const int buttonPin = 12;
const int redLED = 6;
const int yellowLED = 5;
const int greenLED = 3;
double currentTime;
double startTimeRed;
double startTimeYellow;
double startTimeGreen;
double deltaTRed = 1;
double deltaTYellow = 1;
double deltaTGreen = 1;

void setup() {
  // put your setup code here, to run once:
    // Initialize serial communication
  Serial.begin(9600);
  
  // Set the button pin as input
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);

  // initialize timers
  startTimeRed = millis();
  startTimeRed = startTimeRed*.001;
  startTimeYellow = millis();
  startTimeYellow = startTimeYellow*.001;
  startTimeGreen = millis();
  startTimeGreen = startTimeGreen*.001;
  Serial.println("Welcome.\n");

}

void loop() {
  // put your main code here, to run repeatedly:
  currentTime = millis();
  currentTime = currentTime*.001;

  getUserInput();
  updateLEDs();

}

void getUserInput() {
  if (Serial.available() > 0) {
    String str = Serial.readString();
    str.trim();
    int commaIndex = str.indexOf(",");
    String color = str.substring(0, commaIndex);
    double deltaT = str.substring(commaIndex+1, str.length()-1).toDouble();

      if (color == "R" || color == "r") {
        deltaTRed = deltaT;
      }
      else if (color == "Y" || color == "y") {
        deltaTYellow = deltaT;
      }
      else if (color == "G" || color == "g") {
        deltaTGreen = deltaT;
      }
  }
}

void updateLEDs() {
  if ((currentTime - startTimeRed) >= deltaTRed) {
    if (digitalRead(redLED)) {
      digitalWrite(redLED, LOW);
    }
    else {
      digitalWrite(redLED, HIGH);
    }

    startTimeRed = millis();
    startTimeRed = startTimeRed*.001;
  }

  if ((currentTime - startTimeYellow) >= deltaTYellow) {
    if (digitalRead(yellowLED)) {
      digitalWrite(yellowLED, LOW);
    }
    else {
      digitalWrite(yellowLED, HIGH);
    }

    startTimeYellow = millis();
    startTimeYellow = startTimeYellow*.001;
  }

  if ((currentTime - startTimeGreen) >= deltaTGreen) {
    if (digitalRead(greenLED)) {
      digitalWrite(greenLED, LOW);
    }
    else {
      digitalWrite(greenLED, HIGH);
    }

    startTimeGreen = millis();
    startTimeGreen = startTimeGreen*.001;
  }
}