/*
 * Simple OLED Animation for XIAO ESP32-C3
 * Display: 0.96" SSD1306 OLED (128x64)
 * Connection: I2C
 * 
 * Wiring:
 * XIAO ESP32-C3   OLED Display
 * 3V3             VCC
 * GND             GND
 * D4 (SDA)        SDA
 * D5 (SCL)        SCL
 * 
 * Libraries required:
 * - Adafruit SSD1306
 * - Adafruit GFX Library
 */

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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for XIAO ESP32-C3 are D4 (SDA) and D5 (SCL)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C /// < See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Animation variables for bouncing ball
int ballX = 64;
int ballY = 32;
int ballDX = 2;
int ballDY = 1;
int ballRadius = 4;

// Animation variables for starfield
#define NUM_STARS 30
int starX[NUM_STARS];
int starY[NUM_STARS];
int starSpeed[NUM_STARS];

void setup() {
  Serial.begin(115200);

  // Initialize I2C with XIAO ESP32-C3 default pins
  // Wire.begin(SDA, SCL); // For ESP32-C3, D4 is 6, D5 is 7
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(20, 20);
  display.println("XIAO ESP32-C3");
  display.setCursor(25, 35);
  display.println("Animation Start!");
  display.display();
  delay(2000);

  // Initialize stars
  for (int i = 0; i < NUM_STARS; i++) {
    starX[i] = random(0, SCREEN_WIDTH);
    starY[i] = random(0, SCREEN_HEIGHT);
    starSpeed[i] = random(1, 4);
  }
}

void loop() {
  display.clearDisplay();

  // 1. Draw Starfield (Background)
  for (int i = 0; i < NUM_STARS; i++) {
    display.drawPixel(starX[i], starY[i], SSD1306_WHITE);
    starX[i] -= starSpeed[i]; // Move stars to the left
    if (starX[i] < 0) {
      starX[i] = SCREEN_WIDTH;
      starY[i] = random(0, SCREEN_HEIGHT);
    }
  }

  // 2. Draw Bouncing Ball (Foreground)
  display.fillCircle(ballX, ballY, ballRadius, SSD1306_WHITE);
  
  // Update ball position
  ballX += ballDX;
  ballY += ballDY;

  // Bounce off edges
  if (ballX + ballRadius >= SCREEN_WIDTH || ballX - ballRadius <= 0) {
    ballDX = -ballDX;
  }
  if (ballY + ballRadius >= SCREEN_HEIGHT || ballY - ballRadius <= 0) {
    ballDY = -ballDY;
  }

  // 3. Draw some text
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.print("XIAO ESP32-C3");

  display.display();
  delay(20); // Adjust for animation speed
}