const int redLED = 2;             // Red LED pin for traffic light
const int yellowLED = 3;          // Yellow LED pin for traffic light
const int greenLED = 4;           // Green LED pin for traffic light
const int pedestrianButton = 5;   // Pedestrian pushbutton pin
const int reedSwitch = 6;         // Reed switch input pin
const int rgbRed = 9;             // Red segment of the RGB LED
const int rgbGreen = 10;          //Green segment of RGB LED
const int rgbBlue = 11;          // Green segment of the RGB LED

const unsigned long greenDuration = 40000; // Green Light Duration
const unsigned long originalRedDuration = 50000; // Original red light duration
const unsigned long yellowDuration = 3000; // Yellow light duration
const unsigned long extendedRedDuration = 65000; //Extended Red Duration for Pedestrian Crossing

unsigned long lastMillis = 0;
unsigned long currentMillis = 0;
boolean pedestrianCrossing = false;
boolean vehicleDetected = false;

char currentTrafficState = 'R'; //R = RED, G = Green, Y = Yellow

void setup() {
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(pedestrianButton, INPUT_PULLUP);
  pinMode(reedSwitch, INPUT_PULLUP);
  pinMode(rgbRed, OUTPUT);
  pinMode(rgbGreen, OUTPUT);
  pinMode(rgbBlue, OUTPUT);

  updateTrafficLight('R');
  analogWrite(rgbBlue,0);
  analogWrite(rgbGreen,255);
  analogWrite(rgbRed,0);
  Serial.begin(9600);
}

void loop() {
//Serial Debugging
//Serial.print("Pedestrian Crossing State :");
//Serial.println(pedestrianCrossing);
//Serial.print("Pedestrian Button :");
//Serial.println(digitalRead(pedestrianButton));

currentMillis = millis();

if (digitalRead(pedestrianButton) == LOW){
  pedestrianCrossing = true;
}
else{}

if (digitalRead(reedSwitch) == LOW) {
  vehicleDetected = true;
} else {
  vehicleDetected = false;
}

  switch (currentTrafficState) {
    case 'R':
      if (pedestrianCrossing == false && currentMillis - lastMillis >= originalRedDuration) {
        updateTrafficLight('G');
        analogWrite(rgbRed, 255);   // Turn of Pedestrian Red Light
        analogWrite(rgbGreen, 0); // Turn Turn on Pedestrian Green Light
      }

      else if (pedestrianCrossing == true && currentMillis - lastMillis >= extendedRedDuration){
        updateTrafficLight('G');
        analogWrite(rgbRed, 0);   // Turn of Pedestrian Red Light
        analogWrite(rgbGreen, 255); // Turn Turn on Pedestrian Green Light
        pedestrianCrossing = false;
      }
      break;

    case 'G':
      if (vehicleDetected == false && currentMillis - lastMillis >= greenDuration) {
        updateTrafficLight('Y');
        analogWrite(rgbGreen, 0);  // Turn off Pedestrian Green Light
        analogWrite(rgbRed, 255);   // Turn on Pedestrian Stop
      }

      if (vehicleDetected == true) {
        updateTrafficLight('G');
      }
      break;

    case 'Y':
      if (currentMillis - lastMillis >= yellowDuration) {
        updateTrafficLight('R');
        analogWrite(rgbRed, 0);   // Turn off Pedestrian stop Light
        analogWrite(rgbGreen, 255); // Turn on Pedestrian go light
      }
      break;
  }
}

void updateTrafficLight(char newTrafficState) {
  currentTrafficState = newTrafficState;
  lastMillis = currentMillis;

  digitalWrite(redLED, LOW);
  digitalWrite(yellowLED, LOW);
  digitalWrite(greenLED, LOW);

  switch (currentTrafficState) {
    case 'R':
      digitalWrite(redLED, HIGH);
      break;
    case 'G':
      digitalWrite(greenLED, HIGH);
      break;
    case 'Y':
      digitalWrite(yellowLED, HIGH);
      break;
  }
}