#include <MD_MAX72xx.h>
#include <ezButton.h>

// matrix controls
const byte data_pin = 11;
const byte chip_select_pin = 10;
const byte clock_pin = 13;
const byte max_devices = 1;

ezButton button(8);

int head_y = 0;  
int head_x = 0;
int flag=0;



String direction="" , prev_direction = "";
int max_x = 7, max_y = 7;

int snake_x[8];
int snake_y[8];
int snake_length = 2;

long int current_time, prev_time = 0;
int threshold = 800;

int food_x = random(0,8);
int food_y = random(0,8);

// creating matrix object
MD_MAX72XX matrix = MD_MAX72XX(MD_MAX72XX::PAROLA_HW, chip_select_pin, max_devices);

// define the joystick controls
const byte hpin = A0;
const byte vpin = A1;

void setup(){
  Serial.begin(9600);

  matrix.begin();
  matrix.clear();

  button.setDebounceTime(25);
  matrix.setPoint(head_x,head_y,true);
  
}

void loop(){

  button.loop();
  current_time=millis();
  check_direction();

  if(current_time - prev_time >= threshold){
    prev_time = current_time;

    matrix.clear();
    move_sprite();
    update_snake();
    draw_sprite();
  
  }
  food_eat_check();


}

void window_check(){
  if(head_x > max_x) head_x=0;
  else if(head_x < 0) head_x=max_x;
  else if(head_y > max_y) head_y=0;
  else if(head_y < 0) head_y=max_y;
  
}


void check_direction(){

  if(analogRead(hpin)>512 &&  prev_direction  !=  "right")
    direction="left";
  else if(analogRead(hpin)<512 &&  prev_direction  !=  "left")
    direction="right";
  else if(analogRead(vpin)>512 &&  prev_direction  !=  "down")
    direction="up";
  else if(analogRead(vpin)<512 &&  prev_direction  !=  "up")
    direction="down";

  //  updating prev_direction
  prev_direction = direction;

}

void move_sprite(){
  if(direction=="left") head_x++;
  else if(direction=="right") head_x--;
  else if(direction=="up") head_y--;
  else if(direction=="down") head_y++;

  window_check();

  if(button.isPressed()){
    Serial.println("The button is pressed");
    flag=1;
  }
}

void draw_sprite(){

  matrix.setPoint(food_y, food_x, true);

  for (int i = 0; i <= snake_length; i++){
    matrix.setPoint(snake_y[i], snake_x[i], true);
    }
}

void update_snake(){
  for(int i = snake_length; i >= 0; i--){
    if(i != 0){
      snake_x[i] = snake_x[i-1];
      snake_y[i] = snake_y[i-1];
    }
    else{
      snake_x[i] = head_x;
      snake_y[i] = head_y;
    }
  }
}
void food_eat_check(){
  if(head_x == food_x && head_y == food_y){
    food_x = random(0, 8);
    food_y = random(0, 8);

    snake_length++;

    threshold = threshold - 50;

    if(threshold < 100)
      threshold = 80;
  }
}