import time

from sqlalchemy import Boolean, Column, ForeignKey, Integer, String
from sqlalchemy import event

from services.db import Base
from orm.author import get_object, update_follows, update_app_data

class TopicFollower(Base):
    __tablename__ = 'topic_followers'

    id = None  # type: ignore
    follower = Column(ForeignKey('author.id'), primary_key=True)
    topic = Column(ForeignKey('topic.id'), primary_key=True)
    created_at = Column(Integer, nullable=False, default=lambda: int(time.time()))
    auto = Column(Boolean, nullable=False, default=False)


class Topic(Base):
    __tablename__ = 'topic'

    slug = Column(String, unique=True)
    title = Column(String, nullable=False, comment='Title')
    body = Column(String, nullable=True, comment='Body')
    pic = Column(String, nullable=True, comment='Picture')
    community = Column(ForeignKey('community.id'), default=1)
    oid = Column(String, nullable=True, comment='Old ID')


@event.listens_for(TopicFollower, 'after_insert')
@event.listens_for(TopicFollower, 'after_delete')
def after_topic_follower_change(mapper, connection, target):
    topic_id = target.topic
    follower_id = target.follower
    user = get_object(connection, 'authorizer_users', follower_id)
    if user:
        app_data = update_follows(user, 'topic', get_object(connection, 'topic', topic_id))
        update_app_data(connection, follower_id, app_data)