Worker di visione per stazione: modello, API, migrazione 019, execute_task (#45)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NABedeMX43pyXZbDNUgA5B

src/backend/services/vision_service.py

@@ -19,6 +19,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from src.backend.config import settings
 from src.backend.models.orm.measurement import Measurement
 from src.backend.models.orm.recipe import RecipeVersion
+from src.backend.models.orm.station import Station
 from src.backend.models.orm.task import RecipeSubtask, RecipeTask
 from src.backend.models.orm.vision import VisionReferenceImage, VisionResult
 from src.backend.services import measurement_service
@@ -53,6 +54,7 @@ async def _call_worker(
     *,
     recipe_dir: str | None = None,
     calibration: dict | None = None,
+    worker_url: str | None = None,
 ) -> dict:
     """The one place that talks to the worker; the tests replace it.
 
@@ -70,6 +72,8 @@ async def _call_worker(
     # recipe_dir (relativo, #46) e calibration sono opzionali: se assenti non
     # si mandano, il worker usa i suoi default.
     data = {"graph": json.dumps(graph)}
+    # worker della stazione (#45) o, se manca, il centrale; mai un ripiego dall'uno all'altro
+    base = (worker_url or settings.vision_worker_url).rstrip("/")
     if recipe_dir:
         data["recipe_dir"] = recipe_dir
     if calibration:
@@ -77,19 +81,19 @@ async def _call_worker(
     try:
         async with httpx.AsyncClient(timeout=120.0) as client:
             response = await client.post(
-                f"{settings.vision_worker_url}/run",
+                f"{base}/run",
                 files={"image": ("frame.png", image_bytes, "image/png")},
                 data=data,
             )
     except httpx.TimeoutException as exc:
         raise HTTPException(
             status_code=status.HTTP_504_GATEWAY_TIMEOUT,
-            detail=f"the vision worker did not answer in time: {exc}",
+            detail=f"the vision worker did not answer in time: {exc} ({base})",  # #45
         ) from exc
     except (httpx.TransportError, httpx.HTTPError) as exc:
         raise HTTPException(
             status_code=status.HTTP_502_BAD_GATEWAY,
-            detail=f"the vision worker is unreachable: {exc}",
+            detail=f"the vision worker is unreachable: {exc} ({base})",  # #45
         ) from exc
 
     # The worker already gave this fault a name - forward its status and
@@ -352,12 +356,20 @@ async def execute_task(
             detail="this recipe is not active",
         )
 
+    run = None
     if production_run_id is not None:
         # 404 if the run does not exist, 422 if it belongs to another recipe,
         # 409 if it is closed or paused - same rule a manual reading follows.
-        await measurement_service.validate_run_for_version(
+        run = await measurement_service.validate_run_for_version(
             db, production_run_id, version_id,
         )
+    # Worker della stazione della sessione di produzione (#45); senza run o senza URL: centrale
+    station_url = None
+    if run is not None:
+        station = (await db.execute(
+            select(Station).where(Station.id == run.station_id)
+        )).scalar_one_or_none()
+        station_url = (station.vision_worker_url or None) if station is not None else None
 
     if not task.vision_json:
         raise HTTPException(
@@ -411,6 +423,7 @@ async def execute_task(
     # passa `calibration`, la ricetta porta la sua (#46).
     report = await _call_worker(
         image_bytes, task.vision_json, recipe_dir=task.vision_recipe_dir,
+        worker_url=station_url,  # #45
     )
     outputs = report["outputs"]
 
@@ -439,7 +452,10 @@ async def execute_task(
         image_path=image_path,
         overlay_path=overlay_path,
         engine_version=report["engine_version"],
-        executed_on="server",
+        # #45: dove e' girato davvero, e quale worker (copiato come lo snapshot)
+        executed_on="station" if station_url else "server",
+        station_id=run.station_id if run is not None else None,
+        worker_url=(station_url or settings.vision_worker_url).rstrip("/"),
         graph_snapshot=task.vision_json,
         duration_ms=report.get("duration_ms"),
     )