# Pyrogram - Telegram MTProto API Client Library for Python
# Copyright (C) 2017-2018 Dan Tès <https://github.com/delivrance>
#
# This file is part of Pyrogram.
#
# Pyrogram is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Pyrogram is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.

import os

from pyrogram.api import functions, types
from .utils import compute_hash, compute_check, btoi, itob
from ...ext import BaseClient


class ChangeCloudPassword(BaseClient):
    def change_cloud_password(self,
                              current_password: str,
                              new_password: str,
                              new_hint: str = "") -> bool:
        """Use this method to change your Two-Step Verification password (Cloud Password) with a new one.

        Args:
            current_password (``str``):
                Your current password.

            new_password (``str``):
                Your new password.

            new_hint (``str``, *optional*):
                A new password hint.

        Returns:
            True on success.

        Raises:
            :class:`Error <pyrogram.Error>` in case of a Telegram RPC error.
            ``ValueError`` in case there is no cloud password to change.
        """
        r = self.send(functions.account.GetPassword())

        if not r.has_password:
            raise ValueError("There is no cloud password to change")

        r.new_algo.salt1 += os.urandom(32)
        new_hash = btoi(compute_hash(r.new_algo, new_password))
        new_hash = itob(pow(r.new_algo.g, new_hash, btoi(r.new_algo.p)))

        self.send(
            functions.account.UpdatePasswordSettings(
                password=compute_check(r, current_password),
                new_settings=types.account.PasswordInputSettings(
                    new_algo=r.new_algo,
                    new_password_hash=new_hash,
                    hint=new_hint
                )
            )
        )

        return True