/*==========================================================================================
MIT License

Copyright (c) 2023-2025 https://madflight.com

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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copies or substantial portions of the Software.

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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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SOFTWARE.
===========================================================================================*/

#define MF_MOD "AHR"

#include "../madflight_modules.h"
#include "AhrGizmoMahony.h"
#include "AhrGizmoMadgwick.h"
#include "AhrGizmoVqf.h"

//create global module instance
Ahr ahr;

int Ahr::setup() {
  cfg.printModule(MF_MOD);

  B_gyr = lowpass_to_beta(config.gyrLpFreq, config.pimu->config.sample_rate);
  B_acc = lowpass_to_beta(config.accLpFreq, config.pimu->config.sample_rate);
  B_mag = lowpass_to_beta(config.magLpFreq, config.pimu->config.sample_rate);

  //create gizmo
  delete gizmo;
  switch(config.gizmo) {
    case Cfg::ahr_gizmo_enum::mf_MAHONY :
      gizmo = new AhrGizmoMahony(this, false);
      break;
    case Cfg::ahr_gizmo_enum::mf_MAHONY_BF :
      gizmo = new AhrGizmoMahony(this, true);
      break;
    case Cfg::ahr_gizmo_enum::mf_MADGWICK :
      gizmo = new AhrGizmoMadgwick(this);
      break;
    case Cfg::ahr_gizmo_enum::mf_VQF :
      gizmo = new AhrGizmoVqf(this);
      break;
    default:
      gizmo = new AhrGizmoMahony(this, false);
      break;
  }

  return 0;
}

bool Ahr::update() {
  runtimeTrace.start();

  // get sensor data from imu and mag
  // correct the sensor data with the calibration values
  // use simple first-order low-pass filter to get rid of high frequency noise
  // store filtered data in ax ay az gx gy gz mx my mz
  // call the sensor fusion algorithm to update q
  // compute euler angles from q

  //Low-pass filtered, corrected accelerometer data
  ax += B_acc * ((config.pimu->ax - config.acc_offset[0]) - ax);
  ay += B_acc * ((config.pimu->ay - config.acc_offset[1]) - ay);
  az += B_acc * ((config.pimu->az - config.acc_offset[2]) - az);

  //Low-pass filtered, corrected gyro data
  gx += B_gyr * ((config.pimu->gx - config.gyr_offset[0]) - gx);
  gy += B_gyr * ((config.pimu->gy - config.gyr_offset[1]) - gy);
  gz += B_gyr * ((config.pimu->gz - config.gyr_offset[2]) - gz);

  //Magnetometer (External chip, or internal in IMU chip) 
  if(config.pmag) {
    float _mx = config.pmag->mx;
    float _my = config.pmag->my;
    float _mz = config.pmag->mz;
    //update the mag values
    if( ! (_mx == 0 && _my == 0 && _mz == 0) ) {
      //Correct the mag values with the calibration values
      _mx = (_mx - config.mag_offset[0]) * config.mag_scale[0];
      _my = (_my - config.mag_offset[1]) * config.mag_scale[1];
      _mz = (_mz - config.mag_offset[2]) * config.mag_scale[2];
      //Low-pass filtered magnetometer data
      mx += B_mag * (_mx - mx);
      my += B_mag * (_my - my);
      mz += B_mag * (_mz - mz);
    }
  }else{
    mx = 0;
    my = 0;
    mz = 0;
  }

  //update dt and ts for use by gizmo
  dt = (config.pimu->ts - ts) * 1e-6;
  ts = config.pimu->ts;

  //call gizmo to update q
  gizmo->update();

  //update euler angles
  computeAngles();

  topic.publish(this);

  runtimeTrace.stop(true);
  return true;
}

void Ahr::getQFromMag(float *q) {
  //warm up mag by getting 100 samples within max 1 second (imu + mag should be running already)
  uint32_t ts = millis();
  do {
    portYIELD();
  } while( mag.topic.get_generation() < 100 && millis() - ts < 1000 );

  //update mx and my from mag or imu
  update();

  //calculate yaw angle
  if(mx == 0 && my == 0 && mz == 0) {
    yaw = 0;
    pitch = 0;
    roll = 0;
    q[0] = 1;
    q[1] = 0;
    q[2] = 0;
    q[3] = 0;
    Serial.println("AHR: No Magnetometer, yaw:0.00");
  }else{
    float yaw_rad = -atan2(my, mx);
    yaw = yaw_rad * rad_to_deg;
    pitch = 0;
    roll = 0;
    q[0] = cos(yaw_rad/2);
    q[1] = 0;
    q[2] = 0;
    q[3] = sin(yaw_rad/2);
    Serial.printf("AHR: Estimated yaw:%+.2f\n", yaw);
  }
  
  //set dt,ts
  dt = 0;
  ts = micros();
}

//compute euler angles from q
void Ahr::computeAngles() {
  roll = atan2(q[0]*q[1] + q[2]*q[3], 0.5f - q[1]*q[1] - q[2]*q[2]) * rad_to_deg; //degrees - roll right is positive
  pitch = asin(constrain(-2.0f * (q[1]*q[3] - q[0]*q[2]), -1.0, 1.0)) * rad_to_deg; //degrees - pitch up is positive - use constrain() to prevent NaN due to rounding
  yaw = atan2(q[1]*q[2] + q[0]*q[3], 0.5f - q[2]*q[2] - q[3]*q[3]) * rad_to_deg; //degrees - yaw right is positive
}

//get acceleration in earth-frame up direction in [m/s^2]
float Ahr::getAccelUp() {
  return 9.80665 * ((2*q[1]*q[3] - 2*q[0]*q[2])*ax + (2*q[2]*q[3] + 2*q[0]*q[1])*ay + (q[0]*q[0] - q[1]*q[1] - q[2]*q[2] + q[3]*q[3])*az - 1.0);
}

void Ahr::setInitalOrientation() {
  if(!gizmo) return;
  float qnew[4];
  getQFromMag(qnew);
  gizmo->setInitalOrientation(qnew);
}