#define ctsPin 3 // btn
const unsigned long eventInterval = 100;
const unsigned long eventIntervalBr = 5;


int ledPin = 5; // мосфет
int countMs = 0;
bool isEnabled = 0;
bool brDirection = 0;       //0 - вниз. 1 - вверх
int brightness = 255;
int keyStage = 0;      // 0 - not pressed; 1 - pressed; 2 - in long press; 3 - release;
int prevStage = 0;

unsigned long previousTimeBr = 0;
unsigned long previousTime = 0;


void setup() {

  pinMode(ledPin, OUTPUT);

  pinMode(ctsPin, INPUT);

}

void loop() {
  handlePress();

  switch (keyStage) {
    case 1:
      break;
    case 2:
      changeBr();
      break;
    case 3:
      if (prevStage != 2)
        toggleLed();
      break;
  }



}

void swapDirection()
{
  if(brDirection == 0)
    brDirection = 1;
  else
    brDirection = 0;
}

void handlePress()
{
  prevStage = keyStage;
  int ctsValue = digitalRead(ctsPin);
  if (ctsValue == HIGH){

    unsigned long currentTime = millis();                       // округление в десятые доли
    if (currentTime - previousTime <= eventInterval) {
      return;
    }
    previousTime = millis();

    if (keyStage == 0 && countMs > 1 && countMs < 5)
      keyStage = 1;         //Мы нажали на кнопку

    countMs+=1;

    if (countMs >= 5)
      keyStage = 2;         //release event is over.


  }
  else
  {
    previousTime = 0;

    if (keyStage == 3)
      keyStage = 0;         //release event is over.

    if (countMs!=0)
    {
//      Serial.print("TOUCHED + ");
//      Serial.print(countMs);
//      Serial.print(". SWAP = ");
//      Serial.println(brDirection);
      keyStage = 3;
    }

    if(countMs>=5)
      swapDirection();

    countMs=0;
  }
}

void toggleLed()
{
  if(isEnabled == 0)
  {
    isEnabled = 1;
    analogWrite(ledPin, brightness);
  }
  else {
    isEnabled = 0;
    analogWrite(ledPin, 0);
  }
}

void changeBr()
{
  if(isEnabled == 0)                  //long press always turns led on
  {
    isEnabled = 1;
    digitalWrite(ledPin, HIGH);
  }

  unsigned long currentTime = millis();                       // плавная понижайка
  if (currentTime - previousTimeBr <= eventIntervalBr) {
    return;
  }
  previousTimeBr = millis();

  if(brDirection == 0 && brightness>15)
    brightness-=1;
  else if(brDirection == 1 && brightness<255)
    brightness+=1;

  analogWrite(ledPin, brightness);

}