/**
 * Bush — Codels 3D model library
 * License: CC0-1.0 · Units: meters · Y-up · Front: +Z · Origin: center of the base (y = 0)
 * Triangles: 760 · Size (W × H × D): 1.27 × 0.97 × 1.31 m
 *
 * Usage:
 *   import { createBush } from './bush.js';
 *   
 *   const model = createBush();
 *   model.position.set(0, 0, 0);
 *   scene.add(model);
 */
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;
}

export function createBush() {
  const root = new THREE.Group();
  root.name = 'Bush';

  // Materials
  const leafMat = new THREE.MeshStandardMaterial({ name: 'leaf', color: 0x4f8f3e, roughness: 0.85, flatShading: true });
  const leafLightMat = new THREE.MeshStandardMaterial({ name: 'leafLight', color: 0x519848, roughness: 0.85, flatShading: true });
  const leafDarkMat = new THREE.MeshStandardMaterial({ name: 'leafDark', color: 0x447232, roughness: 0.9, flatShading: true });
  const berryMat = new THREE.MeshStandardMaterial({ name: 'berry', color: 0xd93448, roughness: 0.35, flatShading: true });

  // Shared geometries
  const icosahedronGeo = new THREE.IcosahedronGeometry(0.042, 0);

  // Parts
  const bush = new THREE.Group();
  bush.name = 'bush';
  bush.position.set(0, 0.0691, 0);
  root.add(bush);
  const foliage1 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.4347, 1), 0.0565, 30), leafMat);
  foliage1.name = 'foliage1';
  foliage1.position.set(0, 0.42, 0);
  foliage1.rotation.set(deg(54.8202), deg(60.0912), 0);
  foliage1.scale.set(1, 0.82, 1);
  bush.add(foliage1);
  const foliage2 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.3507, 1), 0.0456, 31), leafDarkMat);
  foliage2.name = 'foliage2';
  foliage2.position.set(0.3304, 0.3, 0.143);
  foliage2.rotation.set(deg(59.872), deg(330.3399), 0);
  foliage2.scale.set(1, 0.82, 1);
  bush.add(foliage2);
  const foliage3 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.2979, 1), 0.0387, 32), leafDarkMat);
  foliage3.name = 'foliage3';
  foliage3.position.set(-0.3062, 0.28, 0.225);
  foliage3.rotation.set(deg(33.3982), deg(322.7924), 0);
  foliage3.scale.set(1, 0.82, 1);
  bush.add(foliage3);
  const foliage4 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.3418, 1), 0.0444, 33), leafMat);
  foliage4.name = 'foliage4';
  foliage4.position.set(-0.0078, 0.3, -0.3499);
  foliage4.rotation.set(deg(7.7251), deg(65.4064), 0);
  foliage4.scale.set(1, 0.82, 1);
  bush.add(foliage4);
  const foliage5 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.3069, 1), 0.0399, 34), leafLightMat);
  foliage5.name = 'foliage5';
  foliage5.position.set(0.0977, 0.4, 0.2836);
  foliage5.rotation.set(deg(6.7732), deg(139.3173), 0);
  foliage5.scale.set(1, 0.82, 1);
  bush.add(foliage5);
  const foliage6 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.2787, 1), 0.0362, 35), leafLightMat);
  foliage6.name = 'foliage6';
  foliage6.position.set(-0.1875, 0.62, -0.0697);
  foliage6.rotation.set(deg(44.9884), deg(44.365), 0);
  foliage6.scale.set(1, 0.82, 1);
  bush.add(foliage6);
  const berry1 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry1.name = 'berry1';
  berry1.position.set(0.5758, 0.4724, -0.0034);
  bush.add(berry1);
  const berry2 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry2.name = 'berry2';
  berry2.position.set(-0.37, 0.5033, 0.3439);
  bush.add(berry2);
  const berry3 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry3.name = 'berry3';
  berry3.position.set(0.041, 0.5464, -0.4877);
  bush.add(berry3);
  const berry4 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry4.name = 'berry4';
  berry4.position.set(0.3068, 0.5774, 0.3847);
  bush.add(berry4);
  const berry5 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry5.name = 'berry5';
  berry5.position.set(-0.4628, 0.5985, -0.0878);
  bush.add(berry5);
  const berry6 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry6.name = 'berry6';
  berry6.position.set(0.3318, 0.6127, -0.2138);
  bush.add(berry6);
  const berry7 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry7.name = 'berry7';
  berry7.position.set(-0.0908, 0.6109, 0.332);
  bush.add(berry7);
  const berry8 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry8.name = 'berry8';
  berry8.position.set(-0.1536, 0.6507, -0.3161);
  bush.add(berry8);
  const berry9 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry9.name = 'berry9';
  berry9.position.set(0.313, 0.6829, 0.118);
  bush.add(berry9);
  const berry10 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry10.name = 'berry10';
  berry10.position.set(-0.275, 0.7026, 0.1221);
  bush.add(berry10);
  const berry11 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry11.name = 'berry11';
  berry11.position.set(0.1142, 0.7139, -0.2438);
  bush.add(berry11);
  const berry12 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry12.name = 'berry12';
  berry12.position.set(0.068, 0.7038, 0.2105);
  bush.add(berry12);
  const berry13 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry13.name = 'berry13';
  berry13.position.set(-0.2328, 0.8625, -0.1382);
  bush.add(berry13);
  const berry14 = new THREE.Mesh(icosahedronGeo, berryMat);
  berry14.name = 'berry14';
  berry14.position.set(0.1989, 0.8042, -0.0491);
  bush.add(berry14);

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

export default createBush;