"""download_revisit_days — how far back a tick keeps looking for EDITED posts.

Operator, 2026-09-23, pointing at a Floppystack post: *"this post has been
updated as he implements hot fixes — any chance we have a way to scan for or
see updated posts so we can update ours to match and pull the new attachments
and pictures etc."*

A tick stopped after 20 contiguous already-have-it items. That is the right
instinct and the wrong unit: a post edited three days after publication sits
well below twenty seen items, so the walk turned around before reaching it. The
walk now needs BOTH a run of seen items and a post older than this many days
before it stops.

A settings row rather than a constant (rule 25) because the right window is a
property of the CREATOR, not of FabledCurator — one artist appends hotfix
builds for a fortnight, another never touches a post again. 0 turns the revisit
off entirely and restores the pure count early-out.

30 days is the operator's own number, 2026-09-23.

Revision ID: 0108
Revises: 0107
Create Date: 2026-09-23

"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0108"
down_revision: Union[str, None] = "0107"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # server_default so the existing single settings row gets the window without
    # a data migration — and so an install that predates this column reads 30
    # rather than 0. 0 is a real, meaningful value here (revisit off), so the
    # column must never be allowed to arrive at it by omission.
    op.add_column(
        "import_settings",
        sa.Column(
            "download_revisit_days",
            sa.Integer(),
            nullable=False,
            server_default="30",
        ),
    )


def downgrade() -> None:
    op.drop_column("import_settings", "download_revisit_days")