#!/usr/bin/env python3

import json
import os

from Crypto.PublicKey import RSA

from authentication import Authetication

def generatePrivateKeyForUser(auth: Authetication,username: str, user_passphrase: str, public_server_key: str,address: str) -> bool:
    if auth.checkUserExists(username):
        with open(auth.CONFIG_FILE_LOCATION) as json_file:
            data = json.load(json_file)

        private_key = RSA.generate(8192)
        public_key = private_key.publickey()
        private_key_value = bytes.hex(private_key.exportKey('DER', passphrase=user_passphrase, pkcs=8))
        public_key_value = bytes.hex(public_key.exportKey('DER', pkcs=8))

        ##Save private key in separate file
        user_privatekey = {'address': address,
                           'privateClientKey': private_key_value,
                           'publicServerKey': public_server_key}
        with open(auth.PRIVATE_KEY_DIRECTORY_LOCATION + os.path.sep + str(data['index']) + '.txt',
                  'w+') as outfile:
            json.dump(user_privatekey, outfile)
        outfile.close()

        ##Save public key in users
        for user in data['user']:
            if username == user['username']:
                user['publicKey'] = public_key_value
                with open(auth.CONFIG_FILE_LOCATION, 'w+') as outfile:
                    json.dump(data, outfile)
                break
        outfile.close()
        return True
    else:
        return False


def generatePrivateKeyForServer(auth: Authetication,passphrase: str) -> str:
    with open(auth.CONFIG_FILE_LOCATION) as json_file:
        data = json.load(json_file)
    json_file.close()

    private_key = RSA.generate(8192)
    public_key = private_key.publickey()
    private_key_value = bytes.hex(private_key.exportKey('DER', passphrase=passphrase, pkcs=8, protection="scryptAndAES128-CBC"))
    public_key_value = bytes.hex(public_key.exportKey('DER', pkcs=8))

    data['serverPrivateKey'] = private_key_value
    with open(auth.CONFIG_FILE_LOCATION, 'w+') as outfile:
        json.dump(data, outfile)

    return public_key_value


def generateSourceAddress(index: str) -> chr:
    return chr(ord(index[0]) + 17)


if __name__ == '__main__':
    auth = Authetication()
    auth.initConfig()
    serverPublicKey = generatePrivateKeyForServer(auth, 'admin')
    auth.saveUser('alma', 'alma')
    homeDir = auth.login('alma', 'alma')
    generatePrivateKeyForUser(auth, 'alma', 'amla', serverPublicKey, generateSourceAddress(homeDir))
    auth.saveUser('citrom', 'citrom')
    homeDir = auth.login('citrom', 'citrom')
    generatePrivateKeyForUser(auth, 'citrom', 'mortic', serverPublicKey, generateSourceAddress(homeDir))