const int buttonPin = 2;    // GPIO for Button
const int redPin = 9;       // GPIO for Red LED
const int greenPin = 8;     // GPIO for Green LED
const int bluePin = 7;      // GPIO for Blue LED

int buttonState = 0;        // Current state of the button
int lastButtonState = 0;    // Previous state of the button
int mode = 0;               // Mode to track which LED is ON (0 = all off, 1 = red, 2 = green, 3 = blue)

void setup() {
  // Initialize the button pin as input
  pinMode(buttonPin, INPUT);

  // Initialize RGB LED pins as outputs
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  // Turn off all LEDs initially
  digitalWrite(redPin, LOW);
  digitalWrite(greenPin, LOW);
  digitalWrite(bluePin, LOW);
}

void loop() {
  // Read the current state of the button
  buttonState = digitalRead(buttonPin);

  // Check if the button was pressed (transition from LOW to HIGH)
  if (buttonState == HIGH && lastButtonState == LOW) {
    mode++;  // Increment mode
    if (mode > 3) {
      mode = 1;  // Cycle through modes 1 to 3 (Red -> Green -> Blue)
    }

    // Turn off all LEDs before turning on the next one
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, LOW);
    digitalWrite(bluePin, LOW);

    // Based on the mode, turn on the corresponding LED
    switch (mode) {
      case 1: // First press: Red LED on
        digitalWrite(redPin, HIGH);
        break;
      case 2: // Second press: Green LED on
        digitalWrite(greenPin, HIGH);
        break;
      case 3: // Third press: Blue LED on
        digitalWrite(bluePin, HIGH);
        break;
    }

    // Add a small delay to debounce the button
    delay(50);
  }

  // Save the current button state for the next loop
  lastButtonState = buttonState;
}