refactor(fc2c-i): sweep blueprints + ml tasks onto shared get_session (covers tasks/ml.py, a survey gap)

backend/app/api/aliases.py

@@ -2,27 +2,15 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..services.ml.aliases import AliasService
 
 aliases_bp = Blueprint("aliases", __name__, url_prefix="/api")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 @aliases_bp.route("/aliases", methods=["GET"])
 async def list_aliases():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         rows = await AliasService(session).list_all()
     return jsonify(
         [
@@ -43,8 +31,7 @@ async def create_alias():
     required = {"alias_string", "alias_category", "canonical_tag_id"}
     if not body or not required.issubset(body):
         return jsonify({"error": f"required: {sorted(required)}"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         await AliasService(session).create(
             body["alias_string"],
             body["alias_category"],
@@ -58,8 +45,7 @@ async def create_alias():
     "/aliases/<alias_string>/<alias_category>", methods=["DELETE"]
 )
 async def remove_alias(alias_string: str, alias_category: str):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         await AliasService(session).remove(alias_string, alias_category)
         await session.commit()
     return "", 204

backend/app/api/allowlist.py

@@ -2,28 +2,16 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import TagAllowlist
 from ..services.ml.allowlist import AllowlistService
 
 allowlist_bp = Blueprint("allowlist", __name__, url_prefix="/api")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 @allowlist_bp.route("/allowlist", methods=["GET"])
 async def list_allowlist():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         rows = await AllowlistService(session).list_all()
     return jsonify(
         [
@@ -40,8 +28,7 @@ async def list_allowlist():
 
 @allowlist_bp.route("/tags/<int:tag_id>/allowlist", methods=["GET"])
 async def get_one(tag_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         row = await session.get(TagAllowlist, tag_id)
     if row is None:
         return jsonify({"error": "not on allowlist"}), 404
@@ -58,8 +45,7 @@ async def patch_threshold(tag_id: int):
     mc = float(body["min_confidence"])
     if not (0 < mc <= 1):
         return jsonify({"error": "min_confidence must be in (0, 1]"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         await AllowlistService(session).update_threshold(tag_id, mc)
         await session.commit()
     return "", 204
@@ -67,8 +53,7 @@ async def patch_threshold(tag_id: int):
 
 @allowlist_bp.route("/tags/<int:tag_id>/allowlist", methods=["DELETE"])
 async def remove(tag_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         await AllowlistService(session).remove(tag_id)
         await session.commit()
     return "", 204

backend/app/api/gallery.py

@@ -2,22 +2,11 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..services.gallery_service import GalleryService
 
 gallery_bp = Blueprint("gallery", __name__, url_prefix="/api/gallery")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 @gallery_bp.route("/scroll", methods=["GET"])
 async def scroll():
@@ -29,8 +18,7 @@ async def scroll():
     tag_id_raw = request.args.get("tag_id")
     tag_id = int(tag_id_raw) if tag_id_raw else None
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = GalleryService(session)
         try:
             page = await svc.scroll(cursor=cursor, limit=limit, tag_id=tag_id)
@@ -63,8 +51,7 @@ async def scroll():
 async def timeline():
     tag_id_raw = request.args.get("tag_id")
     tag_id = int(tag_id_raw) if tag_id_raw else None
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = GalleryService(session)
         buckets = await svc.timeline(tag_id=tag_id)
     return jsonify([{"year": b.year, "month": b.month, "count": b.count} for b in buckets])
@@ -79,8 +66,7 @@ async def jump():
         return jsonify({"error": "year and month query params required"}), 400
     tag_id_raw = request.args.get("tag_id")
     tag_id = int(tag_id_raw) if tag_id_raw else None
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = GalleryService(session)
         cursor = await svc.jump_cursor(year=year, month=month, tag_id=tag_id)
     return jsonify({"cursor": cursor})
@@ -88,8 +74,7 @@ async def jump():
 
 @gallery_bp.route("/image/<int:image_id>", methods=["GET"])
 async def image_detail(image_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = GalleryService(session)
         payload = await svc.get_image_with_tags(image_id)
     if payload is None:

backend/app/api/import_admin.py

@@ -5,22 +5,11 @@ from datetime import UTC, datetime, timedelta
 from quart import Blueprint, jsonify, request
 from sqlalchemy import delete, select, update
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import ImportBatch, ImportTask
 
 import_admin_bp = Blueprint("import_admin", __name__, url_prefix="/api/import")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 @import_admin_bp.route("/trigger", methods=["POST"])
 async def trigger_scan():
@@ -39,8 +28,7 @@ async def trigger_scan():
 
 @import_admin_bp.route("/status", methods=["GET"])
 async def status():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         active = (
             await session.execute(
                 select(ImportBatch)
@@ -72,8 +60,7 @@ async def list_tasks():
     cursor_raw = request.args.get("cursor")
     cursor_id = int(cursor_raw) if cursor_raw else None
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         stmt = select(ImportTask).order_by(ImportTask.created_at.desc(), ImportTask.id.desc())
         if status_filter:
             stmt = stmt.where(ImportTask.status == status_filter)
@@ -107,8 +94,7 @@ async def list_tasks():
 
 @import_admin_bp.route("/retry-failed", methods=["POST"])
 async def retry_failed():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         failed_ids = (
             await session.execute(select(ImportTask.id).where(ImportTask.status == "failed"))
         ).scalars().all()
@@ -140,8 +126,7 @@ async def clear_completed():
         datetime.now(UTC) - timedelta(days=int(age_days)) if age_days else None
     )
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         stmt = delete(ImportTask).where(ImportTask.status.in_(status_filter))
         if cutoff is not None:
             stmt = stmt.where(ImportTask.finished_at < cutoff)

backend/app/api/ml_admin.py

@@ -2,22 +2,11 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import MLSettings
 
 ml_admin_bp = Blueprint("ml_admin", __name__, url_prefix="/api/ml")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 _EDITABLE = (
     "suggestion_threshold_artist",
@@ -33,8 +22,7 @@ _EDITABLE = (
 async def get_settings():
     from sqlalchemy import select
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         s = (
             await session.execute(select(MLSettings).where(MLSettings.id == 1))
         ).scalar_one()
@@ -59,8 +47,7 @@ async def patch_settings():
     body = await request.get_json()
     if not isinstance(body, dict):
         return jsonify({"error": "body must be an object"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         s = (
             await session.execute(select(MLSettings).where(MLSettings.id == 1))
         ).scalar_one()

backend/app/api/settings.py

@@ -3,22 +3,11 @@
 from quart import Blueprint, jsonify, request
 from sqlalchemy import func, select
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import ImageRecord, ImportBatch, ImportSettings, ImportTask, Tag
 
 settings_bp = Blueprint("settings", __name__, url_prefix="/api")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 _EDITABLE_FIELDS = (
     "min_width",
@@ -33,8 +22,7 @@ _EDITABLE_FIELDS = (
 
 @settings_bp.route("/settings/import", methods=["GET"])
 async def get_import_settings():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         row = (
             await session.execute(select(ImportSettings).where(ImportSettings.id == 1))
         ).scalar_one()
@@ -55,8 +43,7 @@ async def update_import_settings():
     if not isinstance(body, dict):
         return jsonify({"error": "body must be a JSON object"}), 400
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         row = (
             await session.execute(select(ImportSettings).where(ImportSettings.id == 1))
         ).scalar_one()
@@ -70,8 +57,7 @@ async def update_import_settings():
 
 @settings_bp.route("/system/stats", methods=["GET"])
 async def system_stats():
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         total_images = (await session.execute(select(func.count(ImageRecord.id)))).scalar_one()
         total_tags = (await session.execute(select(func.count(Tag.id)))).scalar_one()
         storage_bytes = (

backend/app/api/suggestions.py

@@ -2,28 +2,16 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..services.ml.allowlist import AllowlistService
 from ..services.ml.suggestions import SuggestionService
 
 suggestions_bp = Blueprint("suggestions", __name__, url_prefix="/api")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 @suggestions_bp.route("/images/<int:image_id>/suggestions", methods=["GET"])
 async def get_suggestions(image_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         sl = await SuggestionService(session).for_image(image_id)
     return jsonify(
         {
@@ -53,8 +41,7 @@ async def accept_suggestion(image_id: int):
     if not body or "tag_id" not in body:
         return jsonify({"error": "tag_id required"}), 400
     tag_id = body["tag_id"]
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         newly_added = await AllowlistService(session).accept(image_id, tag_id)
         await session.commit()
     if newly_added:
@@ -72,8 +59,7 @@ async def alias_suggestion(image_id: int):
     required = {"alias_string", "alias_category", "canonical_tag_id"}
     if not body or not required.issubset(body):
         return jsonify({"error": f"required: {sorted(required)}"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         newly_added = await AllowlistService(session).add_alias_and_accept(
             image_id,
             body["alias_string"],
@@ -95,8 +81,7 @@ async def dismiss_suggestion(image_id: int):
     body = await request.get_json()
     if not body or "tag_id" not in body:
         return jsonify({"error": "tag_id required"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         await AllowlistService(session).dismiss(image_id, body["tag_id"])
         await session.commit()
     return "", 204

backend/app/api/tags.py

@@ -2,23 +2,12 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import TagKind
 from ..services.tag_service import TagService, TagValidationError
 
 tags_bp = Blueprint("tags", __name__, url_prefix="/api")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 def _coerce_kind(raw: str | None) -> TagKind | None:
     if raw is None:
@@ -38,8 +27,7 @@ async def autocomplete():
     except ValueError:
         return jsonify({"error": "limit must be an integer"}), 400
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         hits = await svc.autocomplete(q, kind=kind, limit=limit)
 
@@ -69,8 +57,7 @@ async def create_tag():
         return jsonify({"error": f"invalid kind {body['kind']!r}"}), 400
     fandom_id = body.get("fandom_id")
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         try:
             tag = await svc.find_or_create(name, kind, fandom_id=fandom_id)
@@ -84,8 +71,7 @@ async def create_tag():
 
 @tags_bp.route("/images/<int:image_id>/tags", methods=["GET"])
 async def list_tags_for_image(image_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         tags = await svc.list_for_image(image_id)
     return jsonify(
@@ -108,8 +94,7 @@ async def add_tag_to_image(image_id: int):
         return jsonify({"error": "tag_id required"}), 400
     source = body.get("source", "manual")
 
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         await svc.add_to_image(image_id, body["tag_id"], source=source)
         await session.commit()
@@ -118,8 +103,7 @@ async def add_tag_to_image(image_id: int):
 
 @tags_bp.route("/images/<int:image_id>/tags/<int:tag_id>", methods=["DELETE"])
 async def remove_tag_from_image(image_id: int, tag_id: int):
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         await svc.remove_from_image(image_id, tag_id)
         await session.commit()
@@ -131,8 +115,7 @@ async def rename_tag(tag_id: int):
     body = await request.get_json()
     if not body or "name" not in body:
         return jsonify({"error": "name required"}), 400
-    Session = _session_factory()
+    async with get_session() as session:
-    async with Session() as session:
         svc = TagService(session)
         try:
             tag = await svc.rename(tag_id, body["name"])

backend/app/tasks/ml.py

@@ -305,13 +305,11 @@ def _confidence_for_tag(session, tag, preds: dict) -> float | None:
 def recompute_centroid(self, tag_id: int) -> bool:
     import asyncio
 
-    from ..extensions import make_engine, make_session_factory
+    from ..extensions import get_session
     from ..services.ml.centroids import CentroidService
 
     async def _run() -> bool:
-        engine = make_engine()
+        async with get_session() as session:
-        Session = make_session_factory(engine)
-        async with Session() as session:
             svc = CentroidService(session)
             result = await svc.recompute_for_tag(tag_id)
             await session.commit()
@@ -325,13 +323,11 @@ def recompute_centroids(self) -> int:
     """Daily: find drifted centroids, enqueue recompute_centroid for each."""
     import asyncio
 
-    from ..extensions import make_engine, make_session_factory
+    from ..extensions import get_session
     from ..services.ml.centroids import CentroidService
 
     async def _list() -> list[int]:
-        engine = make_engine()
+        async with get_session() as session:
-        Session = make_session_factory(engine)
-        async with Session() as session:
             return await CentroidService(session).list_drifted()
 
     drifted = asyncio.run(_list())