#define FORWARD_BUTTON 13
#define RIGHT_BUTTON 12
#define LEFT_BUTTON 11
#define BACKWARD_BUTTON 10

#define BUZZER 8

int FORWARD_BUTTON_PREVIOUS_STATE = 1;
int RIGHT_BUTTON_PREVIOUS_STATE = 1;
int LEFT_BUTTON_PREVIOUS_STATE = 1;
int BACKWARD_BUTTON_PREVIOUS_STATE = 1;

void setup() {
  // put your setup code here, to run once:
  pinMode(FORWARD_BUTTON, INPUT_PULLUP);
  pinMode(RIGHT_BUTTON, INPUT_PULLUP);
  pinMode(LEFT_BUTTON, INPUT_PULLUP);
  pinMode(BACKWARD_BUTTON, INPUT_PULLUP);
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
  Serial.println();

}

void loop() {
  // -------------- FORWARD_BUTTON START
  int FORWARD_BUTTON_STATE;
  int FORWARD_BUTTON_PRESSED;
  FORWARD_BUTTON_STATE = digitalRead(FORWARD_BUTTON);
  FORWARD_BUTTON_PRESSED = digitalRead(FORWARD_BUTTON);
  
  if (FORWARD_BUTTON_STATE == 0){
    if (FORWARD_BUTTON_PREVIOUS_STATE == 1){
      Serial.println("Forward Button pressed");
      Serial.println("");
      while (FORWARD_BUTTON_PRESSED == 0) {
        tone(BUZZER, 1200, 300);
        delay(50);
        FORWARD_BUTTON_PRESSED = digitalRead(FORWARD_BUTTON);
      }
      tone(BUZZER, 1200, 300);
      //Serial.println("Forward Button released");
      Serial.println("");
      Serial.flush();
      FORWARD_BUTTON_PREVIOUS_STATE = 0;
    }else{
      FORWARD_BUTTON_PREVIOUS_STATE = 1;
    }
  }

  // -------------- FORWARD_BUTTON END

  // -------------- RIGHT_BUTTON START
  int RIGHT_BUTTON_STATE;
  int RIGHT_BUTTON_PRESSED;
  RIGHT_BUTTON_STATE = digitalRead(RIGHT_BUTTON);
  RIGHT_BUTTON_PRESSED = digitalRead(RIGHT_BUTTON);

  if (RIGHT_BUTTON_STATE == 0){
    if (RIGHT_BUTTON_PREVIOUS_STATE == 1){
      Serial.println("Right Button pressed");
      Serial.println("");
      while (RIGHT_BUTTON_PRESSED == 0) {
        tone(BUZZER, 1300, 250);
        delay(50);
        RIGHT_BUTTON_PRESSED = digitalRead(RIGHT_BUTTON);
      }
      tone(BUZZER, 1300, 250);
      //Serial.println("Right Button released");
      Serial.println("");
      Serial.flush();
      RIGHT_BUTTON_PREVIOUS_STATE = 0;
    }else{
      RIGHT_BUTTON_PREVIOUS_STATE = 1;
    }
  }
  // -------------- RIGHT_BUTTON END

  // -------------- LEFT_BUTTON START
  int LEFT_BUTTON_STATE;
  int LEFT_BUTTON_PRESSED;
  LEFT_BUTTON_STATE = digitalRead(LEFT_BUTTON);
  LEFT_BUTTON_PRESSED = digitalRead(LEFT_BUTTON);

  if (LEFT_BUTTON_STATE == 0){
    if (LEFT_BUTTON_PREVIOUS_STATE == 1){
      Serial.println("Left Button pressed");
      Serial.println("");
      while (LEFT_BUTTON_PRESSED == 0) {
        tone(BUZZER, 1400, 250);
        delay(50);
        LEFT_BUTTON_PRESSED = digitalRead(LEFT_BUTTON);
      }
      tone(BUZZER, 1400, 250);
      //Serial.println("Left Button released");
      Serial.println("");
      Serial.flush();
      LEFT_BUTTON_PREVIOUS_STATE = 0;
    }else{
      LEFT_BUTTON_PREVIOUS_STATE = 1;
    }
  }
  // -------------- LEFT_BUTTON END

  // -------------- BACKWARD_BUTTON START
  int BACKWARD_BUTTON_STATE;
  int BACKWARD_BUTTON_PRESSED;
  BACKWARD_BUTTON_STATE = digitalRead(BACKWARD_BUTTON);
  BACKWARD_BUTTON_PRESSED = digitalRead(BACKWARD_BUTTON);

  if (BACKWARD_BUTTON_STATE == 0){
    if (BACKWARD_BUTTON_PREVIOUS_STATE == 1){
      Serial.println("Backward Button pressed");
      Serial.println("");
      while (BACKWARD_BUTTON_PRESSED == 0) {
        tone(BUZZER, 1100, 250);
        delay(50);
        BACKWARD_BUTTON_PRESSED = digitalRead(BACKWARD_BUTTON);
      }
      tone(BUZZER, 1100, 250);
      //Serial.println("Backward Button released");
      Serial.println("");
      Serial.flush();
      BACKWARD_BUTTON_PREVIOUS_STATE = 0;
    }else{
      BACKWARD_BUTTON_PREVIOUS_STATE = 1;
    }
  }
  // -------------- LEFT_BUTTON END

  delay(50);
  
}