"""patreon_seen_media: per-source ledger of already-ingested Patreon media

Revision ID: 0037
Revises: 0036
Create Date: 2026-06-05

Native Patreon ingester (build step 2a). Replaces gallery-dl's
archive.sqlite3 with our own queryable table. The downloader upserts one
row per (source, media) so routine walks skip media we've already
processed; a future "recovery" mode bypasses the ledger to re-walk.

`filehash` is a 32-hex Patreon CDN MD5, OR a video sentinel of the form
``video:<post_id>:<media_id>`` — hence String(128). The unique
constraint on (source_id, filehash) is the dedup upsert key.
"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0037"
down_revision: Union[str, None] = "0036"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "patreon_seen_media",
        sa.Column("id", sa.Integer, primary_key=True),
        sa.Column(
            "source_id",
            sa.Integer,
            sa.ForeignKey("source.id", ondelete="CASCADE"),
            nullable=False,
            index=True,
        ),
        sa.Column("filehash", sa.String(128), nullable=False),
        sa.Column("post_id", sa.String(64), nullable=True),
        sa.Column(
            "seen_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("NOW()"),
        ),
        sa.UniqueConstraint(
            "source_id", "filehash", name="uq_patreon_seen_media_source_id"
        ),
    )


def downgrade() -> None:
    op.drop_table("patreon_seen_media")