/**
 * Asteroid — Codels 3D model library
 * License: CC0-1.0 · Units: meters · Y-up · Front: +Z · Origin: center of the model (it floats — pickups, planets)
 * Triangles: 668 · Size (W × H × D): 3.30 × 2.58 × 2.85 m
 *
 * Usage:
 *   import { createAsteroid } from './asteroid.js';
 *   
 *   const model = createAsteroid();
 *   model.position.set(0, 0, 0);
 *   scene.add(model);
 *   
 *   // Animations: idle
 *   const mixer = new THREE.AnimationMixer(model);
 *   mixer.clipAction(THREE.AnimationClip.findByName(model.animations, 'idle')).play();
 *   // in your render loop: mixer.update(clock.getDelta());
 */
import * as THREE from 'three';

const deg = THREE.MathUtils.degToRad;

// Deterministic vertex displacement (organic low-poly look).
function jitter(geometry, amount, seed) {
  const pos = geometry.attributes.position;
  const h = (a, b, c, s) => {
    let x = Math.imul(a, 73856093) ^ Math.imul(b, 19349663) ^ Math.imul(c, 83492791) ^ Math.imul(s, 2654435761);
    x = Math.imul(x ^ (x >>> 16), 2246822507);
    x = Math.imul(x ^ (x >>> 13), 3266489909);
    return ((x ^ (x >>> 16)) >>> 0) / 4294967295 - 0.5;
  };
  for (let i = 0; i < pos.count; i++) {
    const x = pos.getX(i), y = pos.getY(i), z = pos.getZ(i);
    const qx = Math.round(x * 1000), qy = Math.round(y * 1000), qz = Math.round(z * 1000);
    pos.setXYZ(i, x + h(qx, qy, qz, seed) * 2 * amount, y + h(qx, qy, qz, seed + 1) * 2 * amount, z + h(qx, qy, qz, seed + 2) * 2 * amount);
  }
  pos.needsUpdate = true;
  geometry.computeVertexNormals();
  return geometry;
}

// Revolve a 2D profile [[radius, y], ...] around the Y axis.
function lathe(points, segments, phiStart = 0, phiLength = Math.PI * 2) {
  return new THREE.LatheGeometry(points.map(([x, y]) => new THREE.Vector2(x, y)), segments, phiStart, phiLength);
}

// Build animation clips from simple descriptions (Codels). Play them with THREE.AnimationMixer.
function codelsClips(THREE, entries) {
  var TAU = Math.PI * 2;
  var DEG = Math.PI / 180;
  var AX = { x: new THREE.Vector3(1, 0, 0), y: new THREE.Vector3(0, 1, 0), z: new THREE.Vector3(0, 0, 1) };
  var periodOf = function (a) { return a.type === 'spin' ? 360 / Math.abs(a.speed) : a.period; };
  var clips = [];

  // loops → 'idle'
  var loops = [];
  entries.forEach(function (e) {
    var l = e.anim.filter(function (a) { return a.type !== 'hinge'; });
    if (l.length) loops.push({ target: e.target, anim: l });
  });
  if (loops.length) {
    var periods = [];
    loops.forEach(function (e) { e.anim.forEach(function (a) { periods.push(periodOf(a)); }); });
    var longest = Math.max.apply(null, periods);
    var D = longest;
    var bestErr = Infinity;
    for (var m = 1; m <= 6 && bestErr > 0.01; m++) {
      var err = 0;
      periods.forEach(function (p) {
        var n = Math.max(1, Math.round((longest * m) / p));
        err = Math.max(err, Math.abs((longest * m) / n - p) / p);
      });
      if (err < bestErr - 1e-9) { bestErr = err; D = longest * m; }
    }
    var cycles = function (a) { return Math.max(1, Math.round(D / periodOf(a))); };
    var steps = 24;
    loops.forEach(function (e) { e.anim.forEach(function (a) { steps = Math.max(steps, cycles(a) * 24); }); });
    steps = Math.min(steps, 720);
    var tracks = [];
    loops.forEach(function (e) {
      var o = e.target;
      var q0 = o.quaternion.clone(), p0 = o.position.clone(), s0 = o.scale.clone();
      var q = new THREE.Quaternion(), turn = new THREE.Quaternion(), p = new THREE.Vector3(), s = new THREE.Vector3();
      var has = function (type) { return e.anim.some(function (a) { return a.type === type; }); };
      var turns = has('spin') || has('swing'), moves = has('bob'), grows = has('pulse');
      var times = [], qv = [], pv = [], sv = [];
      for (var k = 0; k <= steps; k++) {
        var t = (D * k) / steps;
        q.copy(q0); p.copy(p0); s.copy(s0);
        e.anim.forEach(function (a) {
          var n = cycles(a);
          var w = Math.sin(TAU * ((n * t) / D + (a.phase || 0)));
          if (a.type === 'spin') q.multiply(turn.setFromAxisAngle(AX[a.axis], (a.speed < 0 ? -TAU : TAU) * ((n * t) / D)));
          else if (a.type === 'swing') q.multiply(turn.setFromAxisAngle(AX[a.axis], a.angle * DEG * w));
          else if (a.type === 'bob') p.addScaledVector(AX[a.axis], a.distance * w);
          else if (a.type === 'pulse') s.multiplyScalar(1 + a.amount * w);
        });
        times.push(t);
        if (turns) qv.push(q.x, q.y, q.z, q.w);
        if (moves) pv.push(p.x, p.y, p.z);
        if (grows) sv.push(s.x, s.y, s.z);
      }
      if (turns) tracks.push(new THREE.QuaternionKeyframeTrack(o.uuid + '.quaternion', times, qv));
      if (moves) tracks.push(new THREE.VectorKeyframeTrack(o.uuid + '.position', times, pv));
      if (grows) tracks.push(new THREE.VectorKeyframeTrack(o.uuid + '.scale', times, sv));
    });
    clips.push(new THREE.AnimationClip('idle', D, tracks));
  }

  // hinge moves → one-shot clips ('open' …)
  var shots = {};
  entries.forEach(function (e) {
    e.anim.forEach(function (a) {
      if (a.type !== 'hinge') return;
      var name = a.clip || 'open';
      (shots[name] = shots[name] || []).push({ target: e.target, a: a });
    });
  });
  Object.keys(shots).forEach(function (name) {
    var tracks = [];
    var length = 0;
    shots[name].forEach(function (h) {
      var o = h.target, q0 = o.quaternion.clone(), q = new THREE.Quaternion(), turn = new THREE.Quaternion();
      var n = Math.max(4, Math.ceil(Math.abs(h.a.angle) / 10));
      var times = [], qv = [];
      for (var k = 0; k <= n; k++) {
        var f = k / n;
        var eased = f * f * (3 - 2 * f);
        q.copy(q0).multiply(turn.setFromAxisAngle(AX[h.a.axis], h.a.angle * DEG * eased));
        times.push(h.a.duration * f);
        qv.push(q.x, q.y, q.z, q.w);
      }
      length = Math.max(length, h.a.duration);
      tracks.push(new THREE.QuaternionKeyframeTrack(o.uuid + '.quaternion', times, qv));
    });
    clips.push(new THREE.AnimationClip(name, length, tracks));
  });
  return clips;
}

export function createAsteroid() {
  const root = new THREE.Group();
  root.name = 'Asteroid';

  // Materials
  const rockMat = new THREE.MeshStandardMaterial({ name: 'rock', color: 0x625952, roughness: 0.95, flatShading: true });
  const darkMat = new THREE.MeshStandardMaterial({ name: 'dark', color: 0x3e3732, roughness: 0.95, flatShading: true });

  // Parts
  const asteroid = new THREE.Group();
  asteroid.name = 'asteroid';
  asteroid.scale.setScalar(3);
  root.add(asteroid);
  const body = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.5, 2), 0.03, 7), rockMat);
  body.name = 'body';
  body.scale.set(1.0892, 0.8051, 0.951);
  asteroid.add(body);
  const bulge1a = new THREE.Mesh(jitter(new THREE.DodecahedronGeometry(0.2209, 0), 0.0331, 7), darkMat);
  bulge1a.name = 'bulge1a';
  bulge1a.position.set(-0.2263, -0.2165, -0.113);
  bulge1a.rotation.set(deg(78.938), deg(48.9414), 0);
  asteroid.add(bulge1a);
  const bulge1b = new THREE.Mesh(jitter(new THREE.DodecahedronGeometry(0.1705, 0), 0.0256, 8), rockMat);
  bulge1b.name = 'bulge1b';
  bulge1b.position.set(0.2263, 0.2165, 0.113);
  bulge1b.rotation.set(deg(5.0502), deg(58.5076), 0);
  asteroid.add(bulge1b);
  const bulge2a = new THREE.Mesh(jitter(new THREE.DodecahedronGeometry(0.2071, 0), 0.0311, 10), rockMat);
  bulge2a.name = 'bulge2a';
  bulge2a.position.set(0.3214, -0.1459, 0.0938);
  bulge2a.rotation.set(deg(38.22), deg(55.6337), 0);
  asteroid.add(bulge2a);
  const bulge2b = new THREE.Mesh(jitter(new THREE.DodecahedronGeometry(0.1907, 0), 0.0286, 11), rockMat);
  bulge2b.name = 'bulge2b';
  bulge2b.position.set(-0.3214, 0.1459, -0.0938);
  bulge2b.rotation.set(deg(18.7105), deg(81.5237), 0);
  asteroid.add(bulge2b);
  const crater1 = new THREE.Group();
  crater1.name = 'crater1';
  crater1.position.set(0.2815, 0.1779, 0.3486);
  crater1.rotation.set(deg(54.5429), 0, deg(-26.6296));
  asteroid.add(crater1);
  const cylinder8 = new THREE.Mesh(new THREE.CylinderGeometry(0.1237, 0.0781, 0.06, 8), darkMat);
  cylinder8.position.set(0, -0.018, 0);
  crater1.add(cylinder8);
  const lathe9 = new THREE.Mesh(lathe([[0.1954, -0.04], [0.1407, 0.026], [0.1224, 0.02], [0.1146, -0.03]], 9), rockMat);
  crater1.add(lathe9);
  const crater2 = new THREE.Group();
  crater2.name = 'crater2';
  crater2.position.set(-0.1652, 0.3446, 0.1989);
  crater2.rotation.set(deg(22.4759), 0, deg(13.6077));
  asteroid.add(crater2);
  const cylinder11 = new THREE.Mesh(new THREE.CylinderGeometry(0.1226, 0.0774, 0.06, 8), darkMat);
  cylinder11.position.set(0, -0.018, 0);
  crater2.add(cylinder11);
  const lathe12 = new THREE.Mesh(lathe([[0.1936, -0.04], [0.1394, 0.026], [0.1213, 0.02], [0.1136, -0.03]], 9), rockMat);
  crater2.add(lathe12);
  const crater3 = new THREE.Group();
  crater3.name = 'crater3';
  crater3.position.set(0.2221, 0.1614, -0.3901);
  crater3.rotation.set(deg(-60.0049), 0, deg(-20.6021));
  asteroid.add(crater3);
  const cylinder14 = new THREE.Mesh(new THREE.CylinderGeometry(0.1084, 0.0685, 0.06, 8), darkMat);
  cylinder14.position.set(0, -0.018, 0);
  crater3.add(cylinder14);
  const lathe15 = new THREE.Mesh(lathe([[0.1712, -0.04], [0.1233, 0.026], [0.1073, 0.02], [0.1005, -0.03]], 9), rockMat);
  crater3.add(lathe15);
  const crater4 = new THREE.Group();
  crater4.name = 'crater4';
  crater4.position.set(0.079, 0.3368, -0.2512);
  crater4.rotation.set(deg(-28.1328), 0, deg(-6.4463));
  asteroid.add(crater4);
  const cylinder17 = new THREE.Mesh(new THREE.CylinderGeometry(0.0802, 0.0507, 0.06, 8), darkMat);
  cylinder17.position.set(0, -0.018, 0);
  crater4.add(cylinder17);
  const lathe18 = new THREE.Mesh(lathe([[0.1266, -0.04], [0.0912, 0.026], [0.0794, 0.02], [0.0743, -0.03]], 9), rockMat);
  crater4.add(lathe18);

  // Animations ('idle') — play them with THREE.AnimationMixer
  root.animations = codelsClips(THREE, [
    { target: asteroid, anim: [{ type: 'spin', axis: 'y', speed: 12 }, { type: 'swing', axis: 'x', angle: 25, period: 10 }] },
  ]);

  root.traverse((o) => {
    if (o.isMesh) {
      o.castShadow = true;
      o.receiveShadow = true;
    }
  });
  return root;
}

export default createAsteroid;