"""add_description_to_validation_policy

Revision ID: 7703bbc038bd
Revises: c9d8e7f6a5b4
Create Date: 2026-05-31 21:07:34.291012

"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa
from sqlalchemy import inspect

# revision identifiers, used by Alembic.
revision: str = '7703bbc038bd'
down_revision: Union[str, Sequence[str], None] = 'c9d8e7f6a5b4'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def _table_exists(table_name: str) -> bool:
    conn = op.get_bind()
    inspector = inspect(conn)
    return table_name in inspector.get_table_names()


def upgrade() -> None:
    """Add description column to validation_policies."""
    if not _table_exists("validation_policies"):
        return
    op.add_column('validation_policies', sa.Column('description', sa.Text(), nullable=True))


def downgrade() -> None:
    """Remove description column from validation_policies."""
    op.drop_column('validation_policies', 'description')
