/*
  https://forum.arduino.cc/t/attiny10-button-input-wired-with-external-pull-down/1264601
  Test setup:
  Button Side 1 --> 4.7k Resistor --> PB1 --> Ground
  Button Side 2 --> VCC (3,3V or 5V)

  LED (+) Color 1 --> 1K resistor --> Pin 1 (PB0)
  LED (+) Color 2 --> 1K resistor --> Pin 1 (PB2)
  LED (-) --> (GND)
*/


#define LED1_PIN PB0
#define LED2_PIN PB2
#define BTN_PIN  PB1


unsigned long lastCheck;
//needs a bit more time than 500 ms
unsigned long intervalCheck = 1000;// 1000 ms to press buttons..
unsigned long lastPress;
unsigned long intervalDebounce = 20;
byte lastState = 0;
bool timerStarted = false;

void setup() {
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);
  pinMode(BTN_PIN, INPUT);
}

void loop() {

  unsigned long now = millis();
  static uint8_t multiclick = 0;

  if (now - lastPress >= intervalDebounce) {
    byte state = digitalRead(BTN_PIN);
    if (state != lastState) {
      lastPress = now;
      lastState = state;
      //start timer to count press..
      if (!timerStarted) {
        timerStarted = true;
        lastCheck = now;
      }
      if (state == HIGH) multiclick++;
    }
  }


  if (timerStarted) {
    if (now - lastCheck >= intervalCheck) {
      lastCheck = now;
      switch (multiclick) {
        case 1: // it was a single long click
          digitalWrite(LED1_PIN, !digitalRead(LED1_PIN));
          digitalWrite(LED2_PIN, !digitalRead(LED2_PIN));
          multiclick = 0;
          break;
        case 2: // doubleclick
          digitalWrite(LED1_PIN, !digitalRead(LED1_PIN)); // toggle PB0
          multiclick = 0;
          break;
        case 3: // tripleclick
          digitalWrite(LED2_PIN, !digitalRead(LED2_PIN)); // toggle PB2
          multiclick = 0;
          break;
        default:
          multiclick = 0; // undefined # of clicks
          break;
      }
      //reset for next shot
      timerStarted = false;
      multiclick = 0;
    }
  }

}