#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <array>
#include <chrono>
#include <cmath>
#include <functional>
#include <mutex>
#include <thread>

#include "frc971/wpilib/ahal/AnalogInput.h"
#include "frc971/wpilib/ahal/Counter.h"
#include "frc971/wpilib/ahal/DigitalGlitchFilter.h"
#include "frc971/wpilib/ahal/DriverStation.h"
#include "frc971/wpilib/ahal/Encoder.h"
#include "frc971/wpilib/ahal/VictorSP.h"
#undef ERROR

#include "aos/commonmath.h"
#include "aos/events/event_loop.h"
#include "aos/events/shm_event_loop.h"
#include "aos/init.h"
#include "aos/logging/logging.h"
#include "aos/make_unique.h"
#include "aos/realtime.h"
#include "aos/robot_state/robot_state_generated.h"
#include "aos/time/time.h"
#include "aos/util/log_interval.h"
#include "aos/util/phased_loop.h"
#include "aos/util/wrapping_counter.h"
#include "frc971/autonomous/auto_mode_generated.h"
#include "frc971/control_loops/drivetrain/drivetrain_position_generated.h"
#include "frc971/wpilib/ADIS16470.h"
#include "frc971/wpilib/buffered_pcm.h"
#include "frc971/wpilib/buffered_solenoid.h"
#include "frc971/wpilib/dma.h"
#include "frc971/wpilib/drivetrain_writer.h"
#include "frc971/wpilib/encoder_and_potentiometer.h"
#include "frc971/wpilib/joystick_sender.h"
#include "frc971/wpilib/logging_generated.h"
#include "frc971/wpilib/loop_output_handler.h"
#include "frc971/wpilib/pdp_fetcher.h"
#include "frc971/wpilib/sensor_reader.h"
#include "frc971/wpilib/wpilib_robot_base.h"
#include "y2020/constants.h"
#include "y2020/control_loops/superstructure/superstructure_output_generated.h"
#include "y2020/control_loops/superstructure/superstructure_position_generated.h"

using ::aos::monotonic_clock;
using ::y2020::constants::Values;
namespace superstructure = ::y2020::control_loops::superstructure;
namespace chrono = ::std::chrono;
using aos::make_unique;

namespace y2020 {
namespace wpilib {
namespace {

constexpr double kMaxBringupPower = 12.0;

// TODO(Brian): Fix the interpretation of the result of GetRaw here and in the
// DMA stuff and then removing the * 2.0 in *_translate.
// The low bit is direction.

// TODO(brian): Use ::std::max instead once we have C++14 so that can be
// constexpr.
template <typename T>
constexpr T max(T a, T b) {
  return (a > b) ? a : b;
}

template <typename T, typename... Rest>
constexpr T max(T a, T b, T c, Rest... rest) {
  return max(max(a, b), c, rest...);
}

double drivetrain_translate(int32_t in) {
  return ((static_cast<double>(in) /
           Values::kDrivetrainEncoderCountsPerRevolution()) *
          (2.0 * M_PI)) *
         Values::kDrivetrainEncoderRatio() *
         control_loops::drivetrain::kWheelRadius;
}

double drivetrain_velocity_translate(double in) {
  return (((1.0 / in) / Values::kDrivetrainCyclesPerRevolution()) *
          (2.0 * M_PI)) *
         Values::kDrivetrainEncoderRatio() *
         control_loops::drivetrain::kWheelRadius;
}

constexpr double kMaxFastEncoderPulsesPerSecond =
    Values::kMaxDrivetrainEncoderPulsesPerSecond();
static_assert(kMaxFastEncoderPulsesPerSecond <= 1300000,
              "fast encoders are too fast");
constexpr double kMaxMediumEncoderPulsesPerSecond = kMaxFastEncoderPulsesPerSecond;

static_assert(kMaxMediumEncoderPulsesPerSecond <= 400000,
              "medium encoders are too fast");

}  // namespace

// Class to send position messages with sensor readings to our loops.
class SensorReader : public ::frc971::wpilib::SensorReader {
 public:
  SensorReader(::aos::ShmEventLoop *event_loop)
      : ::frc971::wpilib::SensorReader(event_loop),
        auto_mode_sender_(
            event_loop->MakeSender<::frc971::autonomous::AutonomousMode>(
                "/autonomous")),
        superstructure_position_sender_(
            event_loop->MakeSender<superstructure::Position>(
                "/superstructure")),
        drivetrain_position_sender_(
            event_loop
                ->MakeSender<::frc971::control_loops::drivetrain::Position>(
                    "/drivetrain")) {
    // Set to filter out anything shorter than 1/4 of the minimum pulse width
    // we should ever see.
    UpdateFastEncoderFilterHz(kMaxFastEncoderPulsesPerSecond);
    UpdateMediumEncoderFilterHz(kMaxMediumEncoderPulsesPerSecond);
  }

  // Auto mode switches.
  void set_autonomous_mode(int i, ::std::unique_ptr<frc::DigitalInput> sensor) {
    autonomous_modes_.at(i) = ::std::move(sensor);
  }

  void set_imu(frc971::wpilib::ADIS16470 *imu) { imu_ = imu; }

  void RunIteration() override {
    CHECK_NOTNULL(imu_)->DoReads();

    {
      auto builder = drivetrain_position_sender_.MakeBuilder();
      frc971::control_loops::drivetrain::Position::Builder drivetrain_builder =
          builder.MakeBuilder<frc971::control_loops::drivetrain::Position>();
      drivetrain_builder.add_left_encoder(
          drivetrain_translate(drivetrain_left_encoder_->GetRaw()));
      drivetrain_builder.add_left_speed(
          drivetrain_velocity_translate(drivetrain_left_encoder_->GetPeriod()));

      drivetrain_builder.add_right_encoder(
          -drivetrain_translate(drivetrain_right_encoder_->GetRaw()));
      drivetrain_builder.add_right_speed(-drivetrain_velocity_translate(
          drivetrain_right_encoder_->GetPeriod()));

      builder.Send(drivetrain_builder.Finish());
    }

    {
      auto builder = superstructure_position_sender_.MakeBuilder();
      superstructure::Position::Builder position_builder =
          builder.MakeBuilder<superstructure::Position>();
      builder.Send(position_builder.Finish());
    }

    {
      auto builder = auto_mode_sender_.MakeBuilder();

      uint32_t mode = 0;
      for (size_t i = 0; i < autonomous_modes_.size(); ++i) {
        if (autonomous_modes_[i] && autonomous_modes_[i]->Get()) {
          mode |= 1 << i;
        }
      }

      auto auto_mode_builder =
          builder.MakeBuilder<frc971::autonomous::AutonomousMode>();

      auto_mode_builder.add_mode(mode);

      builder.Send(auto_mode_builder.Finish());
    }
  }

 private:
  ::aos::Sender<::frc971::autonomous::AutonomousMode> auto_mode_sender_;
  ::aos::Sender<superstructure::Position> superstructure_position_sender_;
  ::aos::Sender<::frc971::control_loops::drivetrain::Position>
      drivetrain_position_sender_;

  ::std::array<::std::unique_ptr<frc::DigitalInput>, 2> autonomous_modes_;

  frc971::wpilib::ADIS16470 *imu_ = nullptr;
};

class SuperstructureWriter
    : public ::frc971::wpilib::LoopOutputHandler<superstructure::Output> {
 public:
  SuperstructureWriter(::aos::EventLoop *event_loop)
      : ::frc971::wpilib::LoopOutputHandler<superstructure::Output>(
            event_loop, "/superstructure") {}

 private:
  void Write(const superstructure::Output & /*output*/) override {}

  void Stop() override { AOS_LOG(WARNING, "Superstructure output too old.\n"); }
};

class WPILibRobot : public ::frc971::wpilib::WPILibRobotBase {
 public:
  ::std::unique_ptr<frc::Encoder> make_encoder(int index) {
    return make_unique<frc::Encoder>(10 + index * 2, 11 + index * 2, false,
                                     frc::Encoder::k4X);
  }

  void Run() override {
    aos::FlatbufferDetachedBuffer<aos::Configuration> config =
        aos::configuration::ReadConfig("config.json");

    // Thread 1.
    ::aos::ShmEventLoop joystick_sender_event_loop(&config.message());
    ::frc971::wpilib::JoystickSender joystick_sender(
        &joystick_sender_event_loop);
    AddLoop(&joystick_sender_event_loop);

    // Thread 2.
    ::aos::ShmEventLoop pdp_fetcher_event_loop(&config.message());
    ::frc971::wpilib::PDPFetcher pdp_fetcher(&pdp_fetcher_event_loop);
    AddLoop(&pdp_fetcher_event_loop);

    // Thread 3.
    ::aos::ShmEventLoop sensor_reader_event_loop(&config.message());
    SensorReader sensor_reader(&sensor_reader_event_loop);
    sensor_reader.set_drivetrain_left_encoder(make_encoder(0));
    sensor_reader.set_drivetrain_right_encoder(make_encoder(1));

    auto imu_trigger = make_unique<frc::DigitalInput>(0);
    auto imu_reset = make_unique<frc::DigitalOutput>(1);
    auto spi = make_unique<frc::SPI>(frc::SPI::Port::kOnboardCS2);
    frc971::wpilib::ADIS16470 imu(&sensor_reader_event_loop, spi.get(),
                                  imu_trigger.get(), imu_reset.get());
    sensor_reader.set_imu(&imu);

    AddLoop(&sensor_reader_event_loop);

    // Thread 4.
    ::aos::ShmEventLoop output_event_loop(&config.message());
    output_event_loop.set_name("output_writer");
    ::frc971::wpilib::DrivetrainWriter drivetrain_writer(&output_event_loop);
    drivetrain_writer.set_left_controller0(
        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(0)), true);
    drivetrain_writer.set_right_controller0(
        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(1)), false);

    SuperstructureWriter superstructure_writer(&output_event_loop);

    AddLoop(&output_event_loop);

    RunLoops();
  }
};

}  // namespace wpilib
}  // namespace y2020

AOS_ROBOT_CLASS(::y2020::wpilib::WPILibRobot);