// Copyright 2018 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 "ios/web/public/thread/web_thread.h"

#include "base/bind.h"
#include "base/task/post_task.h"
#include "base/test/bind_test_util.h"
#include "ios/web/public/test/web_task_environment.h"
#include "ios/web/public/thread/web_task_traits.h"
#include "ios/web/web_thread_impl.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/platform_test.h"

using testing::NotNull;

namespace web {

class WebThreadTest : public PlatformTest {
 protected:
  static void BasicFunction(base::OnceClosure continuation,
                            WebThread::ID target) {
    EXPECT_TRUE(WebThread::CurrentlyOn(target));
    std::move(continuation).Run();
  }

  web::WebTaskEnvironment task_environment_;
};

TEST_F(WebThreadTest, PostTask) {
  base::RunLoop run_loop;
  EXPECT_TRUE(base::PostTask(
      FROM_HERE, {WebThread::IO},
      base::BindOnce(&BasicFunction, run_loop.QuitWhenIdleClosure(),
                     WebThread::IO)));
  run_loop.Run();
}

TEST_F(WebThreadTest, PostTaskViaTaskRunner) {
  scoped_refptr<base::TaskRunner> task_runner =
      base::CreateTaskRunner({WebThread::IO});
  base::RunLoop run_loop;
  EXPECT_TRUE(task_runner->PostTask(
      FROM_HERE, base::BindOnce(&BasicFunction, run_loop.QuitWhenIdleClosure(),
                                WebThread::IO)));
  run_loop.Run();
}

TEST_F(WebThreadTest, PostTaskViaSequencedTaskRunner) {
  scoped_refptr<base::SequencedTaskRunner> task_runner =
      base::CreateSequencedTaskRunner({WebThread::IO});
  base::RunLoop run_loop;
  EXPECT_TRUE(task_runner->PostTask(
      FROM_HERE, base::BindOnce(&BasicFunction, run_loop.QuitWhenIdleClosure(),
                                WebThread::IO)));
  run_loop.Run();
}

TEST_F(WebThreadTest, PostTaskViaSingleThreadTaskRunner) {
  scoped_refptr<base::SingleThreadTaskRunner> task_runner =
      base::CreateSingleThreadTaskRunner({WebThread::IO});
  base::RunLoop run_loop;
  EXPECT_TRUE(task_runner->PostTask(
      FROM_HERE, base::BindOnce(&BasicFunction, run_loop.QuitWhenIdleClosure(),
                                WebThread::IO)));
  run_loop.Run();
}

TEST_F(WebThreadTest, CurrentThread) {
  base::RunLoop run_loop;

  base::PostTask(
      FROM_HERE, {base::CurrentThread()}, base::BindLambdaForTesting([&]() {
        PostTask(FROM_HERE, {base::CurrentThread()}, run_loop.QuitClosure());
      }));

  run_loop.Run();
}

TEST_F(WebThreadTest, GetContinuationTaskRunner) {
  base::RunLoop run_loop;
  auto task_runner =
      base::CreateSingleThreadTaskRunner({base::CurrentThread()});

  task_runner->PostTask(FROM_HERE, base::BindLambdaForTesting([&]() {
                          EXPECT_EQ(task_runner,
                                    base::GetContinuationTaskRunner());
                          run_loop.Quit();
                        }));

  run_loop.Run();
}

TEST_F(WebThreadTest, GetContinuationTaskRunnerWithNoTaskRunning) {
  // TODO(scheduler-dev): GetContinuationTaskRunner should DCHECK if there's no
  // task running.
  EXPECT_EQ(base::CreateSequencedTaskRunner({base::CurrentThread()}),
            base::GetContinuationTaskRunner());
  EXPECT_THAT(base::GetContinuationTaskRunner().get(), NotNull());
}

}  // namespace web