor) {
  visitor->Trace(worker_object_);
  ThreadedMessagingProxyBase::Trace(visitor);
}

base::Optional<WorkerBackingThreadStartupData>
DedicatedWorkerMessagingProxy::CreateBackingThreadStartupData(
    v8::Isolate* isolate) {
  using HeapLimitMode = WorkerBackingThreadStartupData::HeapLimitMode;
  using AtomicsWaitMode = WorkerBackingThreadStartupData::AtomicsWaitMode;
  return WorkerBackingThreadStartupData(
      isolate->IsHeapLimitIncreasedForDebugging()
          ? HeapLimitMode::kIncreasedForDebugging
          : HeapLimitMode::kDefault,
      AtomicsWaitMode::kAllow);
}

std::unique_ptr<WorkerThread>
DedicatedWorkerMessagingProxy::CreateWorkerThread() {
  return std::make_unique<DedicatedWorkerThread>(GetExecutionContext(),
                                                 WorkerObjectProxy());
}

}  // namespace blink