Method fetchFiatRates

rate/rate.ts:286–321

(base: string)

    const cached = this.fiatRatesCache[key];
    if (cached && now - cached.ts < 5 * 60 * 1000) return cached.rates;
    const endpoints = [
      `https://api.exchangerate.host/latest?base=${encodeURIComponent(key)}`,
      `https://open.er-api.com/v6/latest/${encodeURIComponent(key)}`,
      `https://api.frankfurter.app/latest?from=${encodeURIComponent(key)}`,
      // Coinbase 公共汇率（含法币与加密货币）
      `https://api.coinbase.com/v2/exchange-rates?currency=${encodeURIComponent(key.toUpperCase())}`,
      // jsDelivr 镜像的每日更新静态汇率（无钥，稳定）
      `https://cdn.jsdelivr.net/gh/fawazahmed0/currency-api@1/latest/currencies/${encodeURIComponent(key.toLowerCase())}.json`
    ];
    for (const url of endpoints) {
      try {
        const { data } = await axios.get(url, { timeout: 8000 });
        let rates: Record<string, number> | null = null;
        // 标准结构与 open.er-api、frankfurter
        if (data?.rates) rates = data.rates;
        if (data?.result === 'success' && data?.rates) rates = data.rates;
        // Coinbase 结构: { data: { rates: { USD: "1", ... } } }
        if (!rates && data?.data?.rates) rates = data.data.rates;
        // Fawaz Ahmed currency API: { date: '...', usd: { eur: 0.93, ... } }
        if (!rates && typeof data === 'object' && data && data[key]) rates = data[key];
        if (rates) {
          const normalized = Object.fromEntries(
            Object.entries(rates).map(([k, v]) => [k.toLowerCase(), Number(v)])
          );
          this.fiatRatesCache[key] = { rates: normalized, ts: now };
          return normalized;
        }
      } catch {}
    }
    throw new Error('法币汇率服务不可用');
  }

  // 智能解析参数：抓取两种货币与数量（数量可在任意位置）
  private parseArgs(args: string[]): { base: string, quote: string, amount: number } {
    const tokens = (args || []).map(a => this.normalizeCode(a));
    let amount = 1;
    const curr: string[] = [];
    for (const t of tokens) {
      const n = parseFloat(t);