"""fc3h: backup_* knobs on import_settings

Revision ID: 0018
Revises: 0017
Create Date: 2026-05-24

Adds four columns to the singleton import_settings row:
  - backup_db_nightly_enabled (default False — opt-in)
  - backup_db_nightly_hour_utc (default 3)
  - backup_db_keep_last_n (default 14)
  - backup_images_keep_last_n (default 3)

server_default ensures the singleton row is backfilled in place
without an UPDATE statement.
"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0018"
down_revision: Union[str, None] = "0017"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.add_column(
        "import_settings",
        sa.Column(
            "backup_db_nightly_enabled", sa.Boolean(),
            nullable=False, server_default=sa.false(),
        ),
    )
    op.add_column(
        "import_settings",
        sa.Column(
            "backup_db_nightly_hour_utc", sa.Integer(),
            nullable=False, server_default="3",
        ),
    )
    op.add_column(
        "import_settings",
        sa.Column(
            "backup_db_keep_last_n", sa.Integer(),
            nullable=False, server_default="14",
        ),
    )
    op.add_column(
        "import_settings",
        sa.Column(
            "backup_images_keep_last_n", sa.Integer(),
            nullable=False, server_default="3",
        ),
    )


def downgrade() -> None:
    op.drop_column("import_settings", "backup_images_keep_last_n")
    op.drop_column("import_settings", "backup_db_keep_last_n")
    op.drop_column("import_settings", "backup_db_nightly_hour_utc")
    op.drop_column("import_settings", "backup_db_nightly_enabled")
