import { Document, NodeIO } from "@gltf-transform/core";
import { readFileSync, mkdirSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { buildGeometry } from "./geometry.mjs";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const manifestPath = path.resolve(
  __dirname,
  process.argv[2] ?? "../seed/manifest-tegumentar.json",
);
const outDir = path.resolve(__dirname, "../seed/models");
mkdirSync(outDir, { recursive: true });

const { structures } = JSON.parse(readFileSync(manifestPath, "utf-8"));

function eulerToQuat([x, y, z]) {
  const cx = Math.cos(x / 2), sx = Math.sin(x / 2);
  const cy = Math.cos(y / 2), sy = Math.sin(y / 2);
  const cz = Math.cos(z / 2), sz = Math.sin(z / 2);
  return [
    sx * cy * cz - cx * sy * sz,
    cx * sy * cz + sx * cy * sz,
    cx * cy * sz - sx * sy * cz,
    cx * cy * cz + sx * sy * sz,
  ];
}

function hexToRgb(hex) {
  const n = parseInt(hex.replace("#", ""), 16);
  return [((n >> 16) & 255) / 255, ((n >> 8) & 255) / 255, (n & 255) / 255, 1];
}

const bySystem = new Map();
for (const s of structures) {
  if (!bySystem.has(s.system)) bySystem.set(s.system, []);
  bySystem.get(s.system).push(s);
}

const systemColors = {
  esqueletico: "#e8e2d0",
  muscular: "#b5433a",
  nervoso: "#f2c14e",
  cardiovascular: "#c1121f",
  respiratorio: "#4f7cff",
  tegumentar: "#e0a96d",
};

for (const [systemSlug, items] of bySystem) {
  const doc = new Document();
  const buffer = doc.createBuffer();
  const scene = doc.createScene(systemSlug);
  doc.getRoot().setDefaultScene(scene);

  // Cada item pode pedir uma cor própria (opts.color) pra se distinguir dos
  // demais (ex: glândula amarela, vaso vermelho/azul, pelo castanho) em vez
  // de todo o sistema sair de uma cor só — cache por hex evita recriar
  // material repetido.
  const materialCache = new Map();
  function materialFor(hex) {
    if (materialCache.has(hex)) return materialCache.get(hex);
    const mat = doc
      .createMaterial(hex)
      .setBaseColorFactor(hexToRgb(hex))
      .setRoughnessFactor(0.6)
      .setMetallicFactor(0.05);
    materialCache.set(hex, mat);
    return mat;
  }
  const defaultHex = systemColors[systemSlug] ?? "#cccccc";

  for (const item of items) {
    const material = materialFor(item.color ?? defaultHex);
    const geo = buildGeometry(item.shape);
    const posAccessor = doc
      .createAccessor()
      .setType("VEC3")
      .setArray(geo.positions)
      .setBuffer(buffer);
    const normAccessor = doc
      .createAccessor()
      .setType("VEC3")
      .setArray(geo.normals)
      .setBuffer(buffer);
    const idxAccessor = doc
      .createAccessor()
      .setType("SCALAR")
      .setArray(geo.indices)
      .setBuffer(buffer);

    const prim = doc
      .createPrimitive()
      .setAttribute("POSITION", posAccessor)
      .setAttribute("NORMAL", normAccessor)
      .setIndices(idxAccessor)
      .setMaterial(material);

    const mesh = doc.createMesh(item.meshName).addPrimitive(prim);
    const node = doc
      .createNode(item.meshName)
      .setMesh(mesh)
      .setTranslation(item.position)
      .setRotation(eulerToQuat(item.rotation ?? [0, 0, 0]))
      .setExtras({ slug: item.slug });

    scene.addChild(node);
  }

  const io = new NodeIO();
  const outFile = path.join(outDir, `${systemSlug}.glb`);
  await io.write(outFile, doc);
  console.log(`✓ ${outFile} (${items.length} estruturas)`);
}