import datetime

import jwt
from flask import current_app

from mpwo_api import bcrypt, db


class User(db.Model):
    __tablename__ = "users"
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    created_at = db.Column(db.DateTime, nullable=False)
    admin = db.Column(db.Boolean, default=False, nullable=False)

    def __repr__(self):
        return '<User %r>' % self.username

    def __init__(
            self, username, email, password,
            created_at=datetime.datetime.utcnow()):
        self.username = username
        self.email = email
        self.password = bcrypt.generate_password_hash(
            password, current_app.config.get('BCRYPT_LOG_ROUNDS')
        ).decode()
        self.created_at = created_at

    @staticmethod
    def encode_auth_token(user_id):
        """Generates the auth token"""
        try:
            payload = {
                'exp': datetime.datetime.utcnow() + datetime.timedelta(
                    days=current_app.config.get('TOKEN_EXPIRATION_DAYS'),
                    seconds=current_app.config.get('TOKEN_EXPIRATION_SECONDS')
                ),
                'iat': datetime.datetime.utcnow(),
                'sub': user_id
            }
            return jwt.encode(
                payload,
                current_app.config.get('SECRET_KEY'),
                algorithm='HS256'
            )
        except Exception as e:
            return e

    @staticmethod
    def decode_auth_token(auth_token):
        """
        Decodes the auth token
        :param auth_token: -
        :return: integer|string
        """
        try:
            payload = jwt.decode(
                auth_token,
                current_app.config.get('SECRET_KEY'))
            return payload['sub']
        except jwt.ExpiredSignatureError:
            return 'Signature expired. Please log in again.'
        except jwt.InvalidTokenError:
            return 'Invalid token. Please log in again.'