"""add escalation_reason to messages (Спринт 6b блок E)

Revision ID: h4b52e9dc0f83
Revises: g3a71d4fc285
Create Date: 2026-04-26 10:00:00.000000

Причина передачи оператору: acute_pain / surgery / angry /
explicit_request / routing_loop. Хранится на реплике ассистента,
в которой ветка escalate_human первый раз ответила в треде.
"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa


revision: str = 'h4b52e9dc0f83'
down_revision: Union[str, None] = 'g3a71d4fc285'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    with op.batch_alter_table('messages', recreate='always') as batch:
        batch.add_column(sa.Column('escalation_reason', sa.String(50), nullable=True))


def downgrade() -> None:
    with op.batch_alter_table('messages', recreate='always') as batch:
        batch.drop_column('escalation_reason')