"""add confidence and expires_at columns to global_knowledge table

Revision ID: 010_add_global_knowledge
Revises: 009_notif_sched_feishu
Create Date: 2026-05-06
"""
from alembic import op
import sqlalchemy as sa


revision = "010_add_global_knowledge"
down_revision = "009_notif_sched_feishu"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # Add confidence column (if table doesn't exist, this is a no-op handled below)
    try:
        op.add_column(
            "global_knowledge",
            sa.Column("confidence", sa.String(20), default="medium", comment="置信度: low/medium/high"),
        )
    except Exception:
        pass

    # Add expires_at column
    try:
        op.add_column(
            "global_knowledge",
            sa.Column("expires_at", sa.DateTime(), nullable=True, comment="过期时间，NULL 表示永不过期"),
        )
    except Exception:
        pass


def downgrade() -> None:
    try:
        op.drop_column("global_knowledge", "expires_at")
    except Exception:
        pass
    try:
        op.drop_column("global_knowledge", "confidence")
    except Exception:
        pass