// 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.

// Needed for BUILDFLAG(IS_WIN)
#include "build/build_config.h"

// Windows headers must come first.
#if BUILDFLAG(IS_WIN)
#include <windows.h>
#endif

// Proceed with header includes in usual order.
#include "content/browser/scheduler/responsiveness/native_event_observer.h"

#include "ui/events/platform/platform_event_source.h"

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
#include "ui/events/platform/platform_event_source.h"
#endif

#if BUILDFLAG(IS_WIN)
#include "base/task/current_thread.h"
#endif

namespace content {
namespace responsiveness {

BrowserUINativeEventObserver::BrowserUINativeEventObserver(
    WillRunEventCallback will_run_event_callback,
    DidRunEventCallback did_run_event_callback)
    : will_run_event_callback_(will_run_event_callback),
      did_run_event_callback_(did_run_event_callback) {
  RegisterObserver();
}

BrowserUINativeEventObserver::~BrowserUINativeEventObserver() {
  UnregisterObserver();
}

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
void BrowserUINativeEventObserver::RegisterObserver() {
  CHECK(ui::PlatformEventSource::GetInstance());
  ui::PlatformEventSource::GetInstance()->AddPlatformEventObserver(this);
}

void BrowserUINativeEventObserver::UnregisterObserver() {
  if (ui::PlatformEventSource::GetInstance()) {
    ui::PlatformEventSource::GetInstance()->RemovePlatformEventObserver(this);
  }
}

void BrowserUINativeEventObserver::WillProcessEvent(
    const ui::PlatformEvent& event) {
  uintptr_t id = reinterpret_cast<uintptr_t>(&event);
  EventInfo info{id};
  events_being_processed_.push_back(info);
  will_run_event_callback_.Run(id);
}

void BrowserUINativeEventObserver::DidProcessEvent(
    const ui::PlatformEvent& event) {
  EventInfo& info = events_being_processed_.back();
  did_run_event_callback_.Run(info.unique_id);
  events_being_processed_.pop_back();
}

void BrowserUINativeEventObserver::PlatformEventSourceDestroying() {
  CHECK(ui::PlatformEventSource::GetInstance());
  UnregisterObserver();
}

#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)

#if BUILDFLAG(IS_WIN)
void BrowserUINativeEventObserver::RegisterObserver() {
  base::CurrentUIThread::Get()->RegisterNativeEventObserver(this);
}

void BrowserUINativeEventObserver::UnregisterObserver() {
  base::CurrentUIThread::Get()->UnregisterNativeEventObserver(this);
}

void BrowserUINativeEventObserver::WillRunNativeEvent(uintptr_t identifier) {
  will_run_event_callback_.Run(identifier);
}

void BrowserUINativeEventObserver::DidRunNativeEvent(uintptr_t identifier) {
  did_run_event_callback_.Run(identifier);
}
#endif  // BUILDFLAG(IS_WIN)

#if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_IOS)
void BrowserUINativeEventObserver::RegisterObserver() {}
void BrowserUINativeEventObserver::UnregisterObserver() {}
#endif

}  // namespace responsiveness
}  // namespace content