// Constants for 32x32 matrix
#define X_SEGMENTS   4
#define Y_SEGMENTS   4
#define NUM_SEGMENTS (X_SEGMENTS * Y_SEGMENTS)
#define MAX_X        31
#define MAX_Y        31
#include <MD_MAX72xx.h>
#include <Servo.h>
// Snake game variables
int snakeX[100], snakeY[100];  // Snake position
int snakeLength = 3;           // Initial snake length
int snakeDir = 0;              // Snake direction (0: right, 1: down, 2: left, 3: up)
int foodX, foodY;              // Food position
#define CLK 13
#define DIN 11
#define CS 10
byte fb[8 * NUM_SEGMENTS];
void setup() {
  // Initialization code for 32x32 matrix
  pinMode(CLK, OUTPUT);
  pinMode(DIN, OUTPUT);
  pinMode(CS, OUTPUT);
  
  shiftAll(0x0f, 0x00); // Display test register - test mode off
  shiftAll(0x0b, 0x07); // Scan limit register - display digits 0 thru 7
  shiftAll(0x0c, 0x01); // Shutdown register - normal operation
  shiftAll(0x0a, 0x0f); // Intensity register - max brightness
  shiftAll(0x09, 0x00); // Decode mode register - No decode

  // Initialize snake and food
  resetGame();
}

void loop() {
  moveSnake();
  show();
  delay(100);  // Adjust snake speed
}

void show() {
  for (byte row = 0; row < 8; row++) {
    digitalWrite(CS, LOW);
    for (byte segment = 0; segment < NUM_SEGMENTS; segment++) {
      byte x = segment % X_SEGMENTS;
      byte y = segment / X_SEGMENTS * 8;
      byte addr = (row + y) * X_SEGMENTS;

      if (segment & X_SEGMENTS) { // Odd rows of segments
        shiftOut(DIN, CLK, MSBFIRST, 8 - row);
        shiftOut(DIN, CLK, LSBFIRST, fb[addr + x]);
      } else { // Even rows of segments
        shiftOut(DIN, CLK, MSBFIRST, 1 + row);
        shiftOut(DIN, CLK, MSBFIRST, fb[addr - x + X_SEGMENTS - 1]);
      }
    }
    digitalWrite(CS, HIGH);
  }
}

void moveSnake() {
  // Move the body of the snake
  for (int i = snakeLength - 1; i > 0; --i) {
    snakeX[i] = snakeX[i - 1];
    snakeY[i] = snakeY[i - 1];
  }

  // Move the head of the snake based on the current direction
  switch (snakeDir) {
    case 0: // Right
      snakeX[0]++;
      break;
    case 1: // Down
      snakeY[0]++;
      break;
    case 2: // Left
      snakeX[0]--;
      break;
    case 3: // Up
      snakeY[0]--;
      break;
  }

  // Check if the snake eats the food, increase length and respawn food
  if (snakeX[0] == foodX && snakeY[0] == foodY) {
    snakeLength++;
    spawnFood();
  }

  // Check if the snake hits the boundary, reset the game
  if (snakeX[0] < 0 || snakeX[0] > MAX_X || snakeY[0] < 0 || snakeY[0] > MAX_Y) {
    resetGame();
  }
}

void spawnFood() {
  // Randomly generate food position
  foodX = random(0, MAX_X + 1);
  foodY = random(0, MAX_Y + 1);
}

void resetGame() {
  // Reset game parameters
  snakeLength = 3;
  snakeX[0] = 0;
  snakeY[0] = 0;
  snakeX[1] = 1;
  snakeY[1] = 0;
  snakeX[2] = 2;
  snakeY[2] = 0;
  snakeDir = 0;
  spawnFood(); // Respawn food
}

void shiftAll(byte send_to_address, byte send_this_data) {
  digitalWrite(CS, LOW);
  for (int i = 0; i < NUM_SEGMENTS; i++) {
    shiftOut(DIN, CLK, MSBFIRST, send_to_address);
    shiftOut(DIN, CLK, MSBFIRST, send_this_data);
  }
  digitalWrite(CS, HIGH);
}

void set_pixel(uint8_t x, uint8_t y, uint8_t mode) {
  byte *addr = &fb[x / 8 + y * X_SEGMENTS];
  byte mask = 128 >> (x % 8);
  switch (mode) {
    case 0: // Clear pixel
      *addr &= ~mask;
      break;
    case 1: // Plot pixel
      *addr |= mask;
      break;
    case 2: // XOR pixel
      *addr ^= mask;
      break;
  }
}