perf: persistance du cache concerts en SQLite (survit aux redémarrages)

Le cache en mémoire (6h TTL) est désormais sauvegardé dans concerts_cache.
Au redémarrage, si le cache SQLite est récent, aucune requête réseau n'est faite.
Le bouton Rafraîchir vide aussi le cache SQLite pour forcer un re-scrape.

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

arte_api.py

@@ -1,4 +1,5 @@
 import re
+import sqlite3
 import time
 import logging
 import asyncio
@@ -11,8 +12,51 @@ import tmdb as _tmdb
 logger = logging.getLogger(__name__)
 
 CACHE_TTL = 6 * 3600
+DB_PATH = "arte_dl.db"
 _cache: dict = {"data": [], "ts": 0}
 
+
+def _db():
+    conn = sqlite3.connect(DB_PATH)
+    conn.row_factory = sqlite3.Row
+    return conn
+
+
+def _init_concerts_cache_table():
+    with _db() as conn:
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS concerts_cache (
+                id      INTEGER PRIMARY KEY CHECK (id = 1),
+                data    TEXT NOT NULL,
+                ts      REAL NOT NULL
+            )
+        """)
+
+
+_init_concerts_cache_table()
+
+
+def _load_db_cache() -> tuple[list, float]:
+    try:
+        with _db() as conn:
+            row = conn.execute("SELECT data, ts FROM concerts_cache WHERE id=1").fetchone()
+        if row:
+            return json.loads(row["data"]), row["ts"]
+    except Exception:
+        pass
+    return [], 0.0
+
+
+def _save_db_cache(data: list, ts: float):
+    try:
+        with _db() as conn:
+            conn.execute(
+                "INSERT OR REPLACE INTO concerts_cache (id, data, ts) VALUES (1, ?, ?)",
+                (json.dumps(data), ts),
+            )
+    except Exception as e:
+        logger.warning("Failed to save concerts cache: %s", e)
+
 PLAYER_API = "https://api.arte.tv/api/player/v2/config/fr/{pid}"
 SEARCH_URL = "https://www.arte.tv/fr/search/?q={q}"
 
@@ -157,11 +201,21 @@ async def get_all_concerts() -> list[dict]:
     now = time.time()
     if _cache["data"] and now - _cache["ts"] < CACHE_TTL:
         return _cache["data"]
+
+    # Try SQLite cache before hitting the network
+    db_data, db_ts = _load_db_cache()
+    if db_data and now - db_ts < CACHE_TTL:
+        logger.info("Concerts cache loaded from DB (%d concerts)", len(db_data))
+        _cache["data"] = db_data
+        _cache["ts"] = db_ts
+        return _cache["data"]
+
     loop = asyncio.get_event_loop()
     data = await loop.run_in_executor(None, _fetch_all_sync)
     if data:
         _cache["data"] = data
         _cache["ts"] = now
+        _save_db_cache(data, now)
     return _cache["data"]
 
 
@@ -208,5 +262,10 @@ async def fetch_concerts(page: int = 1, search: str = "", page_size: int = 24, c
 
 async def invalidate_cache() -> int:
     _cache["ts"] = 0
+    try:
+        with _db() as conn:
+            conn.execute("DELETE FROM concerts_cache")
+    except Exception:
+        pass
     data = await get_all_concerts()
     return len(data)