feat: add repair parts tracking

backend/app/components/repository.py

@@ -0,0 +1,143 @@
+"""PostgreSQL persistence for the minimal component registry."""
+
+from collections.abc import Callable, Iterator
+from contextlib import contextmanager
+from uuid import UUID
+
+import psycopg
+from psycopg.errors import UniqueViolation
+from psycopg.rows import dict_row
+
+from app.components.exceptions import DuplicateComponentAssetID
+from app.config import settings
+
+
+ConnectionFactory = Callable[[], psycopg.Connection]
+COMPONENT_ASSET_ID_CONSTRAINT = "uq_components_normalized_asset_id"
+
+
+def default_connection_factory() -> psycopg.Connection:
+    return psycopg.connect(
+        host=settings.postgres_host,
+        port=settings.postgres_port,
+        dbname=settings.postgres_db,
+        user=settings.postgres_user,
+        password=settings.postgres_password,
+        connect_timeout=5,
+    )
+
+
+class ComponentRepository:
+    """Persistence boundary for minimal component identity."""
+
+    def __init__(
+        self,
+        connection_factory: ConnectionFactory | None = None,
+        *,
+        connection: psycopg.Connection | None = None,
+    ):
+        self._connection_factory = connection_factory or default_connection_factory
+        self._connection = connection
+
+    @contextmanager
+    def transaction(self) -> Iterator["ComponentRepository"]:
+        if self._connection is not None:
+            yield self
+            return
+
+        connection = self._connection_factory()
+        repository = ComponentRepository(
+            self._connection_factory,
+            connection=connection,
+        )
+        try:
+            yield repository
+            connection.commit()
+        except UniqueViolation as exc:
+            connection.rollback()
+            if exc.diag.constraint_name == COMPONENT_ASSET_ID_CONSTRAINT:
+                raise DuplicateComponentAssetID("normalized Asset ID") from exc
+            raise
+        except Exception:
+            connection.rollback()
+            raise
+        finally:
+            connection.close()
+
+    @contextmanager
+    def _connection_scope(self) -> Iterator[psycopg.Connection]:
+        if self._connection is not None:
+            yield self._connection
+            return
+
+        connection = self._connection_factory()
+        try:
+            yield connection
+        finally:
+            connection.close()
+
+    def create_component(
+        self,
+        *,
+        component_type: str,
+        asset_id: str | None,
+        manufacturer: str | None,
+        model: str | None,
+        manufacturer_serial: str | None,
+        created_by: UUID,
+    ) -> dict:
+        with self._connection_scope() as connection:
+            with connection.cursor(row_factory=dict_row) as cur:
+                cur.execute(
+                    """
+                    INSERT INTO components (
+                        component_type,
+                        asset_id,
+                        manufacturer,
+                        model,
+                        manufacturer_serial,
+                        created_by
+                    )
+                    VALUES (%s, %s, %s, %s, %s, %s)
+                    RETURNING
+                        id AS component_id,
+                        component_type,
+                        asset_id,
+                        manufacturer,
+                        model,
+                        manufacturer_serial,
+                        created_at,
+                        created_by
+                    """,
+                    (
+                        component_type,
+                        asset_id,
+                        manufacturer,
+                        model,
+                        manufacturer_serial,
+                        created_by,
+                    ),
+                )
+                return dict(cur.fetchone())
+
+    def get_component(self, component_id: UUID) -> dict | None:
+        with self._connection_scope() as connection:
+            with connection.cursor(row_factory=dict_row) as cur:
+                cur.execute(
+                    """
+                    SELECT
+                        id AS component_id,
+                        component_type,
+                        asset_id,
+                        manufacturer,
+                        model,
+                        manufacturer_serial,
+                        created_at,
+                        created_by
+                    FROM components
+                    WHERE id = %s
+                    """,
+                    (component_id,),
+                )
+                row = cur.fetchone()
+                return dict(row) if row else None