#include <LiquidCrystal.h>


LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

int upPin = 5 , downPin=3 , rightPin =4 ,leftPin=6;
int stepPin=2;
int ledTest = 13;

bool upState=false ,rightState=false ,leftState=false;
bool stepState=false,downState=false;



short const screenWidth = 5*16; // set the screen dimension
short const screenHeight = 8*2;
bool display[screenWidth * screenHeight];

const char arraySize = 30;

class vector{
public:
	char x,y;
	vector(){ x=-1,y=0; }
	
	vector(char Xinput ,char Yinput)
	{
		x = Xinput;
		y = Yinput;
	}

	vector operator + (const vector &right)	{return addition(right);}
	vector operator +=(const vector &right)	{return addition(right);}
	
	vector addition(const vector &right)
	{
		vector copy = *this;
		copy.x +=right.x;
		copy.y +=right.y;
		return copy;
	}

};
vector direction = vector(1,0); // parameter
vector currentHeadPosition = vector(3,5);
vector newHeadPosition;

vector divmod(unsigned char numerator , unsigned char denumerator)
{
	unsigned char value=0;
	while (value <= numerator)
		value += denumerator;

	if (value > numerator)
		value -= denumerator;
	return vector(value/denumerator ,numerator-value);
}

unsigned char getRand(unsigned char number)
{
	unsigned char numerator = rand();
	unsigned char value=0;
	while (value <= numerator)
		value += number;

	if (value > numerator)
		value -= number;
	return numerator-value;
}

inline bool vectorIntersection(vector &v1 , vector &v2)
	{ return v1.x == v2.x && v1.y == v2.y; }

class snakeBody{
public:
	vector bodyArray[arraySize];
	unsigned short indexStart = -1; 
	unsigned short indexEnd = 2;

	snakeBody() {
		bodyArray[0] = vector(1,5);
		bodyArray[1] = vector(2,5);
		bodyArray[2] = vector(3,5);
	}

	void makeMove()
	{
		++indexStart;++indexEnd;
		bodyArray[(divmod(indexStart,arraySize)).y] = vector(-1,0);
		bodyArray[(divmod(indexEnd,arraySize)).y] = newHeadPosition;
		currentHeadPosition = newHeadPosition;
	}
	bool checkForHit(){
		for (unsigned char index =0 ; index < arraySize ; ++index)
		{
			if ((bodyArray[index]).x != -1)
			{
				if (vectorIntersection(bodyArray[index], newHeadPosition))
					return false;
			}
		}
		return true;
	}
	void writeBody()
	{
		for (unsigned short index=0 ; index < arraySize ; ++index)
		{
			vector v = bodyArray[index];
			if (v.x != -1)
				display[v.y * screenWidth + v.x] = 1;
		}
	}
	void increaseSize()
	{
		--indexStart;
	}
};
snakeBody snakeInstance;


class food {
public:
	vector foodTopLeftPosition;

	food(){selectPosition();}

	food(unsigned char x, unsigned char y)
	{
		foodTopLeftPosition = vector(x,y);
	}

	void writeFoodPositions(){
		display[foodTopLeftPosition.y * screenWidth + foodTopLeftPosition.x]=true;
	}

	void checkForIntersection()
	{
		if (vectorIntersection(foodTopLeftPosition , currentHeadPosition))
		{
			hitFood();
		}
	}

	void hitFood()
		{
		selectPosition();
		snakeInstance.increaseSize(); 
		}

	void setPoint(unsigned char x , unsigned char y)
	{
		foodTopLeftPosition = vector(x,y);
	}

private:
	void selectPosition()
	{
		// srand(time(0));
		unsigned char x = getRand(screenWidth-2);
		unsigned char y = getRand(screenHeight-2);
		foodTopLeftPosition = vector(x,y);
	}

};
food foodInstance = food(10,5);



inline unsigned char powFoTwo(unsigned char power) 
{
	unsigned char value=1;
	while (power >=1)
		{value *=2;--power;}
	return value;
}

/*
verticalBlock *640
charactor 		*5
veritcalLIne  *80
iteration
*/

void generateCharactor()
{
	for (unsigned char verticalBlock=0 ; verticalBlock<2 ; ++verticalBlock)
	{
		for (unsigned char charactor=0 ; charactor < 16 ; ++charactor)
		{
			byte cell[8];
			for (unsigned char verticalLine=0 ; verticalLine<8 ; ++verticalLine)
			{
				unsigned char lineValue=0;
				for (unsigned char iteration = 0 ; iteration<5 ; ++iteration)
				{
					bool element = display[verticalBlock*640 + charactor*5 + verticalLine*80 + iteration];
					if(element)
						{lineValue += powFoTwo(5-iteration);}
				}
				cell[verticalLine] = (byte)lineValue;
			}
			lcd.createChar(charactor+verticalBlock*16+1,cell);
		}
	}
}

void writeCharater()
{
	for (unsigned short y=0 ; y <2 ;++y)
	{
		for (unsigned short x=0 ; x < 16 ; ++x)
		{
			lcd.setCursor(x,y);
			lcd.write(1+y*16+x);
		}
	}
}


void cleanDisplay()
{
	for (bool &c:display)
	{
		c = false;
	}
}


void makeOneMove(){
	if (snakeInstance.checkForHit())
		{
		snakeInstance.makeMove();
			snakeInstance.writeBody();
		}
	else {} // game over 
		

}


void lifeCircle(){
	cleanDisplay();
	newHeadPosition = direction + currentHeadPosition;		
	foodInstance.checkForIntersection();
	foodInstance.writeFoodPositions();
	makeOneMove();
	generateCharactor();
	writeCharater();

}

// end of the program


void setup()
{
  pinMode(upPin,INPUT);
  pinMode(downPin,INPUT);
  pinMode(rightPin,INPUT);
  pinMode(leftPin,INPUT);
  pinMode(stepPin,INPUT);
  pinMode(ledTest,OUTPUT);

  lcd.begin(16, 2); 
	

	for (int index=0 ; index < 16 ; ++index)
	{
		byte oneChar[8];
		for (int oneLine=0 ; oneLine < 8 ; ++oneLine)
		{
			oneChar[oneLine] = index;
		}
		lcd.createChar(index ,oneChar);
		lcd.setCursor(index,0);
		lcd.write(index);
	}


}


void loop()
{
  if (!upState && digitalRead(upPin)== HIGH)
    {
      upState = true;

    }
  else if (upState && digitalRead(upPin)== LOW)
    {
      upState = true;
    }
    

  if (!downState && digitalRead(downPin)== HIGH)
    {
      downState = true;

      }
  else if (downState && digitalRead(downPin)== LOW)
    {
      downState = true;

      }

  if (!rightState && digitalRead(rightPin)== HIGH)
    {
      rightState = true;

      }
  else if (rightState && digitalRead(rightPin)== LOW)
    {
      rightState = true;

      }

  if (!leftState && digitalRead(leftPin)== HIGH)
    {
      leftState = true;

      }
  else if (leftState && digitalRead(leftPin)== LOW)
    {
      leftState = true;

      }

  if (!stepState && digitalRead(stepPin)== HIGH)
    {
      stepState = true;

      }
  else if (stepState && digitalRead(stepPin)== LOW)
    {
      stepState = true;

      }  
}