"""移除 memory_chunks.content_tsv（FTS 列已停用，检索统一向量）。

Revision ID: 0007_drop_chunk_content_tsv
Revises: 0006_segment_memoir_phases
"""

from typing import Sequence, Union

import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

from alembic import op

revision: str = "0007_drop_chunk_content_tsv"
down_revision: Union[str, None] = "0006_segment_memoir_phases"
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("memory_chunks")
    if "content_tsv" in columns:
        op.drop_column("memory_chunks", "content_tsv")


def downgrade() -> None:
    columns = _column_names("memory_chunks")
    if "content_tsv" not in columns:
        op.add_column(
            "memory_chunks",
            sa.Column("content_tsv", postgresql.TSVECTOR(), nullable=True),
        )