/*
 * Copyright 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "message_loop_thread.h"

#include <condition_variable>
#include <memory>
#include <mutex>

#include <gtest/gtest.h>

#include <base/bind.h>
#include <base/threading/platform_thread.h>
#include <sys/capability.h>
#include <syscall.h>

using bluetooth::common::MessageLoopThread;

/**
 * Unit tests to verify MessageLoopThread. Must have CAP_SYS_NICE capability.
 */
class MessageLoopThreadTest : public ::testing::Test {
 public:
  void ShouldNotHappen() { FAIL() << "Should not happen"; }

  void GetThreadId(std::promise<base::PlatformThreadId> thread_id_promise) {
    thread_id_promise.set_value(base::PlatformThread::CurrentId());
  }

  void GetLinuxTid(std::promise<pid_t> tid_promise) {
    tid_promise.set_value(static_cast<pid_t>(syscall(SYS_gettid)));
  }

  void GetName(std::promise<std::string> name_promise) {
    char my_name[256];
    pthread_getname_np(pthread_self(), my_name, sizeof(my_name));
    name_promise.set_value(my_name);
  }

  void GetSchedulingPolicyAndPriority(int* scheduling_policy,
                                      int* schedule_priority,
                                      std::promise<void> execution_promise) {
    *scheduling_policy = sched_getscheduler(0);
    struct sched_param param = {};
    ASSERT_EQ(sched_getparam(0, &param), 0);
    *schedule_priority = param.sched_priority;
    execution_promise.set_value();
  }

  void SleepAndGetName(std::promise<std::string> name_promise, int sleep_ms) {
    std::this_thread::sleep_for(std::chrono::milliseconds(sleep_ms));
    GetName(std::move(name_promise));
  }

 protected:
  static bool CanSetCurrentThreadPriority() {
    struct __user_cap_header_struct linux_user_header = {
        .version = _LINUX_CAPABILITY_VERSION_3};
    struct __user_cap_data_struct linux_user_data = {};
    if (capget(&linux_user_header, &linux_user_data) != 0) {
      LOG(ERROR) << "Failed to get capability for current thread, error: "
                 << strerror(errno);
      // Log record in XML
      RecordProperty("MessageLoopThreadTestCannotGetCapabilityReason",
                     strerror(errno));
      return false;
    }
    return ((linux_user_data.permitted >> CAP_SYS_NICE) & 0x1) != 0;
  }
};

TEST_F(MessageLoopThreadTest, get_weak_ptr) {
  base::WeakPtr<MessageLoopThread> message_loop_thread_ptr;
  {
    MessageLoopThread message_loop_thread("test_thread");
    message_loop_thread_ptr = message_loop_thread.GetWeakPtr();
    ASSERT_NE(message_loop_thread_ptr, nullptr);
  }
  ASSERT_EQ(message_loop_thread_ptr, nullptr);
}

TEST_F(MessageLoopThreadTest, test_running_thread) {
  MessageLoopThread message_loop_thread("test_thread");
  message_loop_thread.StartUp();
  ASSERT_GE(message_loop_thread.GetThreadId(), 0);
  ASSERT_TRUE(message_loop_thread.IsRunning());
  message_loop_thread.ShutDown();
  ASSERT_LT(message_loop_thread.GetThreadId(), 0);
  ASSERT_FALSE(message_loop_thread.IsRunning());
}

TEST_F(MessageLoopThreadTest, test_not_self) {
  MessageLoopThread message_loop_thread("test_thread");
  message_loop_thread.StartUp();
  ASSERT_GE(message_loop_thread.GetThreadId(), 0);
  ASSERT_NE(message_loop_thread.GetThreadId(),
            base::PlatformThread::CurrentId());
}

TEST_F(MessageLoopThreadTest, test_shutdown_without_start) {
  MessageLoopThread message_loop_thread("test_thread");
  message_loop_thread.ShutDown();
  ASSERT_LT(message_loop_thread.GetThreadId(), 0);
}

TEST_F(MessageLoopThreadTest, test_do_in_thread_before_start) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  ASSERT_FALSE(message_loop_thread.DoInThread(
      FROM_HERE, base::Bind(&MessageLoopThreadTest::ShouldNotHappen,
                            base::Unretained(this))));
}

TEST_F(MessageLoopThreadTest, test_do_in_thread_after_shutdown) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  message_loop_thread.ShutDown();
  ASSERT_FALSE(message_loop_thread.DoInThread(
      FROM_HERE, base::Bind(&MessageLoopThreadTest::ShouldNotHappen,
                            base::Unretained(this))));
}

TEST_F(MessageLoopThreadTest, test_name) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  ASSERT_GE(message_loop_thread.GetThreadId(), 0);
  std::promise<std::string> name_promise;
  std::future<std::string> name_future = name_promise.get_future();
  message_loop_thread.DoInThread(
      FROM_HERE,
      base::BindOnce(&MessageLoopThreadTest::GetName, base::Unretained(this),
                     std::move(name_promise)));
  std::string my_name = name_future.get();
  ASSERT_EQ(name, my_name);
  ASSERT_EQ(name, message_loop_thread.GetName());
}

TEST_F(MessageLoopThreadTest, test_thread_id) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  base::PlatformThreadId thread_id = message_loop_thread.GetThreadId();
  ASSERT_GE(thread_id, 0);
  std::promise<base::PlatformThreadId> thread_id_promise;
  std::future<base::PlatformThreadId> thread_id_future =
      thread_id_promise.get_future();
  message_loop_thread.DoInThread(
      FROM_HERE,
      base::BindOnce(&MessageLoopThreadTest::GetThreadId,
                     base::Unretained(this), std::move(thread_id_promise)));
  base::PlatformThreadId my_thread_id = thread_id_future.get();
  ASSERT_EQ(thread_id, my_thread_id);
}

TEST_F(MessageLoopThreadTest, test_set_realtime_priority_fail_before_start) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  ASSERT_FALSE(message_loop_thread.EnableRealTimeScheduling());
}

TEST_F(MessageLoopThreadTest, test_set_realtime_priority_success) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  bool ret = message_loop_thread.EnableRealTimeScheduling();
  if (!ret) {
    if (CanSetCurrentThreadPriority()) {
      FAIL() << "Cannot set real time priority even though we have permission";
    } else {
      LOG(WARNING) << "Allowing EnableRealTimeScheduling to fail because we"
                      " don't have CAP_SYS_NICE capability";
      // Log record in XML
      RecordProperty("MessageLoopThreadTestConditionalSuccess",
                     "Mark test as success even though EnableRealTimeScheduling"
                     " failed because we don't have CAP_SYS_NICE capability");
      // Quit early since further verification is no longer needed
      return;
    }
  }
  std::promise<void> execution_promise;
  std::future<void> execution_future = execution_promise.get_future();
  int scheduling_policy = -1;
  int scheduling_priority = -1;
  message_loop_thread.DoInThread(
      FROM_HERE,
      base::BindOnce(&MessageLoopThreadTest::GetSchedulingPolicyAndPriority,
                     base::Unretained(this), &scheduling_policy,
                     &scheduling_priority, std::move(execution_promise)));
  execution_future.wait();
  ASSERT_EQ(scheduling_policy, SCHED_FIFO);
  // Internal implementation verified here
  ASSERT_EQ(scheduling_priority, 1);
  std::promise<pid_t> tid_promise;
  std::future<pid_t> tid_future = tid_promise.get_future();
  message_loop_thread.DoInThread(
      FROM_HERE,
      base::BindOnce(&MessageLoopThreadTest::GetLinuxTid,
                     base::Unretained(this), std::move(tid_promise)));
  pid_t linux_tid = tid_future.get();
  ASSERT_GT(linux_tid, 0);
  ASSERT_EQ(sched_getscheduler(linux_tid), SCHED_FIFO);
  struct sched_param param = {};
  ASSERT_EQ(sched_getparam(linux_tid, &param), 0);
  // Internal implementation verified here
  ASSERT_EQ(param.sched_priority, 1);
}

TEST_F(MessageLoopThreadTest, test_message_loop_null_before_start) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  ASSERT_EQ(message_loop_thread.message_loop(), nullptr);
}

TEST_F(MessageLoopThreadTest, test_message_loop_not_null_start) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  ASSERT_NE(message_loop_thread.message_loop(), nullptr);
}

TEST_F(MessageLoopThreadTest, test_message_loop_null_after_stop) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  ASSERT_NE(message_loop_thread.message_loop(), nullptr);
  message_loop_thread.ShutDown();
  ASSERT_EQ(message_loop_thread.message_loop(), nullptr);
}

TEST_F(MessageLoopThreadTest, test_to_string_method) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  std::string thread_string_before_start = message_loop_thread.ToString();
  ASSERT_FALSE(thread_string_before_start.empty());
  LOG(INFO) << "Before start: " << message_loop_thread;
  message_loop_thread.StartUp();
  std::string thread_string_running = message_loop_thread.ToString();
  ASSERT_FALSE(thread_string_running.empty());
  LOG(INFO) << "Running: " << message_loop_thread;
  // String representation should look different when thread is not running
  ASSERT_STRNE(thread_string_running.c_str(),
               thread_string_before_start.c_str());
  message_loop_thread.ShutDown();
  std::string thread_string_after_shutdown = message_loop_thread.ToString();
  LOG(INFO) << "After shutdown: " << message_loop_thread;
  // String representation should look the same when thread is not running
  ASSERT_STREQ(thread_string_after_shutdown.c_str(),
               thread_string_before_start.c_str());
}

// Verify the message loop thread will shutdown after callback finishes
TEST_F(MessageLoopThreadTest, shut_down_while_in_callback) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  std::promise<std::string> name_promise;
  std::future<std::string> name_future = name_promise.get_future();
  uint32_t delay_ms = 5;
  message_loop_thread.DoInThread(
      FROM_HERE, base::BindOnce(&MessageLoopThreadTest::SleepAndGetName,
                                base::Unretained(this), std::move(name_promise),
                                delay_ms));
  message_loop_thread.ShutDown();
  std::string my_name = name_future.get();
  ASSERT_EQ(name, my_name);
}

// Verify the message loop thread will shutdown after callback finishes
TEST_F(MessageLoopThreadTest, shut_down_while_in_callback_check_lock) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  message_loop_thread.DoInThread(
      FROM_HERE,
      base::BindOnce([](MessageLoopThread* thread) { thread->IsRunning(); },
                     &message_loop_thread));
  message_loop_thread.ShutDown();
}

// Verify multiple threads try shutdown, no deadlock/crash
TEST_F(MessageLoopThreadTest, shut_down_multi_thread) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  auto thread = std::thread(&MessageLoopThread::ShutDown, &message_loop_thread);
  message_loop_thread.ShutDown();
  thread.join();
}

// Verify multiple threads try startup, no deadlock/crash
TEST_F(MessageLoopThreadTest, start_up_multi_thread) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  auto thread = std::thread(&MessageLoopThread::StartUp, &message_loop_thread);
  thread.join();
}

// Verify multiple threads try startup/shutdown, no deadlock/crash
TEST_F(MessageLoopThreadTest, start_up_shut_down_multi_thread) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  auto thread = std::thread(&MessageLoopThread::ShutDown, &message_loop_thread);
  thread.join();
}

// Verify multiple threads try shutdown/startup, no deadlock/crash
TEST_F(MessageLoopThreadTest, shut_down_start_up_multi_thread) {
  std::string name = "test_thread";
  MessageLoopThread message_loop_thread(name);
  message_loop_thread.StartUp();
  message_loop_thread.ShutDown();
  auto thread = std::thread(&MessageLoopThread::StartUp, &message_loop_thread);
  thread.join();
}