int redCarPin = 8;
int yellowCarPin = 9;
int greenCarPin = 10;


int greenWalkPin = 11;
int redWalkPin = 12;


int soundPin = 6;
int buttonPin = 7;

int time = 2000;
int soundTime = 500;

bool isPressed = false;


enum State 
{
  NONE = 0,
  RED = 1,
  YELLOW_RED = 2,
  YELLOW = 3,
  GREEN = 4,
  GREEN_PUMP = 5
};


State state = GREEN;


void SoundSignal(int pin, int duration, int& pauseTime, int frequency)
{
  for(int i = 0; i < 200; i += 10, soundTime -= 10)
  {
    tone(pin, frequency, duration);
    delay(soundTime);
  }
}

void setup()
{
  // For car.
  pinMode(greenCarPin, OUTPUT);
  pinMode(yellowCarPin, OUTPUT);
  pinMode(redCarPin, OUTPUT);

  // For walker.
  pinMode(redWalkPin, OUTPUT);
  pinMode(greenWalkPin, OUTPUT);

  // For button.
  pinMode(buttonPin, INPUT);

  // For dunamic.
  pinMode(soundPin, OUTPUT);
}



void loop()
{
  if (digitalRead(buttonPin) == HIGH && !isPressed)  // If button was pressed.
  {
    isPressed = true;
    delay(time * 2);  // Stopping the execution, because the cars have
                      // to have time to pass the traffic lighter.
  }

  switch(state)
  {
    case GREEN: // Green light for car.
      // If the green light is lighting for car
      // for pedestrian it will be red.
      digitalWrite(greenCarPin, HIGH);
      digitalWrite(redWalkPin, HIGH);

      if(isPressed) // The pedestrian pressed the button.
      {
        soundTime = 500;    // Set the time of the sound alert.
        state = GREEN_PUMP;  // Switch to next traffic light state.
      }
      break;

    case GREEN_PUMP:  // Flashing of green light for cars.
      for(int i = 0; i < 6; i++)
      {
        digitalWrite(greenCarPin, LOW);
        delay(200);
        digitalWrite(greenCarPin, HIGH);
        delay(200);
      }

      digitalWrite(greenCarPin, LOW);  // Turn off the green light.

      state = YELLOW; // Move to next state.
      break;

    case YELLOW:  // Yellow light for cars.
      digitalWrite(yellowCarPin, HIGH);  // Turn on the yellow light for cas.
      delay(time);

      digitalWrite(yellowCarPin, LOW);  // Turn off the yellow light for cars. 
      digitalWrite(redWalkPin, LOW);    // Turn off the red light for pedestrians.

      state = RED; // Swiching to the next state. 
      break;

    case RED:  // Red light for cars.
      digitalWrite(redCarPin, HIGH);  // Turn on the red light for cars. 
      digitalWrite(greenWalkPin, HIGH); // Turn on the green light for pedestriants.
      
      SoundSignal(soundPin, 250, soundTime, 250);  // Turn on the sound alert.

      state = YELLOW_RED;  // Move to the next state.
      break;

    case YELLOW_RED:  // The bright of yellow and red lights for cars. 
      digitalWrite(yellowCarPin, HIGH); // Turn on the yellow light for cars.

      SoundSignal(soundPin, 250, soundTime, 250);  // Turn on the sound alert.

      // Turning off yellow and red lights for cars.
      digitalWrite(redCarPin, LOW); 
      digitalWrite(yellowCarPin, LOW);

      digitalWrite(greenWalkPin, LOW);  // Turn off the green light for pedestriants.

      state = GREEN;  // Move to the next state.
      isPressed = false;   // Set the button to released state.
      break;
  }
}