"""Make musehub_commit_graph global — drop repo_id, PK becomes commit_id alone.

Commits are content-addressed like snapshots; repo_id was the wrong abstraction.
Dropping it also fixes the bug where re-pushed commits (already in musehub_commits)
never got a graph row because the ON CONFLICT key included repo_id.
"""

from __future__ import annotations

import sqlalchemy as sa
from alembic import op

revision = "0061"
down_revision = "0060"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.drop_index("ix_musehub_commit_graph_repo_generation", table_name="musehub_commit_graph")
    op.drop_constraint("musehub_commit_graph_pkey", "musehub_commit_graph", type_="primary")
    op.drop_constraint("musehub_commit_graph_repo_id_fkey", "musehub_commit_graph", type_="foreignkey")
    op.drop_column("musehub_commit_graph", "repo_id")
    op.create_primary_key("musehub_commit_graph_pkey", "musehub_commit_graph", ["commit_id"])
    op.create_index("ix_musehub_commit_graph_generation", "musehub_commit_graph", ["generation"])


def downgrade() -> None:
    op.drop_index("ix_musehub_commit_graph_generation", table_name="musehub_commit_graph")
    op.drop_constraint("musehub_commit_graph_pkey", "musehub_commit_graph", type_="primary")
    op.add_column(
        "musehub_commit_graph",
        sa.Column("repo_id", sa.String(128), nullable=False, server_default=""),
    )
    op.create_foreign_key(
        "musehub_commit_graph_repo_id_fkey",
        "musehub_commit_graph", "musehub_repos",
        ["repo_id"], ["repo_id"],
        ondelete="CASCADE",
    )
    op.create_primary_key(
        "musehub_commit_graph_pkey", "musehub_commit_graph", ["repo_id", "commit_id"]
    )
    op.create_index(
        "ix_musehub_commit_graph_repo_generation",
        "musehub_commit_graph",
        ["repo_id", "generation"],
    )