// PROCITY Lane C — buy loop v0 (round 8). In-memory wallet: seeded starting cash, purchases, inventory.
// RUNTIME state only — reload resets, world generation is untouched (purchases never enter the plan or
// the seeded room build). One wallet is shared across dig sessions + shops so F's shell can render the
// same cash chip on the street. Economy is deliberately shallow (no persistence, no backend) — v0.

import { mulberry32 } from '../core/prng.js';

export function createWallet(seed = 1) {
  const r = mulberry32(seed >>> 0);
  const start = 60 + ((r() * 140) | 0);        // seeded starting cash ~$60–200
  let cash = start;
  const inv = [];
  const listeners = new Set();
  const notify = () => listeners.forEach(fn => { try { fn(); } catch (e) {} });
  return {
    cash: () => cash,
    start: () => start,
    canBuy: (price) => (price || 0) <= cash,
    // buy(offer) — offer is a dig offer ({a:artist, t:title, price, ...}) or a pack item ({title,artist,price}).
    // Returns false (no state change) if broke. Deducts + records on success.
    buy(o) {
      const price = (o && o.price) || 0;
      if (price > cash) return false;
      cash -= price;
      inv.push({ title: o.t || o.title || '?', artist: o.a || o.artist || '', price, band: (o.s || o.price_band || '') });
      notify();
      return true;
    },
    // [R30 §9.3] sell(item, offer) — the credit side of the counter, the exact mirror of buy(): adds the
    // offer (computed by sell.js sellOffer — this file never prices) and drops the matching v0-inventory
    // entry if one exists (by identity first, then title+artist). The GAME collection is NOT touched
    // here — that removal is the consumer's, via the game API (LANE_C_PUB §9.3).
    sell(o, offer) {
      const amt = Math.max(0, Math.floor(+offer || 0));
      cash += amt;
      let i = inv.indexOf(o);
      if (i < 0) i = inv.findIndex((x) => x.title === (o.t || o.title) && x.artist === (o.a || o.artist || ''));
      if (i >= 0) inv.splice(i, 1);
      notify();
      return true;
    },
    inventory: () => inv.slice(),
    count: () => inv.length,
    onChange(fn) { listeners.add(fn); return () => listeners.delete(fn); },
  };
}