"""add 'failed' to hr_sync_batches status enum

Revision ID: 016
Revises: 015
Create Date: 2026-04-15
"""
import sqlalchemy as sa
from alembic import op

revision = '016'
down_revision = '015'
branch_labels = None
depends_on = None


def _table_exists(conn, table_name):
    result = conn.execute(sa.text(
        "SELECT COUNT(*) FROM information_schema.tables "
        "WHERE table_schema = DATABASE() AND table_name = :t"
    ), {"t": table_name})
    return result.scalar() > 0


def upgrade():
    conn = op.get_bind()
    if not _table_exists(conn, 'hr_sync_batches'):
        return
    op.execute(
        "ALTER TABLE hr_sync_batches MODIFY COLUMN status "
        "ENUM('pending_review', 'confirmed', 'cancelled', 'failed') "
        "NOT NULL DEFAULT 'pending_review'"
    )


def downgrade():
    conn = op.get_bind()
    if not _table_exists(conn, 'hr_sync_batches'):
        return
    op.execute(
        "ALTER TABLE hr_sync_batches MODIFY COLUMN status "
        "ENUM('pending_review', 'confirmed', 'cancelled') "
        "NOT NULL DEFAULT 'pending_review'"
    )