#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 = 4;

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

ezButton button(8);

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

int snake_x[64];
int snake_y[64];

int snake_length = 4;

int head_x = 0;
int head_y = 0;

int max_x = 31;
int max_y = 7;

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

int flag = 0;

String prev_dir = "";
String dir = "";

long int current_time = 0, prev_time = 0;
int threshold = 700;

void setup()
{
  Serial.begin(9600);
  // delay(20);
  matrix.begin();
  matrix.clear();
  button.setDebounceTime(25);
  show_message("Welcome");
  matrix.setPoint(head_y , head_x , true);
            // (right left ,up down, true--> pint visible, false --> no visible)
}

void loop()
{
  button.loop();
  //returns the number of milliseconds passed since the Arduino board began 
  //running the current program
  current_time = millis(); //
  checkDirection();

  if (current_time - prev_time >= threshold)
  {
      prev_time = current_time;
      matrix.clear();
      moveSprite();
      update_snake();
      draw_sprite();
  }
  food_eat_check();

}

void checkDirection()
{
  if ((analogRead(hpin) > 512) && (prev_dir != "Right"))
    dir = "Left";
  else if ((analogRead(hpin) < 512) && (prev_dir != "Left"))
    dir = "Right"; 
  else if ((analogRead(vpin) > 512) && (prev_dir != "Down"))
    dir = "Up";
  else if ((analogRead(vpin) < 512) && (prev_dir != "Up"))
    dir = "Down";
  prev_dir = dir;
}

void moveSprite()
{
  if (dir == "Left" )
  {
    head_x += 1;
  }
  else if (dir == "Right" )
  {
    head_x -= 1;
  }
  else if (dir == "Up" )
  {
    head_y -= 1;// has been switched wantedly, only then sprite is moving according tot the joystick
  }
  else if (dir == "Down" )
  {
    head_y += 1;// has been switched wantedly, only then sprite is moving according tot the joystick
  }

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

}

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 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 -= 50;
    if (threshold <100)
        threshold = 80;
  }
}

void all_animate()
{
  for (int i = 0 ; i < 3 ; i++)
  {
      for (int x = 0; x < 32; x++)
      {
          for (int y = 0; y < 8; y++)
          {
              matrix.setPoint(y,x,true);
          }
      }
      delay(500);
      matrix.clear();
      delay(500);
  }
}

void show_message(char messageToShow[])
{
    all_animate();
    int i = 0,start = 30;
    int vals[] = {30,25,20,18,13,8,3};
    while (messageToShow[i]!='\0')
    {
      matrix.setChar(vals[i] , messageToShow[i]);
      delay(500);
      i++;
    }
}