"""device.kill_alert_pending (无障碍掉线「后置检测」待提醒标记)

Revision ID: device_kill_alert_pending
Revises: device_liveness_table
Create Date: 2026-06-19

后置检测 pull 版(spec/accessibility-liveness-pull-prompt.md):worker 检出心跳掉线即置此标记,
客户端下次进 App 拉取到 → 弹「开启自启动」引导,交互后 ack 清回。与 liveness_state 解耦,故单列。
"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa


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


def upgrade() -> None:
    # server_default=sa.false() 跨方言: SQLite 渲染 0 / PG 渲染 false(别用 sa.text("0"),PG 布尔严格会报错),
    # 给存量行回填 False。
    with op.batch_alter_table('device_liveness', schema=None) as batch_op:
        batch_op.add_column(
            sa.Column(
                'kill_alert_pending',
                sa.Boolean(),
                nullable=False,
                server_default=sa.false(),
            )
        )


def downgrade() -> None:
    with op.batch_alter_table('device_liveness', schema=None) as batch_op:
        batch_op.drop_column('kill_alert_pending')