from enum import Enum as Enumeration

from sqlalchemy import JSON as JSONType, func, cast
from sqlalchemy import Column, Enum, ForeignKey, Integer
from sqlalchemy.orm import relationship

from orm.author import Author
from services.db import Base


class NotificationEntity(Enumeration):
    REACTION = 1
    SHOUT = 2
    FOLLOWER = 3


class NotificationAction(Enumeration):
    CREATE = 1
    UPDATE = 2
    DELETE = 3
    SEEN = 4
    FOLLOW = 5
    UNFOLLOW = 6


class NotificationSeen(Base):
    __tablename__ = "notification_seen"

    viewer = Column(ForeignKey("author.id"))
    notification = Column(ForeignKey("notification.id"))


class Notification(Base):
    __tablename__ = "notification"

    created_at = Column(Integer, server_default=cast(func.current_timestamp(), Integer))
    entity = Column(Enum(NotificationEntity), nullable=False)
    action = Column(Enum(NotificationAction), nullable=False)
    payload = Column(JSONType, nullable=True)

    seen = relationship(lambda: Author, secondary="notification_seen")