Property-type override beats the lodged EPC 🟩

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/app/modelling/property_filters.py

@@ -12,6 +12,8 @@ from typing import Optional
 from pydantic import BaseModel, ConfigDict
 from sqlmodel import Session, col, select
 
+from infrastructure.postgres.epc_property_table import EpcPropertyModel
+from infrastructure.postgres.property_override_table import PropertyOverrideRow
 from infrastructure.postgres.property_table import PropertyRow
 
 
@@ -54,8 +56,53 @@ def resolve_filtered_property_ids(
     if filters.postcodes is not None:
         statement = statement.where(col(PropertyRow.postcode).in_(filters.postcodes))
     rows = session.exec(statement).all()
+    candidates = [row for row in rows if row.id is not None]
+
+    if filters.property_types is not None:
+        wanted = set(filters.property_types)
+        types = _resolved_property_types(
+            session, [row.id for row in candidates if row.id is not None]
+        )
+        candidates = [
+            row
+            for row in candidates
+            if row.id is not None and types.get(row.id) in wanted
+        ]
+
     return [
         FilteredProperty(property_id=row.id, postcode=row.postcode)
-        for row in rows
+        for row in candidates
         if row.id is not None
     ]
+
+
+def _resolved_property_types(
+    session: Session, property_ids: list[int]
+) -> dict[int, str]:
+    """Each property's effective property_type per the ADR-0056 precedence:
+    override (building_part 0) → lodged EPC."""
+    overrides = session.exec(
+        select(PropertyOverrideRow)
+        .where(col(PropertyOverrideRow.property_id).in_(property_ids))
+        .where(PropertyOverrideRow.building_part == 0)
+        .where(PropertyOverrideRow.override_component == "property_type")
+    ).all()
+    by_override = {o.property_id: o.override_value for o in overrides}
+
+    epcs = session.exec(
+        select(EpcPropertyModel)
+        .where(col(EpcPropertyModel.property_id).in_(property_ids))
+        .where(EpcPropertyModel.source == "lodged")
+    ).all()
+    by_lodged_epc = {
+        epc.property_id: epc.property_type
+        for epc in epcs
+        if epc.property_id is not None and epc.property_type is not None
+    }
+
+    resolved: dict[int, str] = {}
+    for pid in property_ids:
+        value = by_override.get(pid) or by_lodged_epc.get(pid)
+        if value is not None:
+            resolved[pid] = value
+    return resolved