Fix #515 -- Add check-in lists (#693)

* Data model and migration

* Some backwards compatibility

* CRUD for checkin lists

* Show and perform checkins

* Correct numbers in table and dashboard widget

* event creation and cloning

* Allow to link specific exports and pass options per query

* Play with the CSV export

* PDF export

* Collapse exports by default

* Improve PDF exporter

* Addon stuff

* Subevent stuff, pretixdroid tests

* pretixdroid tests

* Add CRUD API

* Test compatibility

* Fix test

* DB-independent sorting behavior

* Add CRUD and coyp tests

* Re-enable pretixdroid plugin

* pretixdroid config

* Tests & fixes

src/pretix/base/models/checkin.py

@@ -1,5 +1,76 @@
 from django.db import models
+from django.db.models import Case, Count, F, OuterRef, Q, Subquery, When
+from django.db.models.functions import Coalesce
 from django.utils.timezone import now
+from django.utils.translation import pgettext_lazy, ugettext_lazy as _
+
+from pretix.base.models import LoggedModel
+
+
+class CheckinList(LoggedModel):
+    event = models.ForeignKey('Event', related_name='checkin_lists')
+    name = models.CharField(max_length=190)
+    all_products = models.BooleanField(default=True, verbose_name=_("All products (including newly created ones)"))
+    limit_products = models.ManyToManyField('Item', verbose_name=_("Limit to products"), blank=True)
+    subevent = models.ForeignKey('SubEvent', null=True, blank=True,
+                                 verbose_name=pgettext_lazy('subevent', 'Date'))
+
+    @staticmethod
+    def annotate_with_numbers(qs, event):
+        from . import Order, OrderPosition
+        cqs = Checkin.objects.filter(
+            position__order__event=event,
+            position__order__status=Order.STATUS_PAID,
+            list=OuterRef('pk')
+        ).filter(
+            # This assumes that in an event with subevents, *all* positions have subevents
+            # and *all* checkin lists have a subevent assigned
+            Q(position__subevent=OuterRef('subevent'))
+            | (Q(position__subevent__isnull=True))
+        ).order_by().values('list').annotate(
+            c=Count('*')
+        ).values('c')
+        pqs_all = OrderPosition.objects.filter(
+            order__event=event,
+            order__status=Order.STATUS_PAID,
+        ).filter(
+            # This assumes that in an event with subevents, *all* positions have subevents
+            # and *all* checkin lists have a subevent assigned
+            Q(subevent=OuterRef('subevent'))
+            | (Q(subevent__isnull=True))
+        ).order_by().values('order__event').annotate(
+            c=Count('*')
+        ).values('c')
+        pqs_limited = OrderPosition.objects.filter(
+            order__event=event,
+            order__status=Order.STATUS_PAID,
+            item__in=OuterRef('limit_products')
+        ).filter(
+            # This assumes that in an event with subevents, *all* positions have subevents
+            # and *all* checkin lists have a subevent assigned
+            Q(subevent=OuterRef('subevent'))
+            | (Q(subevent__isnull=True))
+        ).order_by().values('order__event').annotate(
+            c=Count('*')
+        ).values('c')
+
+        return qs.annotate(
+            checkin_count=Coalesce(Subquery(cqs, output_field=models.IntegerField()), 0),
+            position_count=Coalesce(Case(
+                When(all_products=True, then=Subquery(pqs_all, output_field=models.IntegerField())),
+                default=Subquery(pqs_limited, output_field=models.IntegerField()),
+                output_field=models.IntegerField()
+            ), 0)
+        ).annotate(
+            percent=Case(
+                When(position_count__gt=0, then=F('checkin_count') * 100 / F('position_count')),
+                default=0,
+                output_field=models.IntegerField()
+            )
+        )
+
+    def __str__(self):
+        return self.name
 
 
 class Checkin(models.Model):
@@ -9,3 +80,11 @@ class Checkin(models.Model):
     position = models.ForeignKey('pretixbase.OrderPosition', related_name='checkins')
     datetime = models.DateTimeField(default=now)
     nonce = models.CharField(max_length=190, null=True, blank=True)
+    list = models.ForeignKey(
+        'pretixbase.CheckinList', related_name='checkins', on_delete=models.PROTECT,
+    )
+
+    def __repr__(self):
+        return "<Checkin: pos {} on list '{}' at {}>".format(
+            self.position, self.list, self.datetime
+        )