"""In-app notifications. Mail is out-of-scope for v1 (spec §4)."""

from __future__ import annotations

import uuid
from datetime import datetime
from typing import Any, TYPE_CHECKING

from sqlalchemy import DateTime, ForeignKey, Index, String, Uuid
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base import Base
from app.db.mixins import TimestampMixin, UuidPkMixin

if TYPE_CHECKING:
    from app.models.auth import User


class Notification(Base, UuidPkMixin, TimestampMixin):
    __tablename__ = "notifications"

    user_id: Mapped[uuid.UUID] = mapped_column(
        Uuid(as_uuid=True),
        ForeignKey("users.id", ondelete="CASCADE"),
        nullable=False,
    )
    type: Mapped[str] = mapped_column(String(64), nullable=False)
    payload: Mapped[Any] = mapped_column(JSONB, nullable=False, server_default="{}")
    read_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    user: Mapped["User"] = relationship(back_populates="notifications")

    __table_args__ = (
        Index(
            "ix_notifications_user_unread",
            "user_id",
            "created_at",
            postgresql_where="read_at IS NULL",
        ),
    )