cron.py

"""This module provides endpoint logic for cron jobs that send team update
reminder emails and digest emails.
"""

import datetime
import functools
import logging
import webapp2
import yaml

from google.appengine.api import mail
from google.appengine.api import app_identity

import model


class CronUpdateHandler(webapp2.RequestHandler):

    with open('config.yaml', 'r') as f:
        doc = yaml.load(f);
    
    appname = doc["appname"]

    @classmethod
    def get_reply_address(cls, urlsafe):
        """Return update email reply address given supplied urlsafe string."""
        app_id = app_identity.get_application_id()
        return '%s <update+%s@%s.appspotmail.com>' % (cls.appname, urlsafe, app_id)

    @classmethod
    def get_update_message(cls, team, to, sender, date):
        """Return unsent update EmailMessage."""
        day = "{:%b %d, %Y}".format(date)

        header = "Just reply with a few brief bullets starting with *. "
        header += "Finish with [DONE] if there is extraneous or quoted "
        header += "text at the end of the e-mail reply."

        fields = dict(
            sender=sender,
            to=to,
            reply_to=sender,
            subject='[%s] Send %s updates - %s' % (cls.appname, team.upper(), day),
            body=header)
        return mail.EmailMessage(**fields)

    @classmethod
    def process_subscriber_update(cls, date, subscriber):
        """Create new SubscriberUpdate and send update email to subscriber."""
        subscriber_update = model.SubscriberUpdate.get_or_insert(
            name=subscriber.name, mail=subscriber.mail, team=subscriber.team,
            date=date)
        sender = cls.get_reply_address(subscriber_update.key.urlsafe())
        message = cls.get_update_message(
            subscriber.team, subscriber.mail, sender, date)
        message.send()
        subscriber_update.sent = True
        subscriber_update.put()

    @classmethod
    def process_update(cls, team, date):
        """Create new Update for supplied team and send team update emails."""
        update = model.Update.get_or_insert(team, date=date)
        f = functools.partial(cls.process_subscriber_update, update.date)
        map(f, model.Subscriber.subscribed(team))

    def update(self, team):
        """Sends update reminder emails to all subscribers."""
        self.process_update(team, datetime.datetime.now())


class CronDigestHandler(webapp2.RequestHandler):

    with open('config.yaml', 'r') as f:
        doc = yaml.load(f);
    
    appname = doc["appname"]

    @classmethod
    def get_digest_message(cls, team, digest, date, to):
        """Sends update reminder email to subscriber."""
        day = "{:%b %d, %Y}".format(date)
        app_id = app_identity.get_application_id()
        reply_to = '%s <noreply@%s.appspotmail.com>' % (cls.appname, app_id)
        fields = dict(
            sender=reply_to,
            to=to,
            reply_to=reply_to,
            subject='[%s] %s team updates - %s' % (cls.appname, team.upper(), day),
            body=digest)
        return mail.EmailMessage(**fields)

    @classmethod
    def get_subscriber_updates(cls, team, date):
        """Return list of SubscriberUpdate for team and date with messages."""
        return [x for x in
                model.SubscriberUpdate.get_updates(date, team)
                if x.message]

    @classmethod
    def get_update(cls, x):
        """Return formatted update string for supplied SubscriberUpdate x."""
        update = x.to_dict()
        update['message'] = update['message'].encode('utf8')
        return '{name} <{mail}>\n{message}\n\n'.format(**update)

    @classmethod
    def process_digest(cls, team, test=None):
        update = model.Update.latest(team)
        if not update:
            logging.info('No Update to process for digest')
            return
        digest = ''.join(
            map(cls.get_update, cls.get_subscriber_updates(team, update.date)))
        if test:
            return digest
        if not digest:
            logging.info('No subscriber updates to process for digest')
            return
        for subscriber in model.Subscriber.subscribed(team):
            subscriber_digest = model.SubscriberDigest.get_or_insert(
                mail=subscriber.mail, team=team, date=update.date)
            if not subscriber_digest.sent:
                message = cls.get_digest_message(
                    team, digest, update.date, subscriber.mail)
                message.send()
                subscriber_digest.sent = True
                subscriber_digest.put()
        return digest

    def digest(self, team):
        test = self.request.get('test')
        if test:
            digest = self.process_digest(team, test=test)
            self.response.out.write(digest)
        else:
            self.process_digest(team)

routes = [
    webapp2.Route('/cron/update/<team:.*>', handler=CronUpdateHandler,
                  handler_method='update'),
    webapp2.Route('/cron/digest/<team:.*>', handler=CronDigestHandler,
                  handler_method='digest'),
]

handlers = webapp2.WSGIApplication(routes, debug=True)