/* code modified base on example from:
 *  https://playground.arduino.cc/Code/HoldButton
 */

int buttonPin = 7;
int ledPin = 3;
int buttonState = 0;

unsigned long firstTime;
byte previous = HIGH;

long millis_held; 
long secs_held;
long prev_secs_held;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
  
}

void loop() {
  
  buttonState = digitalRead(buttonPin);

  /* if button gets pushed, update start time */
  if (buttonState == LOW && previous == HIGH && (millis() - firstTime) > 10) {
    firstTime = millis();
  }

  millis_held = (millis() - firstTime);
  secs_held = millis_held / 1000;

  /* if button pressed more than 10ms debounce */
  if (millis_held > 10) {             

      /* when button is pressed down */
      if (buttonState == LOW && secs_held > prev_secs_held) {
          digitalWrite(ledPin, HIGH); 
          }

      /* when button is released */
      if (buttonState == HIGH && previous == LOW) {
          
          /* if hold button for more than 3 sec 
          LED on */
          if (secs_held >= 3) {
              digitalWrite(ledPin, HIGH); 
              }

          /* if hold button from 1-3 sec 
          quickly blink 10 times */
          if (secs_held >= 1 && secs_held < 3) {
              ledblink(10,80);
              }
              
          /* if hold button less than 1 sec 
          blink once */
          if (secs_held < 1) {
              ledblink(1, 100);
              }

        }
    }

   /* update */
   previous = buttonState;
   prev_secs_held = secs_held;
}

/* blink function */
void ledblink(int times, int lengthms){
  for (int x=0; x<times;x++) {
    digitalWrite(ledPin, HIGH);
    delay(lengthms);
    digitalWrite(ledPin, LOW);
    delay(lengthms);
  }
}