fix(mediaserver): sync library data incrementally

database/versions/b8f6e3a1c2d4_2_2_5.py

@@ -0,0 +1,87 @@
+"""2.2.5
+mediaserveritem 改为按 server + item_id 唯一
+
+Revision ID: b8f6e3a1c2d4
+Revises: 93f8cb6a4d1e
+Create Date: 2026-05-09
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "b8f6e3a1c2d4"
+down_revision = "93f8cb6a4d1e"
+branch_labels = None
+depends_on = None
+
+TABLE_NAME = "mediaserveritem"
+INDEX_NAME = "ux_mediaserveritem_server_item_id"
+INDEX_COLUMNS = ["server", "item_id"]
+
+mediaserveritem = sa.table(
+    TABLE_NAME,
+    sa.column("id", sa.Integer),
+    sa.column("server", sa.String),
+    sa.column("item_id", sa.String),
+)
+
+
+def _table_exists(inspector: sa.Inspector) -> bool:
+    return TABLE_NAME in inspector.get_table_names()
+
+
+def _has_index_signature(inspector: sa.Inspector, unique: bool) -> bool:
+    target_columns = tuple(INDEX_COLUMNS)
+    for index in inspector.get_indexes(TABLE_NAME):
+        if tuple(index.get("column_names") or []) == target_columns and bool(index.get("unique")) == unique:
+            return True
+    return False
+
+
+def _drop_index_if_exists(inspector: sa.Inspector) -> None:
+    for index in inspector.get_indexes(TABLE_NAME):
+        if index.get("name") == INDEX_NAME:
+            op.drop_index(INDEX_NAME, table_name=TABLE_NAME)
+            return
+
+
+def _deduplicate_rows() -> None:
+    bind = op.get_bind()
+    keep_ids = (
+        sa.select(sa.func.max(mediaserveritem.c.id))
+        .where(
+            mediaserveritem.c.server.is_not(None),
+            mediaserveritem.c.item_id.is_not(None),
+        )
+        .group_by(mediaserveritem.c.server, mediaserveritem.c.item_id)
+    )
+    bind.execute(
+        mediaserveritem.delete().where(
+            sa.and_(
+                mediaserveritem.c.server.is_not(None),
+                mediaserveritem.c.item_id.is_not(None),
+                mediaserveritem.c.id.not_in(keep_ids),
+            )
+        )
+    )
+
+
+def upgrade() -> None:
+    inspector = sa.inspect(op.get_bind())
+    if not _table_exists(inspector):
+        return
+
+    _deduplicate_rows()
+
+    inspector = sa.inspect(op.get_bind())
+    if not _has_index_signature(inspector, unique=True):
+        op.create_index(INDEX_NAME, TABLE_NAME, INDEX_COLUMNS, unique=True)
+
+
+def downgrade() -> None:
+    inspector = sa.inspect(op.get_bind())
+    if not _table_exists(inspector):
+        return
+
+    _drop_index_if_exists(inspector)