"""refresh_tokens：轮换 lineage（replaced_by_token_id + rotated_at）

Revision ID: 0020_refresh_rt_lineage
Revises: 0019_align_legacy_schema
"""

from typing import Sequence, Union

import sqlalchemy as sa

from alembic import op

revision: str = "0020_refresh_rt_lineage"
down_revision: Union[str, None] = "0019_align_legacy_schema"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def _column_names(table_name: str) -> set[str]:
    bind = op.get_bind()
    inspector = sa.inspect(bind)
    return {column["name"] for column in inspector.get_columns(table_name)}


def upgrade() -> None:
    columns = _column_names("refresh_tokens")
    if "replaced_by_token_id" not in columns:
        op.add_column(
            "refresh_tokens",
            sa.Column("replaced_by_token_id", sa.String(), nullable=True),
        )
        op.create_index(
            "ix_refresh_tokens_replaced_by_token_id",
            "refresh_tokens",
            ["replaced_by_token_id"],
            unique=False,
        )
        op.create_foreign_key(
            "fk_refresh_tokens_replaced_by_token_id",
            "refresh_tokens",
            "refresh_tokens",
            ["replaced_by_token_id"],
            ["id"],
            ondelete="SET NULL",
        )
    if "rotated_at" not in columns:
        op.add_column(
            "refresh_tokens",
            sa.Column("rotated_at", sa.DateTime(timezone=True), nullable=True),
        )


def downgrade() -> None:
    columns = _column_names("refresh_tokens")
    if "replaced_by_token_id" in columns:
        op.drop_constraint(
            "fk_refresh_tokens_replaced_by_token_id",
            "refresh_tokens",
            type_="foreignkey",
        )
        op.drop_index("ix_refresh_tokens_replaced_by_token_id", table_name="refresh_tokens")
        op.drop_column("refresh_tokens", "replaced_by_token_id")
    if "rotated_at" in columns:
        op.drop_column("refresh_tokens", "rotated_at")