#!/usr/bin/env python3

import requests

from getpass import getpass
import json
import os


class AuthenticationError(Exception):
    pass


class PhoneValidationError(Exception):
    pass


class TokenValidationError(Exception):
    pass


client_id = "2274003"
client_secret = "hHbZxrka2uZ6jB1inYsH"
api_ver = "5.89"
scope = "all"
user_agent = "VKAndroidApp/6.2-5091 (Android 9; SDK 28; samsungexynos7870; samsung j6lte; 720x1450)"
api_url = "https://api.vk.com/method/"
receipt = "fkdoOMX_yqQ:APA91bHbLn41RMJmAbuFjqLg5K-QW7si9KajBGCDJxcpzbuvEcPIk9rwx5HWa1yo1pTzpaKL50mXiWvtqApBzymO2sRKlyRiWqqzjMTXUyA5HnRJZyXWWGPX8GkFxQQ4bLrDCcnb93pn"


def request_auth(login: str, password: str, scope: str = "", code: str = "") -> str:
    if not (login or password):
        raise ValueError
    url = (
        "https://oauth.vk.com/token?grant_type=password&client_id="
        + client_id
        + "&client_secret="
        + client_secret
        + "&username="
        + login
        + "&password="
        + password
        + "&v="
        + api_ver
        + "&2fa_supported=1&force_sms=1"
    )
    if scope:
        url += "&scope=" + scope
    if code:
        url += "&code=" + code
    headers = {"User-Agent": user_agent}
    r = requests.get(url, headers=headers)
    if r.status_code == 200 and "access_token" in r.text:
        res = r.json()
        access_token = res["access_token"]
        return access_token
    elif "need_validation" in r.text:
        res = r.json()
        sid = res["validation_sid"]
        code = handle_2fa(sid)
        access_token = request_auth(login, password, scope=scope, code=code)
        return access_token
    else:
        raise AuthenticationError(r.text)


def handle_2fa(sid: str) -> str:
    if not sid:
        raise ValueError("No sid is given")
    url = api_url + "auth.validatePhone?sid=" + sid + "&v=" + api_ver
    headers = {"User-Agent": user_agent}
    r = requests.get(url, headers=headers)
    if r.status_code == 200:
        print("Two factor authentication is required")
        code = ""
        while not code:
            code = input("SMS code: ")
            if len(code) != 6 or not code.isdigit():
                print("SMS code must be a string of 6 digits")
                continue
            return code
    else:
        raise PhoneValidationError(r.text)


def validate_token(token: str) -> str:
    if not (token):
        raise ValueError("Required argument is missing")
    url = api_url + "auth.refreshToken?access_token=" + token + "&receipt=" + receipt + "&v=" + api_ver
    headers = {"User-Agent": user_agent}
    r = requests.get(url, headers=headers)
    if r.status_code == 200 and "token" in r.text:
        res = r.json()
        received_token = res["response"]["token"]
        if not received_token:
            raise TokenValidationError(r.text)
        else:
            return received_token
    else:
        raise TokenValidationError(r.text)


def main():
    login = ""
    password = ""
    try:
        print("VK Authentication Helper for TTMediaBot")
        print()
        print("Enter your VK credentials to continue")
        while not login:
            login = input("Phone, email or  login: ")
        while not password:
            password = getpass("Password: ")
        token = request_auth(login, password, scope=scope)
        validated_token = validate_token(token)
        y_or_n = input("Do you want to save the token to the configuration file? y/n")
        if y_or_n == "y":
            config_file = input("Configuration file path: ")
            with open(config_file, "r") as f:
                data = json.load(f)
            data["services"]["vk"]["token"] = validated_token
            with open(config_file, "w") as f:
                json.dump(data, f, indent=4, ensure_ascii=False)
            print("Your token has been successfully saved to the configuration file")
        else:
            print("Your VK token:")
            print(validated_token)
    except Exception as e:
        print(e)
    input("Press enter to continue")


if __name__ == "__main__":
    main()