/*
 * peripherals_imu_icm.hpp
 *
 *  Created on: Mar 5, 2021
 *      Author: erki
 */

#ifndef SKULLC_PERIPHERALS_IMU_ICM_HPP_
#define SKULLC_PERIPHERALS_IMU_ICM_HPP_

#include <array>
#include <limits>

#include "peripherals_imu.hpp"
#include "peripherals_utility.hpp"

namespace Peripherals
{

template<typename T, typename HAL>
class ImuIcm : public IImu
{
public:
  using registers_handle = T;
  using hal = HAL;

  enum class GyroScale : std::uint32_t
  {
    DPS_250 = 0,
    DPS_500,
    DPS_1000,
    DPS_2000
  };

  enum class AccelerometerScale : std::uint32_t
  {
    G2 = 0,
    G4,
    G8,
    G16
  };

  registers_handle registers;

  ImuIcm() = delete;
  ImuIcm(const registers_handle& registers) : registers(registers) {}

  void setup() override
  {
    registers.writeRegister(Registers_::PWR_MGMT_1 & Registers_::WRITE_MASK,
                            0b10000000);
    hal::delay(10);

    registers.writeRegister(Registers_::USER_CTRL & Registers_::WRITE_MASK,
                            0b00010000);
    hal::delay(10);

    registers.writeRegister(Registers_::PWR_MGMT_1 & Registers_::WRITE_MASK,
                            0b00000000);
    hal::delay(10);

    registers.writeRegister(Registers_::PWR_MGMT_1 & Registers_::WRITE_MASK,
                            0b00000001);
    hal::delay(10);

    registers.writeRegister(Registers_::CONFIG & Registers_::WRITE_MASK,
                            0x03);// DLPF_CFG = 3, gyro filter = 41/59.0, gyro
                                  // rate = 1KHz, temp filter = 42
    hal::delay(10);

    setGyroscopeScale(scale_gyro_);

    setAccelerometerScale(scale_accel_);

    // ACCEL_FCHOICE_B = 0, A_DLPF_CFG = 3 filter=44.8/61.5 rate=1KHz
    registers.writeRegister(Registers_::ACCEL_CONFIG2 & Registers_::WRITE_MASK,
                            0x03);
    hal::delay(10);

    // SAMPLE_RATE = INTERNAL_SAMPLE_RATE / (1 + SMPLRT_DIV) Where
    // INTERNAL_SAMPLE_RATE = 1kHz
    registers.writeRegister(Registers_::SMPLRT_DIV & Registers_::WRITE_MASK, 0);
    hal::delay(10);

    // Enable interrupt

    // The logic level for INT/DRDY pin is active high.
    // INT/DRDY pin is configured as push-pull.
    // INT/DRDY pin indicates interrupt pulse's width is 50us.
    // Interrupt status is cleared only by reading INT_STATUS register
    registers.writeRegister(Registers_::INT_PIN_CFG & Registers_::WRITE_MASK,
                            0);
    hal::delay(10);

    registers.writeRegister(Registers_::INT_ENABLE & Registers_::WRITE_MASK, 1);
    hal::delay(10);
  }

  void calibrate(const std::uint32_t samples) override
  {
    std::array<std::int32_t, 3> avg_gyro;
    std::array<std::int32_t, 3> avg_accel;

    for (std::uint32_t i = 0; i < samples; i++)
    {
      std::array<std::int16_t, 3> raw;
      auto add_to_avg = [&raw](std::array<std::int32_t, 3>& out) {
        for (std::uint32_t j = 0; j < 3; j++)
          out[j] += raw[j];
      };

      readGyroRaw(raw.data());
      add_to_avg(avg_gyro);

      readAccelerometerRaw(raw.data());
      add_to_avg(avg_accel);
    }

    for (std::uint32_t i = 0; i < 3; i++)
    {
      const std::int32_t max = std::numeric_limits<std::int16_t>::max();
      const std::int32_t min = std::numeric_limits<std::int16_t>::min();

      bias_gyro_[i] = clamp(avg_gyro[i], max, min);
      bias_accel_[i] = clamp(avg_accel[i], max, min);
    }

    bias_accel_[2] -= accelerometerReadingToRaw(1);
  }

  void setGyroscopeScale(const GyroScale scale)
  {
    const std::uint8_t current_config =
            registers.readRegister(Registers_::GYRO_CONFIG | Registers_::READ_MASK);
    const std::uint8_t new_config =
            (current_config & 0xE7) | (std::uint8_t(scale) << 3);
    registers.writeRegister(Registers_::GYRO_CONFIG & Registers_::WRITE_MASK,
                            new_config);

    scale_gyro_ = scale;
  }

  void setAccelerometerScale(const AccelerometerScale scale)
  {
    const std::uint8_t current_config = registers.readRegister(
            Registers_::ACCEL_CONFIG | Registers_::READ_MASK);
    const std::uint8_t new_config =
            (current_config & 0xE7) | (std::uint8_t(scale) << 3);
    registers.writeRegister(Registers_::ACCEL_CONFIG & Registers_::WRITE_MASK,
                            new_config);

    scale_accel_ = scale;
  }

  void readGyro(float* output) override
  {
    uint8_t data[6] = {0};
    registers.readRegisterMultibyte(
            Registers_::GYRO_XOUT_H | Registers_::READ_MASK, data, 6);

    for (std::uint32_t i = 0; i < 3; i++)
    {
      const std::int16_t bit = byteToTypeBE<std::int16_t, 2>(&data[i * 2]);
      output[i] = gyroRawToReading(bit);
    }
  }

  void readGyroRaw(std::int16_t* output) override
  {
    uint8_t data[6] = {0};
    registers.readRegisterMultibyte(
            Registers_::GYRO_XOUT_H | Registers_::READ_MASK, data, 6);

    for (std::uint32_t i = 0; i < 3; i++)
    {
      output[i] = byteToTypeBE<std::int16_t, 2>(&data[i * 2]);
    }
  }

  void readAccelerometer(float* output) override
  {
    uint8_t data[6] = {0};
    registers.readRegisterMultibyte(
            Registers_::ACCEL_XOUT_H | Registers_::READ_MASK, data, 6);

    for (std::uint32_t i = 0; i < 3; i++)
    {
      const std::int16_t bit = byteToTypeBE<std::int16_t, 2>(&data[i * 2]);
      output[i] = accelerometerRawToReading(bit);
    }
  }

  void readAccelerometerRaw(std::int16_t* output) override
  {
    uint8_t data[6] = {0};
    registers.readRegisterMultibyte(
            Registers_::ACCEL_XOUT_H | Registers_::READ_MASK, data, 6);

    for (std::uint32_t i = 0; i < 3; i++)
    {
      output[i] = byteToTypeBE<std::int16_t, 2>(&data[i * 2]);
    }
  }

  std::int16_t accelerometerReadingToRaw(const float& fs) const
  {
    return fs / accel_fs_to_bit_constants_[std::uint32_t(scale_accel_)];
  }

  std::int16_t gyroReadingToRaw(const float& fs) const
  {
    return fs / gyro_fs_to_bit_constants_[std::uint32_t(scale_gyro_)];
  }

  float accelerometerRawToReading(const std::int16_t bit) const
  {
    return float(bit) * accel_fs_to_bit_constants_[std::uint32_t(scale_accel_)];
  }

  float gyroRawToReading(const std::int16_t bit) const
  {
    return float(bit) * gyro_fs_to_bit_constants_[std::uint32_t(scale_gyro_)];
  }

  std::uint8_t readProductId()
  {
    return registers.readRegister(Registers_::WHO_AM_I | Registers_::READ_MASK);
  }

private:
  GyroScale scale_gyro_ = GyroScale::DPS_2000;
  AccelerometerScale scale_accel_ = AccelerometerScale::G16;

  std::array<std::int16_t, 3> bias_gyro_;
  std::array<std::int16_t, 3> bias_accel_;

  static constexpr float accel_fs_to_bit_constants_[4] = {
          (2.0f / 32768.0f), (4.0f / 32768.0f), (8.0f / 32768.0f),
          (16.0f / 32768.0f)};

  static constexpr float gyro_fs_to_bit_constants_[4] = {
          (250.0f / 32768.0f), (500.0f / 32768.0f), (1000.0f / 32768.0f),
          (2000.0f / 32768.0f)};

  struct Registers_
  {
    static constexpr std::uint32_t ICM20689_ID = 0x98;

    static constexpr std::uint8_t READ_MASK = 0x80;
    static constexpr std::uint8_t WRITE_MASK = 0x7F;

    static constexpr std::uint8_t SMPLRT_DIV = 0x19;
    static constexpr std::uint8_t CONFIG = 0x1A;
    static constexpr std::uint8_t GYRO_CONFIG = 0x1B;
    static constexpr std::uint8_t ACCEL_CONFIG = 0x1C;
    static constexpr std::uint8_t ACCEL_CONFIG2 = 0x1D;

    static constexpr std::uint8_t INT_PIN_CFG = 0x37;
    static constexpr std::uint8_t INT_ENABLE = 0x38;
    static constexpr std::uint8_t INT_STATUS = 0x3A;

    static constexpr std::uint8_t GYRO_XOUT_H = 0x43;
    static constexpr std::uint8_t GYRO_XOUT_L = 0x44;
    static constexpr std::uint8_t GYRO_YOUT_H = 0x45;
    static constexpr std::uint8_t GYRO_YOUT_L = 0x46;
    static constexpr std::uint8_t GYRO_ZOUT_H = 0x47;
    static constexpr std::uint8_t GYRO_ZOUT_L = 0x48;

    static constexpr std::uint8_t ACCEL_XOUT_H = 0x3B;
    static constexpr std::uint8_t ACCEL_XOUT_L = 0x3C;
    static constexpr std::uint8_t ACCEL_YOUT_H = 0x3D;
    static constexpr std::uint8_t ACCEL_YOUT_L = 0x3E;
    static constexpr std::uint8_t ACCEL_ZOUT_H = 0x3F;
    static constexpr std::uint8_t ACCEL_ZOUT_L = 0x40;

    static constexpr std::uint8_t USER_CTRL = 0x6A;
    static constexpr std::uint8_t PWR_MGMT_1 = 0x6B;
    static constexpr std::uint8_t PWR_MGMT_2 = 0x6C;
    static constexpr std::uint8_t WHO_AM_I = 0x75;

    static constexpr std::uint8_t XG_OFFSET_H = 0x13;
    static constexpr std::uint8_t XG_OFFSET_L = 0x14;
    static constexpr std::uint8_t YG_OFFSET_H = 0x15;
    static constexpr std::uint8_t YG_OFFSET_L = 0x16;
    static constexpr std::uint8_t ZG_OFFSET_H = 0x17;
    static constexpr std::uint8_t ZG_OFFSET_L = 0x18;

    static constexpr std::uint8_t XA_OFFSET_H = 0x77;
    static constexpr std::uint8_t XA_OFFSET_L = 0x78;
    static constexpr std::uint8_t YA_OFFSET_H = 0x7A;
    static constexpr std::uint8_t YA_OFFSET_L = 0x7B;
    static constexpr std::uint8_t ZA_OFFSET_H = 0x7D;
    static constexpr std::uint8_t ZA_OFFSET_L = 0x7E;
  };
};

template<typename T, typename HAL>
constexpr float ImuIcm<T, HAL>::accel_fs_to_bit_constants_[4];

template<typename T, typename HAL>
constexpr float ImuIcm<T, HAL>::gyro_fs_to_bit_constants_[4];

}// namespace Peripherals

#endif /* SKULLC_PERIPHERALS_IMU_ICM_HPP_ */