Harden request cache titles and cache-only reads

backend/app/db.py

@@ -24,6 +24,58 @@ def _connect() -> sqlite3.Connection:
     return sqlite3.connect(_db_path())
 
 
+def _normalize_title_value(title: Optional[str]) -> Optional[str]:
+    if not isinstance(title, str):
+        return None
+    trimmed = title.strip()
+    return trimmed if trimmed else None
+
+
+def _normalize_year_value(year: Optional[Any]) -> Optional[int]:
+    if isinstance(year, int):
+        return year
+    if isinstance(year, str):
+        trimmed = year.strip()
+        if trimmed.isdigit():
+            return int(trimmed)
+    return None
+
+
+def _is_placeholder_title(title: Optional[str], request_id: Optional[int]) -> bool:
+    if not isinstance(title, str):
+        return True
+    normalized = title.strip().lower()
+    if not normalized:
+        return True
+    if normalized == "untitled":
+        return True
+    if request_id and normalized == f"request {request_id}":
+        return True
+    return False
+
+
+def _extract_title_year_from_payload(payload_json: Optional[str]) -> tuple[Optional[str], Optional[int]]:
+    if not payload_json:
+        return None, None
+    try:
+        payload = json.loads(payload_json)
+    except json.JSONDecodeError:
+        return None, None
+    if not isinstance(payload, dict):
+        return None, None
+    media = payload.get("media") or {}
+    title = None
+    year = None
+    if isinstance(media, dict):
+        title = media.get("title") or media.get("name")
+        year = media.get("year")
+    if not title:
+        title = payload.get("title") or payload.get("name")
+    if year is None:
+        year = payload.get("year")
+    return _normalize_title_value(title), _normalize_year_value(year)
+
+
 def init_db() -> None:
     with _connect() as conn:
         conn.execute(
@@ -603,7 +655,34 @@ def upsert_request_cache(
     updated_at: Optional[str],
     payload_json: str,
 ) -> None:
+    normalized_title = _normalize_title_value(title)
+    normalized_year = _normalize_year_value(year)
+    derived_title = None
+    derived_year = None
+    if not normalized_title or normalized_year is None:
+        derived_title, derived_year = _extract_title_year_from_payload(payload_json)
+    if _is_placeholder_title(normalized_title, request_id):
+        normalized_title = None
+    if derived_title and not normalized_title:
+        normalized_title = derived_title
+    if normalized_year is None and derived_year is not None:
+        normalized_year = derived_year
     with _connect() as conn:
+        existing_title = None
+        existing_year = None
+        if normalized_title is None or normalized_year is None:
+            row = conn.execute(
+                "SELECT title, year FROM requests_cache WHERE request_id = ?",
+                (request_id,),
+            ).fetchone()
+            if row:
+                existing_title, existing_year = row[0], row[1]
+                if _is_placeholder_title(existing_title, request_id):
+                    existing_title = None
+        if normalized_title is None and existing_title:
+            normalized_title = existing_title
+        if normalized_year is None and existing_year is not None:
+            normalized_year = existing_year
         conn.execute(
             """
             INSERT INTO requests_cache (
@@ -637,8 +716,8 @@ def upsert_request_cache(
                 media_id,
                 media_type,
                 status,
-                title,
-                year,
+                normalized_title,
+                normalized_year,
                 requested_by,
                 requested_by_norm,
                 created_at,
@@ -741,22 +820,11 @@ def get_cached_requests(
         title = row[4]
         year = row[5]
         if (not title or not year) and row[8]:
-            try:
-                payload = json.loads(row[8])
-                if isinstance(payload, dict):
-                    media = payload.get("media") or {}
-                    if not title:
-                        title = (
-                            (media.get("title") if isinstance(media, dict) else None)
-                            or (media.get("name") if isinstance(media, dict) else None)
-                            or payload.get("title")
-                            or payload.get("name")
-                        )
-                    if not year:
-                        year = media.get("year") if isinstance(media, dict) else None
-                        year = year or payload.get("year")
-            except json.JSONDecodeError:
-                pass
+            derived_title, derived_year = _extract_title_year_from_payload(row[8])
+            if not title:
+                title = derived_title
+            if not year:
+                year = derived_year
         results.append(
             {
                 "request_id": row[0],
@@ -788,18 +856,8 @@ def get_request_cache_overview(limit: int = 50) -> list[Dict[str, Any]]:
     for row in rows:
         title = row[4]
         if not title and row[9]:
-            try:
-                payload = json.loads(row[9])
-                if isinstance(payload, dict):
-                    media = payload.get("media") or {}
-                    title = (
-                        (media.get("title") if isinstance(media, dict) else None)
-                        or (media.get("name") if isinstance(media, dict) else None)
-                        or payload.get("title")
-                        or payload.get("name")
-                    )
-            except json.JSONDecodeError:
-                title = row[4]
+            derived_title, _ = _extract_title_year_from_payload(row[9])
+            title = derived_title or row[4]
         results.append(
             {
                 "request_id": row[0],
@@ -825,7 +883,9 @@ def get_request_cache_count() -> int:
 def update_request_cache_title(
     request_id: int, title: str, year: Optional[int] = None
 ) -> None:
-    if not title:
+    normalized_title = _normalize_title_value(title)
+    normalized_year = _normalize_year_value(year)
+    if not normalized_title:
         return
     with _connect() as conn:
         conn.execute(
@@ -834,10 +894,38 @@ def update_request_cache_title(
             SET title = ?, year = COALESCE(?, year)
             WHERE request_id = ?
             """,
-            (title, year, request_id),
+            (normalized_title, normalized_year, request_id),
         )
 
 
+def repair_request_cache_titles() -> int:
+    updated = 0
+    with _connect() as conn:
+        rows = conn.execute(
+            """
+            SELECT request_id, title, year, payload_json
+            FROM requests_cache
+            """
+        ).fetchall()
+        for row in rows:
+            request_id, title, year, payload_json = row
+            if not _is_placeholder_title(title, request_id):
+                continue
+            derived_title, derived_year = _extract_title_year_from_payload(payload_json)
+            if not derived_title:
+                continue
+            conn.execute(
+                """
+                UPDATE requests_cache
+                SET title = ?, year = COALESCE(?, year)
+                WHERE request_id = ?
+                """,
+                (derived_title, derived_year, request_id),
+            )
+            updated += 1
+    return updated
+
+
 def prune_duplicate_requests_cache() -> int:
     with _connect() as conn:
         cursor = conn.execute(