import hashlib
import os
import uuid

import jwt
from apiflask import abort
from flask import request

from db import db
from models import User


def hash_password(password):
    salt = uuid.uuid4().hex
    return hashlib.sha256(salt.encode() + password.encode()).hexdigest() + ':' + salt


def check_password(hashed_password, user_password):
    password, salt = hashed_password.split(':')
    return password == hashlib.sha256(salt.encode() + user_password.encode()).hexdigest()


def get_token():
    token = None
    if 'Authorization' in request.headers:
        token = request.headers['Authorization'].split(" ")[1]

    return token


def extract_token_data(token):
    if token is not None:
        try:
            return jwt.decode(token, os.getenv('SECRET_KEY'), algorithms=["HS256"])
        except jwt.exceptions.DecodeError:
            return None
    else:
        return None


def get_username_from_token_data(token_data):
    if token_data is not None:
        return token_data['username']
    else:
        return None


def get_user_id_from_username(username):
    if username is not None:
        return db.session.query(User).filter_by(username=username).first().user_id
    else:
        return None


def get_username_or_abort_401():
    # get username from jwt token
    username = get_username_from_token_data(extract_token_data(get_token()))

    if username is None:  # If token not provided or invalid -> return 401 code
        abort(401, message="Unable to login")

    return username


def abort_if_no_admin():
    if not is_user_admin():
        abort(401, message="Only admin users can access this")


def is_user_admin():
    username = get_username_or_abort_401()

    return db.session.query(User).filter_by(username=username).first().admin