#include <Servo.h>
#include <MD_MAX72xx.h>

#define CLK_PIN    13
#define DATA_PIN   11
#define CS_PIN     10
#define MAX_DEVICES 4

#define VERT_PIN A0
#define HORZ_PIN A1
#define SEL_PIN  2

const int maxX = MAX_DEVICES * 8 - 1;
const int maxY = 31;

MD_MAX72XX mx = MD_MAX72XX(MD_MAX72XX::PAROLA_HW, CS_PIN, MAX_DEVICES);
Servo myservo;

int snakeX[100] = {0, 1, 2};
int snakeY[100] = {0, 0, 0};
int snakeLength = 3;
int beanX, beanY;
bool gameRunning = true;
char direction = 'R'; // Initial direction: 'U', 'D', 'L', 'R'

void setup() {
  myservo.attach(9);
  mx.begin();

  // Initialize snake and bean
  drawSnake();
  generateBean();

  pinMode(VERT_PIN, INPUT);
  pinMode(HORZ_PIN, INPUT);
  pinMode(SEL_PIN, INPUT_PULLUP);

  randomSeed(analogRead(0)); // Seed random number generator
}

void loop() {
  if (digitalRead(SEL_PIN) == LOW) {
    restartGame();
    return;
  }

  if (!gameRunning) {
    return;
  }

  readJoystick();

  int x = snakeX[0];
  int y = snakeY[0];

  // Update position based on direction
  switch (direction) {
    case 'U': y = max(y - 1, 0); break;
    case 'D': y = min(y + 1, maxY); break;
    case 'L': x = max(x - 1, 0); break;
    case 'R': x = min(x + 1, maxX); break;
  }

  // Check collision with bean
  if (x == beanX && y == beanY) {
    snakeLength++;
    generateBean();
    if (snakeLength == 10) {
      for (int i = 0; i < 3; i++) {
        myservo.write(180);
        delay(500);
        myservo.write(0);
        delay(500);
      }
    }
  }

  // Check collision with boundaries or self
  if (x < 0 || x > maxX || y < 0 || y > maxY || checkSelfCollision(x, y)) {
    gameRunning = false;
    return;
  }

  // Update snake position
  for (int i = snakeLength - 1; i > 0; i--) {
    snakeX[i] = snakeX[i - 1];
    snakeY[i] = snakeY[i - 1];
  }
  snakeX[0] = x;
  snakeY[0] = y;

  // Update display
  mx.clear();
  drawSnake();
  mx.setPoint(beanY, beanX, true);
  mx.update();

  delay(100);
}

void readJoystick() {
  int vert = analogRead(VERT_PIN);
  int horz = analogRead(HORZ_PIN);

  if (vert < 300 && direction != 'D') {
    direction = 'U';
  }
  if (vert > 700 && direction != 'U') {
    direction = 'D';
  }
  if (horz > 700 && direction != 'L') {
    direction = 'R';
  }
  if (horz < 300 && direction != 'R') {
    direction = 'L';
  }
}

void generateBean() {
  beanX = random(0, maxX + 1);
  beanY = random(0, maxY + 1);
  while (checkSelfCollision(beanX, beanY)) {
    beanX = random(0, maxX + 1);
    beanY = random(0, maxY + 1);
  }
  mx.setPoint(beanY, beanX, true);
}

bool checkSelfCollision(int x, int y) {
  for (int i = 0; i < snakeLength; i++) {
    if (snakeX[i] == x && snakeY[i] == y) {
      return true;
    }
  }
  return false;
}

void drawSnake() {
  for (int i = 0; i < snakeLength; i++) {
    mx.setPoint(snakeY[i], snakeX[i], true);
  }
}

void restartGame() {
  snakeLength = 3;
  for (int i = 0; i < snakeLength; i++) {
    snakeX[i] = i;
    snakeY[i] = 0;
  }
  direction = 'R';
  gameRunning = true;
  mx.clear();
  drawSnake();
  generateBean();
}