// 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 <stdint.h>

#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "base/memory/raw_ptr.h"
#include "base/run_loop.h"
#include "base/task/current_thread.h"
#include "base/win/message_window.h"
#include "content/browser/scheduler/responsiveness/native_event_observer.h"
#include "content/public/test/browser_test.h"
#include "content/public/test/content_browser_test.h"

namespace content {
namespace responsiveness {

namespace {

bool HandleMessage(UINT message,
                   WPARAM wparam,
                   LPARAM lparam,
                   LRESULT* result) {
  return false;
}

}  // namespace

class ResponsivenessNativeEventObserverBrowserTest : public ContentBrowserTest {
 public:
  void WillRunEvent(uintptr_t opaque_id) {
    // Multiple overlapping events are expected because all peek operations
    // trigger native events. Track the latest triggered event.
    will_run_id_ = opaque_id;
  }
  void DidRunEvent(uintptr_t opaque_id) {
    did_run_id_ = opaque_id;
    // Trigger quit closure once we've dispatched our posted test message.
    if (quit_closure_) {
      std::move(quit_closure_).Run();
    }
  }

 protected:
  uintptr_t will_run_id_ = 0;
  uintptr_t did_run_id_ = 0;
  base::OnceClosure quit_closure_;
};

IN_PROC_BROWSER_TEST_F(ResponsivenessNativeEventObserverBrowserTest,
                       EventForwarding) {
  base::win::MessageWindow window;
  EXPECT_TRUE(window.Create(base::BindRepeating(&HandleMessage)));

  // The production Watcher already registered a NativeEventObserver.
  // Overwrite it for this test to avoid the CHECK(!native_event_observer_) in
  // BrowserUINativeEventObserver's constructor.
  base::MessagePumpForUI::NativeEventObserver* old_observer =
      base::CurrentUIThread::Get()->ResetNativeEventObserverForTesting(nullptr);

  {
    BrowserUINativeEventObserver observer(
        base::BindRepeating(
            &ResponsivenessNativeEventObserverBrowserTest::WillRunEvent,
            base::Unretained(this)),
        base::BindRepeating(
            &ResponsivenessNativeEventObserverBrowserTest::DidRunEvent,
            base::Unretained(this)));

    EXPECT_FALSE(will_run_id_);
    EXPECT_FALSE(did_run_id_);

    EXPECT_NE(PostMessage(window.hwnd(), WM_USER, 100, 0), 0);
    base::RunLoop run_loop;
    quit_closure_ = run_loop.QuitClosure();
    run_loop.Run();

    EXPECT_EQ(will_run_id_, did_run_id_);
    EXPECT_NE(will_run_id_, 0u);
  }

  // Restore the original observer.
  base::CurrentUIThread::Get()->ResetNativeEventObserverForTesting(
      old_observer);
}

}  // namespace responsiveness
}  // namespace content