"""patreon_failed_media: per-source dead-letter ledger for failing Patreon media

Revision ID: 0038
Revises: 0037
Create Date: 2026-06-06

Plan #705 (#7). Media that keeps failing to download/validate (404'd CDN,
deleted post, geo-blocked Mux, persistently-corrupt bytes) gets recorded here
with an attempt counter; once it crosses the dead-letter threshold the ingester
skips it on routine walks (recovery still re-attempts). A clean download clears
the row. UNIQUE (source_id, filehash) is the upsert key (same media key the
seen-ledger uses).
"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0038"
down_revision: Union[str, None] = "0037"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "patreon_failed_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("attempts", sa.Integer, nullable=False, server_default="1"),
        sa.Column("last_error", sa.Text, nullable=True),
        sa.Column(
            "first_failed_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("NOW()"),
        ),
        sa.Column(
            "last_failed_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("NOW()"),
        ),
        sa.UniqueConstraint(
            "source_id", "filehash", name="uq_patreon_failed_media_source_id"
        ),
    )


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