fix(migrations): add mcp resource preferences

src/langbot/pkg/persistence/alembic/versions/0008_add_mcp_resource_preferences.py

@@ -0,0 +1,95 @@
+"""add mcp resource preferences to pipelines
+
+Revision ID: 0008_add_mcp_resource_preferences
+Revises: 0007_add_bot_admins
+Create Date: 2026-06-30
+"""
+
+from __future__ import annotations
+
+import json
+from typing import Any
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = '0008_add_mcp_resource_preferences'
+down_revision = '0007_add_bot_admins'
+branch_labels = None
+depends_on = None
+
+
+_PIPELINE_TABLE = sa.table(
+    'legacy_pipelines',
+    sa.column('uuid', sa.String(255)),
+    sa.column('extensions_preferences', sa.JSON()),
+)
+
+
+def _has_extensions_preferences_table(conn: sa.Connection) -> bool:
+    inspector = sa.inspect(conn)
+    if 'legacy_pipelines' not in inspector.get_table_names():
+        return False
+    columns = {column['name'] for column in inspector.get_columns('legacy_pipelines')}
+    return 'extensions_preferences' in columns
+
+
+def _decode_preferences(value: Any) -> dict[str, Any]:
+    if value is None:
+        return {}
+    if isinstance(value, dict):
+        return dict(value)
+    if isinstance(value, str):
+        try:
+            decoded = json.loads(value)
+        except json.JSONDecodeError:
+            return {}
+        if isinstance(decoded, dict):
+            return decoded
+    return {}
+
+
+def _update_preferences(conn: sa.Connection, uuid: str, preferences: dict[str, Any]) -> None:
+    conn.execute(
+        _PIPELINE_TABLE.update().where(_PIPELINE_TABLE.c.uuid == uuid).values(extensions_preferences=preferences)
+    )
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+    if not _has_extensions_preferences_table(conn):
+        return
+
+    rows = conn.execute(sa.select(_PIPELINE_TABLE.c.uuid, _PIPELINE_TABLE.c.extensions_preferences)).all()
+    for uuid, raw_preferences in rows:
+        preferences = _decode_preferences(raw_preferences)
+        changed = False
+
+        if 'mcp_resources' not in preferences:
+            preferences['mcp_resources'] = []
+            changed = True
+        if 'mcp_resource_agent_read_enabled' not in preferences:
+            preferences['mcp_resource_agent_read_enabled'] = True
+            changed = True
+
+        if changed:
+            _update_preferences(conn, uuid, preferences)
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+    if not _has_extensions_preferences_table(conn):
+        return
+
+    rows = conn.execute(sa.select(_PIPELINE_TABLE.c.uuid, _PIPELINE_TABLE.c.extensions_preferences)).all()
+    for uuid, raw_preferences in rows:
+        preferences = _decode_preferences(raw_preferences)
+        changed = False
+
+        for key in ('mcp_resources', 'mcp_resource_agent_read_enabled'):
+            if key in preferences:
+                preferences.pop(key)
+                changed = True
+
+        if changed:
+            _update_preferences(conn, uuid, preferences)