let stars = [];
let angle = 0;
let earthRotation = 0;

function setup() {
  createCanvas(800, 600);
  for (let i = 0; i < 500; i++) {
    stars.push({
      x: random(width),
      y: random(height),
      size: random(1, 3),
      speed: random(0.1, 0.5)
    });
  }
}

function draw() {
  background(2, 5, 15);

  // --- Background Stars ---
  fill(255);
  noStroke();
  for (let star of stars) {
    ellipse(star.x, star.y, star.size);
    star.x -= star.speed;
    if (star.x < 0) star.x = width;
  }

  translate(width / 2, height / 2);

  // --- 1. Draw Earth ---
  drawEarth(200);

  // --- 2. Draw Moon ---
  push();
  rotate(angle * 0.3); // Moon moves slower than the station
  translate(300, 0);   // Moon distance
  drawMoon(70);
  pop();

  // --- 3. Draw Space Station ---
  push();
  rotate(angle);
  translate(200, 0);
  rotate(-angle); // Keep upright
  drawStation();
  pop();

  angle += 0.01;
  earthRotation += 0.005; // The speed of the day/night cycle
}

function drawEarth(d) {
  push();
  
  // Base Ocean
  fill(10, 40, 120);
  noStroke();
  ellipse(0, 0, d, d);

  // Rotating Surface (Land and Lights)
  push();
  rotate(earthRotation);

  // Irregular Landmasses
  fill(40, 120, 50);
  drawLand(-70,-60, 1.3);//north america
  drawLand(-65,2, 1.2);//south america
  drawLand(10, -0, 1.1);//africa
  drawLand(10,-60,1 );//europe
  drawLand(40, -30, 1.3);//asia
  drawLand(-20, 50, 1);//an
  pop();

  // THE SHADOW (Day/Night Mask)
  // This stays still while the Earth rotates underneath it
  fill(0, 0, 0, 180); 
  arc(0, 0, d+2, d+2, -HALF_PI, HALF_PI, CHORD); // Darkens the right side
  
  // Atmosphere Rim
  noFill();
  stroke(100, 180, 255, 80);
  strokeWeight(3);
  ellipse(0, 0, d, d);
  pop();
}

function drawLand(x, y, s) {
  push();
  translate(x, y);
  scale(s);
  beginShape();
  vertex(0, 0);
  vertex(20, -10);
  vertex(40, 5);
  vertex(35, 30);
  vertex(10, 45);
  vertex(-15, 25);
  vertex(-5, 10);
  endShape(CLOSE);
  pop();
}

function drawMoon(d) {
  // Moon Body
  fill(180);
  noStroke();
  ellipse(0, 0, d, d);
  
  // Craters
  fill(150);
  ellipse(-d*0.2, -d*0.1, d*0.2);
  ellipse(d*0.1, d*0.2, d*0.15);
  ellipse(d*0.3, -d*0.2, d*0.1);

  // Moon Shadow
  fill(0, 120);
  arc(0, 0, d, d, -HALF_PI, HALF_PI, CHORD);
}

function drawStation() {
  fill(220);
  stroke(50);
  rectMode(CENTER);
  rect(0, 0, 30, 10); // Core
  fill(0, 80, 180);
  rect(-25, 0, 20, 40); // Solar Left
  rect(25, 0, 20, 40);  // Solar Right
}