"""实时通知体系：notifications 表扩展（分类/事件码/级别/深链/引用/已读时间）+ 索引 + 广播公告表

Revision ID: 0057
Revises: 0056
Create Date: 2026-09-05
"""
from alembic import op
import sqlalchemy as sa

revision = "0057"
down_revision = "0056"
branch_labels = None
depends_on = None


def upgrade():
    # notifications 扩展列（MySQL VARCHAR 可带 DEFAULT；禁止 TEXT/JSON DEFAULT）
    for col, ctype, default in [
        ("category", sa.String(32), "system"),
        ("event_code", sa.String(64), ""),
        ("level", sa.String(16), "info"),
        ("link", sa.String(255), ""),
        ("ref_type", sa.String(64), ""),
        ("ref_id", sa.String(64), ""),
        ("read_at", sa.String(32), ""),
    ]:
        try:
            op.add_column("notifications", sa.Column(col, ctype, nullable=False, server_default=default))
        except Exception:  # noqa: BLE001 — 列已存在时跳过
            pass

    # 查询索引：用户未读角标 + 分页
    try:
        op.create_index("ix_notifications_user_read", "notifications", ["user_id", "read"])
    except Exception:  # noqa: BLE001
        pass
    try:
        op.create_index("ix_notifications_user_created", "notifications", ["user_id", "created_at"])
    except Exception:  # noqa: BLE001
        pass

    # 广播公告表
    op.create_table(
        "announcements",
        sa.Column("id", sa.String(32), primary_key=True),
        sa.Column("title", sa.String(200), default=""),
        sa.Column("content", sa.String(1000), default=""),
        sa.Column("category", sa.String(32), default="system"),
        sa.Column("level", sa.String(16), default="info"),
        sa.Column("link", sa.String(255), default=""),
        sa.Column("created_by", sa.String(32), default=""),
        sa.Column("published_at", sa.String(32), default=""),
    )


def downgrade():
    op.drop_table("announcements")
    try:
        op.drop_index("ix_notifications_user_created", table_name="notifications")
    except Exception:  # noqa: BLE001
        pass
    try:
        op.drop_index("ix_notifications_user_read", table_name="notifications")
    except Exception:  # noqa: BLE001
        pass
    for col in ["read_at", "ref_id", "ref_type", "link", "level", "event_code", "category"]:
        try:
            op.drop_column("notifications", col)
        except Exception:  # noqa: BLE001
            pass