Fix username taken check, return json

import os

import logging

import sys

import json

ch = logging.StreamHandler(sys.stdout)

ch.setLevel(logging.DEBUG)

        target_username = target_email.split('@')[0]

        with open('forbidden_usernames') as f:

            if target_username in f.read().splitlines():

                self.respond(403, 'this username is not allowed')

                data = json.dumps({'success': False, 'message': 'username_forbidden'})

                self.respond(403, data)

                return

        # create account via postfixadmin ssh

        with paramiko.SSHClient() as ssh:

            ssh.connect(hostname='postfixadmin', username='pfexec', password=os.environ['POSTFIXADMIN_SSH_PASSWORD'])

            stdin, stdout, stderr = ssh.exec_command(f'/postfixadmin/scripts/postfixadmin-cli mailbox view "{target_email}"')

            if b"error: the email is not valid!" in stderr.read().lower():

                self.respond(403, 'this username is already used')

            if b"error: the email is not valid!" not in stderr.read().lower():

                data = json.dumps({'success': True, 'message': 'username_taken'})

                self.respond(403, data)

                return

            ssh.exec_command(f'/postfixadmin/scripts/postfixadmin-cli mailbox add "{target_email}" ' +

        print(f'status code: {r.status_code}')

        # TODO: check status code

        self.respond(200, "account created")

        self.respond(200, json.dumps({'success', True}))

    def respond(self, status: int, message: str):

        print(f'sending response status {status}, message {message}')

        self.send_response(status)

        self.end_headers()

        self.wfile.write(message.encode())