#define IS_SIMULATION true

#include <TimerOne.h>

const int cfgFan1ControlPinFromIC = A0;
const int cfgFan1FeedbackPinToIC = 2;
const int cfgFan1ControlPinToFan = 3;
const int cfgFan1Mapping[] = { 21700, 25, 65 }; // Fan RPM Max, Remapped Duty Min, Remapped Duty Max

/*
const int cfgFan2ControlPinFromIC = A1;
const int cfgFan2FeedbackPinToIC = -1;
const int cfgFan2ControlPinToFan = -1;
const int cfgFan2Mapping[] = { 21700, 25, 65 }; // Fan RPM Max, Remapped Duty Min, Remapped Duty Max

const int cfgFan3ControlPinFromIC = A2;
const int cfgFan3FeedbackPinToIC = -1;
const int cfgFan3ControlPinToFan = -1;
const int cfgFan3Mapping[] = { 21700, 25, 65 }; // Fan RPM Max, Remapped Duty Min, Remapped Duty Max

const int cfgFan4ControlPinFromIC = A3;
const int cfgFan4FeedbackPinToIC = -1;
const int cfgFan4ControlPinToFan = -1;
const int cfgFan4Mapping[] = { 21700, 25, 65 }; // Fan RPM Max, Remapped Duty Min, Remapped Duty Max
*/

void setup() {
  Serial.begin(115200);

  Timer1.initialize(40); // 25 kHz
}

void loop() {
  float fan1DutyCycleFromIC = readDutyCycleFromPin(cfgFan1ControlPinFromIC);
  float fan1RPMExpectedFromIC = mapFloat(fan1DutyCycleFromIC, 0, 100, 0, cfgFan1Mapping[0]);
  float fan1FeedbackToIC = calculateFrequencyForSpecificRPM(fan1RPMExpectedFromIC);
  float fan1DutyCycleToFan = mapFloat(fan1DutyCycleFromIC, 0, 100, cfgFan1Mapping[1], cfgFan1Mapping[2]);
  float fan1RPMExpectedToFan = mapFloat(fan1DutyCycleToFan, 0, 100, 0, cfgFan1Mapping[0]);

  /*
  float fan2DutyCycleFromIC = readDutyCycleFromPin(cfgFan2ControlPinFromIC);
  float fan2RPMExpectedFromIC = mapFloat(fan2DutyCycleFromIC, 0, 100, 0, cfgFan2Mapping[0]);
  float fan2FeedbackToIC = calculateFrequencyForSpecificRPM(fan2RPMExpectedFromIC);
  float fan2DutyCycleToFan = mapFloat(fan2DutyCycleFromIC, 0, 100, cfgFan2Mapping[1], cfgFan2Mapping[2]);
  float fan2RPMExpectedToFan = mapFloat(fan2DutyCycleToFan, 0, 100, 0, cfgFan2Mapping[0]);

  float fan3DutyCycleFromIC = readDutyCycleFromPin(cfgFan3ControlPinFromIC);
  float fan3RPMExpectedFromIC = mapFloat(fan3DutyCycleFromIC, 0, 100, 0, cfgFan3Mapping[0]);
  float fan3FeedbackToIC = calculateFrequencyForSpecificRPM(fan3RPMExpectedFromIC);
  float fan3DutyCycleToFan = mapFloat(fan3DutyCycleFromIC, 0, 100, cfgFan3Mapping[1], cfgFan3Mapping[2]);
  float fan3RPMExpectedToFan = mapFloat(fan3DutyCycleToFan, 0, 100, 0, cfgFan3Mapping[0]);

  float fan4DutyCycleFromIC = readDutyCycleFromPin(cfgFan4ControlPinFromIC);
  float fan4RPMExpectedFromIC = mapFloat(fan4DutyCycleFromIC, 0, 100, 0, cfgFan4Mapping[0]);
  float fan4FeedbackToIC = calculateFrequencyForSpecificRPM(fan4RPMExpectedFromIC);
  float fan4DutyCycleToFan = mapFloat(fan4DutyCycleFromIC, 0, 100, cfgFan4Mapping[1], cfgFan4Mapping[2]);
  float fan4RPMExpectedToFan = mapFloat(fan4DutyCycleToFan, 0, 100, 0, cfgFan4Mapping[0]);
  */

  #if !IS_SIMULATION
    if (cfgFan1FeedbackPinToIC != -1) tone(cfgFan1FeedbackPinToIC, fan1FeedbackToIC);
    if (cfgFan1ControlPinToFan != -1) Timer1.pwm(cfgFan1ControlPinToFan, (fan1DutyCycleToFan / 100) * 1023);

    /*
    if (cfgFan2FeedbackPinToIC != -1) tone(cfgFan2FeedbackPinToIC, fan2FeedbackToIC);
    if (cfgFan2ControlPinToFan != -1) Timer1.pwm(cfgFan2ControlPinToFan, (fan2DutyCycleToFan / 100) * 1023);

    if (cfgFan3FeedbackPinToIC != -1) tone(cfgFan3FeedbackPinToIC, fan3FeedbackToIC);
    if (cfgFan3ControlPinToFan != -1) Timer1.pwm(cfgFan3ControlPinToFan, (fan3DutyCycleToFan / 100) * 1023);

    if (cfgFan4FeedbackPinToIC != -1) tone(cfgFan4FeedbackPinToIC, fan4FeedbackToIC);
    if (cfgFan4ControlPinToFan != -1) Timer1.pwm(cfgFan4ControlPinToFan, (fan4DutyCycleToFan / 100) * 1023);
    */
  #endif

  #if IS_SIMULATION
    Serial.print("Fan 1\tIC DC: ");
    Serial.print((int)fan1DutyCycleFromIC);
    Serial.print("%\tIC RPM EXP: ");
    Serial.print((int)fan1RPMExpectedFromIC);
    Serial.print("\tIC FB EXP: ");
    Serial.print(fan1FeedbackToIC);
    Serial.print(" Hz\tFan DC: ");
    Serial.print((int)fan1DutyCycleToFan);
    Serial.print("%\tFan RPM EXP: ");
    Serial.println((int)fan1RPMExpectedToFan);

    /*
    Serial.print("Fan 2\tIC DC: ");
    Serial.print((int)fan2DutyCycleFromIC);
    Serial.print("%\tIC RPM EXP: ");
    Serial.print((int)fan2RPMExpectedFromIC);
    Serial.print("\tIC FB EXP: ");
    Serial.print(fan2FeedbackToIC);
    Serial.print(" Hz\tFan DC: ");
    Serial.print((int)fan2DutyCycleToFan);
    Serial.print("%\tFan RPM EXP: ");
    Serial.println((int)fan2RPMExpectedToFan);

    Serial.print("Fan 3\tIC DC: ");
    Serial.print((int)fan3DutyCycleFromIC);
    Serial.print("%\tIC RPM EXP: ");
    Serial.print((int)fan3RPMExpectedFromIC);
    Serial.print("\tIC FB EXP: ");
    Serial.print(fan3FeedbackToIC);
    Serial.print(" Hz\tFan DC: ");
    Serial.print((int)fan3DutyCycleToFan);
    Serial.print("%\tFan RPM EXP: ");
    Serial.println((int)fan3RPMExpectedToFan);

    Serial.print("Fan 4\tIC DC: ");
    Serial.print((int)fan4DutyCycleFromIC);
    Serial.print("%\tIC RPM EXP: ");
    Serial.print((int)fan4RPMExpectedFromIC);
    Serial.print("\tIC FB EXP: ");
    Serial.print(fan4FeedbackToIC);
    Serial.print(" Hz\tFan DC: ");
    Serial.print((int)fan4DutyCycleToFan);
    Serial.print("%\tFan RPM EXP: ");
    Serial.println((int)fan4RPMExpectedToFan);
    */
  #endif

  #if IS_SIMULATION
    delay(100);
  #else
    delay(50);
  #endif
}

float readDutyCycleFromPin(int pin) { // In simulation it will use a analog pin instead of a real PWM signal
  #if IS_SIMULATION
    return (float)mapFloat(analogRead(pin), 0, 1023, 0, 100);
  #else
    // https://forum.arduino.cc/t/reading-pwm-duty-cycle/258521
    unsigned long highTime = pulseIn(pin, HIGH);
    unsigned long lowTime = pulseIn(pin, LOW);

    return (float)highTime / float(highTime + lowTime);
  #endif
}

int calculateFrequencyForSpecificRPM(int rpm) {
  return rpm / 30;
}

float mapFloat(float x, float in_min, float in_max, float out_min, float out_max) {
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}