Fix #293 -- Add ticket downloading reminder (#567)

Closes https://github.com/pretix/pretix/issues/293

src/pretix/base/migrations/0072_order_download_reminder_sent.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.4 on 2017-08-04 13:42
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0071_auto_20170729_1616'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='order',
+            name='download_reminder_sent',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/models/orders.py

@@ -92,6 +92,8 @@ class Order(LoggedModel):
     :type total: decimal.Decimal
     :param comment: An internal comment that will only be visible to staff, and never displayed to the user
     :type comment: str
+    :param download_reminder_sent: A field to indicate whether a download reminder has been sent.
+    :type download_reminder_sent: boolean
     :param meta_info: Additional meta information on the order, JSON-encoded.
     :type meta_info: str
     """
@@ -181,6 +183,10 @@ class Order(LoggedModel):
     expiry_reminder_sent = models.BooleanField(
         default=False
     )
+
+    download_reminder_sent = models.BooleanField(
+        default=False
+    )
     meta_info = models.TextField(
         verbose_name=_("Meta information"),
         null=True, blank=True

src/pretix/base/services/orders.py

@@ -528,6 +528,46 @@ def send_expiry_warnings(sender, **kwargs):
                 logger.exception('Reminder email could not be sent')
 
 
+@receiver(signal=periodic_task)
+def send_download_reminders(sender, **kwargs):
+    eventcache = {}
+    today = now().replace(hour=0, minute=0, second=0)
+
+    for e in Event.objects.filter(date_from__gte=today):
+        eventsettings = eventcache.get(e.pk, None)
+        if eventsettings is None:
+            eventsettings = e.settings
+            eventcache[e.pk] = eventsettings
+
+        days = eventsettings.get('mail_days_download_reminder', as_type=int)
+        if days is not None:
+            continue
+
+        reminder_date = (e.date_from - timedelta(days=days)).replace(hour=0, minute=0, second=0)
+
+        if (today > reminder_date):
+            continue
+        for o in e.orders.filter(status="paid", download_reminder_sent=False):
+            o.download_reminder_sent = True
+            o.save()
+            email_template = eventsettings.mail_text_download_reminder
+            email_context = {
+                'event': o.event.name,
+                'url': build_absolute_uri(o.event, 'presale:event.order', kwargs={
+                    'order': o.code,
+                    'secret': o.secret
+                }),
+            }
+            email_subject = _('Your ticket is ready for download: %(code)s') % {'code': o.code}
+            try:
+                o.send_mail(
+                    email_subject, email_template, email_context,
+                    'pretix.event.order.email.expire_warning_sent'
+                )
+            except SendMailException:
+                logger.exception('Reminder email could not be sent')
+
+
 class OrderChangeManager:
     error_messages = {
         'free_to_paid': _('You cannot change a free order to a paid order.'),

src/pretix/base/settings.py

@@ -360,6 +360,21 @@ Your {event} team"""))
 You can change your order details and view the status of your order at
 {url}
 
+Best regards,
+Your {event} team"""))
+    },
+    'mail_days_download_reminder': {
+        'type': int,
+        'default': None
+    },
+    'mail_text_download_reminder': {
+        'type': LazyI18nString,
+        'default': LazyI18nString.from_gettext(ugettext_noop("""Hello,
+
+you bought a ticket for {event}.
+
+This is to remind you that your ticket is ready for downloading!
+
 Best regards,
 Your {event} team"""))
     },