"""add language column to waitlist_entries

Revision ID: 003
Revises: 002
Create Date: 2026-04-12
"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa

revision: str = "003"
down_revision: Union[str, None] = "002"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # Guard: column may already exist from a prior manual migration
    op.execute("""
        DO $$
        BEGIN
            IF NOT EXISTS (
                SELECT 1 FROM information_schema.columns
                WHERE table_name = 'waitlist_entries' AND column_name = 'language'
            ) THEN
                ALTER TABLE waitlist_entries ADD COLUMN language VARCHAR(5) NOT NULL DEFAULT 'en';
            END IF;
        END $$;
    """)


def downgrade() -> None:
    op.drop_column("waitlist_entries", "language")