#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>

const int HEIGHHT = 64;
const int WIDHT = 128;

int vert = A0;
int horz = A1;
int button = 2;

int xShift = -1;    //для двежения по вертекали 
int snakeXOld = -1;

int yShift = 0;     //для двежения в горезонтали
int snakeYOld = -1;

bool headSnake[8][8] = 
{
  {0,0,0,0,1,1,1,0},
  {0,0,1,1,0,1,1,1},
  {1,1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1,1},
  {0,0,1,1,0,1,1,1},
  {0,0,0,0,1,1,1,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0}
};

bool apple[8][8] =
{
  {0,0,0,0,1,0,0,0},
  {0,0,0,1,0,0,0,0},
  {0,1,1,0,1,1,0,0},
  {1,0,0,0,0,0,1,0},
  {1,0,0,0,0,0,1,0},
  {1,0,0,0,0,0,1,0},
  {0,1,0,0,0,1,0,0},
  {0,0,1,1,1,0,0,0}
};

const int CAPACITY = 15;
int bodyX[CAPACITY];
int bodyY[CAPACITY];
int countBody = 0;

int appleX = -1;
int appleY = -1;

int screanGame = 0;
int scoreApple = 0;

#define OLED_RESET 7
Adafruit_SSD1306 display(WIDHT, HEIGHHT, &Wire, OLED_RESET); 

void setup()
{
 display.begin(SSD1306_SWITCHCAPVCC, 0X3C);
 display.clearDisplay();
 display.setTextColor(WHITE);
 Serial.begin(9600);
 pinMode(vert, INPUT);
 pinMode(horz, INPUT);
 pinMode(button, INPUT);

 randomSeed(analogRead(A2));

 initSnake();
}

void loop() 
{
  while(screanGame == 0)
  {
    display.setCursor(40,10);
    display.print("Snake");
    display.setCursor(20,30);
    display.print("Press button");
    display.display();
    if(digitalRead(button) == 1)
    {
      display.clearDisplay();
      screanGame = 1;
    }
  }

 while (screanGame == 1) 
 {
  DrawPicture(apple, appleX, appleY);
  ViewSnake();
  MoveSnake(xShift, yShift);

  if(analogRead(horz) == 0)  //для двежения влево
  {
   xShift = 1;
   yShift = 0;
  }

  if(analogRead(vert) == 0)  //для двежения в вниз
  {
   xShift = 0; 
   yShift = 1;
  }

  if(analogRead(horz) == 1023)  //для двежения в право
  {
   xShift = -1;
   yShift = 0;
  }

  if(analogRead(vert) == 1023)  //для двежения вверх
  {
   xShift = 0; 
   yShift = -1;
  } 

  delay(100);  

  if(bodyX[0] == appleX && bodyY[0] == appleY)
  {
    EatApple();
    scoreApple++;
  }

  if(IsCrashed())
  {    
    display.clearDisplay();
    screanGame = 2;
    initSnake();
    xShift = -1;
    yShift = 0;
  }
 }

  while(screanGame == 2)
  {
    display.setCursor(20,10);
    display.print("End game");
    display.setCursor(10,30);
    display.print("Score:");
    display.setCursor(50,30);
    display.print(scoreApple);
    display.display();

    delay(5000);
    display.clearDisplay();
    screanGame = 0;
    scoreApple = 0;
  }

}

void ClearObjakt(int x, int y)
{
  const int size = 8;
  display.fillRect(x * size, y * size, size, size, SSD1306_BLACK);
  display.display();
}

void DrawPicture(bool dataPicture[8][8], int x, int y)
{
  const int SIZE = 8;

  for(int i = 0; i < SIZE; i++)
  {
    for(int j = 0; j < SIZE; j++)
    {
      if(dataPicture[i][j] == 1)
      {
        display.drawPixel(j + (x * SIZE), i + (y * SIZE), SSD1306_WHITE);
      }
    }
  }
  display.display();
}

void ViewSnake()
{
  for(int i=0; i < countBody; i++)
  {
    DrawPicture(headSnake, bodyX[i], bodyY[i]);
  }
  ClearObjakt(snakeXOld, snakeYOld);
}

void MoveSnake(int directionX, int directionY)
{
  snakeXOld = bodyX[countBody - 1];
  snakeYOld = bodyY[countBody - 1];

  for(int i = countBody - 2; i >= 0; i--)
  {
    bodyX[i + 1] = bodyX[i]; 
    bodyY[i + 1] = bodyY[i];
  }

  bodyX[0] += directionX;
  bodyY[0] += directionY;

  if(bodyX[0] > 15)  
  {
    bodyX[0] = 0; 
  }

  if(bodyX[0] < 0)  
  {
    bodyX[0] = 15; 
  }

  if(bodyY[0] > 7)  
  {
    bodyY[0] = 0; 
  }

  if(bodyY[0] < 0)  
  {
    bodyY[0] = 7; 
  }
}

void AddBody()
{
  bodyX[countBody] = bodyX[countBody] - 1;
  bodyY[countBody] = bodyY[countBody] - 1;
  countBody++;
}

void EatApple()
{
 ClearObjakt(appleX, appleY);
 AddBody();
 appleX = random(0,15);
 appleY = random(0,7);
}

bool IsCrashed()
{
  bool isLose = false;

  for(int i = 4; i < countBody; i++)
  {
    if(bodyX[0] == bodyX[i] && bodyY[0] == bodyY[i])
    {
      isLose = true;
      break;
    }
  }

  return isLose;
}

void initSnake()
{
 bodyX[0] = 4;
 bodyY[0] = 4;

 bodyX[1] = 5;
 bodyY[1] = 4;
 
 bodyX[2] = 6;
 bodyY[2] = 4;
 
 bodyX[3] = 7;
 bodyY[3] = 4;

 bodyX[4] = 8;
 bodyY[4] = 4;

 countBody = 5;

 appleX = random(0,15);
 appleY = random(0,7); 
}