// PROCITY Lane C — the sell counter (v7.0-alpha, R30 ledger #2). Walk to the keeper's counter holding
// items the shop trades in → a sell card (the mirror of the dig's price sticker): item, OFFER, SELL.
// Contract: LANE_C_PUB §9 — this file is the loader-exact authority (the §7 rule applies here too).
//
// THE NO-PUMP LAW IS STRUCTURAL, NOT TUNED (charter law #2): sellOffer() is strictly below what the
// player paid for every pricePaid ≥ 1, so buy-then-immediately-sell loses ≥ $1 per round trip by
// construction — F's monotonic-loss gate holds against the formula's shape, not a balance pass.
//
// Consumer pattern mirrors dig.js: C ships the interaction, F owns the in-game input hook. C consumes
// the game collection READ-ONLY — the single side-effect is onSell(item, offer); the CONSUMER credits
// the wallet and removes the item via the game API (never this file, never a splice of game state).
// DOM-only: zero draws, zero GPU resources; dispose() removes every node + listener. No game layer
// (?classic=1 / ?game=0) → the consumer never constructs/opens this, and open() itself returns false
// on an empty sellable list — zero errors, zero DOM.

import { sellBasis, guideText } from './bible.js';   // [R32] THE BIBLE — the §9.1 beta basis + the card's guide line

export const SELL_MULT = 0.5;   // the keeper pays half of what he'll sticker it at (§9.1 — he eats too)
export const SELL_DIST = 2.0;   // metres from room.counter.pose (bench centre, room-local)

// The offer (§9.1). [R32 — the pre-ratified beta swap, executed] Basis = bandLow when the entry carries
// a band the BIBLE knows (sellBasis, bible.js), else the alpha basis (pricePaid) — so alpha-era finds
// sell exactly as they always did. THE CLAMP SHAPE IS UNTOUCHED: the offer sits strictly below the
// BASIS for every basis ≥ 1, which with bandLow as basis is the no-pump law's beta form — "every sell
// price < the buy-side guide band, structurally" (charter law #2). A gem (bought UNDER band) nets its
// finder margin against the band, never against the keeper; scarcity (the save's pulls) makes that
// margin a finite find, not a loop. p=1 → $0 (the SELL button disables).
export function sellOffer(basis) {
  const p = Math.floor(+basis || 0);
  if (p <= 0) return 0;
  return Math.min(p - 1, Math.max(1, Math.floor(p * SELL_MULT)));
}

// Alpha matcher (§9.2): any shop of the item's type buys it — strict equality, and FAIL-CLOSED on an
// untyped item (vacuous-gate law: a matcher that passes an untyped item would "match" everywhere).
// Per-keeper taste / haggling / pawn-buys-everything: beta — do not widen here.
export function sellableIn(shopType, item) {
  return !!(item && item.type && shopType && item.type === shopType);
}

// Proximity test (§9.4) — pos is the interior camera position (room-local, the same frame the
// counter pose is published in).
export function nearCounter(room, pos, dist = SELL_DIST) {
  const c = room && room.counter && room.counter.pose;
  if (!c || !pos) return false;
  return Math.hypot(pos.x - c.x, pos.z - c.z) <= dist;
}

// [R28 pattern] one-shot distance gain from the counter emitter — same math as dig.js's till.
function emitterGain(em) {
  if (!em) return 1;
  const cam = window.PROCITY && window.PROCITY.camera && window.PROCITY.camera.position;
  if (!cam) return 1;
  const d = Math.hypot(cam.x - em.x, cam.z - em.z);
  const prox = Math.max(0, Math.min(1, (em.r - d) / em.r));
  return em.floor + (1 - em.floor) * prox;
}
function ringTill(em) {
  const eng = window.PROCITY && window.PROCITY.audio;
  if (!eng || !eng.playSfx) return;             // no engine → silent-and-happy (?mute/?noassets inside)
  eng.playSfx('till', { gain: emitterGain(em) });
}

export function createSell() {
  const el = (tag, cls) => { const e = document.createElement(tag); if (cls) e.className = cls; return e; };
  // The buy card's manila sticker, mirrored to the LEFT (the sell side of the counter). Same
  // typewriter/stamp treatment as .pcdg-panel so the two cards read as one shop's stationery.
  const css = el('style'); css.textContent = `
    .pcsl-panel{position:fixed;left: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}
    .pcsl-panel .sticker{float:right;width:54px;height:54px;border-radius:50%;background:#bfe3c0;border:1px solid #5a9a5e;color:#1c5e2a;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)}
    .pcsl-panel h3{margin:.1em 0 3px;color:#241f18;font-size:15px;font-weight:700;text-transform:uppercase;letter-spacing:.02em}
    .pcsl-panel .ttl{color:#4c4436;font-size:13px;font-style:italic;margin:0 0 9px;line-height:1.25}
    .pcsl-panel .meta{clear:both;color:#6f6553;font-size:11px;letter-spacing:.05em;min-height:1px}
    .pcsl-panel .nav{display:flex;justify-content:space-between;align-items:center;margin-top:9px;color:#6f6553;font-size:12px}
    .pcsl-panel .nav span{cursor:pointer;padding:0 8px;user-select:none}
    .pcsl-panel .nav span:hover{color:#241f18}
    .pcsl-panel button{margin-top:11px;width:100%;padding:9px;border:1px solid #5a7a5e;background:#dcead0;color:#1c5e2a;font:700 13px "Courier New",monospace;letter-spacing:.06em;cursor:pointer}
    .pcsl-panel button:hover:not(:disabled){background:#1c5e2a;color:#dcead0;border-color:#1c5e2a}
    .pcsl-panel button:disabled{color:#9a917c;border-color:#c3b99f;background:#e7dcc2;cursor:default}
    .pcsl-panel .x{position:absolute;top:4px;left:8px;cursor:pointer;color:#a89e86;font-size:13px}
    .pcsl-toast{position:fixed;left:50%;top:40%;transform:translate(-50%,-50%);background:#0e160e;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 panel = el('div', 'pcsl-panel');
  const toast = el('div', 'pcsl-toast');
  document.body.append(panel, toast);

  let active = false, items = [], idx = 0;
  let onSellCb = null, onCloseCb = null, emitters = null, shopName = '';

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

  const esc = (s) => String(s).replace(/[&<>"]/g, (m) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;' }[m]));
  const labelOf = (it) => it.artist || it.a || '';   // headline line (artist), may be empty
  const titleOf = (it) => it.title || it.t || it.sku || it.slotId || 'item';   // §9.2 fallback: honest, ugly

  function render() {
    const it = items[idx];
    if (!it) { close(); return; }
    const offer = sellOffer(sellBasis(it));            // [R32] bandLow basis when banded, pricePaid else
    const head = labelOf(it) || titleOf(it);
    const ttl = labelOf(it) ? titleOf(it) : '';
    const paid = it.pricePaid != null ? it.pricePaid : it.price;
    const guide = guideText(it.type, it.band);         // [R32] '' when unbanded → no stray separator (§7.2c)
    panel.innerHTML = `<div class="x">✕</div>`
      + `<div class="sticker">$${esc(offer)}</div>`
      + `<h3>${esc(head)}</h3>`
      + (ttl ? `<div class="ttl">“${esc(ttl)}”</div>` : '')
      + `<div class="meta">${paid != null ? 'you paid $' + esc(paid) : ''}${guide ? ' · ' + esc(guide) : ''}${it.dayFound != null ? ' · day ' + esc(it.dayFound) : ''}</div>`
      + (items.length > 1 ? `<div class="nav"><span class="pv">‹</span>${idx + 1} of ${items.length}<span class="nx">›</span></div>` : '')
      + `<button ${offer <= 0 ? 'disabled' : ''}>${offer <= 0 ? 'NOT WORTH BUYING' : 'SELL — $' + esc(offer)}</button>`;
    panel.style.display = 'block';
    panel.querySelector('.x').onclick = () => close();
    const pv = panel.querySelector('.pv'), nx = panel.querySelector('.nx');
    if (pv) pv.onclick = () => { idx = (idx + items.length - 1) % items.length; render(); };
    if (nx) nx.onclick = () => { idx = (idx + 1) % items.length; render(); };
    const b = panel.querySelector('button');
    if (b && !b.disabled) b.onclick = () => {
      // The single side-effect (§9.3): the consumer credits the wallet AND removes the item via the
      // game API. false = keeper veto → card unchanged, nothing moves. C never touches game state.
      const ok = onSellCb ? onSellCb(it, offer) : false;
      if (ok === false) return;
      ringTill(emitters && emitters.counter);
      showToast(`SOLD — ${esc(head)} · +$${offer}`);
      items.splice(idx, 1);                      // the LOCAL sellable list only, never the collection
      if (!items.length) { close(); return; }
      idx = Math.min(idx, items.length - 1);
      render();
    };
  }

  const onKey = (e) => { if (!active) return; if (e.key === 'Escape') { e.stopPropagation(); close(); } };

  // open({ shopType, shopName, items, getCash, onSell, onClose, emitters }) → bool (§9.6).
  // `items` = the game collection (read-only; a filtered COPY is carded). Nothing sellable → false,
  // no card, no DOM — the fail-soft half of the classic-pure law lives here too.
  function open(opts = {}) {
    if (active) return true;
    const src = Array.isArray(opts.items) ? opts.items : [];
    const sellable = src.filter((it) => sellableIn(opts.shopType, it));
    if (!sellable.length) return false;
    items = sellable; idx = 0; active = true;
    onSellCb = opts.onSell || null; onCloseCb = opts.onClose || null;
    emitters = opts.emitters || null; shopName = opts.shopName || '';
    document.addEventListener('keydown', onKey, true);
    render();
    return true;
  }

  function close() {
    if (!active) return;
    active = false; items = []; idx = 0;
    panel.style.display = 'none';
    document.removeEventListener('keydown', onKey, true);
    const cb = onCloseCb; onCloseCb = null; onSellCb = null; emitters = null;
    if (cb) cb();
  }

  function dispose() {
    close();
    clearTimeout(toastT);
    [css, panel, toast].forEach((e) => e.remove());
  }

  return { open, close, dispose, get active() { return active; } };
}