export type ExchangeListing = {
  id: string;
  kind: "wts" | "wtb";
  title: string;
  body: string;
  price: string;
  currency: "BTC" | "XMR" | "USD";
  author: string;
  ts: number;
};

const KEY = "cyberlux-exchange-v1";

function uid(): string {
  if (typeof crypto !== "undefined" && "randomUUID" in crypto) return crypto.randomUUID();
  return `e_${Date.now()}_${Math.random().toString(36).slice(2, 10)}`;
}

const seed: ExchangeListing[] = [
  {
    id: "es-1",
    kind: "wts",
    title: "Hardware entropy module (listing)",
    body: "Open-box. Local pickup on this onion only. Meet at public node.",
    price: "0.015",
    currency: "BTC",
    author: "EntropyCorp",
    ts: Date.now() - 3600000 * 20,
  },
  {
    id: "es-2",
    kind: "wtb",
    title: "Looking for vintage cipher manuals (replica)",
    body: "Budget flexible for the right scan quality.",
    price: "120",
    currency: "USD",
    author: "Collector42",
    ts: Date.now() - 3600000 * 8,
  },
];

export function loadExchange(): ExchangeListing[] {
  if (typeof window === "undefined") return seed;
  try {
    const raw = localStorage.getItem(KEY);
    if (!raw) {
      saveExchange(seed);
      return seed;
    }
    const v = JSON.parse(raw) as ExchangeListing[];
    return Array.isArray(v) && v.length ? v : seed;
  } catch {
    return seed;
  }
}

export function saveExchange(list: ExchangeListing[]): void {
  if (typeof window === "undefined") return;
  localStorage.setItem(KEY, JSON.stringify(list));
}

export function addListing(
  L: Omit<ExchangeListing, "id" | "ts">,
): ExchangeListing {
  const row: ExchangeListing = {
    id: uid(),
    ts: Date.now(),
    kind: L.kind,
    title: L.title.trim(),
    body: L.body.trim(),
    price: L.price.trim(),
    currency: L.currency,
    author: L.author.trim() || "Anonymous",
  };
  const all = [row, ...loadExchange()];
  saveExchange(all);
  return row;
}