#include "PseudoSensorControl.hpp"
#include <Arduino.h>

// CONTROLLER CONSTANTS
float MAX_INTEGRAL_TERM = 1e4;

PinPair pinMap[4] = {{dirFL, pwmFL}, {dirFR, pwmFR}, {dirBL, pwmBL}, {dirBR, pwmBR}};

void PseudoSensorController::update() {

  Left.readMM();
  Right.readMM();
  Front.readMM();
  Back.readMM(); // read and update dists/oor for all sensors.

  oor = Left.oor || Right.oor || Front.oor || Back.oor;

  control();

  for (uint8_t i = 0; i < 4; i++) {
    PWMs[i] = slewLimit(PWMs[i], Prevs[i]);
    Prevs[i] = PWMs[i];
  }
}

void PseudoSensorController::zeroPWMs() {
  memset(PWMs, 0, sizeof(PWMs));
}

void PseudoSensorController::sendOutputs() {
  if (!outputOn) zeroPWMs();

  for (uint8_t i = 0; i < 4; i++) {
    // The following assumes 0 direction drives repulsion and 1 direction drives attraction.
    digitalWrite(pinMap[i].dir, PWMs[i] < 0);
    analogWrite(pinMap[i].pwm, abs(PWMs[i]));
  }
}

void PseudoSensorController::control() {
  float avg = (Left.mmVal + Right.mmVal + Front.mmVal + Back.mmVal) * 0.25f;
  float pseudos[4] = {Front.mmVal + Left.mmVal - avg,
                      Front.mmVal + Right.mmVal - avg,
                      Back.mmVal + Left.mmVal - avg,
                      Back.mmVal + Right.mmVal - avg};

  for (uint8_t i = 0; i < 4; i++) {
    float eCurr = Refs[i] - pseudos[i]; // Above reference is positive error.
    
    errors[i].eDiff = (eCurr - errors[i].e); // rise over run
    errors[i].eInt += eCurr;
    errors[i].eInt = constrain(errors[i].eInt, -MAX_INTEGRAL_TERM, MAX_INTEGRAL_TERM);
    errors[i].e = eCurr;

    PWMs[i] = pwmFunc(Consts, errors[i]);
  }
}

int16_t PseudoSensorController::pwmFunc(K_MAP consts, Errors errs) {
  if (oor) return 0;
  Constants constants = (errs.e < 0) ? consts.attracting : consts.repelling;
  return (int)constrain(constants.kp*errs.e + constants.ki*errs.eInt + constants.kd*errs.eDiff, -(float)CAP,(float)CAP);
}

int16_t PseudoSensorController::slewLimit(int16_t target, int16_t prev) {
  int16_t delta = target - prev;
  if (abs(delta) <= slewRateLimit) return target;
  return prev + (delta > 0 ? slewRateLimit : -slewRateLimit);
}

void PseudoSensorController::report() {
  Serial.print("CONTROL ON - ");
  Serial.print(outputOn);
  Serial.print("\n");

  Serial.print("SENSORS - Left: ");
  Serial.print(Left.mmVal);
  Serial.print("mm, Right: ");
  Serial.print(Right.mmVal);
  Serial.print("mm, Front: ");
  Serial.print(Front.mmVal);
  Serial.print("mm, Back: ");
  Serial.print(Back.mmVal);
  Serial.print("mm,\n");

  Serial.print("PWMS - FL_PWM: ");
  Serial.print(PWMs[0]);
  Serial.print(", FR_PWM: ");
  Serial.print(PWMs[1]);
  Serial.print("BL_PWM: ");
  Serial.print(PWMs[2]);
  Serial.print("BR_PWM: ");
  Serial.print(PWMs[3]);
  Serial.print("\n");
}