"""add_notifications

Revision ID: b8c9d0e1f2a3
Revises: a7b8c9d0e1f2
Create Date: 2026-08-07
"""
from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa

revision: str = "b8c9d0e1f2a3"
down_revision: Union[str, None] = "a7b8c9d0e1f2"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "notifications",
        sa.Column("id", sa.UUID(), primary_key=True, server_default=sa.text("gen_random_uuid()")),
        sa.Column("user_id", sa.String(64), nullable=False, index=True, comment="接收人ID（逻辑外键→老系统）"),
        sa.Column("title", sa.String(200), nullable=False, comment="通知标题"),
        sa.Column("content", sa.Text(), nullable=False, comment="通知内容详情"),
        sa.Column("type", sa.String(20), nullable=False, comment="通知类型: TRANSFER(转交派发) | REJECT(驳回)"),
        sa.Column("task_id", sa.UUID(), sa.ForeignKey("tasks.id", ondelete="SET NULL"), nullable=True, comment="关联任务ID"),
        sa.Column("is_read", sa.Boolean(), server_default=sa.text("false"), comment="是否已读"),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), comment="创建时间"),
    )


def downgrade() -> None:
    op.drop_table("notifications")