#include "IMU.h"

void calibrateMagn();
void imuAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz);
float invSqrt(float x);

/******************************************************************************
 * IMU module                                                                 *
 ******************************************************************************/
// #define S_SCL   33
// #define S_SDA   32

AK09918_err_type_t err;

QMI8658 qmi8658_;
AK09918 magnetometer_;

int16_t offset_x = -12, offset_y = 0, offset_z = 0;
int16_t x, y, z;
// Find the magnetic declination at your location
// http://www.magnetic-declination.com/
double declination_shenzhen = -3.22;

#define Kp 4.50f   // proportional gain governs rate of convergence to accelerometer/magnetometer
#define Ki 1.0f    // integral gain governs rate of convergence of gyroscope biases

float angles[3];
float q0, q1, q2, q3; 
float exInt = 0.0f;
float eyInt = 0.0f;
float ezInt = 0.0f;
uint32_t lastFilterUpdateUs = 0;

namespace {
constexpr float kDegToRad = 0.01745329251994329577f;
constexpr float kDefaultSampleDt = 0.01f;
constexpr float kMaxSampleDt = 0.1f;

float clampUnit(float value)
{
  if (value > 1.0f) {
    return 1.0f;
  }
  if (value < -1.0f) {
    return -1.0f;
  }
  return value;
}

void resetFilterState()
{
  q0 = 1.0f;
  q1 = 0.0f;
  q2 = 0.0f;
  q3 = 0.0f;
  exInt = 0.0f;
  eyInt = 0.0f;
  ezInt = 0.0f;
  lastFilterUpdateUs = micros();
}

float getSampleDeltaSeconds()
{
  const uint32_t nowUs = micros();

  if (lastFilterUpdateUs == 0) {
    lastFilterUpdateUs = nowUs;
    return kDefaultSampleDt;
  }

  const uint32_t elapsedUs = nowUs - lastFilterUpdateUs;
  lastFilterUpdateUs = nowUs;

  const float deltaSeconds = elapsedUs * 1.0e-6f;
  if (deltaSeconds <= 0.0f || deltaSeconds > kMaxSampleDt) {
    return kDefaultSampleDt;
  }

  return deltaSeconds;
}

bool normalizeVector(float *xAxis, float *yAxis, float *zAxis)
{
  const float normSquared = (*xAxis * *xAxis) + (*yAxis * *yAxis) + (*zAxis * *zAxis);
  if (normSquared <= 1.0e-12f) {
    return false;
  }

  const float norm = invSqrt(normSquared);
  *xAxis *= norm;
  *yAxis *= norm;
  *zAxis *= norm;
  return true;
}
}  // namespace

void imuInit()
{
    // Wire.begin(S_SDA, S_SCL);
    // Serial.begin(115200);
   
    if (qmi8658_.begin() == 0)
	      Serial.println("qmi8658_init fail");

    if (magnetometer_.initialize())
        Serial.println("AK09918_init fail") ;
    magnetometer_.switchMode(AK09918_CONTINUOUS_100HZ);
    err = magnetometer_.isDataReady();
    int retry_times = 0;
    while (err != AK09918_ERR_OK) {
        Serial.println(err);
        Serial.println("Waiting Sensor");
        delay(100);
        magnetometer_.reset();
        delay(100);
        magnetometer_.switchMode(AK09918_CONTINUOUS_100HZ);
        err = magnetometer_.isDataReady();
        retry_times ++;
        if (retry_times > 10) {
          break;
        }
    }
    // Serial.println("Start figure-8 calibration after 1 seconds.");
    // delay(1000);
    // calibrate(10000, &offset_x, &offset_y, &offset_z);
    // calibrateMagn();
    resetFilterState();
}

void imuDataGet(EulerAngles *pstAngles, 
                IMU_ST_SENSOR_DATA_FLOAT *pstGyroRawData,
                IMU_ST_SENSOR_DATA_FLOAT *pstAccelRawData,
                IMU_ST_SENSOR_DATA *pstMagnRawData)
{
  if (pstAngles == nullptr || pstGyroRawData == nullptr ||
      pstAccelRawData == nullptr || pstMagnRawData == nullptr) {
    return;
  }

  float  acc[3] = {0.0f, 0.0f, 0.0f};
  float  gyro[3] = {0.0f, 0.0f, 0.0f};
  float MotionVal[9];

  const AK09918_err_type_t magErr = magnetometer_.getData(&x, &y, &z);
  if (magErr == AK09918_ERR_OVERFLOW) {
    Serial.println("AK09918 overflow detected, keeping last valid magnetic sample.");
  }

  pstMagnRawData->s16X = x- offset_x;
  pstMagnRawData->s16Y = y- offset_y;
  pstMagnRawData->s16Z = z- offset_z;

  // qmi8658_.GetEulerAngles(&pstAngles->pitch,&pstAngles->roll,&pstAngles->yaw,acc,gyro);
  qmi8658_.read_sensor_data(acc,gyro);

  // pstAngles->roll = atan2((float)acc[1], (float)acc[2]);
  // pstAngles->pitch = atan2(-(float)acc[0], sqrt((float)(acc[1] * acc[1]) + (float)(acc[2] * acc[2])));

  // double Xheading = pstMagnRawData->s16X * cos(pstAngles->pitch) + pstMagnRawData->s16Y * sin(pstAngles->roll) * sin(pstAngles->pitch) + pstMagnRawData->s16Z * cos(pstAngles->roll) * sin(pstAngles->pitch);
  // double Yheading = pstMagnRawData->s16Y * cos(pstAngles->roll) - pstMagnRawData->s16Z * sin(pstAngles->pitch);
  
  // pstAngles->yaw = /*180 + */57.3 * atan2(Yheading, Xheading) + declination_shenzhen;

  // pstAngles->roll = atan2((float)acc[1], (float)acc[2]) * 57.3;
  // pstAngles->pitch = atan2(-(float)acc[0], sqrt((float)(acc[1] * acc[1]) + (float)(acc[2] * acc[2]))) * 57.3;
  MotionVal[0]=gyro[0];
  MotionVal[1]=gyro[1];
  MotionVal[2]=gyro[2];
  MotionVal[3]=acc[0];
  MotionVal[4]=acc[1];
  MotionVal[5]=acc[2];
  MotionVal[6]=pstMagnRawData->s16X;
  MotionVal[7]=pstMagnRawData->s16Y;
  MotionVal[8]=pstMagnRawData->s16Z;

  imuAHRSupdate((float)MotionVal[0] * kDegToRad, (float)MotionVal[1] * kDegToRad, (float)MotionVal[2] * kDegToRad,
                (float)MotionVal[3], (float)MotionVal[4], (float)MotionVal[5], 
                (float)MotionVal[6], (float)MotionVal[7], MotionVal[8]);

  pstAngles->pitch = asinf(clampUnit(-2.0f * q1 * q3 + 2.0f * q0 * q2)) * 57.2957795f;
  pstAngles->roll = atan2f(2.0f * q2 * q3 + 2.0f * q0 * q1,
                           -2.0f * q1 * q1 - 2.0f * q2 * q2 + 1.0f) * 57.2957795f;
  pstAngles->yaw = atan2f(-2.0f * q1 * q2 - 2.0f * q0 * q3,
                          2.0f * q2 * q2 + 2.0f * q3 * q3 - 1.0f) * 57.2957795f;

  pstGyroRawData->X = gyro[0];
  pstGyroRawData->Y = gyro[1];
  pstGyroRawData->Z = gyro[2];

  pstAccelRawData->X = acc[0];
  pstAccelRawData->Y = acc[1];
  pstAccelRawData->Z = acc[2];

  return;  
}

bool imuRecalibrate()
{
  qmi8658_.autoOffsets();
  resetFilterState();
  return true;
}

void imuGetMagnOffsets(IMU_ST_SENSOR_DATA *pstMagnOffset)
{
  if (pstMagnOffset == nullptr) {
    return;
  }

  pstMagnOffset->s16X = offset_x;
  pstMagnOffset->s16Y = offset_y;
  pstMagnOffset->s16Z = offset_z;
}

void imuSetMagnOffsets(int16_t inputX, int16_t inputY, int16_t inputZ)
{
  offset_x = inputX;
  offset_y = inputY;
  offset_z = inputZ;
  resetFilterState();
}

float imuGetTemperature()
{
  return qmi8658_.read_temperature();
}

void imuAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) 
{
  const float sampleDt = getSampleDeltaSeconds();
  const float halfT = 0.5f * sampleDt;
  float hx = 0.0f, hy = 0.0f, hz = 0.0f, bx = 0.0f, bz = 0.0f;
  float vx = 0.0f, vy = 0.0f, vz = 0.0f, wx = 0.0f, wy = 0.0f, wz = 0.0f;
  float ex = 0.0f, ey = 0.0f, ez = 0.0f;

  float q0q0 = q0 * q0;
  float q0q1 = q0 * q1;
  float q0q2 = q0 * q2;
  float q0q3 = q0 * q3;
  float q1q1 = q1 * q1;
  float q1q2 = q1 * q2;
  float q1q3 = q1 * q3;
  float q2q2 = q2 * q2;   
  float q2q3 = q2 * q3;
  float q3q3 = q3 * q3;          

  const bool accelValid = normalizeVector(&ax, &ay, &az);
  const bool magnValid = normalizeVector(&mx, &my, &mz);

  if (accelValid) {
    vx = 2.0f * (q1q3 - q0q2);
    vy = 2.0f * (q0q1 + q2q3);
    vz = q0q0 - q1q1 - q2q2 + q3q3;

    ex += (ay * vz - az * vy);
    ey += (az * vx - ax * vz);
    ez += (ax * vy - ay * vx);
  }

  if (magnValid) {
    hx = 2.0f * mx * (0.5f - q2q2 - q3q3) + 2.0f * my * (q1q2 - q0q3) + 2.0f * mz * (q1q3 + q0q2);
    hy = 2.0f * mx * (q1q2 + q0q3) + 2.0f * my * (0.5f - q1q1 - q3q3) + 2.0f * mz * (q2q3 - q0q1);
    hz = 2.0f * mx * (q1q3 - q0q2) + 2.0f * my * (q2q3 + q0q1) + 2.0f * mz * (0.5f - q1q1 - q2q2);
    bx = sqrtf((hx * hx) + (hy * hy));
    bz = hz;

    wx = 2.0f * bx * (0.5f - q2q2 - q3q3) + 2.0f * bz * (q1q3 - q0q2);
    wy = 2.0f * bx * (q1q2 - q0q3) + 2.0f * bz * (q0q1 + q2q3);
    wz = 2.0f * bx * (q0q2 + q1q3) + 2.0f * bz * (0.5f - q1q1 - q2q2);

    ex += (my * wz - mz * wy);
    ey += (mz * wx - mx * wz);
    ez += (mx * wy - my * wx);
  }

  if (accelValid || magnValid) {
    exInt += ex * Ki * sampleDt;
    eyInt += ey * Ki * sampleDt;
    ezInt += ez * Ki * sampleDt;

    gx = gx + Kp * ex + exInt;
    gy = gy + Kp * ey + eyInt;
    gz = gz + Kp * ez + ezInt;
  }

  const float q0Prev = q0;
  const float q1Prev = q1;
  const float q2Prev = q2;
  const float q3Prev = q3;

  q0 = q0Prev + (-q1Prev * gx - q2Prev * gy - q3Prev * gz) * halfT;
  q1 = q1Prev + (q0Prev * gx + q2Prev * gz - q3Prev * gy) * halfT;
  q2 = q2Prev + (q0Prev * gy - q1Prev * gz + q3Prev * gx) * halfT;
  q3 = q3Prev + (q0Prev * gz + q1Prev * gy - q2Prev * gx) * halfT;

  const float normSquared = q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3;
  if (normSquared <= 1.0e-12f) {
    resetFilterState();
    return;
  }

  const float norm = invSqrt(normSquared);
  q0 = q0 * norm;
  q1 = q1 * norm;
  q2 = q2 * norm;
  q3 = q3 * norm;
}

float invSqrt(float x) 
{
  if (x <= 0.0f) {
    return 0.0f;
  }

  float halfx = 0.5f * x;
  union {
    float f;
    uint32_t i;
  } conv = { x };

  conv.i = 0x5f3759df - (conv.i >> 1);

  float y = conv.f;
  y = y * (1.5f - (halfx * y * y));

  return y;
}

void calibrateMagn(void)
{
  int16_t temp[9];
  Serial.printf("keep 10dof-imu device horizontal and it will read x y z axis offset value after 4 seconds\n");
  delay(4000);
  Serial.printf("start read all axises offset value\n");
  magnetometer_.getData(&x, &y, &z);
  temp[0] = x;
  temp[1] = y;
  temp[2] = z;
  
  Serial.printf("rotate z axis 180 degrees and it will read all axises offset value after 4 seconds\n");
  delay(4000);
  Serial.printf("start read all axises offset value\n");
  magnetometer_.getData(&x, &y, &z);
  temp[3] = x;
  temp[4] = y;
  temp[5] = z;

  Serial.printf("flip 10dof-imu device and keep it horizontal and it will read all axises offset value after 4 seconds\n");
  delay(4000);
  Serial.printf("start read all axises offset value\n");
  magnetometer_.getData(&x, &y, &z);
  temp[6] = x;
  temp[7] = y;
  temp[8] = z;

  offset_x = (temp[0]+temp[3])/2;
  offset_y = (temp[1]+temp[4])/2;
  offset_z = (temp[5]+temp[8])/2;
}