from __future__ import annotations

from datetime import datetime
from typing import Optional

from sqlalchemy import DateTime, ForeignKey, Integer, JSON, String, Text, Index
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.sql import func

from .database import Base


class Alert(Base):
    __tablename__ = "alerts"
    __table_args__ = (
        Index("idx_alerts_created_at", "created_at"),
        Index("idx_alerts_user_id", "user_id"),
        Index("idx_alerts_category", "category"),
        Index("idx_alerts_read_at", "read_at"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    user_id: Mapped[Optional[int]] = mapped_column(Integer, ForeignKey("users.id", ondelete="SET NULL"))

    category: Mapped[str] = mapped_column(String(50), nullable=False)
    level: Mapped[Optional[str]] = mapped_column(String(20))
    title: Mapped[Optional[str]] = mapped_column(String(255))
    message: Mapped[str] = mapped_column(Text, nullable=False)
    source: Mapped[Optional[str]] = mapped_column(String(50))
    details: Mapped[Optional[dict]] = mapped_column(JSON)

    read_at: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())

    def __repr__(self) -> str:
        return f"<Alert id={self.id} category={self.category} user_id={self.user_id} read={self.read_at is not None}>"