text: # -*- coding: utf-8 -*-
  """
      :author: Grey Li (李辉)
      :url: http://greyli.com
      :copyright: © 2018 Grey Li <withlihui@gmail.com>
      :license: MIT, see LICENSE for more details.
  """
  from datetime import datetime
  
  from flask_login import UserMixin
  from werkzeug.security import generate_password_hash, check_password_hash
  
  from bluelog.extensions import db
  #from extensions import db
  
  
  class Admin(db.Model, UserMixin):
      id = db.Column(db.Integer, primary_key=True)
      username = db.Column(db.String(20))
      password_hash = db.Column(db.String(128))
      blog_title = db.Column(db.String(60))
      blog_sub_title = db.Column(db.String(100))
      name = db.Column(db.String(30))
      about = db.Column(db.Text)
  
      def set_password(self, password):
          self.password_hash = generate_password_hash(password)
  
      def validate_password(self, password):
          return check_password_hash(self.password_hash, password)
  
  
  class Category(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      name = db.Column(db.String(30), unique=True)
      posts = db.relationship('Post', back_populates='category')
      
      def delete(self):
          default_category = Category.query.get(1)
          posts = self.posts[:]
          for post in posts:
              post.category = default_category
          db.session.delete(self)
          db.session.commit()
  
  
  class Post(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      title = db.Column(db.String(200))
      body = db.Column(db.Text)
      timestamp = db.Column(db.DateTime, default=datetime.utcnow, index=True)
      can_comment = db.Column(db.Boolean, default=True)
  
      category_id = db.Column(db.Integer, db.ForeignKey('category.id'))
  
      category = db.relationship('Category', back_populates='posts')
      comments = db.relationship('Comment', back_populates='post', cascade='all, delete-orphan')
  
  
  class Comment(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      author = db.Column(db.String(30))
      email = db.Column(db.String(254))
      site = db.Column(db.String(255))
      body = db.Column(db.Text)
      from_admin = db.Column(db.Boolean, default=False)
      reviewed = db.Column(db.Boolean, default=False)
      timestamp = db.Column(db.DateTime, default=datetime.utcnow, index=True)
  
      replied_id = db.Column(db.Integer, db.ForeignKey('comment.id'))
      post_id = db.Column(db.Integer, db.ForeignKey('post.id'))
  
      post = db.relationship('Post', back_populates='comments')
      replies = db.relationship('Comment', back_populates='replied', cascade='all, delete-orphan')
      replied = db.relationship('Comment', back_populates='replies', remote_side=[id])
      # Same with:
      # replies = db.relationship('Comment', backref=db.backref('replied', remote_side=[id]),
      # cascade='all,delete-orphan')
  
  
  class Link(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      name = db.Column(db.String(30))
      url = db.Column(db.String(255))
  