"""为 predictions 表增加 agent_weights 列

Revision ID: 0014_predictions_agent_weights
Revises: 0013_predictions_unique_constraint_mode_run_type
Create Date: 2026-09-20

背景:
  multi-agent 终裁的 agent_weights 原本只在 raw_response JSON 中,
  无独立列,评估不便。本迁移增加 agent_weights JSONB 列,可空,旧行保持 NULL。
"""

from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision: str = '0014_predictions_agent_weights'
down_revision: Union[str, None] = '0013_predictions_unique_constraint_mode_run_type'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # 新增 agent_weights 列(JSONB, 可空, 旧行保持 NULL)
    op.add_column(
        "predictions",
        sa.Column(
            "agent_weights",
            sa.dialects.postgresql.JSONB(),
            nullable=True,
            comment="multi-agent 终裁各专家权重, 格式: {expert_name: weight}",
        ),
    )


def downgrade() -> None:
    # 删除 agent_weights 列
    op.drop_column("predictions", "agent_weights")