WIP:Add Reminder Email for events

amivapi/cron.py

@@ -99,7 +99,11 @@ def wrapped():
 
 def schedule_task(time, func, *args):
     """ Schedule a task at some point in the future. """
-    func_s = func_str(func)
+    if func_str(func) is "remindermail":
+        item = pickle.load(args)
+        func_s = "remindermail"+str(item['_id'])
+    else:
+        func_s = func_str(func)
 
     if func_s not in schedulable_functions:
         raise NotSchedulable("%s is not schedulable. Did you forget the "
@@ -114,7 +118,11 @@ def schedule_task(time, func, *args):
 
 def update_scheduled_task(time, func, *args):
     """ Update a scheduled task that was previously registered. """
-    func_s = func_str(func)
+    if func_str(func) is "remindermail":
+        item = pickle.load(args)
+        func_s = "remindermail_"+str(item['_id'])
+    else:
+        func_s = func_str(func)
 
     if func_s not in schedulable_functions:
         raise NotSchedulable("%s is not schedulable. Did you forget the "

amivapi/events/__init__.py

@@ -13,9 +13,11 @@
 from amivapi.events.emails import (
     add_confirmed_before_insert,
     add_confirmed_before_insert_bulk,
+    add_scheduled_remindermail,
+    add_scheduled_remindermail_bulk,
     email_blueprint,
     send_confirmmail_to_unregistered_users,
-    send_confirmmail_to_unregistered_users_bulk
+    send_confirmmail_to_unregistered_users_bulk,
 )
 from amivapi.events.model import eventdomain
 from amivapi.events.projections import (
@@ -71,4 +73,8 @@ def init_app(app):
     app.on_inserted_eventsignups += update_waiting_list_after_insert_collection
     app.on_deleted_item_eventsignups += update_waiting_list_after_delete
 
+    # Schedule sending of reminder email at event creation
+    app.on_inserted_item_events += add_scheduled_remindermail
+    app.on_inserted_events += add_scheduled_remindermail_bulk
+
     app.register_blueprint(email_blueprint)

amivapi/events/emails.py

@@ -7,12 +7,14 @@
 Needed when external users want to sign up for public events.
 """
 from bson import ObjectId
+from datetime import datetime, timedelta
 from eve.methods.delete import deleteitem_internal
 from eve.methods.patch import patch_internal
 from flask import Blueprint, current_app, redirect, url_for
 from itsdangerous import BadSignature, Signer
 
 from amivapi.events.queue import update_waiting_list
+from amivapi.cron import schedulable, schedule_task, update_scheduled_task
 from amivapi.utils import mail
 
 email_blueprint = Blueprint('emails', __name__)
@@ -59,6 +61,91 @@ def send_confirmmail_to_unregistered_users_bulk(items):
         send_confirmmail_to_unregistered_users(item)
 
 
+@schedulable
+def remindermail(item):
+    """Send a reminder email to all participants registered to an event
+
+    Args:
+        item: The item, which was just inserted into the database
+    """
+    event = item
+
+    # Fetch all the infos needed for the content
+    if event['title_en'] is not "":
+        title = event['title_en']
+    else:
+        title = event['title_de']
+
+    if event['location'] is not "":
+        location = event['location']
+    else:
+        location = ""
+
+    if event['time_start'] is not None:
+        date_time_event = event['time_start'].strftime(' %d %B %Y at %-H:%M ')
+    else:
+        date_time_event = " NaN "
+
+    fields = {
+        'location': location,
+        'datetime': date_time_event,
+        'title': title
+    }
+
+    # Populate content text with fetched infos
+    email_content = current_app.config['REMINDER_EMAIL_TEXT'] % fields
+
+    # Fetch the related eventsignups to get the emails.
+    eventsignups = current_app.data.find(
+        'eventsignups',
+        **{current_app.config['event']: item['event']})
+
+    participants_list = list()
+    for signup in eventsignups:
+        participants_list.append(signup['email'])
+
+    mail(current_app.config['API_MAIL'],
+         participants_list,
+         'Reminder for AMIV event %s' % title,
+         email_content)
+
+
+def add_scheduled_remindermail(item):
+    """ Schedule the sending of a remindermail by [REMINDER_EMAIL_DAYS2EVENT]
+    days before the event time_start. If no time_start is defined,
+    then no remindermail will be sent.
+    """
+    if 'time_start' in item:
+        time_start_event = datetime.strptime(item['time_start'],
+                                             '%Y-%m-%dT%H:%M:%SZ')
+        datetime_reminder = time_start_event - \
+            timedelta(
+                  days=int(current_app.config['REMINDER_EMAIL_DAYS2EVENT']))
+        schedule_task(datetime_reminder,
+                      remindermail,
+                      item)
+
+
+def add_scheduled_remindermail_bulk(items):
+    for item in items:
+        add_scheduled_remindermail(item)
+
+
+def update_scheduled_remindermail(item):
+    """ Update the schedule of a remindermal to fit updated time_start
+    or other infos of the event
+    """
+    if 'time_start' in item:
+        time_start_event = datetime.strptime(item['time_start'],
+                                             '%Y-%m-%dT%H:%M:%SZ')
+        datetime_reminder = time_start_event - \
+            timedelta(
+                  days=int(current_app.config['REMINDER_EMAIL_DAYS2EVENT']))
+        update_scheduled_task(datetime_reminder,
+                              remindermail,
+                              item)
+
+
 def add_confirmed_before_insert(item):
     """Add the confirmed field to a event signup before it is inserted to the
     database. We accept all registered users instantly, others need to click the