"""tree_visibility: add 'site_members' value

Revision ID: d4a9c1e7b2f3
Revises: c7e1a4f2d3b8
Create Date: 2026-06-09

"""
from collections.abc import Sequence

from alembic import op

revision: str = "d4a9c1e7b2f3"
down_revision: str | None = "c7e1a4f2d3b8"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    # ALTER TYPE ... ADD VALUE cannot run inside a transaction block on older
    # Postgres; run it in an autocommit block so it applies regardless of version.
    with op.get_context().autocommit_block():
        op.execute("ALTER TYPE tree_visibility ADD VALUE IF NOT EXISTS 'site_members'")


def downgrade() -> None:
    # Postgres cannot drop an enum value without rebuilding the type; treat the
    # added value as irreversible. (Rows using it would block a rebuild anyway.)
    pass