feat(backend): service cache Redis pour identifications

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/services/meteo.py

@@ -0,0 +1,127 @@
+"""Client Open-Meteo (gratuit, sans clé API)."""
+import json
+import os
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any
+
+import httpx
+
+CACHE_PATH = Path(os.environ.get("UPLOAD_DIR", "/data")).parent / "meteo_cache.json"
+CACHE_TTL_SECONDS = 3 * 3600  # 3h
+
+WMO_LABELS = {
+    0: "Ensoleillé",
+    1: "Principalement ensoleillé",
+    2: "Partiellement nuageux",
+    3: "Couvert",
+    45: "Brouillard",
+    48: "Brouillard givrant",
+    51: "Bruine légère",
+    53: "Bruine modérée",
+    55: "Bruine dense",
+    61: "Pluie légère",
+    63: "Pluie modérée",
+    65: "Pluie forte",
+    71: "Neige légère",
+    73: "Neige modérée",
+    75: "Neige forte",
+    80: "Averses légères",
+    81: "Averses modérées",
+    82: "Averses violentes",
+    85: "Averses de neige",
+    95: "Orage",
+    96: "Orage avec grêle",
+    99: "Orage violent",
+}
+WMO_ICONS = {
+    0: "☀️",
+    1: "🌤",
+    2: "⛅",
+    3: "☁️",
+    45: "🌫",
+    48: "🌫",
+    51: "🌦",
+    53: "🌦",
+    55: "🌧",
+    61: "🌦",
+    63: "🌧",
+    65: "🌧",
+    71: "🌨",
+    73: "🌨",
+    75: "❄️",
+    80: "🌦",
+    81: "🌧",
+    82: "⛈",
+    85: "🌨",
+    95: "⛈",
+    96: "⛈",
+    99: "⛈",
+}
+
+
+def _cache_fresh() -> dict | None:
+    if not CACHE_PATH.exists():
+        return None
+    try:
+        data = json.loads(CACHE_PATH.read_text())
+        cached_at = datetime.fromisoformat(
+            data.get("cached_at", "2000-01-01T00:00:00+00:00")
+        )
+        if (datetime.now(timezone.utc) - cached_at).total_seconds() < CACHE_TTL_SECONDS:
+            return data
+    except Exception:
+        pass
+    return None
+
+
+def fetch_forecast(
+    lat: float = 45.14, lon: float = 4.12, days: int = 14
+) -> dict[str, Any]:
+    cached = _cache_fresh()
+    if cached:
+        return cached
+
+    url = "https://api.open-meteo.com/v1/forecast"
+    params = {
+        "latitude": lat,
+        "longitude": lon,
+        "daily": "temperature_2m_max,temperature_2m_min,precipitation_sum,windspeed_10m_max,weathercode",
+        "timezone": "Europe/Paris",
+        "forecast_days": min(days, 16),
+    }
+    try:
+        r = httpx.get(url, params=params, timeout=10)
+        r.raise_for_status()
+        raw = r.json()
+    except Exception as e:
+        return {"error": str(e), "days": []}
+
+    daily = raw.get("daily", {})
+    dates = daily.get("time", [])
+    result_days = []
+    for i, d in enumerate(dates):
+        code = int(daily.get("weathercode", [0] * len(dates))[i] or 0)
+        result_days.append(
+            {
+                "date": d,
+                "t_max": daily.get("temperature_2m_max", [None] * len(dates))[i],
+                "t_min": daily.get("temperature_2m_min", [None] * len(dates))[i],
+                "pluie_mm": daily.get("precipitation_sum", [0] * len(dates))[i] or 0,
+                "vent_kmh": daily.get("windspeed_10m_max", [0] * len(dates))[i] or 0,
+                "code": code,
+                "label": WMO_LABELS.get(code, "Inconnu"),
+                "icone": WMO_ICONS.get(code, "🌡"),
+            }
+        )
+
+    data = {
+        "cached_at": datetime.now(timezone.utc).isoformat(),
+        "days": result_days,
+    }
+    try:
+        CACHE_PATH.parent.mkdir(parents=True, exist_ok=True)
+        CACHE_PATH.write_text(json.dumps(data, ensure_ascii=False))
+    except Exception:
+        pass
+    return data