// Blue button has bouncing simulation disabled.
    
#define BUTTON_PIN A1
#define LED_red_PIN 5
#define LED_green_PIN 4
#define LED_yellow_PIN 6

void setup() {
  // we setup the pins and connection
  pinMode(LED_red_PIN, OUTPUT);
  pinMode(LED_green_PIN, OUTPUT);
  pinMode(LED_yellow_PIN, OUTPUT);

  pinMode(BUTTON_PIN, INPUT_PULLUP);

  digitalWrite(LED_green_PIN, HIGH); // Green is ON
}

// global variables
char current_light = 'G'; // G, Y, R
//int last_button_state = HIGH;

void loop() {
  // MAJOR REQUIREMENT: ONLY ONE LIGHT CAN BE ON AT AN TIME
  //delay(1000);

  int current_button_state = digitalRead((BUTTON_PIN));
  // if the button is pressed, button_state = LOW
  if (current_button_state == LOW) {
    // if the button is pressed, then change the light:
    // G -> Y -> R, or R -> Y -> G... and wait in Yellow for 1 second
    if (current_light == 'G') { // go to Y -> R 
      // first turn OFF the Green
      digitalWrite(LED_green_PIN, LOW);

      // TURN ON the YELLOW, and wait for 1 second
      digitalWrite(LED_yellow_PIN, HIGH);
      delay(1000); // ms
      digitalWrite(LED_yellow_PIN, LOW);

      // TURN ON the RED
      digitalWrite(LED_red_PIN, HIGH);
      current_light = 'R';
    }

    else if (current_light == 'R') { // go to Y -> G 
      digitalWrite(LED_red_PIN, LOW);

      // TURN ON the YELLOW, and wait for 1 second
      digitalWrite(LED_yellow_PIN, HIGH);
      delay(1000); // ms
      digitalWrite(LED_yellow_PIN, LOW);

      // TURN ON the green
      digitalWrite(LED_green_PIN, HIGH);
      current_light = 'G';
    }

  }

/*
  int current_button_state = digitalRead((BUTTON_PIN));
  // if the button is pressed, button_state = LOW
  if (lastState != current_button_state) {
    lastState = current_button_state;
    if (current_button_state == HIGH) {
      digitalWrite(LED_red_PIN, LOW); // off
      digitalWrite(LED_green_PIN, HIGH); // on
    }
    if (current_button_state == LOW) {
      digitalWrite(LED_red_PIN, HIGH); // on
      digitalWrite(LED_green_PIN, LOW); // off
    }
  }*/
}