feat: 开发采集、采集箱和商品编辑功能

server/services/fx.py

@@ -0,0 +1,58 @@
+"""汇率服务：CNY→RUB。数据源三级降级（FloatRates → 俄央行 → 兜底），服务端缓存。"""
+from __future__ import annotations
+
+import time
+
+import httpx
+
+_FALLBACK_RATE = 11.5
+_MIN, _MAX = 5.0, 25.0
+_CACHE_TTL = 3600  # 秒
+
+_cache: dict = {"rate": None, "source": "", "ts": 0.0}
+
+
+def _valid(rate: float) -> bool:
+    return _MIN <= rate <= _MAX
+
+
+async def _fetch_floatrates() -> float | None:
+    async with httpx.AsyncClient(timeout=10.0, follow_redirects=True) as client:
+        resp = await client.get("https://www.floatrates.com/daily/cny.json")
+        resp.raise_for_status()
+        rub = resp.json().get("rub", {})
+        rate = rub.get("rate")
+        return float(rate) if rate else None
+
+
+async def _fetch_cbr() -> float | None:
+    async with httpx.AsyncClient(timeout=10.0, follow_redirects=True) as client:
+        resp = await client.get("https://www.cbr-xml-daily.ru/daily_json.js")
+        resp.raise_for_status()
+        cny = resp.json().get("Valute", {}).get("CNY", {})
+        value = cny.get("Value")
+        return float(value) if value else None
+
+
+async def get_fx_rate() -> dict:
+    """返回 {rate, source, updated_at}。带 1 小时内存缓存。"""
+    now = time.time()
+    if _cache["rate"] and (now - _cache["ts"]) < _CACHE_TTL:
+        return dict(_cache)
+
+    rate = None
+    source = ""
+    for name, fn in (("floatrates", _fetch_floatrates), ("cbr", _fetch_cbr)):
+        try:
+            r = await fn()
+            if r is not None and _valid(r):
+                rate, source = r, name
+                break
+        except Exception:  # noqa: BLE001 - 数据源失败降级
+            continue
+
+    if rate is None:
+        rate, source = _FALLBACK_RATE, "fallback"
+
+    _cache.update({"rate": rate, "source": source, "ts": now})
+    return dict(_cache)