// PROCITY Lane C — crate riffle, ported from 90sDJsim/web/world/dig.js (itself from thriftgod/RecordGod).
// v2 headline behind `?dig=1`: walk to a record bin → flip through its sleeves, pull one, "buy" it.
//
// Scope (round 5): the riffled items are the EXISTING procedural stock — a seeded sleeve list per bin
// (same seed ⇒ same order). Real records feed in later via `stockAdapter(shop, 'sleeve')` (round 6+,
// GODVERSE/mint). **Buy is STUBBED** (a toast + remove-from-bin; getCash returns a constant).
//
// Self-contained: own scene + camera, procedural fwip/thunk audio (no assets), and LEAK-FREE — every
// geometry/material/CanvasTexture minted here is tracked and freed on close()/dispose(). Nothing here
// runs unless the shell/test-page opens it, so `?dig=0` is byte-identical to v1.

import { mulberry32, xmur3 } from '../core/prng.js';
import { BANDS, guideText } from './bible.js';   // [R32] THE BIBLE — band ranges + the card's guide stamp

const MAXFLIP = 1.95, BACK = -0.12;
const SLEEVE = [0.31, 0.31, 0.0060];           // w, h, thickness (packed a touch chunkier than vinyl)
// 90s-Australian crate genres → sleeve card colour.
const GENRE = [['ROCK', '#7a2a3a'], ['SOUL', '#b0894a'], ['JAZZ', '#2a4a6a'], ['DISCO', '#8a3a7a'],
               ['COUNTRY', '#6a5a2a'], ['PUNK', '#3a3a3a'], ['REGGAE', '#2a6a4a'], ['POP', '#b05a8a']];
// [R35] exported: the shell seeds a fresh game's FIRST WANT from this roster (THE FIRST FIVE MINUTES).
export const ARTISTS = ['THE VERANDAHS', 'DEZ & THE UTES', 'MERINO', 'HILLS HOIST', 'THE ESKIES', 'GOON BAG',
                        'STOBIE POLES', 'THE FIBROS', 'WARATAH', 'THONGS', 'THE CLOTHESLINE', 'GALAH'];
const TITLES = ['Sunburnt', 'Back o’ Bourke', 'Servo at Midnight', 'Long Weekend', 'Tinny',
                'Southerly Buster', 'Milk Bar Dreams', 'Cane Toad Blues', 'Ute Muster', 'Arvo'];
const CONDS = ['VG+', 'VG', 'G+', 'NM', 'EX'];

// Deterministic sleeve list for a bin — the "existing procedural stock" as riffle-able offers.
// [R32 — THE BIBLE + THE GEM] Every parody sleeve now rolls a seeded BAND (the guide's range) and an
// ASKING price with seeded variance: non-gems price INSIDE their band; a 10% gem roll (collector/grail
// only — an under-band bargain is not a thrill) prices UNDER the band's low edge, which is the entire
// op-shop fantasy made mechanical. Draw COUNT is fixed per item (9 rolls, outcome-independent) so the
// stream stays deterministic and re-orderable never. `rare` (the ★) now means grail, matching the real
// packs — the card never says "gem"; spotting the asking-under-guide gap is the player's skill.
const PARODY_BAND = (roll) => (roll < 0.25 ? 'bargain' : roll < 0.70 ? 'standard' : roll < 0.92 ? 'collector' : 'grail');
const GRAIL_ASK_HI = 120;               // parody grail asking ceiling (band renders "$60+")
function proceduralSleeves(seed, n) {
  const r = mulberry32(seed >>> 0);
  const out = [];
  for (let i = 0; i < n; i++) {
    const g = GENRE[(r() * GENRE.length) | 0];
    const a = ARTISTS[(r() * ARTISTS.length) | 0];
    const t = TITLES[(r() * TITLES.length) | 0];
    const y = 1971 + ((r() * 28) | 0);
    const cond = CONDS[(r() * CONDS.length) | 0];
    const band = PARODY_BAND(r());
    const [lo, hi] = BANDS.record[band];
    const priceRoll = r(), gemRoll = r(), gemPriceRoll = r();   // always drawn — fixed stream shape
    const gem = gemRoll < 0.10 && (band === 'collector' || band === 'grail');
    // gem asking sits STRICTLY under the keeper's own bandLow offer (min(lo−1, floor(lo/2)) — sell.js),
    // so a spotted gem always nets margin: collector asks $2–9 vs offer $12 · grail $5–20 vs $30.
    const price = gem
      ? (band === 'grail' ? 5 + ((gemPriceRoll * 16) | 0) : 2 + ((gemPriceRoll * 8) | 0))
      : lo + ((priceRoll * ((hi == null ? GRAIL_ASK_HI : hi) - lo + 1)) | 0);
    out.push({ i, kind: 'record', a, t, y, s: g[0], color: g[1], cond, price, band, rare: band === 'grail' });
  }
  return out;
}

export function createDig(THREE, renderer) {
  // ── tracked resources (leak-free) ──
  // Persistent (p*): the fixed set — floor, backdrop, shared sleeve geometry — freed only on dispose().
  // Per-open (o*): sleeve textures/materials + crate parts — freed on EVERY close() so repeated
  // open/close (e.g. the soak entering a dig per interior) returns to baseline.
  const pGeo = new Set(), pMat = new Set(), pTex = new Set();
  const oGeo = new Set(), oMat = new Set(), oTex = new Set();
  const trackGeo = g => (pGeo.add(g), g);
  const trackMat = m => (pMat.add(m), m);
  const trackTex = t => (pTex.add(t), t);

  const scene = new THREE.Scene();
  scene.background = new THREE.Color(0x14110c);
  const camera = new THREE.PerspectiveCamera(45, innerWidth / innerHeight, 0.01, 50);
  camera.position.set(0, 0.5, 0.92);
  camera.lookAt(0, 0.12, -0.2);
  const onResize = () => { camera.aspect = innerWidth / innerHeight; camera.updateProjectionMatrix(); };
  addEventListener('resize', onResize);

  scene.add(new THREE.AmbientLight(0xfff4de, 0.55));
  const spot = new THREE.SpotLight(0xfff2e6, 26, 5, 0.7, 0.5, 1.2);
  spot.position.set(0.4, 1.5, 0.9); spot.target.position.set(0, 0, -0.3);
  scene.add(spot, spot.target);
  const floor = new THREE.Mesh(trackGeo(new THREE.BoxGeometry(1.4, 0.02, 1.4)),
    trackMat(new THREE.MeshStandardMaterial({ color: 0x2a2318, roughness: 0.9 })));
  floor.position.set(0.3, -0.011, -0.35); scene.add(floor);
  // a warm gradient backdrop (canvas — no external art), so the sleeves stay the subject
  const back = new THREE.Mesh(trackGeo(new THREE.PlaneGeometry(5.5, 3.1)),
    trackMat(new THREE.MeshBasicMaterial({ map: backdropTex() })));
  back.position.set(0, 0.35, -2.8); scene.add(back);
  function backdropTex() {
    const cv = document.createElement('canvas'); cv.width = 64; cv.height = 48;
    const x = cv.getContext('2d');
    const g = x.createLinearGradient(0, 0, 0, 48);
    g.addColorStop(0, '#2a2016'); g.addColorStop(1, '#0e0b07');
    x.fillStyle = g; x.fillRect(0, 0, 64, 48);
    const t = new THREE.CanvasTexture(cv); t.colorSpace = THREE.SRGBColorSpace; return trackTex(t);
  }

  // ── sleeve art (cardboard card + genre + $ sticker) — matches the interior stock aesthetic ──
  function sleeveTexture(o) {
    const cv = document.createElement('canvas'); cv.width = cv.height = 256;
    const c = cv.getContext('2d');
    c.fillStyle = o.color; c.fillRect(0, 0, 256, 256);
    c.fillStyle = 'rgba(0,0,0,.22)'; c.fillRect(0, 0, 256, 12); c.fillRect(0, 244, 256, 12);
    c.strokeStyle = 'rgba(255,255,255,.28)'; c.lineWidth = 3; c.strokeRect(14, 14, 228, 228);
    c.fillStyle = 'rgba(255,255,255,.92)'; c.textAlign = 'center';
    c.font = '700 22px "Courier New",monospace'; c.fillText(o.a.slice(0, 18), 128, 80);
    c.fillStyle = 'rgba(255,255,255,.75)'; c.font = '17px "Courier New",monospace';
    c.fillText('“' + o.t + '”', 128, 116);
    c.fillStyle = 'rgba(0,0,0,.4)'; c.font = '14px "Courier New",monospace';
    c.fillText(`${o.y} · ${o.s} · ${o.cond}`, 128, 210);
    c.beginPath(); c.arc(210, 48, 30, 0, 7); c.fillStyle = '#f4e11a'; c.fill();  // price sticker
    c.fillStyle = '#c1121f'; c.font = '700 20px Arial'; c.fillText('$' + o.price, 210, 55);
    if (o.rare) { c.fillStyle = '#ffd23d'; c.font = '20px monospace'; c.fillText('★', 34, 232); }
    const t = new THREE.CanvasTexture(cv); t.colorSpace = THREE.SRGBColorSpace; t.anisotropy = 4;
    oTex.add(t); return t;   // per-open → freed on close()
  }

  let recs = [], cursor = 0, vel = 0, active = false, pulled = null, lastFloor = -1;
  let crate = null, offers = [], onCloseCb = null, onBuyCb = null, getCashCb = null;
  let onWantCb = null, isWantedCb = null;   // [R33] the wantlist seams — absent (?game=0/classic) ⇒ no WANT DOM at all
  let emitters = null;   // [R28] room.audio.emitters, per open — where the till sounds from. Optional.
  // shared across opens (persistent): sleeves are all the same box; sides + crate timber never vary
  const sleeveGeo = trackGeo(new THREE.BoxGeometry(SLEEVE[0], SLEEVE[1], SLEEVE[2]));
  const sideMat = trackMat(new THREE.MeshStandardMaterial({ color: 0x8a8070, roughness: 0.85 }));
  const crateWood = trackMat(new THREE.MeshStandardMaterial({ color: 0x8a6a45, roughness: 0.85 }));

  // ── DOM overlay (hint / cursor label / pull panel / walk-out) ──
  const el = (tag, cls, txt) => { const e = document.createElement(tag); e.className = cls; if (txt) e.textContent = txt; return e; };
  const css = el('style'); css.textContent = `
    .pcdg-hint{position:fixed;left:50%;bottom:16px;transform:translateX(-50%);background:rgba(0,0,0,.7);color:#d8d8e0;padding:6px 14px;font:13px "Courier New",monospace;pointer-events:none;display:none;z-index:60}
    .pcdg-cur{position:fixed;left:50%;top:64px;transform:translateX(-50%);color:#ffd23d;font:700 15px "Courier New",monospace;text-shadow:0 1px 4px #000;pointer-events:none;text-align:center;max-width:80%;display:none;z-index:60}
    /* The pull panel is the shop's PRICE STICKER, not a data readout: manila card, typewriter ink, the
       round yellow $ sticker that already sits on the sleeve art (see the sleeve canvas above), a rubber-
       stamped condition grade. Fields render only when present — a missing one leaves no stray separator. */
    .pcdg-panel{position:fixed;right:6%;top:50%;transform:translateY(-50%) rotate(-1.1deg);width:262px;background:#f4ecd8;border:1px solid #cbbf9e;box-shadow:0 10px 26px rgba(0,0,0,.55);padding:15px 16px 14px;color:#241f18;font:14px "Courier New",monospace;display:none;z-index:61}
    .pcdg-panel .sticker{float:right;width:54px;height:54px;border-radius:50%;background:#f4e11a;border:1px solid #d3bf00;color:#c1121f;font:700 18px Arial;line-height:54px;text-align:center;transform:rotate(5deg);margin:-2px -4px 4px 10px;box-shadow:0 1px 3px rgba(0,0,0,.25)}
    .pcdg-panel h3{margin:.1em 0 3px;color:#241f18;font-size:15px;font-weight:700;text-transform:uppercase;letter-spacing:.02em}
    .pcdg-panel .ttl{color:#4c4436;font-size:13px;font-style:italic;margin:0 0 9px;line-height:1.25}
    .pcdg-panel .stamps{clear:both;display:flex;gap:6px;align-items:center;flex-wrap:wrap;min-height:1px}
    .pcdg-panel .grade{border:1.5px solid #b3121f;color:#b3121f;padding:1px 6px;font:700 11px "Courier New",monospace;letter-spacing:.08em;transform:rotate(-2.5deg)}
    .pcdg-panel .tag{color:#6f6553;font-size:11px;letter-spacing:.05em}
    .pcdg-panel .star{color:#b3121f;font-size:13px}
    .pcdg-panel button{margin-top:13px;width:100%;padding:9px;border:1px solid #8a7f66;background:#e7dcc2;color:#241f18;font:700 13px "Courier New",monospace;letter-spacing:.06em;cursor:pointer}
    .pcdg-panel button:hover:not(:disabled){background:#241f18;color:#f4e11a;border-color:#241f18}
    .pcdg-panel button:disabled{color:#9a917c;border-color:#c3b99f;cursor:default}
    .pcdg-panel .want{margin-top:7px;text-align:center;font:700 11px "Courier New",monospace;letter-spacing:.08em;color:#8a7f66;cursor:pointer;user-select:none}
    .pcdg-panel .want:hover{color:#241f18}
    .pcdg-panel .want.on{color:#b3121f;cursor:default}
    .pcdg-panel .x{position:absolute;top:4px;left:8px;cursor:pointer;color:#a89e86;font-size:13px}
    .pcdg-out{position:fixed;left:16px;top:16px;background:#1d1d2b;border:1px solid #666;color:#d8d8e0;padding:8px 14px;font:13px "Courier New",monospace;cursor:pointer;display:none;z-index:60}
    .pcdg-out:hover{border-color:#3dff8b;color:#3dff8b}
    .pcdg-toast{position:fixed;left:50%;top:40%;transform:translate(-50%,-50%);background:#0e0e16;border:1px solid #3dff8b;color:#3dff8b;padding:14px 22px;font:700 15px "Courier New",monospace;z-index:62;display:none}`;
  document.head.appendChild(css);
  const hint = el('div', 'pcdg-hint', 'scroll / drag to riffle · click the front sleeve to pull it · Esc / WALK OUT to leave');
  const curLbl = el('div', 'pcdg-cur');
  const panel = el('div', 'pcdg-panel');
  const outBtn = el('div', 'pcdg-out', '← WALK OUT');
  const toast = el('div', 'pcdg-toast');
  outBtn.onclick = () => close();
  document.body.append(hint, curLbl, panel, outBtn, toast);

  // ── procedural audio ──
  // [R28] HOUSE AUDIO LAW (audio.js, Lane B): (1) ONE AudioContext; (2) ?mute=1 forces silence. This
  // file broke both from R5 to R28 — a second, private AudioContext wired straight to `destination`,
  // so the riffle sang right through ?mute=1 and never saw B's master gain. It survived three epochs
  // because NO gate asserts mute ⇒ silence: the engine dutifully returns its silent surface, `?mute`
  // looks honest from the engine's side, and the sound came from somewhere the engine never knew about.
  // A gate that asks the engine whether it's muted can only ever answer yes. -> F: assert SILENCE, not
  // muted-state (there is no second AudioContext ⇔ the law holds).
  // The blips STAY procedural on purpose: zero-fetch, deterministic, and they still work under
  // ?noassets=1, where a sampled riffle cannot. Only mute was broken; fix only mute.
  // Routing them through B's bus (so master gain applies) needs a ctx/bus seam this lane must not open
  // unilaterally — published as the R28 ask in LANE_C_AUDIO.md §Emitters.
  const MUTED_BY_URL = (() => {
    try { const p = new URLSearchParams(location.search).get('mute'); return p != null && p !== '0'; }
    catch { return false; }
  })();
  function muted() {
    const eng = window.PROCITY && window.PROCITY.audio;   // B's PUBLIC getter — consulted, not modified
    if (eng && typeof eng.muted === 'boolean') return eng.muted;
    return MUTED_BY_URL;                                  // standalone interior_test: no engine to ask
  }
  let actx;
  function blip(kind) {
    if (muted()) return;
    try {
      actx = actx || new (window.AudioContext || window.webkitAudioContext)();
      if (kind === 'fwip') {
        const n = Math.floor(actx.sampleRate * 0.05), buf = actx.createBuffer(1, n, actx.sampleRate), d = buf.getChannelData(0);
        for (let i = 0; i < n; i++) d[i] = (Math.sin(i * 0.7) * (1 - i / n)) * 0.6;   // deterministic-ish fwip (no Math.random)
        const s = actx.createBufferSource(); s.buffer = buf;
        const f = actx.createBiquadFilter(); f.type = 'bandpass'; f.frequency.value = 2100; f.Q.value = 0.7;
        const g = actx.createGain(); g.gain.value = 0.2;
        s.connect(f); f.connect(g); g.connect(actx.destination); s.start();
      } else {
        const o = actx.createOscillator(); o.type = 'sine'; o.frequency.value = 105;
        const g = actx.createGain(); g.gain.setValueAtTime(0.0001, actx.currentTime);
        g.gain.exponentialRampToValueAtTime(0.5, actx.currentTime + 0.005);
        g.gain.exponentialRampToValueAtTime(0.0001, actx.currentTime + 0.28);
        o.connect(g); g.connect(actx.destination); o.start(); o.stop(actx.currentTime + 0.3);
      }
    } catch (e) {}
  }

  function buildCrate(depth) {
    if (crate) { scene.remove(crate); crate = null; }
    crate = new THREE.Group();
    const [w, h] = SLEEVE;
    const W = w + 0.06, H = h * 0.72, D = depth + 0.10, th = 0.016;
    const add = (bw, bh, bd, x, y, z) => { const g = new THREE.BoxGeometry(bw, bh, bd); oGeo.add(g); const m = new THREE.Mesh(g, crateWood); m.position.set(x, y, z); crate.add(m); };
    add(W, th, D, 0, -th / 2, -D / 2 + 0.05);
    add(th, H, D, -W / 2, H / 2, -D / 2 + 0.05); add(th, H, D, W / 2, H / 2, -D / 2 + 0.05);
    add(W, H, th, 0, H / 2, -D + 0.05); add(W, H * 0.55, th, 0, H * 0.275, 0.05);
    scene.add(crate);
  }

  function buildStack(list) {
    recs.forEach(r => scene.remove(r.group)); recs = [];
    const [w, h, th] = SLEEVE;
    let z = -0.05;
    list.forEach((o, i) => {
      const grp = new THREE.Group(); grp.position.set(0, 0, z);
      let mesh;
      if (o.real) {                                    // ?stock=real: a cover PLANE sampling the pack atlas
        const g = new THREE.PlaneGeometry(w, h); oGeo.add(g);
        const [u0, v0, u1, v1] = o.pack.uvRect(o.item);
        const a = g.attributes.uv; a.setXY(0, u0, v1); a.setXY(1, u1, v1); a.setXY(2, u0, v0); a.setXY(3, u1, v0); a.needsUpdate = true;
        mesh = new THREE.Mesh(g, o.pack.material(o.item));   // shared atlas material (not disposed here)
      } else {
        const face = new THREE.MeshStandardMaterial({ map: sleeveTexture(o), roughness: 0.75 }); oMat.add(face);
        mesh = new THREE.Mesh(sleeveGeo, [sideMat, sideMat, sideMat, sideMat, face, sideMat]);   // shared sleeve geo
      }
      mesh.position.y = h / 2;
      grp.add(mesh); grp.rotation.x = BACK;
      grp.rotation.z = (((i * 2654435761) >>> 0) % 100 - 50) / 1800;   // each sleeve leans its own way (seeded by index)
      grp.position.x = (((i * 40503) >>> 0) % 100 - 50) / 12000;
      scene.add(grp);
      recs.push({ group: grp, offer: o, angle: BACK, homeZ: z });
      z -= th + 0.010;
    });
    buildCrate(Math.max(0.2, -z));
    cursor = 0; vel = 0; lastFloor = -1; updateCur();
  }

  function updateCur() {
    const r = recs[Math.round(cursor)];
    curLbl.textContent = r ? `${r.offer.a} — “${r.offer.t}”` : (recs.length ? '' : 'bin’s cleaned out');
  }

  function removeEntry(entry) {
    const idx = recs.indexOf(entry); if (idx < 0) return;
    scene.remove(entry.group); recs.splice(idx, 1);
    let z = -0.05;
    recs.forEach(x => { x.homeZ = z; x.group.position.z = z; z -= SLEEVE[2] + 0.010; });
    cursor = Math.min(cursor, Math.max(0, recs.length - 1));
    pulled = null; panel.style.display = 'none'; updateCur();
  }

  function showPanel(entry) {
    const o = entry.offer;
    const cash = getCashCb ? getCashCb() : 999;
    // A price sticker, composed from what this item ACTUALLY has. Real pack items carry no year (and
    // may carry no grade); procedural ones carry both. Build the stamp row from present parts only —
    // never emit a separator around a hole (that's what read as a database row). §7.2c.
    const esc = (s) => String(s).replace(/[&<>"]/g, m => ({ '&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;' }[m]));
    const stamps = [];
    if (o.cond) stamps.push(`<span class="grade">${esc(o.cond)}${o.sleeveCond ? '/' + esc(o.sleeveCond) : ''}</span>`);
    const line = [o.y, o.s].filter(Boolean).join(' ');          // "1974 SOUL" | "SOUL" | "" — never " · "
    if (line) stamps.push(`<span class="tag">${esc(line)}</span>`);
    if (o.rare) stamps.push(`<span class="star">★ ${o.real ? 'GRAIL' : 'RARE'}</span>`);
    // [R32 THE BIBLE] the guide stamp — a RANGE off the 90s guide book, never a verdict. Present-fields-
    // only law holds: an unknown band leaves no stamp (guideText returns ''). The asking price sits on
    // the sticker; whether it's under the guide is for the PLAYER to notice — the card never says gem.
    const guide = guideText('record', o.band);
    if (guide) stamps.push(`<span class="tag">${esc(guide)}</span>`);
    // [R33] the WANT line — only when the game layer wired the seams (construction-gated DOM: a
    // ?game=0 / classic card carries no wantlist trace). Already-wanted reads as a stamp, not a button.
    const wanted = isWantedCb ? !!isWantedCb(o) : false;
    const wantLine = onWantCb
      ? `<div class="want${wanted ? ' on' : ''}">${wanted ? '★ ON THE WANTLIST' : '☆ WANT IT — hunt one cheaper'}</div>`
      : '';
    panel.innerHTML = `<div class="x">✕</div>`
      + `<div class="sticker">$${esc(o.price)}</div>`
      + `<h3>${esc(o.a)}</h3>`
      + (o.t ? `<div class="ttl">“${esc(o.t)}”</div>` : '')
      + (stamps.length ? `<div class="stamps">${stamps.join('')}</div>` : '')
      + `<button ${o.price > cash ? 'disabled' : ''}>${o.price > cash ? 'NOT ENOUGH CASH' : 'BUY IT'}</button>`
      + wantLine;
    panel.style.display = 'block';
    panel.querySelector('.x').onclick = unpull;
    const wantEl = panel.querySelector('.want');
    if (wantEl && !wanted) wantEl.onclick = () => {
      if (onWantCb(o) !== false) { wantEl.classList.add('on'); wantEl.textContent = '★ ON THE WANTLIST'; wantEl.onclick = null; }
    };
    const b = panel.querySelector('button');
    if (b && !b.disabled) b.onclick = () => {
      // STUB economy (round 6+): onBuy may veto; default is a toast + remove-from-bin.
      const ok = onBuyCb ? onBuyCb(o) : true;
      if (ok === false) { unpull(); return; }
      // [R28] the sale rings on the till across the shop; the thunk stays as the no-engine fallback so
      // the standalone harness (and ?noassets) keeps its sold cue.
      if (!sfxFrom('till', emitters && emitters.counter)) blip('thunk');
      showToast(`SOLD — ${o.a} · $${o.price}`);
      removeEntry(entry);
    };
  }
  // [R28 audioEmitter] The till rings from the COUNTER, not from inside your head. You riffle at a bin,
  // so the counter is 2.83–8.15 m away (measured, 8 types × 4 seeds) — a real distance to carry.
  // This needs NO engine seam: B's playSfx(key,{gain}) is already public, so C does its own distance
  // math and hands B a scalar. That is the whole reason a ONE-SHOT is tractable and a BED is not — a
  // one-shot resolves its gain once, at fire time, from a position C already knows; a bed has to be
  // re-gained every frame from inside the engine's update loop, which is B's file. Hence the split ask.
  // `sfx-till.ogg` has been on disk since 15 Jul and has never once played: this is routing, not content.
  // No emitter (F hasn't plumbed it, or no counter) ⇒ gain 1 ⇒ a plain, un-positioned till. No engine
  // ⇒ silence. Both fail soft, both still ring true.
  function emitterGain(em) {
    if (!em) return 1;
    const cam = window.PROCITY && window.PROCITY.camera && window.PROCITY.camera.position;
    if (!cam) return 1;                                  // no camera to measure from → room-filling
    const d = Math.hypot(cam.x - em.x, cam.z - em.z);    // emitters are ROOM-LOCAL; so is the interior camera
    const prox = Math.max(0, Math.min(1, (em.r - d) / em.r));
    return em.floor + (1 - em.floor) * prox;             // never 0 — a till across the shop is quiet, not absent
  }
  function sfxFrom(key, em) {
    const eng = window.PROCITY && window.PROCITY.audio;
    if (!eng || !eng.playSfx) return false;              // standalone/no engine → silent-and-happy
    eng.playSfx(key, { gain: emitterGain(em) });         // ?mute / ?noassets / pre-gesture handled inside
    return true;
  }

  let toastT = null;
  function showToast(msg) { toast.textContent = msg; toast.style.display = 'block'; clearTimeout(toastT); toastT = setTimeout(() => (toast.style.display = 'none'), 1400); }

  function pull() { const r = recs[Math.round(cursor)]; if (!r) return; pulled = r; blip('thunk'); showPanel(r); }
  function unpull() { if (pulled) pulled.group.position.set(pulled.group.position.x, 0, pulled.homeZ); pulled = null; panel.style.display = 'none'; updateCur(); }

  function update(dt) {
    if (!active) return;
    vel *= Math.pow(0.0008, dt);
    cursor += vel * dt;
    if (cursor < 0) { cursor = 0; vel = 0; }
    if (cursor > recs.length - 1) { cursor = Math.max(0, recs.length - 1); vel = 0; }
    const fl = Math.floor(cursor);
    if (fl !== lastFloor) { lastFloor = fl; blip('fwip'); updateCur(); }
    recs.forEach((r, i) => {
      const f = THREE.MathUtils.smoothstep(cursor - i, -0.4, 1.2);
      const target = BACK + f * (MAXFLIP - BACK);
      r.angle += (target - r.angle) * Math.min(1, dt * 12);
      if (r !== pulled) r.group.rotation.x = r.angle;
    });
    if (pulled) {
      pulled.group.position.lerp(new THREE.Vector3(0, 0.42, 0.55), Math.min(1, dt * 5));
      pulled.group.rotation.x += (0 - pulled.group.rotation.x) * Math.min(1, dt * 6);
    }
  }

  // ── input ──
  let dragY = null, moved = 0;
  const onWheel = e => { if (!active) return; e.preventDefault(); vel += e.deltaY * 0.012; };
  const onDown = e => { if (!active) return; dragY = e.clientY; moved = 0; };
  const onMove = e => { if (!active || dragY == null) return; const dy = e.clientY - dragY; moved += Math.abs(dy); cursor += dy * 0.02; vel = dy * 0.6; dragY = e.clientY; };
  const onUp = () => { if (!active) return; if (moved < 4 && !pulled) pull(); dragY = null; };
  const onKey = e => { if (!active) return; if (e.key === 'Escape') { e.stopPropagation(); if (pulled) unpull(); else close(); } };
  renderer.domElement.addEventListener('wheel', onWheel, { passive: false });
  renderer.domElement.addEventListener('pointerdown', onDown);
  renderer.domElement.addEventListener('pointermove', onMove);
  renderer.domElement.addEventListener('pointerup', onUp);
  document.addEventListener('keydown', onKey, true);

  // ?stock=real: seeded pick of real pack items (same bin seed → same crate contents).
  // TIER-2 SEAM (v5.0): `pack.gone` = ids the live read says sold IN THE REAL SHOP. We pick from the
  // FULL, stable `pack.items` and omit gone ids AFTER the draw — never from a filtered array.
  // Measured (R27, 5 crates): filtering the array first reshuffles the crate — one sale changed 21 OTHER
  // records, because every pick indexes by position. Pick-then-omit: 0 collateral, the sold record simply
  // leaves and the survivors keep their slots (a crate with 3 sold shows 13, not a different 16).
  // Both forms hide the sold record, so "the gone item never renders" cannot tell them apart — the
  // collateral is what a gate must assert on. F: update item FIELDS in place (live price) freely; do NOT
  // add, remove, or reorder `pack.items` — that identity/order IS the seeded pick's stability.
  function pickRealOffers(pack, seed, n, pulledGone) {
    const rr = mulberry32(seed >>> 0), out = [];
    const gone = pack.gone instanceof Set ? pack.gone
               : (Array.isArray(pack.gone) ? new Set(pack.gone) : null);
    for (let i = 0; i < n; i++) {
      const it = pack.items[(rr() * pack.items.length) | 0];
      if (gone && gone.has(it.id)) continue;   // sold in the real shop → this slot is simply empty
      // [R32 scarcity] the PLAYER bought it (this day, this bin) → same pick-then-omit seam, same
      // zero-collateral guarantee: the pull leaves, the survivors keep their slots.
      if (pulledGone && pulledGone.has('sku:' + it.id)) continue;
      // Real fields straight off the atlas index (§7.2c): condition/sleeve_cond are OPTIONAL — present on
      // POS-sourced items, absent on mint ones that had no genuine grade. `y` (year) is never in the index,
      // so it stays empty and the card simply omits it. No invented values: an unstated grade stays unstated.
      // `grail` becomes the ★ stamp, so it must NOT also ride in `s` — otherwise the card reads
      // "GRAIL ★ GRAIL". (Procedural sleeves are unaffected: their `s` is a genre, not the band.)
      const band = (it.price_band || '').toUpperCase();
      out.push({ real: true, pack, item: it, a: it.artist, t: it.title, price: it.price,
                 s: band === 'GRAIL' ? '' : band, y: '',
                 cond: it.condition || '', sleeveCond: it.sleeve_cond || '',
                 band: it.price_band || null,   // [R32] canonical band for the guide stamp + the sell basis
                 rare: it.price_band === 'grail' });
    }
    return out;
  }

  // open({ seed, count, shopName, shop, stockAdapter, onClose, onBuy, getCash, emitters, gone })
  // `emitters` [R28, OPTIONAL] — pass `room.audio.emitters` and the till rings from the counter at the
  // right distance. Omit it and the till still rings, just un-positioned. Never required.
  // `gone` [R32, OPTIONAL] — a Set of THIS bin's already-pulled slots ('sku:<id>' for pack items, the
  // stringified offer index for parody), from the save's pull records. Omission happens AFTER the full
  // seeded draw (both paths), so the survivors keep their slots — the R27 zero-collateral law. Absent
  // (?game=0 / classic / fresh day) ⇒ the bin riffles exactly as it always did.
  function open(opts = {}) {
    active = true;
    onCloseCb = opts.onClose || null; onBuyCb = opts.onBuy || null; getCashCb = opts.getCash || null;
    onWantCb = opts.onWant || null; isWantedCb = opts.isWanted || null;   // [R33] wantlist seams
    emitters = opts.emitters || null;
    const count = opts.count || 16;
    const gone = opts.gone instanceof Set && opts.gone.size ? opts.gone : null;
    // riffle items: real pack (?stock=real) via the stockAdapter seam, else seeded procedural sleeves.
    const src = opts.stockAdapter && opts.stockAdapter(opts.shop, 'sleeve');
    offers = (src && src.real) ? pickRealOffers(src.pack, opts.seed ?? 1, count, gone)
           : proceduralSleeves(opts.seed ?? 1, count).filter((o) => !(gone && gone.has(String(o.i))));
    curLbl.textContent = (opts.shopName ? opts.shopName + ' — ' : '');
    [hint, curLbl, outBtn].forEach(e => e.style.display = 'block');
    buildStack(offers);
    if (opts.shopName) curLbl.textContent = opts.shopName + ' — ' + curLbl.textContent;
  }

  function freeOpen() {   // free per-open GPU resources → each open/close is leak-free
    recs.forEach(r => scene.remove(r.group)); recs = [];
    if (crate) { scene.remove(crate); crate = null; }
    for (const g of oGeo) g.dispose(); for (const m of oMat) m.dispose(); for (const t of oTex) t.dispose();
    oGeo.clear(); oMat.clear(); oTex.clear();
  }

  function close() {
    if (!active) return;
    active = false; pulled = null;
    [hint, curLbl, panel, outBtn, toast].forEach(e => e.style.display = 'none');
    freeOpen();
    const cb = onCloseCb; onCloseCb = null;
    if (cb) cb();
  }

  // full teardown — frees the persistent GPU resources + removes listeners/DOM (call when the shell
  // is done with the dig, e.g. leaving interior mode entirely).
  function dispose() {
    close();
    removeEventListener('resize', onResize);
    renderer.domElement.removeEventListener('wheel', onWheel);
    renderer.domElement.removeEventListener('pointerdown', onDown);
    renderer.domElement.removeEventListener('pointermove', onMove);
    renderer.domElement.removeEventListener('pointerup', onUp);
    document.removeEventListener('keydown', onKey, true);
    for (const g of pGeo) g.dispose(); for (const m of pMat) m.dispose(); for (const t of pTex) t.dispose();
    pGeo.clear(); pMat.clear(); pTex.clear();
    [css, hint, curLbl, panel, outBtn, toast].forEach(e => e.remove());
  }

  // [R32 — the honest-gate surface, R24 precedent] What is in THIS open bin, BY IDENTITY: original
  // offer index, asking, band, sku (pack items). Read-only snapshots; null when closed. F's bible/
  // scarcity gate asserts on these instead of trusting "the crate looked right".
  function currentOffers() {
    if (!active) return null;
    return recs.map((r) => ({ i: r.offer.i ?? null, price: r.offer.price, band: r.offer.band || null,
                              sku: r.offer.item ? String(r.offer.item.id) : null }));
  }

  return { scene, camera, open, close, update, dispose, currentOffers, get active() { return active; } };
}

// A stable per-bin seed from the shop + a bin index, so a given bin riffles the same order every time.
export function binSeed(shopSeed, binId) {
  return (xmur3(`dig:${shopSeed}:${binId}`)()) >>> 0;
}