// 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 "modules/fetch/GlobalFetch.h"

#include "core/frame/LocalDOMWindow.h"
#include "core/frame/UseCounter.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/workers/WorkerGlobalScope.h"
#include "modules/fetch/FetchManager.h"
#include "modules/fetch/Request.h"
#include "platform/Supplementable.h"
#include "platform/heap/Handle.h"

namespace blink {

namespace {

template <typename T>
class GlobalFetchImpl final
    : public GarbageCollectedFinalized<GlobalFetchImpl<T>>,
      public GlobalFetch::ScopedFetcher,
      public Supplement<T> {
  USING_GARBAGE_COLLECTED_MIXIN(GlobalFetchImpl);

 public:
  static ScopedFetcher* from(T& supplementable,
                             ExecutionContext* executionContext) {
    GlobalFetchImpl* supplement = static_cast<GlobalFetchImpl*>(
        Supplement<T>::from(supplementable, supplementName()));
    if (!supplement) {
      supplement = new GlobalFetchImpl(executionContext);
      Supplement<T>::provideTo(supplementable, supplementName(), supplement);
    }
    return supplement;
  }

  ScriptPromise fetch(ScriptState* scriptState,
                      const RequestInfo& input,
                      const Dictionary& init,
                      ExceptionState& exceptionState) override {
    ExecutionContext* executionContext = m_fetchManager->getExecutionContext();
    if (!scriptState->contextIsValid() || !executionContext) {
      // TODO(yhirano): Should this be moved to bindings?
      exceptionState.throwTypeError("The global scope is shutting down.");
      return ScriptPromise();
    }

    // "Let |r| be the associated request of the result of invoking the
    // initial value of Request as constructor with |input| and |init| as
    // arguments. If this throws an exception, reject |p| with it."
    Request* r = Request::create(scriptState, input, init, exceptionState);
    if (exceptionState.hadException())
      return ScriptPromise();

    InspectorInstrumentation::willSendXMLHttpOrFetchNetworkRequest(
        executionContext, r->url());
    return m_fetchManager->fetch(scriptState, r->passRequestData(scriptState));
  }

  DEFINE_INLINE_VIRTUAL_TRACE() {
    visitor->trace(m_fetchManager);
    ScopedFetcher::trace(visitor);
    Supplement<T>::trace(visitor);
  }

 private:
  explicit GlobalFetchImpl(ExecutionContext* executionContext)
      : m_fetchManager(FetchManager::create(executionContext)) {}

  static const char* supplementName() { return "GlobalFetch"; }

  Member<FetchManager> m_fetchManager;
};

}  // namespace

GlobalFetch::ScopedFetcher::~ScopedFetcher() {}

GlobalFetch::ScopedFetcher* GlobalFetch::ScopedFetcher::from(
    DOMWindow& window) {
  return GlobalFetchImpl<LocalDOMWindow>::from(toLocalDOMWindow(window),
                                               window.getExecutionContext());
}

GlobalFetch::ScopedFetcher* GlobalFetch::ScopedFetcher::from(
    WorkerGlobalScope& worker) {
  return GlobalFetchImpl<WorkerGlobalScope>::from(worker,
                                                  worker.getExecutionContext());
}

DEFINE_TRACE(GlobalFetch::ScopedFetcher) {}

ScriptPromise GlobalFetch::fetch(ScriptState* scriptState,
                                 DOMWindow& window,
                                 const RequestInfo& input,
                                 const Dictionary& init,
                                 ExceptionState& exceptionState) {
  UseCounter::count(window.getExecutionContext(), UseCounter::Fetch);
  return ScopedFetcher::from(window)->fetch(scriptState, input, init,
                                            exceptionState);
}

ScriptPromise GlobalFetch::fetch(ScriptState* scriptState,
                                 WorkerGlobalScope& worker,
                                 const RequestInfo& input,
                                 const Dictionary& init,
                                 ExceptionState& exceptionState) {
  // Note that UseCounter doesn't work with SharedWorker or ServiceWorker.
  UseCounter::count(worker.getExecutionContext(), UseCounter::Fetch);
  return ScopedFetcher::from(worker)->fetch(scriptState, input, init,
                                            exceptionState);
}

}  // namespace blink