import uuid
from datetime import datetime, timezone

from sqlalchemy import DateTime, ForeignKey, Index, String, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


def _now() -> datetime:
    return datetime.now(timezone.utc)


class NotificationLog(Base):
    __tablename__ = "notification_log"
    __table_args__ = (Index("idx_notification_log_user_id", "user_id"),)

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
    user_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("users.id", ondelete="CASCADE"), nullable=False
    )
    registration_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("registrations.id", ondelete="SET NULL")
    )
    type: Mapped[str] = mapped_column(String(50), nullable=False)
    title: Mapped[str] = mapped_column(String(255), nullable=False)
    body: Mapped[str] = mapped_column(Text, nullable=False)
    sent_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now)
    delivery_status: Mapped[str] = mapped_column(String(30), default="pending")

    user: Mapped["User"] = relationship(back_populates="notification_logs")
    registration: Mapped["Registration | None"] = relationship(
        back_populates="notification_logs"
    )