const int button_pin = 4;  // Pin connected to the button

unsigned long debounce_duration = 50;  // Minimum time to debounce button (in milliseconds)
int previous_button_state = HIGH;      // Previous state of the button
int current_button_state = HIGH;       // Current state of the button
unsigned long last_debounce_time = 0;  // Time when button state last changed
unsigned long press_start_time;        // Time when button press starts
unsigned long release_time;            // Duration of the button press

void setup() {
  pinMode(button_pin, INPUT_PULLUP);  // Configure button pin with internal pull-up resistor
  Serial.begin(115200);
}

void loop() {

  if (debounced_button_press_check(button_pin, LOW)) {
    press_start_time = millis();  // Record the time the button was pressed
    while (!debounced_button_press_check(button_pin, HIGH))
      ;
    release_time = millis() - press_start_time;  // Calculate the button release duration

    if (release_time > 1000) {
      Serial.println("Long press detected");
    } else {
      // Check for single or double press within a specific time frame
      while (1) {
        if (debounced_button_press_check(button_pin, LOW)) {
          Serial.println("Double click detected");
          break;
        }
        if ((millis() - press_start_time) > 400) {
          Serial.println("Single click detected");
          break;
        }
      }
    }
  }
}

//Checks for a debounced button press and returns true if detected, false otherwise.
bool debounced_button_press_check(int pin, bool expected_state) {
  int button_reading = digitalRead(pin);

  // If the button state has changed, reset the debounce timer
  if (button_reading != previous_button_state) {
    last_debounce_time = millis();
  }
  previous_button_state = button_reading;

  // If the state has remained stable beyond the debounce duration, consider it valid
  if ((millis() - last_debounce_time) > debounce_duration) {
    if (button_reading != current_button_state) {
      current_button_state = button_reading;
      if (current_button_state == expected_state) {
        return true;  // Return true if the desired state is detected
      }
    }
  }
  return false;  // Return false if no valid press is detected
}