const int redPin = 2;
const int greenPin = 3;
const int bluePin = 4;
const int buttonPin = 20;
int i = 0;

int colors[7][3] = {
  {0, 255, 255},    // Red
  {255, 0, 255},    // Green
  {255, 255, 0},    // Blue
  {0, 0, 255},  // Yellow
  {255, 0, 0},  // Cyan
  {0, 255, 0},  // Magenta
  {0, 0, 0} // White
};

int lastButtonState = LOW;
int buttonState = LOW;
int colorIndex = 0;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  pinMode(buttonPin, INPUT_PULLUP);

  Serial.begin(9600);
  
  setColor(colorIndex);
}

void loop() {
  int reading = digitalRead(buttonPin);
  
  // If the button state changed (press detected)
  if (reading != lastButtonState) {
    lastDebounceTime = millis();  // Reset debounce timer
  }
  
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH and sufficient time has passed since last "press" (bounce)
      if (buttonState == HIGH) {
        colorIndex = (colorIndex + 1) % 7;
        setColor(colorIndex);
        i++;
      }
    }
  }
  
  lastButtonState = reading;
}

void setColor(int index) {
  analogWrite(redPin, colors[index][0]);
  analogWrite(greenPin, colors[index][1]);
  analogWrite(bluePin, colors[index][2]);
}