from sqlalchemy import String, Integer, ForeignKey, UniqueConstraint, func
from sqlalchemy.orm import Mapped, mapped_column
from datetime import datetime
from app.database import Base


class NtfySent(Base):
    """
    Deduplication table for ntfy notifications.
    Prevents the background job from re-sending the same notification
    within a given time window. Scoped per-user.

    Key format: "{type}:{entity_id}:{date_window}"
    Examples:
      "reminder:42:2026-02-25"
      "event:17:2026-02-25T09:00"
      "todo:8:2026-02-25"
      "project:3:2026-02-25"
    """
    __tablename__ = "ntfy_sent"
    __table_args__ = (
        UniqueConstraint("user_id", "notification_key", name="uq_ntfy_sent_user_key"),
    )

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
    )
    notification_key: Mapped[str] = mapped_column(String(255), index=True)
    sent_at: Mapped[datetime] = mapped_column(default=func.now(), server_default=func.now())