bunalert.py

import boto3
import logging
import phonenumbers
from flask import abort
from flask import Flask
from flask import request
from jinja2 import Environment
from jinja2 import FileSystemLoader
from phonenumbers import carrier
from phonenumbers.phonenumberutil import number_type

app = Flask(__name__)

# Setup logger.
logger = logging.getLogger()
logger.setLevel(logging.INFO)


@app.route('/')
def index():
    """
    This is the main index page function. Nothing fancy here.
    :return: A tuple of an HTML page and an HTTP Status code.
    """
    logging.info('index page started.')
    template = Environment(loader=FileSystemLoader('html/')).get_template('index.j2')
    page = template.render()
    logging.info('index page returned.')
    return page, 200


@app.route('/subscribe', methods=['POST'])
@app.route('/dev/subscribe', methods=['POST'])
def subscribe():
    """
    This is the function for handling subscription requests. It will error clearly if a new phone number wasn't passed
    in when the page was requested.
    :return: A tuple of an HTML page and an HTTP Status code.
    """
    logging.info('subscribe page started.')
    try:
        form_response = request.form
        subscriber_number = form_response['subscriber_number']
        if not subscriber_number:
            raise Exception('No subscriber number was passed in!')

        logging.info('subscribe page checking subscriber_number is valid.')
        # Checking if subscriber_number matches valid format: +18885554444
        carrier._is_mobile(number_type(phonenumbers.parse(subscriber_number)))

        logging.info('subscribe page got valid subscriber_number of {}.'.format(subscriber_number))
        # Try to subscribe the number.
        topic_arn = 'arn:aws:sns:us-west-2:277012880214:BunAlert'
        snsclient = boto3.client(
            'sns',
            region_name='us-west-2'
        )

        logging.info('subscribe page made SNS client.')
        subscribe_response = snsclient.subscribe(
            TopicArn=topic_arn,
            Protocol='sms',
            Endpoint='{}'.format(subscriber_number)
        )

        logging.info('subscribe page subscribed the new subscriber_number.')
        # If all's good, render the response page.
        template = Environment(loader=FileSystemLoader('html/')).get_template('subscribe.j2')
        page = template.render(subscriber_number=subscriber_number)
        logging.info('subscribe page returned.')
        return page, 200

    except Exception as e:
        logging.info('subscribe page errored.')
        page = 'Something went wrong! Exception: {}'.format(e)
        logging.error(page)
        return page, 400


@app.route('/alert', methods=['GET', 'POST'])
@app.route('/dev/alert', methods=['GET', 'POST'])
def alert():
    """
    This is a function with two responsibilities: for providing the form for publishing a new alert to the SNS Topic,
    and also for confirming that the new alert was published successfully.

    :return: A tuple of an HTML page and an HTTP Status code.
    """

    # If the page is being requested from an IP address other than one of the whitelist, return a 403.
    whitelist = [
        '127.0.0.1',
    ]

    if request.remote_addr not in whitelist:
        abort(403, 'IP address {} forbidden.'.format(request.remote_addr))
    else:
        logger.info('alert page opened from IP address {}.'.format(request.remote_addr))

    logging.info('alert page started.')
    if request.method == 'POST':
        logger.info('alert page POST requested.')
        try:
            form_response = request.form
            alert_message = form_response['alert_message']
            if not alert_message:
                raise Exception('No alert message was passed in!')

            logging.info('alert page got an alert_message!')
            # Try to publish that message.
            topic_arn = 'arn:aws:sns:us-west-2:277012880214:BunAlert'
            snsclient = boto3.client(
                'sns',
                region_name='us-west-2'
            )

            snsclient.publish(Message='A Bun has been spotted! {} (Text "STOP" to opt out of Bun Alert.)'.format(alert_message), TopicArn=topic_arn)

            # If all's well, return to the alert page with success message.
            template = Environment(loader=FileSystemLoader('html/')).get_template('alert.j2')
            page = template.render(alert_result='Alert message published successfully!')
            logging.info('alert page returned.')
            return page, 200

        except Exception as e:
            logging.info('alert page errored.')
            page = 'Something went wrong! Exception: {}'.format(e)
            logging.error(page)
            return page, 400
    else:
        # If it's not a POST, must be a GET! Return form page.
        template = Environment(loader=FileSystemLoader('html/')).get_template('alert.j2')
        page = template.render()
        logging.info('alert page returned.')
        return page, 200


if __name__ == '__main__':
    app.run('localhost', '5000')