const int r = 2, y = 3, g = 4;

char mode, userInput;

void setup()
{
  pinMode(r, OUTPUT);
  pinMode(y, OUTPUT);
  pinMode(g, OUTPUT);

  Serial.begin(9600);
  Serial.println("Automatic and Manual Traffic Control");
  Serial.println("Enter: 1 for Manual");
  Serial.println("Enter: 2 for Automatic");
}

void loop()
{
  if (Serial.available() > 0)
  {
    mode = Serial.read();
  
    switch(mode)
    {
      case '1':
        Serial.println("Manual Mode Activated");
        Serial.println("Enter 'r'/'y'/'g'/'o' for Red/ Yellow/ Green/ Turn All OFF");
        while (true)
        {
          if (Serial.available() > 0)
          {
            userInput = Serial.read();
            switch (userInput)
            {
              case 'r':
                digitalWrite(r, HIGH);
                digitalWrite(y, LOW);
                digitalWrite(g, LOW);
                Serial.println("Red ON");
                break;

              case 'y':
                digitalWrite(r, LOW);
                digitalWrite(y, HIGH);
                digitalWrite(g, LOW);
                Serial.println("Yellow ON");
                break;

              case 'g':
                digitalWrite(r, LOW);
                digitalWrite(y, LOW);
                digitalWrite(g, HIGH);
                Serial.println("Green ON");
                break;

              case 'o':
                digitalWrite(r, LOW);
                digitalWrite(y, LOW);
                digitalWrite(g, LOW);
                Serial.println("All Off");
                break;

              default:
                Serial.println("'r' = Red, 'y' = Yellow, 'g' = Green, 'o' = All Off");
                break;
            }
          }

          if (Serial.available() > 0 && Serial.peek() == '1') 
          {
            mode = Serial.read();
            break;
          }
        }
      break;

      case '2':
      Serial.println("Automatic Mode");
      // while(true)
      // {
        digitalWrite(r, HIGH);
        delay(1500);
        digitalWrite(r, LOW);
        digitalWrite(y, HIGH);
        delay(1000);
        digitalWrite(y, LOW);
        digitalWrite(g, HIGH);
        delay(1500);
        digitalWrite(g, LOW);
      // }
      break;

      default:
        Serial.println("Enter '1' for Manual, '2' for Automatic");
      break;
    }
  }
}