"""Add storage_uri to musehub_commits and musehub_snapshots.

Phase 1 of the object-store invariant fix (issue #63): every commit and
snapshot must be written to S3 in muse binary format alongside the DB row.
storage_uri tracks the canonical S3 location, mirroring MusehubObject.
NULL on existing rows — backfill handled in Phase 5.

Revision ID: 0068
Revises: 0067
"""
from __future__ import annotations

import sqlalchemy as sa
from alembic import op

revision: str = "0068"
down_revision: str = "0067"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column(
        "musehub_commits",
        sa.Column("storage_uri", sa.String(length=2048), nullable=True),
    )
    op.add_column(
        "musehub_snapshots",
        sa.Column("storage_uri", sa.String(length=2048), nullable=True),
    )


def downgrade() -> None:
    op.drop_column("musehub_snapshots", "storage_uri")
    op.drop_column("musehub_commits", "storage_uri")