/*
 * Copyright 2017 The Cartographer Authors
 *
 * 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 <condition_variable>
#include <mutex>

#include "cartographer/mapping/internal/test_helpers.h"
#include "cartographer/mapping/local_slam_result_data.h"
#include "cartographer_grpc/client/map_builder_stub.h"
#include "cartographer_grpc/internal/map_builder_server.h"
#include "cartographer_grpc/internal/testing/mock_map_builder.h"
#include "cartographer_grpc/internal/testing/mock_trajectory_builder.h"
#include "cartographer_grpc/map_builder_server_options.h"
#include "glog/logging.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

using ::cartographer::mapping::MapBuilder;
using ::cartographer::mapping::MapBuilderInterface;
using ::cartographer::mapping::PoseGraphInterface;
using ::cartographer::mapping::TrajectoryBuilderInterface;
using ::testing::_;
using SensorId = ::cartographer::mapping::TrajectoryBuilderInterface::SensorId;

namespace cartographer {
namespace cloud {
namespace {

const SensorId kImuSensorId{SensorId::SensorType::IMU, "imu"};
const SensorId kRangeSensorId{SensorId::SensorType::RANGE, "range"};
constexpr double kDuration = 4.;         // Seconds.
constexpr double kTimeStep = 0.1;        // Seconds.
constexpr double kTravelDistance = 1.2;  // Meters.

class ClientServerTest : public ::testing::Test {
 protected:
  void SetUp() override {
    // TODO(cschuet): Due to the hard-coded addresses these tests will become
    // flaky when run in parallel.
    const std::string kMapBuilderServerLua = R"text(
      include "map_builder_server.lua"
      MAP_BUILDER.use_trajectory_builder_2d = true
      MAP_BUILDER.pose_graph.optimize_every_n_nodes = 0
      MAP_BUILDER_SERVER.num_event_threads = 1
      MAP_BUILDER_SERVER.num_grpc_threads = 1
      MAP_BUILDER_SERVER.uplink_server_address = ""
      return MAP_BUILDER_SERVER)text";
    auto map_builder_server_parameters =
        mapping::test::ResolveLuaParameters(kMapBuilderServerLua);
    map_builder_server_options_ =
        CreateMapBuilderServerOptions(map_builder_server_parameters.get());
    const std::string kTrajectoryBuilderLua = R"text(
      include "trajectory_builder.lua"
      TRAJECTORY_BUILDER.trajectory_builder_2d.use_imu_data = false
      TRAJECTORY_BUILDER.trajectory_builder_2d.submaps.num_range_data = 4
      return TRAJECTORY_BUILDER)text";
    auto trajectory_builder_parameters =
        mapping::test::ResolveLuaParameters(kTrajectoryBuilderLua);
    trajectory_builder_options_ = mapping::CreateTrajectoryBuilderOptions(
        trajectory_builder_parameters.get());
    local_slam_result_callback_ =
        [this](
            int, common::Time, transform::Rigid3d local_pose, sensor::RangeData,
            std::unique_ptr<
                const mapping::TrajectoryBuilderInterface::InsertionResult>) {
          std::unique_lock<std::mutex> lock(local_slam_result_mutex_);
          local_slam_result_poses_.push_back(local_pose);
          lock.unlock();
          local_slam_result_condition_.notify_all();
        };
  }

  void InitializeRealServer() {
    auto map_builder = common::make_unique<MapBuilder>(
        map_builder_server_options_.map_builder_options());
    server_ = common::make_unique<MapBuilderServer>(map_builder_server_options_,
                                                    std::move(map_builder));
    EXPECT_TRUE(server_ != nullptr);
  }

  void InitializeServerWithMockMapBuilder() {
    auto mock_map_builder = common::make_unique<testing::MockMapBuilder>();
    mock_map_builder_ = mock_map_builder.get();
    server_ = common::make_unique<MapBuilderServer>(
        map_builder_server_options_, std::move(mock_map_builder));
    EXPECT_TRUE(server_ != nullptr);
    mock_trajectory_builder_ =
        common::make_unique<testing::MockTrajectoryBuilder>();
  }

  void InitializeStub() {
    stub_ = common::make_unique<MapBuilderStub>(
        map_builder_server_options_.server_address());
    EXPECT_TRUE(stub_ != nullptr);
  }

  void WaitForLocalSlamResults(size_t size) {
    std::unique_lock<std::mutex> lock(local_slam_result_mutex_);
    local_slam_result_condition_.wait(
        lock, [&] { return local_slam_result_poses_.size() >= size; });
  }

  proto::MapBuilderServerOptions map_builder_server_options_;
  testing::MockMapBuilder* mock_map_builder_;
  std::unique_ptr<testing::MockTrajectoryBuilder> mock_trajectory_builder_;
  ::cartographer::mapping::proto::TrajectoryBuilderOptions
      trajectory_builder_options_;
  std::unique_ptr<MapBuilderServer> server_;
  std::unique_ptr<MapBuilderStub> stub_;
  TrajectoryBuilderInterface::LocalSlamResultCallback
      local_slam_result_callback_;
  std::condition_variable local_slam_result_condition_;
  std::mutex local_slam_result_mutex_;
  std::vector<transform::Rigid3d> local_slam_result_poses_;
};

TEST_F(ClientServerTest, StartAndStopServer) {
  InitializeRealServer();
  server_->Start();
  server_->Shutdown();
}

TEST_F(ClientServerTest, AddTrajectoryBuilder) {
  InitializeRealServer();
  server_->Start();
  InitializeStub();
  int trajectory_id = stub_->AddTrajectoryBuilder(
      {kImuSensorId}, trajectory_builder_options_, nullptr);
  stub_->FinishTrajectory(trajectory_id);
  server_->Shutdown();
}

TEST_F(ClientServerTest, AddTrajectoryBuilderWithMock) {
  InitializeServerWithMockMapBuilder();
  server_->Start();
  InitializeStub();
  std::set<SensorId> expected_sensor_ids = {kImuSensorId};
  EXPECT_CALL(
      *mock_map_builder_,
      AddTrajectoryBuilder(::testing::ContainerEq(expected_sensor_ids), _, _))
      .WillOnce(::testing::Return(3));
  EXPECT_CALL(*mock_map_builder_, GetTrajectoryBuilder(_))
      .WillRepeatedly(::testing::Return(nullptr));
  int trajectory_id = stub_->AddTrajectoryBuilder(
      expected_sensor_ids, trajectory_builder_options_, nullptr);
  EXPECT_EQ(trajectory_id, 3);
  EXPECT_CALL(*mock_map_builder_, FinishTrajectory(trajectory_id));
  stub_->FinishTrajectory(trajectory_id);
  server_->Shutdown();
}

TEST_F(ClientServerTest, AddSensorData) {
  trajectory_builder_options_.mutable_trajectory_builder_2d_options()
      ->set_use_imu_data(true);
  InitializeRealServer();
  server_->Start();
  InitializeStub();
  int trajectory_id = stub_->AddTrajectoryBuilder(
      {kImuSensorId}, trajectory_builder_options_, nullptr);
  TrajectoryBuilderInterface* trajectory_stub =
      stub_->GetTrajectoryBuilder(trajectory_id);
  sensor::ImuData imu_data{common::FromUniversal(42),
                           Eigen::Vector3d(0., 0., 9.8),
                           Eigen::Vector3d::Zero()};
  trajectory_stub->AddSensorData(kImuSensorId.id, imu_data);
  stub_->FinishTrajectory(trajectory_id);
  server_->Shutdown();
}

TEST_F(ClientServerTest, AddSensorDataWithMock) {
  InitializeServerWithMockMapBuilder();
  server_->Start();
  InitializeStub();
  std::set<SensorId> expected_sensor_ids = {kImuSensorId};
  EXPECT_CALL(
      *mock_map_builder_,
      AddTrajectoryBuilder(::testing::ContainerEq(expected_sensor_ids), _, _))
      .WillOnce(::testing::Return(3));
  int trajectory_id = stub_->AddTrajectoryBuilder(
      expected_sensor_ids, trajectory_builder_options_, nullptr);
  EXPECT_EQ(trajectory_id, 3);
  EXPECT_CALL(*mock_map_builder_, GetTrajectoryBuilder(_))
      .WillRepeatedly(::testing::Return(mock_trajectory_builder_.get()));
  mapping::TrajectoryBuilderInterface* trajectory_stub =
      stub_->GetTrajectoryBuilder(trajectory_id);
  sensor::ImuData imu_data{common::FromUniversal(42),
                           Eigen::Vector3d(0., 0., 9.8),
                           Eigen::Vector3d::Zero()};
  EXPECT_CALL(*mock_trajectory_builder_,
              AddSensorData(::testing::StrEq(kImuSensorId.id),
                            ::testing::Matcher<const sensor::ImuData&>(_)))
      .WillOnce(::testing::Return());
  trajectory_stub->AddSensorData(kImuSensorId.id, imu_data);
  EXPECT_CALL(*mock_map_builder_, FinishTrajectory(trajectory_id));
  stub_->FinishTrajectory(trajectory_id);
  server_->Shutdown();
}

TEST_F(ClientServerTest, LocalSlam2D) {
  InitializeRealServer();
  server_->Start();
  InitializeStub();
  int trajectory_id =
      stub_->AddTrajectoryBuilder({kRangeSensorId}, trajectory_builder_options_,
                                  local_slam_result_callback_);
  TrajectoryBuilderInterface* trajectory_stub =
      stub_->GetTrajectoryBuilder(trajectory_id);
  const auto measurements = mapping::test::GenerateFakeRangeMeasurements(
      kTravelDistance, kDuration, kTimeStep);
  for (const auto& measurement : measurements) {
    trajectory_stub->AddSensorData(kRangeSensorId.id, measurement);
  }
  WaitForLocalSlamResults(measurements.size());
  stub_->FinishTrajectory(trajectory_id);
  EXPECT_EQ(local_slam_result_poses_.size(), measurements.size());
  EXPECT_NEAR(kTravelDistance,
              (local_slam_result_poses_.back().translation() -
               local_slam_result_poses_.front().translation())
                  .norm(),
              0.1 * kTravelDistance);
  server_->Shutdown();
}

TEST_F(ClientServerTest, GlobalSlam3D) {
  map_builder_server_options_.mutable_map_builder_options()
      ->set_use_trajectory_builder_2d(false);
  map_builder_server_options_.mutable_map_builder_options()
      ->set_use_trajectory_builder_3d(true);
  map_builder_server_options_.mutable_map_builder_options()
      ->mutable_pose_graph_options()
      ->set_optimize_every_n_nodes(3);
  trajectory_builder_options_.mutable_trajectory_builder_3d_options()
      ->mutable_motion_filter_options()
      ->set_max_distance_meters(0);
  trajectory_builder_options_.mutable_trajectory_builder_3d_options()
      ->mutable_motion_filter_options()
      ->set_max_angle_radians(0);
  InitializeRealServer();
  server_->Start();
  InitializeStub();
  int trajectory_id = stub_->AddTrajectoryBuilder(
      {kRangeSensorId, kImuSensorId}, trajectory_builder_options_,
      local_slam_result_callback_);
  TrajectoryBuilderInterface* trajectory_stub =
      stub_->GetTrajectoryBuilder(trajectory_id);
  const auto measurements = mapping::test::GenerateFakeRangeMeasurements(
      kTravelDistance, kDuration, kTimeStep);
  for (const auto& measurement : measurements) {
    sensor::ImuData imu_data{
        measurement.time - common::FromSeconds(kTimeStep / 2),
        Eigen::Vector3d(0., 0., 9.8), Eigen::Vector3d::Zero()};
    trajectory_stub->AddSensorData(kImuSensorId.id, imu_data);
    trajectory_stub->AddSensorData(kRangeSensorId.id, measurement);
  }
  // First range data will not call back while initializing PoseExtrapolator, so
  // expect one less.
  WaitForLocalSlamResults(measurements.size() - 1);
  stub_->FinishTrajectory(trajectory_id);
  EXPECT_NEAR(kTravelDistance,
              (local_slam_result_poses_.back().translation() -
               local_slam_result_poses_.front().translation())
                  .norm(),
              0.1 * kTravelDistance);
  server_->Shutdown();
}

}  // namespace
}  // namespace cloud
}  // namespace cartographer