/**
 * Sheep — Codels 3D model library
 * License: CC0-1.0 · Units: meters · Y-up · Front: +Z · Origin: center of the base (y = 0)
 * Triangles: 1,404 · Size (W × H × D): 0.78 × 0.87 × 1.18 m
 *
 * Usage:
 *   import { createSheep } from './sheep.js';
 *   
 *   const model = createSheep();
 *   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 createSheep() {
  const root = new THREE.Group();
  root.name = 'Sheep';

  // Materials
  const woolMat = new THREE.MeshStandardMaterial({ name: 'wool', color: 0xede6d8, roughness: 1, flatShading: true });
  const faceMat = new THREE.MeshStandardMaterial({ name: 'face', color: 0x3a3231, roughness: 0.85, flatShading: true });
  const hoofMat = new THREE.MeshStandardMaterial({ name: 'hoof', color: 0x231d1c, roughness: 0.7, flatShading: true });
  const eyeWhiteMat = new THREE.MeshStandardMaterial({ name: 'eyeWhite', color: 0xfbfaf6, roughness: 0.5, flatShading: true });
  const pupilMat = new THREE.MeshStandardMaterial({ name: 'pupil', color: 0x141112, roughness: 0.3, flatShading: true });
  const noseMat = new THREE.MeshStandardMaterial({ name: 'nose', color: 0xd98c8c, roughness: 0.6, flatShading: true });

  // Shared geometries
  const boxGeo = new THREE.BoxGeometry(0.1, 0.22, 0.1);
  const boxGeo2 = new THREE.BoxGeometry(0.11, 0.05, 0.115);
  const boxGeo3 = new THREE.BoxGeometry(0.08, 0.085, 0.012);
  const boxGeo4 = new THREE.BoxGeometry(0.04, 0.055, 0.01);
  const boxGeo5 = new THREE.BoxGeometry(0.13, 0.05, 0.08);

  // Parts
  const legFL = new THREE.Group();
  legFL.name = 'legFL';
  legFL.position.set(0.13, 0.27, 0.17);
  root.add(legFL);
  const legFLUpper = new THREE.Mesh(boxGeo, faceMat);
  legFLUpper.name = 'legFLUpper';
  legFLUpper.position.set(0, -0.11, 0);
  legFL.add(legFLUpper);
  const legFLHoof = new THREE.Mesh(boxGeo2, hoofMat);
  legFLHoof.name = 'legFLHoof';
  legFLHoof.position.set(0, -0.245, 0.005);
  legFL.add(legFLHoof);
  const legFR = new THREE.Group();
  legFR.name = 'legFR';
  legFR.position.set(-0.13, 0.27, 0.17);
  root.add(legFR);
  const legFRUpper = new THREE.Mesh(boxGeo, faceMat);
  legFRUpper.name = 'legFRUpper';
  legFRUpper.position.set(0, -0.11, 0);
  legFR.add(legFRUpper);
  const legFRHoof = new THREE.Mesh(boxGeo2, hoofMat);
  legFRHoof.name = 'legFRHoof';
  legFRHoof.position.set(0, -0.245, 0.005);
  legFR.add(legFRHoof);
  const legBL = new THREE.Group();
  legBL.name = 'legBL';
  legBL.position.set(0.13, 0.27, -0.19);
  root.add(legBL);
  const legBLUpper = new THREE.Mesh(boxGeo, faceMat);
  legBLUpper.name = 'legBLUpper';
  legBLUpper.position.set(0, -0.11, 0);
  legBL.add(legBLUpper);
  const legBLHoof = new THREE.Mesh(boxGeo2, hoofMat);
  legBLHoof.name = 'legBLHoof';
  legBLHoof.position.set(0, -0.245, 0.005);
  legBL.add(legBLHoof);
  const legBR = new THREE.Group();
  legBR.name = 'legBR';
  legBR.position.set(-0.13, 0.27, -0.19);
  root.add(legBR);
  const legBRUpper = new THREE.Mesh(boxGeo, faceMat);
  legBRUpper.name = 'legBRUpper';
  legBRUpper.position.set(0, -0.11, 0);
  legBR.add(legBRUpper);
  const legBRHoof = new THREE.Mesh(boxGeo2, hoofMat);
  legBRHoof.name = 'legBRHoof';
  legBRHoof.position.set(0, -0.245, 0.005);
  legBR.add(legBRHoof);
  const body = new THREE.Group();
  body.name = 'body';
  root.add(body);
  const woolCore = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.3, 1), 0.02, 3), woolMat);
  woolCore.name = 'woolCore';
  woolCore.position.set(0, 0.49, -0.02);
  woolCore.scale.set(0.95, 0.82, 1.18);
  body.add(woolCore);
  const puff1 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.16, 1), 0.022, 11), woolMat);
  puff1.name = 'puff1';
  puff1.position.set(0, 0.69, 0.12);
  body.add(puff1);
  const puff2 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.17, 1), 0.022, 12), woolMat);
  puff2.name = 'puff2';
  puff2.position.set(0, 0.7, -0.14);
  puff2.rotation.set(deg(37), deg(53), 0);
  body.add(puff2);
  const puff3 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.15, 1), 0.022, 13), woolMat);
  puff3.name = 'puff3';
  puff3.position.set(0.15, 0.64, 0);
  puff3.rotation.set(deg(74), deg(106), 0);
  body.add(puff3);
  const puff4 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.15, 1), 0.022, 14), woolMat);
  puff4.name = 'puff4';
  puff4.position.set(-0.15, 0.64, -0.06);
  puff4.rotation.set(deg(111), deg(159), 0);
  body.add(puff4);
  const puff5 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.14, 1), 0.022, 15), woolMat);
  puff5.name = 'puff5';
  puff5.position.set(0.22, 0.49, 0.14);
  puff5.rotation.set(deg(148), deg(212), 0);
  body.add(puff5);
  const puff6 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.15, 1), 0.022, 16), woolMat);
  puff6.name = 'puff6';
  puff6.position.set(0.23, 0.47, -0.18);
  puff6.rotation.set(deg(185), deg(265), 0);
  body.add(puff6);
  const puff7 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.14, 1), 0.022, 17), woolMat);
  puff7.name = 'puff7';
  puff7.position.set(-0.22, 0.49, 0.12);
  puff7.rotation.set(deg(222), deg(318), 0);
  body.add(puff7);
  const puff8 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.15, 1), 0.022, 18), woolMat);
  puff8.name = 'puff8';
  puff8.position.set(-0.23, 0.47, -0.19);
  puff8.rotation.set(deg(259), deg(371), 0);
  body.add(puff8);
  const puff9 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.15, 1), 0.022, 19), woolMat);
  puff9.name = 'puff9';
  puff9.position.set(0, 0.45, 0.27);
  puff9.rotation.set(deg(296), deg(424), 0);
  body.add(puff9);
  const puff10 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.14, 1), 0.022, 20), woolMat);
  puff10.name = 'puff10';
  puff10.position.set(0, 0.51, -0.35);
  puff10.rotation.set(deg(333), deg(477), 0);
  body.add(puff10);
  const puff11 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.14, 1), 0.022, 21), woolMat);
  puff11.name = 'puff11';
  puff11.position.set(0.1, 0.37, -0.02);
  puff11.rotation.set(deg(370), deg(530), 0);
  body.add(puff11);
  const puff12 = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.14, 1), 0.022, 22), woolMat);
  puff12.name = 'puff12';
  puff12.position.set(-0.1, 0.37, -0.02);
  puff12.rotation.set(deg(407), deg(583), 0);
  body.add(puff12);
  const tail = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.07, 1), 0.012, 41), woolMat);
  tail.name = 'tail';
  tail.position.set(0, 0.57, -0.44);
  body.add(tail);
  const head = new THREE.Group();
  head.name = 'head';
  head.position.set(0, 0.56, 0.4);
  root.add(head);
  const face = new THREE.Mesh(new THREE.BoxGeometry(0.25, 0.28, 0.24), faceMat);
  face.name = 'face';
  face.position.set(0, -0.02, 0.1);
  head.add(face);
  const muzzle = new THREE.Mesh(new THREE.BoxGeometry(0.2, 0.07, 0.05), faceMat);
  muzzle.name = 'muzzle';
  muzzle.position.set(0, -0.11, 0.24);
  head.add(muzzle);
  const nose = new THREE.Mesh(new THREE.BoxGeometry(0.07, 0.03, 0.01), noseMat);
  nose.name = 'nose';
  nose.position.set(0, -0.095, 0.27);
  head.add(nose);
  const eyeL = new THREE.Mesh(boxGeo3, eyeWhiteMat);
  eyeL.name = 'eyeL';
  eyeL.position.set(0.062, 0.015, 0.226);
  head.add(eyeL);
  const pupilL = new THREE.Mesh(boxGeo4, pupilMat);
  pupilL.name = 'pupilL';
  pupilL.position.set(0.056, 0.01, 0.235);
  head.add(pupilL);
  const eyeR = new THREE.Mesh(boxGeo3, eyeWhiteMat);
  eyeR.name = 'eyeR';
  eyeR.position.set(-0.062, 0.015, 0.226);
  head.add(eyeR);
  const pupilR = new THREE.Mesh(boxGeo4, pupilMat);
  pupilR.name = 'pupilR';
  pupilR.position.set(-0.056, 0.01, 0.235);
  head.add(pupilR);
  const earL = new THREE.Mesh(boxGeo5, faceMat);
  earL.name = 'earL';
  earL.position.set(0.175, 0.04, 0.08);
  earL.rotation.set(0, 0, deg(-28));
  head.add(earL);
  const earR = new THREE.Mesh(boxGeo5, faceMat);
  earR.name = 'earR';
  earR.position.set(-0.175, 0.04, 0.08);
  earR.rotation.set(0, 0, deg(28));
  head.add(earR);
  const topknot = new THREE.Mesh(jitter(new THREE.IcosahedronGeometry(0.12, 1), 0.016, 7), woolMat);
  topknot.name = 'topknot';
  topknot.position.set(0, 0.14, 0.07);
  topknot.scale.set(1.1, 0.8, 1);
  head.add(topknot);

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

export default createSheep;