Add offline clip caching

backend/app/routes/games.py

@@ -3,11 +3,13 @@ from __future__ import annotations
 from datetime import datetime, timezone
 
 from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi import Request, Response
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
 from ..auth import require_session
 from ..database import get_db
+from ..http_cache import build_etag, is_matching_etag, set_private_revalidate
 from ..models import AudioClip, GameAssignment, UserSession
 from ..schemas import (
     GameAssignmentCreate,
@@ -37,8 +39,20 @@ def assignment_to_response(assignment: GameAssignment) -> GameAssignmentResponse
     )
 
 
+def prepare_conditional_response(
+    request: Request,
+    payload: object,
+    *,
+    exclude_keys: set[str] | None = None,
+) -> tuple[str, bool]:
+    etag = build_etag(payload, exclude_keys=exclude_keys)
+    return etag, is_matching_etag(request, etag)
+
+
 @router.get("/pins", response_model=list[GameAssignmentResponse])
 def list_pins(
+    request: Request,
+    response: Response,
     external_player_id: str | None = Query(default=None),
     session: UserSession = Depends(require_session),
     db: Session = Depends(get_db),
@@ -52,11 +66,18 @@ def list_pins(
         GameAssignment.external_player_id == player_id,
     )
     pins = db.scalars(query.order_by(GameAssignment.external_game_id.asc(), AudioClip.sort_order.asc())).all()
-    return [assignment_to_response(assignment) for assignment in pins]
+    payload = [assignment_to_response(assignment) for assignment in pins]
+    etag, not_modified = prepare_conditional_response(request, payload)
+    set_private_revalidate(response, etag=etag)
+    if not_modified:
+        return Response(status_code=304, headers=dict(response.headers))
+    return payload
 
 
 @router.get("/{external_game_id}/assignments", response_model=list[GameAssignmentResponse])
 def list_assignments(
+    request: Request,
+    response: Response,
     external_game_id: str,
     external_player_id: str | None = Query(default=None),
     _: UserSession = Depends(require_session),
@@ -69,7 +90,12 @@ def list_assignments(
     if external_player_id:
         query = query.where(GameAssignment.external_player_id == external_player_id)
     assignments = db.scalars(query.order_by(AudioClip.sort_order.asc(), GameAssignment.updated_at.desc())).all()
-    return [assignment_to_response(assignment) for assignment in assignments]
+    payload = [assignment_to_response(assignment) for assignment in assignments]
+    etag, not_modified = prepare_conditional_response(request, payload)
+    set_private_revalidate(response, etag=etag)
+    if not_modified:
+        return Response(status_code=304, headers=dict(response.headers))
+    return payload
 
 
 @router.post("/{external_game_id}/assignments", response_model=GameAssignmentResponse)
@@ -136,6 +162,8 @@ def delete_assignment(
 
 @router.get("/{external_game_id}/prep", response_model=GamePrepResponse)
 def prepare_game(
+    request: Request,
+    response: Response,
     external_game_id: str,
     _: UserSession = Depends(require_session),
     db: Session = Depends(get_db),
@@ -147,9 +175,14 @@ def prepare_game(
         .order_by(AudioClip.sort_order.asc(), GameAssignment.updated_at.desc())
     ).all()
     external_team_id = assignments[0].external_team_id if assignments else ""
-    return GamePrepResponse(
+    payload = GamePrepResponse(
         external_game_id=external_game_id,
         external_team_id=external_team_id,
         prepared_at=datetime.now(timezone.utc),
         assignments=[assignment_to_response(assignment) for assignment in assignments],
     )
+    etag, not_modified = prepare_conditional_response(request, payload, exclude_keys={"prepared_at"})
+    set_private_revalidate(response, etag=etag)
+    if not_modified:
+        return Response(status_code=304, headers=dict(response.headers))
+    return payload