import base64
from datetime import datetime, timedelta
import os

from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash

from wort.ext import login, db


class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), index=True, unique=True)
    email = db.Column(db.String(120), index=True, unique=True)
    password_hash = db.Column(db.String(128))
    token = db.Column(db.String(32), index=True, unique=True)
    token_expiration = db.Column(db.DateTime)
    tasks = db.relationship("Task", backref="user", lazy="dynamic")

    def __repr__(self):
        return "<User {}>".format(self.username)

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

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

    def get_token(self, expires_in=3600):
        now = datetime.utcnow()
        if self.token and self.token_expiration > now + timedelta(seconds=60):
            return self.token

        self.token = base64.b64encode(os.urandom(24)).decode("utf-8")
        self.token_expiration = now + timedelta(seconds=expires_in)
        db.session.add(self)
        return self.token

    def revoke_token(self):
        self.token_expiration = datetime.utcnow() - timedelta(seconds=1)

    @staticmethod
    def check_token(token):
        user = User.query.filter_by(token=token).first()
        if user is None or user.token_expiration < datetime.utcnow():
            return None

        return user


@login.user_loader
def load_user(id):
    return User.query.get(int(id))


class Task(db.Model):
    id = db.Column(db.String(36), primary_key=True)
    name = db.Column(db.String(128), index=True)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"))
    complete = db.Column(db.Boolean, default=False)