import type { AssetClass, InstrumentHint } from "./index.js";

const slug = (s: string) =>
  s
    .toLowerCase()
    .normalize("NFKD")
    .replace(/[̀-ͯ]/g, "")
    .replace(/[^a-z0-9]+/g, "_")
    .replace(/^_+|_+$/g, "");

/**
 * Canonical symbol form used inside instrument ids and for alias matching.
 * "BRK.B", "BRK-B", "BRK/B", "BRK B" → "brk_b".
 */
export function canonicalSymbol(symbol: string): string {
  return slug(symbol.trim());
}

/** Deterministic stable ids; never database sequences. */
export function makeInstrumentId(assetClass: AssetClass, hint: { symbol: string } & Partial<InstrumentHint>): string {
  const sym = canonicalSymbol(hint.symbol);
  switch (assetClass) {
    case "CRYPTO":
      return `crypto_${slug(hint.base ?? sym)}_${slug(hint.quote ?? "usd")}`;
    case "FOREX":
      return `fx_${slug(hint.base ?? sym.slice(0, 3))}_${slug(hint.quote ?? sym.slice(3, 6))}`;
    case "INDEX":
      return `index_${slug(hint.country ?? "xx")}_${sym.replace(/^[_^.]+/, "")}`;
    case "TREASURY":
    case "INTEREST_RATE":
    case "BOND":
      return `rate_${slug(hint.country ?? "xx")}_${sym}`;
    case "COMMODITY":
    case "FUTURE":
      return `${assetClass === "FUTURE" ? "fut" : "cmd"}_${slug(hint.exchangeId ?? "xx")}_${sym}`;
    case "ETF":
    case "ETN":
    case "REIT":
    case "ADR":
    case "GDR":
    case "EQUITY":
    default: {
      const prefix =
        assetClass === "ETF" || assetClass === "ETN"
          ? "etf"
          : assetClass === "MUTUAL_FUND"
            ? "fund"
            : assetClass === "OPTION"
              ? "opt"
              : "eq";
      const venue = slug(hint.mic ?? hint.exchangeId ?? "xxxx");
      return `${prefix}_${slug(hint.country ?? "xx")}_${venue}_${sym}`;
    }
  }
}

export function makeCompanyId(name: string): string {
  return slug(name).replace(/_/g, "-").slice(0, 80);
}

export function makeEventId(ts: number, fingerprint: string): string {
  return `evt_${ts.toString(36)}_${fingerprint.slice(0, 12)}`;
}

/** Split "BTC-USD" / "BTC/USD" / "BTCUSD" (6 letters) into base and quote. */
export function splitPair(symbol: string): { base: string; quote: string } | null {
  const m = symbol.toUpperCase().match(/^([A-Z0-9]{2,10})[-_/]([A-Z0-9]{2,6})$/);
  if (m) return { base: m[1]!, quote: m[2]!, };
  const compact = symbol.toUpperCase();
  if (/^[A-Z]{6}$/.test(compact)) return { base: compact.slice(0, 3), quote: compact.slice(3) };
  return null;
}