from sqlalchemy import CheckConstraint, String, Text, Integer, Boolean, ForeignKey, func
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column
from datetime import datetime
from typing import Optional
from app.database import Base

_NOTIFICATION_TYPES = (
    "connection_request", "connection_accepted", "connection_rejected",
    "calendar_invite", "calendar_invite_accepted", "calendar_invite_rejected",
    "event_invite", "event_invite_response",
    "project_invite", "project_invite_accepted", "project_invite_rejected",
    "task_assigned",
    "info", "warning", "reminder", "system",
)


class Notification(Base):
    __tablename__ = "notifications"
    __table_args__ = (
        CheckConstraint(
            f"type IN ({', '.join(repr(t) for t in _NOTIFICATION_TYPES)})",
            name="ck_notifications_type",
        ),
    )

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    user_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
    )
    type: Mapped[str] = mapped_column(String(50), nullable=False)
    title: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
    message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    data: Mapped[Optional[dict]] = mapped_column(JSONB, nullable=True)
    source_type: Mapped[Optional[str]] = mapped_column(String(50), nullable=True)
    source_id: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
    is_read: Mapped[bool] = mapped_column(Boolean, default=False, server_default="false")
    created_at: Mapped[datetime] = mapped_column(default=func.now(), server_default=func.now())