#include <MD_MAX72xx.h>
#include <SPI.h>

#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define CS_PIN 10

int UP = 5;
int DOWN = 6;
int LEFT = 7;
int RIGHT = 4;

MD_MAX72XX mx(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

int dir = 0;

int lastMove = 0;
int moveDelay = 2000;

const int max_len = 256;
int len = 3;

int snakeX[max_len];
int snakeY[max_len];

int tempX = 0;
int tempY = 0;

void setup() {
  pinMode(UP, INPUT_PULLUP);
  pinMode(DOWN, INPUT_PULLUP);
  pinMode(LEFT, INPUT_PULLUP);
  pinMode(RIGHT, INPUT_PULLUP);

  mx.begin();
  Serial.begin(9600);
  Serial.println("Start");

  snakeX[0] = 0;
  snakeY[0] = 0;

  snakeX[1] = 0;
  snakeY[1] = 1;

  snakeX[2] = 0;
  snakeY[2] = 2;
}

void loop() {
  if (digitalRead(UP) == LOW && dir != 3) {
    dir = 1;
    Serial.println("up");
  }
  if (digitalRead(LEFT) == LOW && dir != 4) {
    dir = 2;
    Serial.println("left");
  }
  if (digitalRead(DOWN) == LOW && dir != 1) {
    dir = 3;
    Serial.println("down");
  }
  if (digitalRead(RIGHT) == LOW && dir !=2) {
    dir = 4;
    Serial.println("right");
  }
    
  if (millis()-lastMove > moveDelay) {
    lastMove = millis();
    mx.clear();

    tempX = snakeX[0]
    tempY = snakeY[0]

    for (int i = len - 1; i > 0; i--) {
      snakeX[i] = snakeX[i - 1];
      snakeY[i] = snakeY[i - 1];
      mx.setPoint(snakeY[i], snakeX[i], true);
    }

    if (dir == 1) {
      snakeY[0]++;
    }

    if (dir == 2) {
      snakeX[0]--;
    }

    if (dir == 3) {
      snakeY[0]--;
    }

    if (dir == 4) {
      snakeX[0]++;
    }

    if (snakeX[0] > 31) snakeX[0] = 0;
    if (snakeX[0] < 0) snakeX[0] = 31;

    if (snakeY[0] > 7) snakeY[0] = 0;
    if (snakeY[0] < 0) snakeY[0] = 7;
  }
}