WebSms class

websms.py

'''
WebSms messaging class.

Copyright © 2018 confirm IT solutions
'''

__all__ = (
    'WebSms',
)

from urllib.request import Request, urlopen
from base64 import b64encode
from json import dumps

API_URL = 'https://api.websms.com/rest'


class WebSms:
    '''
    API class to send text messages and WhatsApp messages via the API of
    websms.com.

    .. seealso::

        https://developer.websms.com/web-api/
    '''

    def __init__(self, token=None, username=None, password=None):
        '''
        :param str token: The token used for a login with an access token (option A)
        :param str username: The username used for a login with credentials (option B)
        :param str password: The password used for a login with credentials (option B)
        '''
        if token:
            authorization_header = 'Bearer ' + token
        elif username and password:
            base64_credentials        = b64encode('{}:{}'.format(username, password))
            authorization_header = 'Basic ' + base64_credentials
        else:
            raise TypeError('WebSms needs to be instantiated with a username & password OR a token')

        self.request_headers = {
            'Accept': 'application/json',
            'Content-Type': 'application/json',
            'Authorization': authorization_header,
        }

    @staticmethod
    def convert_to_msisdn_numbers(numbers):
        '''
        Takes a list of numbers and converts all of them into proper MSISDN
        formatted numbers.

        Please note that currently only Swiss numbers are supported, which is
        achieved by doing the following steps:

            - Extract digits only from the numbers
            - Remove leading `00`
            - Add leading `41` to all numbers starting with `07`

        Finally the number must meet the Swiss format or it will be removed
        from the list.

        :param list numbers: Swiss numbers in any format
        :return: Swiss numbers in the MSISDN format
        :rtype: list
        '''
        if isinstance(numbers, (int, str)):
            numbers = [numbers]

        msisdns = []

        for number in numbers:
            number = ''.join([n for n in number if n.isdigit()])
            if len(number) == 13 and number[0:2] == '00':
                number = number[2:]
            elif len(number) == 10 and number[0:2] == '07':
                number = '41{}'.format(number[1:])

            if len(number) == 11 and number[0:2] == '41':
                msisdns.append(number)

        return msisdns

    def request(self, endpoint, data):
        '''
        Send a HTTP POST request to the API endpoint.

        :param str endpoint: The URL of the API endpoint
        :param dict data: The POST data
        :return: The HTTP (JSON) response
        :rtype: str
        '''
        url      = API_URL + endpoint
        data     = dumps(data).encode()
        request  = Request(url=url, headers=self.request_headers, data=data)
        response = urlopen(request).read().decode()

        return response

    def send_text_message(self, message, recipients, sender_address=None, flash_sms=False):
        '''
        Sends a text message to a list of recipients.

        :param str text: The message content
        :param list recipients: The list of E164 formatted MSISDN recipients
        :param senderAddress: The address of the sender
        :type senderAddress: None or str
        :param bool flashSms: Send the message as flash SMS
        '''
        data = {
            'messageContent': message,
            'recipientAddressList': self.convert_to_msisdn_numbers(recipients),
            'sendAsFlashSms': flash_sms
        }

        if sender_address:
            data['senderAddress'] = sender_address
            if not sender_address.isnumeric():
                data['senderAddressType'] = 'alphanumeric'

        return self.request('/smsmessaging/text', data)

    def send_whatsapp_message(self, message, recipients):
        '''
        Sends a whatsapp message (broadcast) to a list of recipients.

        :param str message: The message content
        :param list recipients: The list of E164 formatted MSISDN recipients
        '''
        data = {
            'messageContent': message,
            'recipientAddressList': self.convert_to_msisdn_numbers(recipients),
        }

        return self.request('/converged/whatsapp', data)