"""Fix ORM↔migration drift: unique constraint, drop unused index, fix merge_strategy default

Migration 0071 created ix_fetch_mpack_cache_repo_tip as a unique index but
the ORM model uses UniqueConstraint. Also drops the unused
ix_proposal_comments_author_user_id index and updates the merge_strategy
server default from state_overlay to overlay (matching migration 0070's data rename).

Revision ID: 0072
Revises: 0071
"""
from __future__ import annotations

from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision: str = '0072'
down_revision: Union[str, None] = '0071'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # ### commands auto generated by Alembic - please adjust! ###
    op.drop_index(op.f('ix_fetch_mpack_cache_repo_tip'), table_name='musehub_fetch_mpack_cache')
    op.create_unique_constraint('uq_fetch_mpack_cache_repo_tip', 'musehub_fetch_mpack_cache', ['repo_id', 'tip_commit_id'])
    op.drop_index(op.f('ix_proposal_comments_author_user_id'), table_name='musehub_proposal_comments')
    op.alter_column('musehub_proposals', 'merge_strategy',
               existing_type=sa.VARCHAR(length=50),
               server_default='overlay',
               existing_nullable=False)
    # ### end Alembic commands ###


def downgrade() -> None:
    # ### commands auto generated by Alembic - please adjust! ###
    op.alter_column('musehub_proposals', 'merge_strategy',
               existing_type=sa.VARCHAR(length=50),
               server_default=sa.text("'state_overlay'::character varying"),
               existing_nullable=False)
    op.create_index(op.f('ix_proposal_comments_author_user_id'), 'musehub_proposal_comments', ['author_user_id'], unique=False)
    op.drop_constraint('uq_fetch_mpack_cache_repo_tip', 'musehub_fetch_mpack_cache', type_='unique')
    op.create_index(op.f('ix_fetch_mpack_cache_repo_tip'), 'musehub_fetch_mpack_cache', ['repo_id', 'tip_commit_id'], unique=True)
    # ### end Alembic commands ###