// props.js — the prop house. Loads GLBs live from the 3GOD depot
// (https://digalot.fyi/3god, GLB at /a/<file>) with a local web/assets/ mirror as
// fallback so the demo never hard-fails offline. GLTFLoader + DRACOLoader are
// wired exactly like thriftgod's. Read-only against the depot — no writes, ever
// (the depot's open-mode/SSRF issue is a write-side problem; see PLAN.md).

import * as THREE from 'three';
import { GLTFLoader } from 'three/addons/loaders/GLTFLoader.js';
import { DRACOLoader } from 'three/addons/loaders/DRACOLoader.js';

export const DEPOT = 'https://digalot.fyi/3god';

const gltfLoader = new GLTFLoader();
{ const d = new DRACOLoader(); d.setDecoderPath('https://unpkg.com/three@0.175.0/examples/jsm/libs/draco/'); gltfLoader.setDRACOLoader(d); }

// The catalog. `depot` = filename on 3GOD; `local` = mirror in web/assets/.
// material tags feed juice.js voices; kind drives interaction in main.js.
export const CATALOG = {
  record:  { local: 'record.glb',                      material: 'vinyl', kind: 'record', brittle: true,  grabbable: true },
  crate:   { local: 'crate.glb',                       material: 'wood',  kind: 'crate' },
  rack:    { local: 'rack.glb',                        material: 'wood',  kind: 'rack' },
  cashbot: { depot: 'cashbot.glb',    local: 'cashbot.glb',     material: 'steel', kind: 'prop' },
  bin:     { depot: 'council-bin.glb', local: 'council-bin.glb', material: 'steel', kind: 'prop' },
  // live-only flavor from the depot (no local mirror — absent gracefully if offline)
  mpc:     { depot: 'akai-mpc-live-iii-6fe39f.glb', material: 'steel',     kind: 'prop' },
  gameboy: { depot: 'gameboybox-3c6cb9.glb',        material: 'cardboard', kind: 'prop' },
};

function depotURL(file) { return `${DEPOT}/a/${encodeURIComponent(file)}`; }
function localURL(file) { return `./assets/${encodeURIComponent(file)}`; }

// tidy a freshly-loaded gltf scene: drop shadow flags (cheap), keep materials.
function prep(scene) {
  scene.traverse(o => {
    if (o.isMesh) { o.castShadow = false; o.receiveShadow = false; o.frustumCulled = true; }
  });
  return scene;
}

const _cache = new Map();   // id -> Promise<{scene, source}>

// Load a prop by catalog id. Tries the live depot first, then the local mirror.
// Resolves to { scene: THREE.Object3D, source: 'depot'|'local' } or null.
export async function loadProp(id) {
  const def = CATALOG[id];
  if (!def) { console.warn('[props] unknown prop', id); return null; }
  if (_cache.has(id)) return cloneResult(await _cache.get(id));

  const promise = (async () => {
    // 1) live depot
    if (def.depot) {
      try {
        const gltf = await gltfLoader.loadAsync(depotURL(def.depot));
        return { scene: prep(gltf.scene), source: 'depot' };
      } catch (e) { /* fall through to local */ }
    }
    // 2) local mirror
    if (def.local) {
      try {
        const gltf = await gltfLoader.loadAsync(localURL(def.local));
        return { scene: prep(gltf.scene), source: 'local' };
      } catch (e) { console.warn('[props] local load failed', id, e && e.message); }
    }
    return null;
  })();

  _cache.set(id, promise);
  const res = await promise;
  return res ? cloneResult(res) : null;
}

// Try to fetch the pre-fractured sibling (Lane 2 contract #2): <base>.fractured.glb.
// Returns an Object3D whose direct children are chunk_* meshes, or null if none.
export async function loadFractured(id) {
  const def = CATALOG[id];
  if (!def) return null;
  const base = (def.depot || def.local || '').replace(/\.glb$/i, '');
  if (!base) return null;
  const tryURLs = [];
  if (def.depot) tryURLs.push(depotURL(base + '.fractured.glb'));
  if (def.local) tryURLs.push(localURL(def.local.replace(/\.glb$/i, '') + '.fractured.glb'));
  for (const url of tryURLs) {
    try {
      const gltf = await gltfLoader.loadAsync(url);
      const hasChunks = gltf.scene.children.some(c => /^chunk/i.test(c.name));
      if (hasChunks) return prep(gltf.scene);
    } catch (e) { /* not shipped yet — brittle props use generative shards */ }
  }
  return null;
}

function cloneResult(res) {
  // clone so each placement is independent (materials shared is fine here)
  return { scene: res.scene.clone(true), source: res.source };
}

// Fetch the live shelf listing (for a quick "N props on the shelf" readout).
export async function fetchShelf() {
  try {
    const r = await fetch(`${DEPOT}/api/list`, { method: 'GET' });
    const j = await r.json();
    return Array.isArray(j.assets) ? j.assets : [];
  } catch (e) { return []; }
}