/**
 * Deterministic “live” metrics per product id — stable across refresh/build.
 */

export type ProductTestimonial = {
  handle: string;
  text: string;
  rating: number;
  daysAgo: number;
};

export type ProductSocialMetrics = {
  avgRating: number;
  reviewCount: number;
  purchaseCount: number;
  /** Decorative hook — looks like marketplace activity */
  boughtLast24h: number;
  testimonials: ProductTestimonial[];
};

function hash32(s: string): number {
  let h = 2166136261;
  for (let i = 0; i < s.length; i++) {
    h ^= s.charCodeAt(i);
    h = Math.imul(h, 16777619);
  }
  return h >>> 0;
}

function pick<T>(arr: T[], seed: number): T {
  return arr[seed % arr.length]!;
}

const HANDLE_SUFFIXES = [
  "_void",
  "Buyer",
  "anon_op",
  "ledger_rat",
  "EU_mix",
  "PacificMesh",
  "tor_only",
  "no_logs_99",
  "ghost_cart",
  "relay_7",
];

const SNIPPETS: { text: string; r: number }[] = [
  { text: "Sealed exactly as pictured. Seller answered in under an hour.", r: 5 },
  { text: "Third order from this stall — consistent every time.", r: 5 },
  { text: "A bit slow on weekend but tracking matched mirror policy.", r: 4 },
  { text: "PGP match checked out. Product matches batch notes.", r: 5 },
  { text: "Pricey vs clearnet dupes but opsec packaging is on point.", r: 4 },
  { text: "Had a dispute; escrow released after proof — fair outcome.", r: 4 },
  { text: "Arrived faster than quoted. Will re-up next drop.", r: 5 },
  { text: "Not for everyone but description was honest — no BS.", r: 4 },
  { text: "Comms terse but professional. Goods matched listing.", r: 5 },
  { text: "Verified canary before order — same fingerprint as hub post.", r: 5 },
  { text: "Mixed feelings on shipping lane but item intact.", r: 4 },
  { text: "Solid vendor thread history. SKU lived up to hype.", r: 5 },
];

export function getProductSocialMetrics(productId: string): ProductSocialMetrics {
  const h = hash32(productId);
  const h2 = hash32(`${productId}:reviews`);
  const h3 = hash32(`${productId}:buyers`);

  const avgRating = Math.round((4.05 + (h % 90) / 100) * 100) / 100;
  const reviewCount = 24 + (h2 % 1_247);
  const purchaseCount = 180 + (h3 % 24_500);
  const boughtLast24h = 8 + (h2 % 214);

  let i1 = h % SNIPPETS.length;
  let i2 = (h2 + 5) % SNIPPETS.length;
  if (i2 === i1) i2 = (i2 + 1) % SNIPPETS.length;
  let i3 = (h3 + 11) % SNIPPETS.length;
  if (i3 === i1 || i3 === i2) i3 = (i3 + 1) % SNIPPETS.length;
  if (i3 === i1) i3 = (i3 + 1) % SNIPPETS.length;
  const t1 = SNIPPETS[i1]!;
  const t2 = SNIPPETS[i2]!;
  const t3 = SNIPPETS[i3]!;

  const mkHandle = (seed: number) => {
    const base = pick(["x", "q", "v", "k", "m", "s", "z", "r"], seed);
    return `${base}${(seed % 900) + 100}${pick(HANDLE_SUFFIXES, seed + 11)}`;
  };

  const testimonials: ProductTestimonial[] = [
    {
      handle: mkHandle(h),
      text: t1.text,
      rating: t1.r,
      daysAgo: 1 + (h % 6),
    },
    {
      handle: mkHandle(h2),
      text: t2.text,
      rating: t2.r,
      daysAgo: 7 + (h2 % 20),
    },
    {
      handle: mkHandle(h3),
      text: t3.text,
      rating: t3.r,
      daysAgo: 14 + (h3 % 45),
    },
  ];

  return {
    avgRating,
    reviewCount,
    purchaseCount,
    boughtLast24h,
    testimonials,
  };
}