// Define pin constants
const int led1Pin = 2;  // LSB of overflow counter
const int led2Pin = 3;  // MSB of overflow counter
const int buttonPin = 4;
const int bargraphPins[] = {22, 23, 24, 25, 26, 27, 28, 29, 30, 31};
const int numBargraphSegments = 10;

// Variables for tracking state
int counter = 0;
int overflowCounter = 0;
bool buttonState = HIGH;      // Initially not pressed (HIGH with INPUT_PULLUP)
bool lastButtonState = HIGH;  // For debouncing
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 150; // 0.15 seconds for debounce

void setup() {
  // Initialize pins
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);  // Using pull-up resistor
  
  // Initialize all bar graph segments as outputs
  for (int i = 0; i < numBargraphSegments; i++) {
    pinMode(bargraphPins[i], OUTPUT);
  }
  
  // Initialize all components to off state
  updateDisplay();
}

void loop() {
  // Read the current button state
  bool reading = digitalRead(buttonPin);
  
  // If button state changed, reset the debounce timer
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }
  
  // Check if button state has been stable for the debounce period
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // If button state has changed since last check
    if (reading != buttonState) {
      buttonState = reading;
      
      // If the button is pressed (LOW with INPUT_PULLUP)
      if (buttonState == LOW) {
        // Increment the counter
        counter++;
        
        // Check for overflow
        if (counter > numBargraphSegments) {
          counter = 0;
          overflowCounter = (overflowCounter + 1) % 4; // Wrap back to 00 after 11
        }
        
        // Update display to reflect new counter values
        updateDisplay();
      }
    }
  }
  
  // Save button state for next loop iteration
  lastButtonState = reading;
}

void updateDisplay() {
  // Update the bar graph segments based on counter value
  for (int i = 0; i < numBargraphSegments; i++) {
    digitalWrite(bargraphPins[i], (i < counter) ? HIGH : LOW);
  }
  
  // Update the LEDs to display overflow counter in binary
  // 00: 0 overflows, 01: 1 overflow, 10: 2 overflows, 11: 3 overflows
  digitalWrite(led1Pin, (overflowCounter & 0x01) ? HIGH : LOW); // Least significant bit
  digitalWrite(led2Pin, (overflowCounter & 0x02) ? HIGH : LOW); // Most significant bit
}