from app import db
from datetime import datetime
from werkzeug.security import generate_password_hash,check_password_hash
from flask_login import UserMixin
from app import login
from hashlib import md5


#userloader function for flask_login
@login.user_loader
def load_user(id):
    return User.query.filter(User.id==int(id)).first()




class User(db.Model,UserMixin):
    id=db.Column(db.Integer,primary_key=True)
    username=db.Column(db.String(64),index=True,unique=True)
    email=db.Column(db.String(64),index=True,unique=True)
    password_hash=db.Column(db.String(128))
    about_me=db.Column(db.String(140))
    last_seen=db.Column(db.DateTime,default=datetime.utcnow)
    posts = db.relationship('Post',backref='author',lazy='dynamic')

    #methods for storing and checking passwords
    def set_password(self,password):
        self.password_hash=generate_password_hash(password)

    def check_password(self,password):
        return check_password_hash(pwhash=self.password_hash,password=password)

    def __repr__(self):
        return '<user {}>'.format(self.username)

    #method for generating user avatar url
    def avatar(self, size):
        digest = md5(self.email.lower().encode('utf-8')).hexdigest()
        return 'https://www.gravatar.com/avatar/{}?d=identicon&s={}'.format(
            digest, size)


class Post(db.Model):
    id=db.Column(db.Integer,primary_key=True)
    body=db.Column(db.String(140))
    timestamp=db.Column(db.DateTime,index=True,default=datetime.utcnow)
    user_id=db.Column(db.Integer,db.ForeignKey('user.id'))

    def __repr__(self):
        return '<post {}>'.format(self.body)