"""Re-enable the ``cmdb.auto_owner_grant_backfill`` scheduled job.

Revision ID: 241
Revises: 240
Create Date: 2026-06-02

Companion to the same-PR code change that adds ``is_backfill=True`` to
``_post_provision_finalize`` (and downstream ``provision_initial_owner_grant``
→ ``_dispatch_grant``) so the cron writes silent + perpetual rows
instead of firing misleading "[已开通] X 已生效" notifications.

Context: PR #671 launched the cron at 2026-06-02 08:42 UTC. By 09:18
UTC it had fired 4 ticks and dispatched 14 "已开通" cards to scope
owners who had been Owner on those projects for months (the scopes
were discovered via sync, not created through scope_request — the cron
caught all of them as "owner has no source='helix' grant"). The cron
was manually disabled in prod at 09:21 UTC via a direct
``UPDATE scheduled_jobs SET enabled=0`` while the fix was prepared.
With the ``is_backfill=True`` plumbing in place, the cron is safe to
run again — the remaining ~77 owners / 182 scopes get their
bookkeeping rows written without any user-visible notification.

The migration is intentionally unconditional ``SET enabled=1`` for
this one job — not gated on ``WHERE enabled=0`` — so it is safe to
re-run and converges fresh deploys (where 239 already set enabled=1)
and the patched prod (where the manual ``SET enabled=0`` is the
current state) to the same end state. The ``updated_at`` bump tells
the scheduler tick its next-fire calculation needs to refresh.
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

revision = "241"
down_revision = "240"
branch_labels = None
depends_on = None


def _table_exists(bind, table: str) -> bool:
    row = bind.execute(
        sa.text(
            "SELECT 1 FROM information_schema.TABLES "
            "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t"
        ),
        {"t": table},
    ).fetchone()
    return row is not None


def upgrade() -> None:
    bind = op.get_bind()
    if not _table_exists(bind, "scheduled_jobs"):
        return
    bind.execute(
        sa.text(
            "UPDATE scheduled_jobs "
            "SET enabled = 1, updated_at = NOW() "
            "WHERE name = 'cmdb.auto_owner_grant_backfill'"
        )
    )


def downgrade() -> None:
    # No-op — re-disabling would be a regression, not a rollback. The
    # cron's purpose is to bottom-out the auto-Owner grant flow; once
    # operations re-enable it, downgrading the migration must not
    # silently turn it back off.
    pass