// PROCITY Lane C — optional GLB-upgrade layer. Reads Lane E's web/assets/manifest.json and swaps a
// primitive fitting for a detailed depot GLB where one exists ("reserve the detailed GLB hero props
// for where the camera gets close" — RESEARCH). Strictly ADDITIVE and OFF by default:
//   • the whole lane runs 100% on primitives with no manifest and no network (LANE_C acceptance);
//   • enable per build with opts.useGLB (interiors.js), or globally via preloadManifest().
//
// Pattern (house law): promise-cached loader, PLACEHOLDER-PERSISTS — the primitive shows immediately
// and stays until the GLB resolves; if the depot is unreachable the primitive stays forever (never a
// crash, never a blank). The GLB is placed at real-metre scale (glb_law), yaw-corrected per kind, and
// clamped to the primitive's reserved footprint, so occupancy/paths already computed by layout.js stay valid.

import { loadGLB } from '../core/loaders.js';
import { clone as skeletonClone } from 'three/addons/utils/SkeletonUtils.js';

// my fitting kind → manifest.fittings id (only kinds with a depot GLB; others stay primitive).
// NOTE: `counter` → `counter_till` (R5): Lane E shipped a proper ~1.6 m timber counter WITH a modelled
// beige till (procity_fit_counter_till_01.glb, base-origin). The old `counter` id is the 4 m till-less
// balcao — do NOT use it here. Because counter_till carries its own till, the separate cash_register
// counter-top attach is dropped whenever the counter GLB is live (see attachCounterTop) — no double till.
const KIND_TO_GLB = {
  crate: 'record_crate', recordBin: 'record_crate',   // R5: record_crate fixed by Lane E (sourceless-texture slots stripped) → bins upgrade now
  metalShelf: 'wire_shelf', wallShelf: 'wire_shelf',
  clothesRack: 'clothes_rack',
  bookshelf: 'bookshelf',
  cubeShelf: 'cube_shelf_wide',
  trestleTable: 'work_table',
  counter: 'counter_till',              // R5: real counter-with-till (NOT the 4 m 'counter'/balcao)
  // Round-4 hero props:
  listeningCorner: 'listening_booth',   // record store focal prop
  fridge: 'drinks_fridge',              // milk bar drinks fridge
  arcadeCabinet: 'arcade_cabinet',      // video store focal prop
  // Round-6 orphans (published R5, mapped now):
  glassCase: 'glass_case',              // toy/pawn/dept/milkbar display case
  magazineRack: 'magazine_rack',        // milkbar/pawn/book magazine rack
  crateStack: 'crate_stack',            // record/opshop back-room dressing
};

// Per-kind facing correction (radians, about +Y). The GLBs follow glb_law (metres, +Y up, base at origin)
// but carry NO automatic facing (manifest.conventions.facing: "Lane B/C rotate directional props"). The
// z-major assets (bookshelf/cube/work_table are modelled wide along Z) need a quarter-turn so their width
// runs along the fitting's X, matching the primitive the layout placed. Tuned by on-screen validation.
const KIND_TO_YAW = {
  bookshelf: Math.PI / 2,
  cubeShelf: Math.PI / 2,
  trestleTable: Math.PI / 2,
  // new hero props — tuned on-screen in R4 (see LANE_C_GLB_VALIDATION.md)
  listeningCorner: 0,
  fridge: 0,
  arcadeCabinet: 0,
  counter: 0,                           // R5 counter_till — tuned on-screen
  glassCase: 0, magazineRack: 0, crateStack: 0,   // R6 orphans — tuned on-screen
};

// Counter-top GLB props: sit ON the counter's benchtop (not a floor swap). Each targets a counterTop
// attach slot exposed by the counter fitting. cash_register is the till stand-in on a PRIMITIVE counter
// (dropped when counter_till is live — that GLB has its own till); milkshake_mixer only on milk-bar counters.
const COUNTERTOP = [
  { id: 'cash_register', slot: 'till', hideTill: true, types: null, yaw: 0, maxFoot: 0.42 },
  { id: 'milkshake_mixer', slot: 'appliance', hideTill: false, types: ['milkbar'], yaw: 0, maxFoot: 0.42 },
];

let _manifestP = null;
// Fetch + cache the manifest. Returns null (not throw) if absent/unreachable → primitives everywhere.
export function preloadManifest(url = 'assets/manifest.json') {
  return (_manifestP ||= fetch(url).then(r => (r.ok ? r.json() : null)).catch(() => null));
}
export function manifestReady() { return _manifestP && typeof _manifestP.then === 'function' ? _manifestP : Promise.resolve(null); }

// Upgrade one placed fitting in-place, if the manifest maps its kind. No-op when disabled/unavailable.
// `manifest` is the resolved object (or null). ctx is the room build context (for the _disposed guard).
// Returns a promise that settles when the swap is done (or immediately when there is nothing to do), so
// callers can await a room's GLB upgrades (buildInterior exposes this as room.glbReady).
// Resolution: production uses `depot:<file>` (loaders.js → depot CDN / local-depot). A manifest may set
// `localBase` (e.g. "assets/_local_glb/") to load straight from a served local dir — used for offline
// GLB validation before the depot is reachable.
export function upgradeFitting(ctx, fitting, kind, manifest) {
  if (!manifest || !manifest.fittings) return Promise.resolve();
  const id = KIND_TO_GLB[kind];
  const entry = id && manifest.fittings[id];
  if (!entry || !entry.file) return Promise.resolve();

  const ref = manifest.localBase ? `${manifest.localBase}${entry.file}` : `depot:${entry.file}`;
  return loadGLB(ref).then(gltf => {
    if (!gltf || ctx._disposed || !fitting.group.parent) return;   // room rebuilt / disposed mid-flight
    const THREE = ctx.THREE;
    const inst = skeletonClone(gltf.scene);                        // clone-safe even if skinned
    // Facing: rotate the directional prop to match the primitive the layout placed (before measuring).
    inst.rotation.y = KIND_TO_YAW[kind] || 0;
    // Scale: GLBs are authored in metres (glb_law), so keep REAL-WORLD scale — only shrink if the prop
    // would overflow the footprint the occupancy grid reserved (never inflate a small prop to fill a slot).
    const bb = new THREE.Box3().setFromObject(inst);
    const size = new THREE.Vector3(); bb.getSize(size);
    const want = fitting.footprint;
    const glbW = Math.max(size.x, size.z) || 1;
    const s = Math.min(1, Math.max(want.w, want.d) / glbW);
    inst.scale.setScalar(s);
    inst.position.y -= bb.min.y * s;                               // plant on the floor (glb_law minY≈0)
    // hide the primitive FRAME (fixture) but keep the procedural STOCK visible on top of the detailed
    // GLB shelf/counter. Post-batch (batch.js) the children are merged meshes tagged isStock / isFrame;
    // pre-batch they're individual meshes (stock tagged isStock, frame untagged). Hide everything that
    // isn't stock and isn't the GLB we're adding.
    for (const c of fitting.group.children) {
      if (c.userData && (c.userData.isStock || c.userData.glbUpgrade)) continue;
      c.visible = false;
    }
    inst.userData = { glbUpgrade: true, kind };
    fitting.group.add(inst);
  });
}

// Place counter-top GLB props (cash_register, milkshake_mixer) onto a counter fitting's benchtop.
// Additive: does NOT hide the counter primitive frame (upgradeFitting does that when counter is GLB-live).
// `counterHasGlb`: when the counter itself upgrades to counter_till (which carries its OWN modelled till),
// cash_register is SKIPPED here to avoid a double till — it only stands in on the primitive counter. The
// benchtop surface is ~0.10 m higher on the taller GLB counter, so counter-top items are lifted to match.
// Fail-soft: unreachable/missing GLB → primitive stays.
export function attachCounterTop(ctx, fitting, manifest, shopType, counterHasGlb) {
  const ct = fitting.counterTop;
  if (!ct || !manifest || !manifest.fittings) return Promise.resolve();
  const topY = ct.y + (counterHasGlb ? 0.10 : 0);                  // GLB counter_till (~1.13) sits above the primitive (~1.03)
  const jobs = [];
  for (const spec of COUNTERTOP) {
    if (spec.types && !spec.types.includes(shopType)) continue;
    if (spec.id === 'cash_register' && counterHasGlb) continue;    // counter_till has its own till → no double
    const entry = manifest.fittings[spec.id];
    if (!entry || !entry.file) continue;
    const ref = manifest.localBase ? `${manifest.localBase}${entry.file}` : `depot:${entry.file}`;
    jobs.push(loadGLB(ref).then(gltf => {
      if (!gltf || ctx._disposed || !fitting.group.parent) return;
      const THREE = ctx.THREE;
      const inst = skeletonClone(gltf.scene);
      inst.rotation.y = spec.yaw || 0;
      const bb = new THREE.Box3().setFromObject(inst);
      const size = new THREE.Vector3(); bb.getSize(size);
      const glbW = Math.max(size.x, size.z) || 1;
      const s = Math.min(1, spec.maxFoot / glbW);                  // clamp to the benchtop slot; never inflate
      inst.scale.setScalar(s);
      const at = ct[spec.slot];
      inst.position.set(at.x, topY - bb.min.y * s, at.z);          // plant base on the benchtop surface
      if (spec.hideTill && !counterHasGlb) for (const c of fitting.group.children) if (c.userData && c.userData.tillPrimitive) c.visible = false;
      inst.userData = { glbUpgrade: true, kind: spec.id, counterTop: true };
      fitting.group.add(inst);
    }));
  }
  return Promise.all(jobs);
}

// Upgrade every placed fitting in a room. Called from buildInterior when GLB mode is on.
// `shopType` gates counter-top props (e.g. milkshake_mixer → milk bar only).
// Returns a promise resolving once all in-room fittings' GLB swaps have settled.
export function upgradeRoom(ctx, placed, manifest, shopType) {
  if (!manifest) return Promise.resolve();
  // counter_till carries its own till → cash_register attach is dropped when the counter GLB is present.
  const counterHasGlb = !!(manifest.fittings && manifest.fittings[KIND_TO_GLB.counter]);
  const jobs = [];
  for (const p of placed) {
    if (p.removed) continue;
    jobs.push(upgradeFitting(ctx, p.fitting, p.kind, manifest));
    if (p.fitting.counterTop) jobs.push(attachCounterTop(ctx, p.fitting, manifest, shopType, counterHasGlb));
  }
  return Promise.all(jobs);
}