"""identity_sync_targets.alert_enabled — per-target failure-alert on/off switch.

Revision ID: 309
Revises: 308
Create Date: 2026-06-19

Adds a NOT NULL boolean (server_default true) master switch for each target's
run-failure alerting. When false the notifier sends nothing — not even to the
configured ``alert_recipient_ids``. Existing rows default to ``true`` so a
target that already has recipients keeps alerting; a target with no recipients
stays silent regardless (the IT-admin fallback was removed in the same change —
see DECISIONS.md 2026-06-19, "不要默认通知管理员"). Idempotent + re-runnable.
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

revision = "309"
down_revision = "308"
branch_labels = None
depends_on = None

_TABLE = "identity_sync_targets"
_COLUMN = "alert_enabled"


def _has_column(bind, table: str, column: str) -> bool:
    insp = sa.inspect(bind)
    return any(c["name"] == column for c in insp.get_columns(table))


def upgrade() -> None:
    bind = op.get_bind()
    if not _has_column(bind, _TABLE, _COLUMN):
        op.add_column(
            _TABLE,
            sa.Column(
                _COLUMN,
                sa.Boolean(),
                nullable=False,
                server_default=sa.text("1"),
            ),
        )


def downgrade() -> None:
    bind = op.get_bind()
    if _has_column(bind, _TABLE, _COLUMN):
        op.drop_column(_TABLE, _COLUMN)