# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2018 New Vector
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#
# This script has been simplified and adapted from
# https://raw.githubusercontent.com/matrix-org/synapse/master/synapse/_scripts/register_new_matrix_user.py
#
# The purpose is to facilitate registration using a shared_secret over the open
# registration that is supported in the matrix spec
#

import hashlib
import hmac
import logging
from typing import Dict, Optional

import requests as _requests

log = logging.getLogger(__name__)


def request_registration(
        user,
        password,
        server_location,
        shared_secret,
        admin=False,
        user_type=None,
        requests=_requests) -> Optional[Dict]:
    url = "%s/_matrix/client/r0/admin/register" % (server_location,)

    # Get the nonce
    r = requests.get(url, verify=False)

    if r.status_code is not 200:
        log.error("ERROR! Received %d %s" % (r.status_code, r.reason))
        if 400 <= r.status_code < 500:
            try:
                log.error(r.json()["error"])
            except Exception as e:
                log.error(e)
        return None

    nonce = r.json()["nonce"]

    mac = hmac.new(key=shared_secret.encode('utf8'), digestmod=hashlib.sha1)

    mac.update(nonce.encode('utf8'))
    mac.update(b"\x00")
    mac.update(user.encode('utf8'))
    mac.update(b"\x00")
    mac.update(password.encode('utf8'))
    mac.update(b"\x00")
    mac.update(b"admin" if admin else b"notadmin")
    if user_type:
        mac.update(b"\x00")
        mac.update(user_type.encode('utf8'))

    mac = mac.hexdigest()

    data = {
        "nonce": nonce,
        "username": user,
        "password": password,
        "mac": mac,
        "admin": admin,
        "user_type": user_type,
    }

    log.debug("Sending registration request...")
    r = requests.post(url, json=data, verify=False)

    if r.status_code is not 200:
        log.error("ERROR! Received %d %s" % (r.status_code, r.reason))
        if 400 <= r.status_code < 500:
            try:
                log.error(r.json()["error"])
            except Exception as e:
                log.error(e)
        return None
    return r.json()


def register_new_user(
        user: str,
        password: str,
        server_location: str,
        shared_secret: str) -> Optional[Dict]:
    return request_registration(
        user, password, server_location, shared_secret, False, None)