M8-T15: add thermal meter cost engine

app/main.py

@@ -2,6 +2,7 @@ import logging
 import os
 from contextlib import asynccontextmanager
 from pathlib import Path
+from typing import Callable
 
 from fastapi import FastAPI, HTTPException, Request
 from fastapi.responses import FileResponse
@@ -38,6 +39,7 @@ from app.services.modbus_poll import poll_all_enabled_devices, BASE_POLL_TICK_SE
 from app.services.ha_discovery import publish_discovery, publish_states
 from app.services.tibber_prices import refresh_prices
 from app.services.energy_cost import compute_closed_periods
+from app.services.meter_cost import compute_closed_periods as compute_closed_meter_cost_periods
 from app.services.warmtelink_worker import warmtelink_worker_manager
 from app.services.timezone import local_tz
 from scripts.app_db_adopt import AppDatabaseAdoptionError, validate_app_runtime_db
@@ -112,22 +114,44 @@ def _run_scheduled_energy_cost() -> None:
     does not crash the scheduler or affect the other background jobs.
     """
     session_local = get_session_local()
-    session: Session = session_local()
-    try:
-        compute_closed_periods(session)
-        # After billing periods are computed, push fresh energy-cost state values
-        # to MQTT/HA.  publish_states is internally guarded by _should_publish
-        # (MQTT disabled / not connected → no-op), so this never raises due to
-        # unconfigured MQTT and does not block the billing job.
+
+    def run_scope(label: str, operation: Callable[[Session], None]) -> None:
+        """Run one best-effort scope in an isolated transaction/session."""
+        session: Session | None = None
         try:
-            from app.services.ha_discovery import publish_states
-            publish_states(session)
+            session = session_local()
+            operation(session)
         except Exception:
-            logger.exception("_run_scheduled_energy_cost: publish_states failed (non-fatal)")
-    except Exception:
-        logger.exception("_run_scheduled_energy_cost: unexpected error")
-    finally:
-        session.close()
+            logger.exception("_run_scheduled_energy_cost: %s failed", label)
+            if session is not None:
+                try:
+                    session.rollback()
+                except Exception:
+                    # A failed cleanup must not replace the operation/factory
+                    # error or prevent the following independent scope.
+                    logger.exception("_run_scheduled_energy_cost: %s rollback failed", label)
+        finally:
+            if session is not None:
+                try:
+                    session.close()
+                except Exception:
+                    # Sessions are intentionally isolated; close failures are
+                    # diagnostic only and must remain best-effort too.
+                    logger.exception("_run_scheduled_energy_cost: %s close failed", label)
+
+    # Electricity, thermal and HA publishing must not share failed transaction
+    # state or accidentally commit each other's partially-flushed changes.
+    run_scope("electricity computation", compute_closed_periods)
+    run_scope("thermal computation", compute_closed_meter_cost_periods)
+
+    def publish(session: Session) -> None:
+        # publish_states is internally guarded by _should_publish (MQTT
+        # disabled / disconnected -> no-op), but gets a clean Session anyway.
+        from app.services.ha_discovery import publish_states
+
+        publish_states(session)
+
+    run_scope("publish_states (non-fatal)", publish)
 
 
 def _run_scheduled_ha_state_publish() -> None: