#include <Adafruit_NeoPixel.h>
#include <LiquidCrystal_I2C.h>

#define PIN_NEO_PIXEL 2  
#define NUM_PIXELS 64    

#define LEFT_BUTTON 4
#define RIGHT_BUTTON 3

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

Adafruit_NeoPixel NeoPixel(NUM_PIXELS, PIN_NEO_PIXEL, NEO_GRB + NEO_KHZ800);
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int posPaddleX = 3;
int posPaddleY = 7;
int posBallX = 3;
int posBallY = 6;
int dirBallX = 1;
int dirBallY = -1;

void setup() {
  NeoPixel.begin();  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("-- PING PONG --");
  pinMode(LEFT_BUTTON, INPUT_PULLUP);
  pinMode(RIGHT_BUTTON, INPUT_PULLUP);

}

void loop() {
  //Read button
  char tecla = 0;

  displayGame();
  if (updateBall()) {
    lcd.setCursor(0, 1);
    lcd.print("PERDIO!");
    while(1) {}
  }
  if (digitalRead(LEFT_BUTTON)==LOW) {
    posPaddleX--;
    if(posPaddleX<0) {
      posPaddleX=0;
    }
  }
  if (digitalRead(RIGHT_BUTTON)==LOW) {
    posPaddleX++;
    if(posPaddleX>6) {
      posPaddleX=6;
    }
  }

  delay(100);
}


void displayGame() {
  NeoPixel.clear(); 
  //Display paddle
  NeoPixel.setPixelColor(posPaddleY*8+posPaddleX, NeoPixel.Color(0, 0, 255));
  NeoPixel.setPixelColor(posPaddleY*8+posPaddleX+1, NeoPixel.Color(0, 0, 255));
  //Display ball
  NeoPixel.setPixelColor(posBallY*8+posBallX, NeoPixel.Color(0, 2550, 0));  
  NeoPixel.show();
}


int updateBall() {
  posBallX += dirBallX;
  posBallY += dirBallY;
  //Collision with left & right walls
  if (posBallX<0) {
    posBallX = 0;
    dirBallX = 1;
  }
  if (posBallX>7) {
    posBallX = 7;
    dirBallX = -1;
  }
  //Collision with top wall
  if (posBallY<0) {
    posBallY = 0;
    dirBallY = 1;
  }
  //Check if collision with paddle
  if (posBallY==7) {
    if((posBallX>=posPaddleX) && (posBallX<posPaddleX+1)) {
      posBallY = 6;
      dirBallY = -1; 
    } else {
      return 1;
    }
  }
  return 0;
}