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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define OLED_RESET     -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Paddle
float paddleX = 60;
const int paddleY = 60;
const int paddleWidth = 20;
const int paddleHeight = 3;

// Ball
float ballX = 64;
float ballY = 32;
float ballSpeedX = 1;
float ballSpeedY = 1;

// Potentiometer
const int potPin = A0;
float smoothedPot = 0.0;

void setup() {
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    for (;;); // Display not found
  }

  display.clearDisplay();
  display.display();
}

void loop() {
  // Read potentiometer
  int potRaw = analogRead(potPin);

  // Smooth the input using low-pass filter
  smoothedPot = smoothedPot * 0.9 + potRaw * 0.1;

  // Map to paddle position
  paddleX = map(smoothedPot, 0, 1023, 0, SCREEN_WIDTH - paddleWidth);

  // Move ball
  ballX += ballSpeedX;
  ballY += ballSpeedY;

  // Bounce ball off walls
  if (ballX <= 0 || ballX >= SCREEN_WIDTH - 1) ballSpeedX *= -1;
  if (ballY <= 0) ballSpeedY *= -1;

  // Bounce off paddle
  if (ballY >= paddleY - 2 && ballX >= paddleX && ballX <= paddleX + paddleWidth) {
    ballSpeedY *= -1;
    ballY = paddleY - 2; // Prevent sticking
  }

  // Missed paddle
  if (ballY > SCREEN_HEIGHT) {
    ballX = 64;
    ballY = 32;
    ballSpeedY = 1;
    ballSpeedX = (random(0, 2) == 0) ? 1 : -1;
  }

  // Draw game
  display.clearDisplay();

  // Paddle
  display.fillRect((int)paddleX, paddleY, paddleWidth, paddleHeight, SSD1306_WHITE);

  // Ball
  display.fillCircle((int)ballX, (int)ballY, 2, SSD1306_WHITE);

  display.display();

  delay(10);  // small delay for timing
}