feat: initial implementation — Arte Concert web GUI

FastAPI backend + HTML/JS frontend pour parcourir et télécharger les
concerts Arte Concert. Cache 6h, recherche live, historique SQLite,
suivi de progression SSE, design sombre Playfair Display + Inter.

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

arte_api.py

@@ -0,0 +1,119 @@
+import asyncio
+import logging
+import time
+import yt_dlp
+
+logger = logging.getLogger(__name__)
+
+CACHE_TTL = 6 * 3600
+_cache: dict = {"data": [], "ts": 0}
+
+ARTE_CONCERT_URL = "https://www.arte.tv/fr/videos/RC-014034/arte-concert/"
+
+
+def _best_thumbnail(entry: dict) -> str:
+    thumbs = entry.get("thumbnails") or []
+    if thumbs:
+        # prefer largest
+        sorted_thumbs = sorted(thumbs, key=lambda t: t.get("width", 0), reverse=True)
+        return sorted_thumbs[0].get("url", "")
+    return entry.get("thumbnail", "")
+
+
+def _normalize(e: dict) -> dict | None:
+    if not e or not e.get("id"):
+        return None
+    video_id = e.get("id", "")
+    url = (
+        e.get("url")
+        or e.get("webpage_url")
+        or f"https://www.arte.tv/fr/videos/{video_id}/"
+    )
+    return {
+        "id": video_id,
+        "title": e.get("title", ""),
+        "url": url,
+        "thumbnail": _best_thumbnail(e),
+        "duration": e.get("duration"),
+        "description": e.get("description", ""),
+        "upload_date": e.get("upload_date", ""),
+        "release_timestamp": e.get("release_timestamp"),
+    }
+
+
+def _fetch_sync() -> list:
+    concerts: list = []
+    seen: set = set()
+
+    ydl_opts = {
+        "quiet": True,
+        "no_warnings": True,
+        "extract_flat": True,
+        "ignoreerrors": True,
+    }
+
+    def _collect(entries: list, ydl, depth: int = 0):
+        for e in entries or []:
+            if not e:
+                continue
+            etype = e.get("_type", "")
+            # sub-collection → recurse one level
+            if etype in ("playlist", "url_transparent") and depth < 1:
+                sub_url = e.get("url") or e.get("webpage_url")
+                if sub_url:
+                    try:
+                        info = ydl.extract_info(sub_url, download=False)
+                        if info:
+                            _collect(info.get("entries", []), ydl, depth + 1)
+                    except Exception as ex:
+                        logger.debug("sub-collection error: %s", ex)
+                continue
+            entry = _normalize(e)
+            if entry and entry["id"] not in seen:
+                seen.add(entry["id"])
+                concerts.append(entry)
+
+    with yt_dlp.YoutubeDL(ydl_opts) as ydl:
+        try:
+            info = ydl.extract_info(ARTE_CONCERT_URL, download=False)
+            if info:
+                _collect(info.get("entries", []), ydl)
+        except Exception as ex:
+            logger.error("fetch error: %s", ex)
+
+    return concerts
+
+
+async def get_all_concerts() -> list:
+    now = time.time()
+    if _cache["data"] and now - _cache["ts"] < CACHE_TTL:
+        return _cache["data"]
+    loop = asyncio.get_event_loop()
+    data = await loop.run_in_executor(None, _fetch_sync)
+    if data:
+        _cache["data"] = data
+        _cache["ts"] = now
+    return _cache["data"]
+
+
+async def fetch_concerts(page: int = 1, search: str = "", page_size: int = 24) -> dict:
+    all_c = await get_all_concerts()
+    filtered = all_c
+    if search:
+        q = search.lower()
+        filtered = [c for c in all_c if q in c["title"].lower() or q in c["description"].lower()]
+    start = (page - 1) * page_size
+    page_data = filtered[start : start + page_size]
+    return {
+        "concerts": page_data,
+        "total": len(filtered),
+        "page": page,
+        "page_size": page_size,
+        "pages": max(1, (len(filtered) + page_size - 1) // page_size),
+    }
+
+
+async def invalidate_cache() -> int:
+    _cache["ts"] = 0
+    data = await get_all_concerts()
+    return len(data)