
#include "bmc/scheduler_bmc.h"

#include <chrono>  // NOLINT(build/c++11)
#include <iostream>
#include <memory>
#include <string_view>

#include "scheduler_interface.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/status/status.h"
#include "absl/time/time.h"
#include "boost/asio/io_context.hpp"  // NOLINT(readability/boost)

namespace safepower_agent {
namespace {

TEST(Scheduler_fixtures, periodicCall) {
  testing::MockFunction<void()> MockedCallBack;
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);
  constexpr std::string_view task_name = "test_task";

  EXPECT_EQ(scheduler->PeriodicCall(MockedCallBack.AsStdFunction(),
                                    absl::Milliseconds(100), task_name),
            absl::OkStatus());
  // wait .5 seconds
  EXPECT_CALL(MockedCallBack, Call()).Times(testing::Between(4, 5));
  test_io->run_for(std::chrono::milliseconds(500));
}

TEST(Scheduler_fixtures, delayCall) {
  testing::MockFunction<void()> MockedCallBack;
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);

  constexpr std::string_view task_name = "test_task_delayCall";
  EXPECT_EQ(scheduler->DelayCall(MockedCallBack.AsStdFunction(),
                                 absl::Milliseconds(100), task_name),
            absl::OkStatus());
  EXPECT_CALL(MockedCallBack, Call()).Times(1);
  test_io->run_for(std::chrono::milliseconds(250));
}

TEST(Scheduler_fixtures, cancelCall) {
  testing::MockFunction<void()> MockedCallBack_1;
  testing::MockFunction<void()> MockedCallBack_2;

  EXPECT_CALL(MockedCallBack_1, Call()).Times(2);
  EXPECT_CALL(MockedCallBack_2, Call()).Times(3);

  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);

  constexpr std::string_view task_name_1 = "test_task_1";
  constexpr std::string_view task_name_2 = "test_task_2";
  ASSERT_EQ(scheduler->PeriodicCall(MockedCallBack_1.AsStdFunction(),
                                    absl::Milliseconds(100), task_name_1),
            absl::OkStatus());
  EXPECT_EQ(scheduler->PeriodicCall(MockedCallBack_2.AsStdFunction(),
                                    absl::Milliseconds(150), task_name_2),
            absl::OkStatus());

  test_io->run_for(std::chrono::milliseconds(250));
  ASSERT_EQ(scheduler->CancelCall(task_name_1), absl::OkStatus());
  test_io->run_for(std::chrono::milliseconds(250));
  ASSERT_EQ(scheduler->CancelCall(task_name_2), absl::OkStatus());
}

TEST(Scheduler_fixtures, cancelAll) {
  testing::MockFunction<void()> MockedCallBack;
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);

  constexpr std::string_view task_name_1 = "test_task_1";
  constexpr std::string_view task_name_2 = "test_task_2";
  EXPECT_CALL(MockedCallBack, Call()).Times(0);
  ASSERT_EQ(scheduler->PeriodicCall(MockedCallBack.AsStdFunction(),
                                    absl::Milliseconds(100), task_name_1),
            absl::OkStatus());
  ASSERT_EQ(scheduler->PeriodicCall(MockedCallBack.AsStdFunction(),
                                    absl::Milliseconds(100), task_name_2),
            absl::OkStatus());
  ASSERT_EQ(scheduler->CancelAll(), absl::OkStatus());
  test_io->run_for(std::chrono::milliseconds(1000));
}

TEST(Scheduler_fixtures, shutdown) {
  testing::MockFunction<void()> MockedCallBack;
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);
  boost::asio::steady_timer testTimer(*test_io);

  constexpr std::string_view task_name_1 = "test_task_1";
  constexpr std::string_view task_name_2 = "test_task_2";
  EXPECT_CALL(MockedCallBack, Call()).Times(4);
  ASSERT_EQ(scheduler->PeriodicCall(MockedCallBack.AsStdFunction(),
                                    absl::Milliseconds(100), task_name_1),
            absl::OkStatus());
  ASSERT_EQ(scheduler->PeriodicCall(MockedCallBack.AsStdFunction(),
                                    absl::Milliseconds(100), task_name_2),
            absl::OkStatus());

  testTimer.expires_from_now(std::chrono::milliseconds(250));
  testTimer.async_wait([scheduler](const boost::system::error_code&) mutable {
    ASSERT_EQ(scheduler->Shutdown(), absl::OkStatus());
  });
  // run the event loop until shutdown is called, and run() stops blocking
  test_io->run();
  // continue running the event loop to ensure the timer is not called again
  test_io->run_for(std::chrono::milliseconds(1000));
}

TEST(Scheduler_fixtures, SelfCancel) {
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);
  int count = 0;
  ASSERT_EQ(scheduler->PeriodicCall(
                [&count, &scheduler]() {
                  count++;
                  if (count == 5) {
                    ASSERT_EQ(scheduler->CancelCall("self_cancel_task"),
                              absl::OkStatus());
                  }
                },
                absl::Milliseconds(100), "self_cancel_task"),
            absl::OkStatus());
  test_io->run_for(std::chrono::milliseconds(1000));
  ASSERT_EQ(count, 5);
}

TEST(Scheduler_fixtures, RescheduleSelf) {
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);
  int count = 0;
  // task A is allowed to reschedule itself
  ASSERT_EQ(scheduler->DelayCall([&count, &scheduler](){
    count++;
    ASSERT_EQ(scheduler->DelayCall([&count, &scheduler](){
      count++;
      ASSERT_EQ(scheduler->DelayCall([&count, &scheduler](){
         count++;
      }, absl::Milliseconds(100), "self_reschedule_task"), absl::OkStatus());
    },
    absl::Milliseconds(100),
    "self_reschedule_task"), absl::OkStatus());
  },
  absl::Milliseconds(100),
  "self_reschedule_task"), absl::OkStatus());

  test_io->run_for(std::chrono::milliseconds(500));
  ASSERT_EQ(count, 3);
}

TEST(Scheduler_fixtures, RescheduleOther) {
  auto test_io = std::make_shared<boost::asio::io_context>();
  std::shared_ptr<SchedulerInterface> scheduler =
      std::make_shared<SchedulerBMC>(*test_io);
  int task_a_ct = 0;
  ASSERT_EQ(scheduler->DelayCall([&task_a_ct, &scheduler](){
    task_a_ct++;
    std::cerr << "task a ran";
  }, absl::Milliseconds(200),
  "task_a"), absl::OkStatus());

  // task_a is already running, so it should fail from caller
  ASSERT_EQ(scheduler->DelayCall([](){
  }, absl::Milliseconds(50),
  "task_a"), absl::AlreadyExistsError("Task already exists"));
  test_io->run_for(std::chrono::milliseconds(500));
  ASSERT_EQ(task_a_ct, 1);
}
// TODO error conditions
// - write a test that cancels a non-existing task
// - write a test that cancels a task twice
// - write a test that schedules two test with the same name
//   - both callback, and periodic
// - write a test that cancels all task, when there are not tasks (maybe)

}  // namespace
}  // namespace safepower_agent