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


//DEFINE UP AND DOWN BUTTON FOR PLAYER PADDLE
#define UP_BUTTON 2
#define DOWN_BUTTON 3
int previousballx = 0;

//DEFINE PADDLE SPEED AND PADDLE RATE FOR PLAYER PADDLE
const unsigned long PADDLE_RATE  = 5;
const uint8_t       PADDLE_SPEED = 2;
//DEFINE PLAYER PADDLE STARTING POSITION(X,Y) AND WIDTH AND HEIGHT (X+W,Y+H)
const uint8_t		PLAYER_X	 = 7;
uint8_t					PLAYER_Y	 = 10;
const uint8_t		PLAYER_W	 = 3;
const uint8_t		PLAYER_H	 = 15;
//DEFINE BALL WIDTH/RADIUS , BALL(X,Y), AND BALL DIRECTIONAL SPEED

int 						BALLX 		 = 64;
int 						BALLY 		 = 32;
const uint8_t		BALL_W		 = 2;
int 						BALLDX		 = 1;
int 						BALLDY		 = 1;

//DEFINE CPU PADDLE STARTING POSITION(X,Y) AND WIDTH AND HEIGHT(X+W,Y+H)
const uint8_t 		CPU_X		 = 120;
uint8_t				    CPU_Y		 = 10;
const uint8_t	  	CPU_W 	 = 3;
const uint8_t		  CPU_H		 = 15;

// DEFINE PLAYER AND CPU SCORE

int 				PLAYERSCORE  = 0;
int 				CPUSCORE 	   = 0;

//DEFINE SCREEN HEIGHT AND WIDTH
const uint8_t		SCREEN_H	 	 = 64;
const uint8_t		SCREEN_W	 	 = 128;
const int				DISPLAY_RST  = -1;

//INITIALIZE DISPLAY

Adafruit_SSD1306 display(SCREEN_W,SCREEN_H,&Wire,DISPLAY_RST);

//DRAWING SCORE FUNCTION 
void drawScore(int PLAYERSCORE,int CPUSCORE);
long randNumber;

void setup()
{
	display.begin(SSD1306_SWITCHCAPVCC,0x3C);
	display.display();

  Serial.begin(115200);
	pinMode(A0, INPUT);
	
	unsigned long start = millis();

	pinMode(UP_BUTTON,	INPUT_PULLUP);
	pinMode(DOWN_BUTTON,INPUT_PULLUP);
	pinMode(5, OUTPUT);
	
	randomSeed(analogRead(A0));

	while(millis() - start < 2000);
	display.clearDisplay();
}

void loop()
{	

  float random_num = random(7);
	display.clearDisplay();

	//READING UP AND DOWN BUTTON FOR PLAYER PADDLE
	int UP_STATE 	= digitalRead(UP_BUTTON);
	int DOWN_STATE  = digitalRead(DOWN_BUTTON);

	//DRAW RECTANGLE AROUND THE SCREEN
	display.drawRect(0,0,128,64,WHITE);
	
	
	if(DOWN_STATE == LOW && (PLAYER_Y+PLAYER_H) < 62)
	{
		PLAYER_Y = PLAYER_Y + PADDLE_RATE;
	}

	
	if(UP_STATE == LOW && PLAYER_Y > 2)
	{
		PLAYER_Y = PLAYER_Y - PADDLE_RATE;
	}
	
	if (random_num < 3) 
	{
			if(previousballx < BALLX && previousballx > 64)
			{
				if(BALLY > (CPU_Y+CPU_H/2)) {
						if((CPU_Y+CPU_H) < 62) {
						CPU_Y += PADDLE_SPEED;
						}
				}
				else if(BALLY < (CPU_Y + CPU_H/2)) {
						if(CPU_Y > 2) {
						CPU_Y -= PADDLE_SPEED;
						}
					}
		}			
	}
  // IF THE RANDOM NUMBER IS GREATER THAN OR EQUAL TO 0.5, DON'T MOVE THE CPU PADDLE

		previousballx = BALLX;		
	
	if(BALLY <= BALL_W || BALLY >= (64-BALL_W))
	{
		BALLDY = BALLDY * (-1);
		soundBouncec();

	}
	if(BALLX <= BALL_W)
	{
		CPUSCORE 	= CPUSCORE + 1;
		soundPoint();
		delay(50);
		BALLX  		= SCREEN_W/2;
		BALLY  		= SCREEN_H/2;
		BALLDX		= 1;
		BALLDY		= 1;
	}
	
	if(BALLX >= (128-BALL_W))
	{
		PLAYERSCORE = PLAYERSCORE + 1;
		soundPoint();
		delay(50);
		BALLX		= 64;
		BALLY		= 32;
		BALLDX		= -1;
		BALLDY		= 1;
	}
	
	if (BALLDX < 0 && BALLX <= PLAYER_X + BALL_W + PLAYER_W && BALLY >= PLAYER_Y && BALLY <= PLAYER_Y + PLAYER_H + BALL_W) 
	{
    Serial.print("changing BALLDX 1"); Serial.print(" ");
    Serial.println("");


    BALLDX = 1; // not toggle, just make it go the other way.
		soundBounce();
  }

  if (BALLDX > 0 && BALLX >= CPU_X - BALL_W && BALLY >= CPU_Y && BALLY <= CPU_Y + CPU_H + BALL_W)
  {
    Serial.print("changing BALLDX 2"); Serial.print(" ");
    Serial.println("");
    BALLDX = -1;
		soundBounce();
  }

	BALLX = BALLX + BALLDX;
	BALLY = BALLY + BALLDY;
	
	display.drawRect(PLAYER_X,PLAYER_Y,PLAYER_W,PLAYER_H,WHITE);
	display.drawRect(CPU_X,CPU_Y,CPU_W,CPU_H,WHITE);
	display.drawCircle(BALLX,BALLY,BALL_W,WHITE);

	//Draw Line middle of the court
	for (int i=0; i<SCREEN_H; i+=4) {
    display.drawFastVLine(SCREEN_W/2, i, 2, WHITE);
  }

	drawScore(PLAYERSCORE,CPUSCORE);
	display.display();

	delay(10);
}

void drawScore(int PLAYERSCORE, int CPUSCORE) {
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(2, 2);
    display.print(PLAYERSCORE);
    display.setCursor(122, 2);
    display.print(CPUSCORE);
}

void soundBounce() 
{
  tone(5, 500, 10);
}

void soundBouncec() 
{
  tone(5, 400, 10);
}
void soundPoint() 
{
  tone(5, 150, 150);
}