#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

int const buttonPinTop = 2;
int const buttonPinBottom = 3;

String const car = "I>>";
String const enemyCar = "<I";
String const spawnedCar = "<";
String const carEnd = "I";

int y = 0;
int del = 150;
int times = 0;
int score = 0;

void setup() {
  lcd.init();
  lcd.backlight();

  pinMode(buttonPinTop, INPUT_PULLUP);
  pinMode(buttonPinBottom, INPUT_PULLUP);
}

void loop() {
  int posY = random(0, 4);
  lcd.setCursor(19, posY);
  lcd.print("XX");

  for (int i = 18; i >= 0; i--) {
    if(digitalRead(buttonPinTop) == LOW)
    {
      moveTop();
    }
    if(digitalRead(buttonPinBottom) == LOW)
    {
      moveBottom();
    }
    validY();
    lcd.clear();
    printCar();
    lcd.setCursor(i, posY);
    lcd.print("<=");
    if(y == posY
      && (i == 0 || i == 1 || i == 2))
    {
      gameOver();
      return;
    }

    delay(del);
  }
  if(del > 10)
  {
    del -= 5;
  }
  score++;
}

void gameOver()
{
  lcd.clear();
  char message1[] = "Game over";
  char message2[] = "Click the button";
  char message3[] = "to continue";
  char message4[] = "Score: ";
  lcd.setCursor(getPosition(message1), 0);
  lcd.print(message1);
  lcd.setCursor(getPosition(message2), 1);
  lcd.print(message2);
  lcd.setCursor(getPosition(message3), 2);
  lcd.print(message3);
  lcd.setCursor(0, 3);
  lcd.print(message4);
  lcd.print(score);

  while((digitalRead(buttonPinBottom) != LOW) && (digitalRead(buttonPinTop) != LOW)){ }

  score = 0;
  del = 150;

  lcd.clear();
  return;
}

int getPosition(char *message)
{
  return (20 - strlen(message))/2;
}

void moveTop()
{
  lcd.setCursor(0, y);
  lcd.print("   ");
  y--;
}

void moveBottom()
{
  lcd.setCursor(0, y);
  lcd.print("   ");
  y++;
}

void validY()
{
  if(y == 4)
  {
    y = 0;
  }
  if(y == -1)
  {
    y = 3;
  }
}

void printCar()
{
  lcd.setCursor(0, y);
  lcd.print(car);
}