// Copyright 2020 The Chromium OS 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 <gtest/gtest.h>

#include <algorithm>
#include <limits>
#include <queue>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include <base/rand_util.h>
#include <base/threading/thread.h>
#include <mojo/core/embedder/scoped_ipc_support.h>
#include <mojo/public/cpp/bindings/receiver_set.h>

#include <libmems/common_types.h>
#include <libmems/test_fakes.h>

#include "iioservice/daemon/samples_handler.h"
#include "iioservice/daemon/test_fakes.h"
#include "iioservice/include/constants.h"
#include "mojo/sensor.mojom.h"

namespace iioservice {

namespace {

constexpr double kMinFrequency = 1.25;
constexpr double kMaxFrequency = 40.0;

constexpr int kFakeTimeoutInMilliseconds = 10;
constexpr double kFooFrequency = 20.0;
constexpr int kNumFailures = 10;

double FixFrequency(double frequency) {
  if (frequency < kFrequencyEpsilon)
    return 0.0;

  if (frequency < kMinFrequency)
    return kMinFrequency;

  if (frequency > kMaxFrequency)
    return kMaxFrequency;

  return frequency;
}

class SamplesHandlerTestOnMinMaxFrequencyWithParam
    : public ::testing::TestWithParam<
          std::tuple<std::string, bool, double, double>> {
 protected:
  void SetUp() override {
    device_ = std::make_unique<libmems::fakes::FakeIioDevice>(
        nullptr, fakes::kAccelDeviceName, fakes::kAccelDeviceId);

    EXPECT_TRUE(device_->WriteStringAttribute(kSamplingFrequencyAvailable,
                                              std::get<0>(GetParam())));

    result_ = SamplesHandler::GetDevMinMaxFrequency(device_.get(), &min_freq_,
                                                    &max_freq_);
  }

  std::unique_ptr<libmems::fakes::FakeIioDevice> device_;
  bool result_;
  double min_freq_ = -1;
  double max_freq_ = -1;
};

TEST_P(SamplesHandlerTestOnMinMaxFrequencyWithParam, ParseMinMaxFrequency) {
  EXPECT_EQ(result_, std::get<1>(GetParam()));
  if (!result_)
    return;

  EXPECT_EQ(min_freq_, std::get<2>(GetParam()));
  EXPECT_EQ(max_freq_, std::get<3>(GetParam()));
}

INSTANTIATE_TEST_SUITE_P(
    SamplesHandlerTestOnMinMaxFrequencyWithParamRun,
    SamplesHandlerTestOnMinMaxFrequencyWithParam,
    ::testing::Values(
        std::make_tuple("  ", false, 0.0, 0.0),
        std::make_tuple("  0abc  ", false, 0.0, 0.0),
        std::make_tuple(" 0.0001 ", false, 0.0, 0.0),
        std::make_tuple("0.5  ", true, 0.5, 0.5),
        std::make_tuple("  1000  ", true, 1000.0, 1000.0),
        std::make_tuple("1.0 100.0 ", true, 1.0, 100.0),
        std::make_tuple("1.0 10.0 100.0 ", true, 1.0, 100.0),
        std::make_tuple("1.0 a b c 100.0 ", true, 1.0, 100.0),
        std::make_tuple("0.0 a b c 100.0 ", false, 0.0, 0.0),
        std::make_tuple("0.0 1.0 100.0 ", true, 1.0, 100.0),
        std::make_tuple("0.0 2.0 a b c 100.0 ", true, 2.0, 100.0)));

class SamplesHandlerTestBase {
 protected:
  void OnSampleUpdatedCallback(mojo::ReceiverId id,
                               libmems::IioDevice::IioSample sample) {
    CHECK(ipc_thread_->task_runner()->BelongsToCurrentThread());
    CHECK_LT(id, observers_.size());

    observers_[id]->OnSampleUpdated(std::move(sample));
  }
  void OnErrorOccurredCallback(mojo::ReceiverId id,
                               cros::mojom::ObserverErrorType type) {
    CHECK(ipc_thread_->task_runner()->BelongsToCurrentThread());
    if (id >= observers_.size()) {
      CHECK_EQ(type, cros::mojom::ObserverErrorType::FREQUENCY_INVALID);
      return;
    }

    observers_[id]->OnErrorOccurred(type);
  }

  void SetUpBase() {
    device_ = std::make_unique<libmems::fakes::FakeIioDevice>(
        nullptr, fakes::kAccelDeviceName, fakes::kAccelDeviceId);
    EXPECT_TRUE(device_->WriteStringAttribute(
        kSamplingFrequencyAvailable, fakes::kFakeSamplingFrequencyAvailable));

    for (int i = 0; i < base::size(libmems::fakes::kFakeAccelChns); ++i) {
      device_->AddChannel(std::make_unique<libmems::fakes::FakeIioChannel>(
          libmems::fakes::kFakeAccelChns[i], true));
    }

    EXPECT_TRUE(
        device_->WriteDoubleAttribute(libmems::kSamplingFrequencyAttr, 0.0));

    ipc_thread_ = std::make_unique<base::Thread>("IPCThread");
    EXPECT_TRUE(ipc_thread_->StartWithOptions(
        base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));

    sample_thread_ = std::make_unique<base::Thread>("SampleThread");
    EXPECT_TRUE(sample_thread_->StartWithOptions(
        base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));

    handler_ = fakes::FakeSamplesHandler::CreateWithFifo(
        ipc_thread_->task_runner(), sample_thread_->task_runner(),
        device_.get(),
        base::BindRepeating(&SamplesHandlerTestBase::OnSampleUpdatedCallback,
                            base::Unretained(this)),
        base::BindRepeating(&SamplesHandlerTestBase::OnErrorOccurredCallback,
                            base::Unretained(this)));
    EXPECT_TRUE(handler_);
  }

  void TearDownBase() {
    handler_.reset();
    sample_thread_->Stop();

    EXPECT_EQ(device_->ReadDoubleAttribute(libmems::kSamplingFrequencyAttr)
                  .value_or(-1),
              0.0);

    observers_.clear();
    ipc_thread_->Stop();
  }

  std::unique_ptr<libmems::fakes::FakeIioDevice> device_;

  std::unique_ptr<base::Thread> ipc_thread_;
  std::unique_ptr<base::Thread> sample_thread_;

  fakes::FakeSamplesHandler::ScopedFakeSamplesHandler handler_ = {
      nullptr, SamplesHandler::SamplesHandlerDeleter};
  std::vector<ClientData> clients_data_;
  std::vector<fakes::FakeSamplesObserver::ScopedFakeSamplesObserver> observers_;
};

class SamplesHandlerTest : public ::testing::Test,
                           public SamplesHandlerTestBase {
 protected:
  void SetUp() override { SetUpBase(); }

  void TearDown() override { TearDownBase(); }
};

// Add clients with only timestamp channel enabled, enable all other channels,
// and disable all channels except for accel_x. Enabled channels are checked
// after each modification.
TEST_F(SamplesHandlerTest, UpdateChannelsEnabled) {
  // No samples in this test
  device_->SetPauseCallbackAtKthSamples(0, base::BindOnce([]() {}));

  std::vector<double> freqs = {0.0, 10.0};
  clients_data_.resize(freqs.size());
  for (size_t i = 0; i < freqs.size(); ++i) {
    ClientData& client_data = clients_data_[i];

    client_data.id = i;
    client_data.iio_device = device_.get();
    client_data.enabled_chn_indices.emplace(3);  // timestamp
    client_data.timeout = 0;
    client_data.frequency = freqs[i];

    handler_->AddClient(&client_data);

    handler_->UpdateChannelsEnabled(
        &client_data, std::vector<int32_t>{1, 0, 2}, true,
        base::BindOnce([](const std::vector<int32_t>& failed_indices) {
          EXPECT_TRUE(failed_indices.empty());
        }));

    handler_->GetChannelsEnabled(
        &client_data, std::vector<int32_t>{1, 0, 2, 3},
        base::BindOnce([](const std::vector<bool>& enabled) {
          EXPECT_EQ(enabled.size(), 4);
          EXPECT_TRUE(enabled[0] && enabled[1] && enabled[2] && enabled[3]);
        }));

    handler_->UpdateChannelsEnabled(
        &client_data, std::vector<int32_t>{2, 1, 3}, false,
        base::BindOnce(
            [](ClientData* client_data, int32_t chn_index,
               const std::vector<int32_t>& failed_indices) {
              EXPECT_EQ(client_data->enabled_chn_indices.size(), 1);
              EXPECT_EQ(*client_data->enabled_chn_indices.begin(), chn_index);
              EXPECT_TRUE(failed_indices.empty());
            },
            &client_data, 0));
  }

  // Remove clients
  for (auto& client_data : clients_data_)
    handler_->RemoveClient(&client_data);
}

TEST_F(SamplesHandlerTest, BadDeviceWithNoSamples) {
  base::MessageLoopForIO message_loop;

  device_->DisableFd();

  std::vector<double> freqs = {5.0, 0.0, 10.0, 100.0};
  clients_data_.resize(freqs.size());
  std::vector<std::unique_ptr<base::RunLoop>> loops;

  std::multiset<std::pair<int, cros::mojom::ObserverErrorType>> rt_failures;
  rt_failures.insert(
      std::make_pair(0, cros::mojom::ObserverErrorType::READ_TIMEOUT));

  size_t fd_failed_cnt = 0;
  for (size_t i = 0; i < freqs.size(); ++i) {
    if (freqs[i] > 0.0)
      ++fd_failed_cnt;
  }

  for (size_t i = 0; i < freqs.size(); ++i) {
    ClientData& client_data = clients_data_[i];
    std::unique_ptr<base::RunLoop> run_loop = std::make_unique<base::RunLoop>();

    client_data.id = i;
    client_data.iio_device = device_.get();
    client_data.enabled_chn_indices.emplace(3);  // timestamp
    client_data.frequency = freqs[i];
    client_data.timeout = kFakeTimeoutInMilliseconds;

    auto failures = rt_failures;
    if (freqs[i] == 0.0) {
      failures.insert(
          std::make_pair(0, cros::mojom::ObserverErrorType::FREQUENCY_INVALID));
    } else {
      for (size_t j = 0; j < fd_failed_cnt; ++j) {
        failures.insert(
            std::make_pair(0, cros::mojom::ObserverErrorType::GET_FD_FAILED));
      }
      --fd_failed_cnt;
    }

    // Don't care about frequencies as there would be no samples.
    auto fake_observer = fakes::FakeSamplesObserver::Create(
        ipc_thread_->task_runner(), run_loop->QuitClosure(), device_.get(),
        std::move(failures), kFooFrequency, kFooFrequency, kFooFrequency,
        kFooFrequency);

    handler_->AddClient(&client_data);

    loops.emplace_back(std::move(run_loop));
    observers_.emplace_back(std::move(fake_observer));
  }

  // Wait until all observers receive the READ_TIMEOUT error
  for (auto& run_loop : loops)
    run_loop->Run();

  // Remove clients
  for (auto& client_data : clients_data_)
    handler_->RemoveClient(&client_data);
}

class SamplesHandlerTestWithParam
    : public ::testing::TestWithParam<std::vector<std::pair<double, double>>>,
      public SamplesHandlerTestBase {
 protected:
  void SetUp() override { SetUpBase(); }

  void TearDown() override { TearDownBase(); }
};

// Add clients with the first frequencies set, update clients with the second
// frequencies, and remove clients. Clients' frequencies and the sample
// handler's |max_frequency_| are checked after each modification.
TEST_P(SamplesHandlerTestWithParam, UpdateFrequency) {
  // No samples in this test
  device_->SetPauseCallbackAtKthSamples(0, base::BindOnce([]() {}));

  clients_data_.resize(GetParam().size());

  std::multiset<double> frequencies;

  // Add clients
  for (size_t i = 0; i < GetParam().size(); ++i) {
    ClientData& client_data = clients_data_[i];

    client_data.id = i;
    client_data.iio_device = device_.get();
    // At least one channel enabled
    client_data.enabled_chn_indices.emplace(3);  // timestamp
    client_data.timeout = 0;
    client_data.frequency = GetParam()[i].first;

    handler_->AddClient(&client_data);

    frequencies.emplace(FixFrequency(client_data.frequency));
    handler_->CheckRequestedFrequency(*frequencies.rbegin());
  }

  base::MessageLoopForIO message_loop;

  // Update clients' frequencies
  for (size_t i = 0; i < GetParam().size(); ++i) {
    ClientData& client_data = clients_data_[i];

    double new_freq = GetParam()[i].second;
    handler_->UpdateFrequency(
        &client_data, new_freq,
        base::BindOnce(
            [](ClientData* client_data, double fixed_new_freq,
               double result_freq) {
              EXPECT_EQ(client_data->frequency, fixed_new_freq);
              EXPECT_EQ(result_freq, fixed_new_freq);
            },
            &client_data, FixFrequency(new_freq)));

    auto it = frequencies.find(FixFrequency(GetParam()[i].first));
    EXPECT_TRUE(it != frequencies.end());
    frequencies.erase(it);
    frequencies.emplace(FixFrequency(new_freq));

    handler_->CheckRequestedFrequency(*frequencies.rbegin());
  }

  // Remove clients
  for (size_t i = 0; i < GetParam().size(); ++i) {
    ClientData& client_data = clients_data_[i];

    handler_->RemoveClient(&client_data);
    auto it = frequencies.find(FixFrequency(GetParam()[i].second));
    EXPECT_TRUE(it != frequencies.end());
    frequencies.erase(it);

    handler_->CheckRequestedFrequency(
        i == GetParam().size() - 1 ? 0.0 : *frequencies.rbegin());
  }
}

// Add all clients into the sample handler, read the first |kPauseIndex|
// samples and pause reading, update clients' frequencies and enable accel_y
// channel, and read the rest samples. All samples are checked when received by
// observers.
TEST_P(SamplesHandlerTestWithParam, ReadSamplesWithFrequency) {
  base::MessageLoopForIO message_loop;

  base::RunLoop pause_loop;
  // Set the pause in the beginning to prevent reading samples before all
  // clients added.
  device_->SetPauseCallbackAtKthSamples(
      0, base::BindOnce([](base::Closure quit_closure) { quit_closure.Run(); },
                        pause_loop.QuitClosure()));

  std::multiset<std::pair<int, cros::mojom::ObserverErrorType>> rf_failures;
  for (int i = 0; i < kNumFailures; ++i) {
    int k = base::RandInt(0, base::size(libmems::fakes::kFakeAccelSamples) - 1);

    device_->AddFailedReadAtKthSample(k);
    rf_failures.insert(
        std::make_pair(k, cros::mojom::ObserverErrorType::READ_FAILED));
  }

  clients_data_.resize(GetParam().size());
  std::vector<std::unique_ptr<base::RunLoop>> loops;

  double max_freq = -1, max_freq2 = -1;
  for (size_t i = 0; i < GetParam().size(); ++i) {
    max_freq = std::max(max_freq, GetParam()[i].first);
    max_freq2 = std::max(max_freq2, GetParam()[i].second);
  }

  max_freq = FixFrequency(max_freq);
  max_freq2 = FixFrequency(max_freq2);

  for (size_t i = 0; i < GetParam().size(); ++i) {
    ClientData& client_data = clients_data_[i];
    std::unique_ptr<base::RunLoop> run_loop = std::make_unique<base::RunLoop>();

    client_data.id = i;
    client_data.iio_device = device_.get();
    client_data.enabled_chn_indices.emplace(0);  // accel_x
    client_data.enabled_chn_indices.emplace(2);  // accel_y
    client_data.enabled_chn_indices.emplace(3);  // timestamp
    client_data.frequency = GetParam()[i].first;

    auto failures = rf_failures;
    if (GetParam()[i].first == 0.0) {
      failures.insert(
          std::make_pair(0, cros::mojom::ObserverErrorType::FREQUENCY_INVALID));
    }

    // The fake observer needs |max_freq| and |max_freq2| to calculate the
    // correct values of samples
    auto fake_observer = fakes::FakeSamplesObserver::Create(
        ipc_thread_->task_runner(), run_loop->QuitClosure(), device_.get(),
        std::move(failures), FixFrequency(GetParam()[i].first),
        FixFrequency(GetParam()[i].second), max_freq, max_freq2);

    handler_->AddClient(&client_data);

    loops.emplace_back(std::move(run_loop));
    observers_.emplace_back(std::move(fake_observer));
  }
  pause_loop.Run();

  device_->SetPauseCallbackAtKthSamples(
      fakes::kPauseIndex,
      base::BindOnce(
          [](fakes::FakeSamplesHandler* handler,
             std::vector<ClientData>* clients_data,
             libmems::fakes::FakeIioDevice* device) {
            for (int i = 0; i < clients_data->size(); ++i) {
              ClientData& client_data = clients_data->at(i);

              // Update to the second frequency
              handler->UpdateFrequency(
                  &client_data, GetParam()[i].second,
                  base::BindOnce(
                      [](double fixed_new_freq, double result_freq) {
                        EXPECT_EQ(result_freq, fixed_new_freq);
                      },
                      FixFrequency(GetParam()[i].second)));

              // Enable accel_y
              handler->UpdateChannelsEnabled(
                  &client_data, std::vector<int32_t>{1}, true,
                  base::BindOnce(
                      [](const std::vector<int32_t>& failed_indices) {
                        EXPECT_TRUE(failed_indices.empty());
                      }));
            }

            handler->ResumeReading();  // Read the rest samples
          },
          handler_.get(), &clients_data_, device_.get()));

  handler_->ResumeReading();  // Start reading |kPauseIndex| samples

  // Wait until all observers receive all samples
  for (auto& run_loop : loops)
    run_loop->Run();

  // Remove clients
  for (auto& client_data : clients_data_)
    handler_->RemoveClient(&client_data);
}

INSTANTIATE_TEST_SUITE_P(
    SamplesHandlerTestWithParamRun,
    SamplesHandlerTestWithParam,
    ::testing::Values(std::vector<std::pair<double, double>>(3, {10.0, 10.0}),
                      std::vector<std::pair<double, double>>{
                          {20.0, 50.0}, {10.0, 10.0}, {2.0, 3.0}},
                      std::vector<std::pair<double, double>>{
                          {10.0, 20.0}, {20.0, 30.0}, {0.0, 0.0}},
                      std::vector<std::pair<double, double>>{
                          {80.0, 50.0}, {10.0, 10.0}, {2.0, 3.0}},
                      std::vector<std::pair<double, double>>{
                          {10.0, 40.0}, {0.0, 20.0}, {2.0, 3.0}, {40.0, 10.0}},
                      std::vector<std::pair<double, double>>{
                          {2.0, 10.0}, {10.0, 30.0}, {80.0, 0.0}},
                      std::vector<std::pair<double, double>>{
                          {0.0, 10.0}, {10.0, 30.0}, {80.0, 60.0}},
                      std::vector<std::pair<double, double>>{
                          {2.0, 10.0}, {50.0, 30.0}, {80.0, 60.0}},
                      std::vector<std::pair<double, double>>{{20.0, 30.0},
                                                             {10.0, 10.0}}));

}  // namespace

}  // namespace iioservice