from sqlalchemy import Column, Integer, String, Boolean, DateTime, ForeignKey
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from database import Base


class Notification(Base):
    """站内通知：评论/收藏/系统消息。"""
    __tablename__ = "notifications"

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True)
    actor_id = Column(Integer, nullable=True)
    ntype = Column(String(32), nullable=False, default="comment")
    title = Column(String(200), nullable=False)
    content = Column(String(500), default="")
    link = Column(String(255), default="")
    is_read = Column(Boolean, default=False)
    created_at = Column(DateTime, server_default=func.now())

    user = relationship("User", back_populates="notifications")