API: CartPositions (#948)

src/pretix/api/serializers/cart.py

@@ -0,0 +1,115 @@
+from datetime import timedelta
+
+from django.utils.crypto import get_random_string
+from django.utils.timezone import now
+from django.utils.translation import ugettext_lazy
+from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
+
+from pretix.api.serializers.i18n import I18nAwareModelSerializer
+from pretix.api.serializers.order import (
+    AnswerCreateSerializer, AnswerSerializer,
+)
+from pretix.base.models import Quota
+from pretix.base.models.orders import CartPosition
+
+
+class CartPositionSerializer(I18nAwareModelSerializer):
+    answers = AnswerSerializer(many=True)
+
+    class Meta:
+        model = CartPosition
+        fields = ('id', 'cart_id', 'item', 'variation', 'price', 'attendee_name', 'attendee_email',
+                  'voucher', 'addon_to', 'subevent', 'datetime', 'expires', 'includes_tax',
+                  'answers',)
+
+
+class CartPositionCreateSerializer(I18nAwareModelSerializer):
+    answers = AnswerCreateSerializer(many=True, required=False)
+    expires = serializers.DateTimeField(required=False)
+
+    class Meta:
+        model = CartPosition
+        fields = ('cart_id', 'item', 'variation', 'price', 'attendee_name', 'attendee_email',
+                  'subevent', 'expires', 'includes_tax', 'answers',)
+
+    def create(self, validated_data):
+        answers_data = validated_data.pop('answers')
+        if not validated_data.get('cart_id'):
+            cid = "{}@api".format(get_random_string(48))
+            while CartPosition.objects.filter(cart_id=cid).exists():
+                cid = "{}@api".format(get_random_string(48))
+            validated_data['cart_id'] = cid
+
+        if not validated_data.get('expires'):
+            validated_data['expires'] = now() + timedelta(
+                minutes=self.context['event'].settings.get('reservation_time', as_type=int)
+            )
+
+        with self.context['event'].lock():
+            new_quotas = (validated_data.get('variation').quotas.filter(subevent=validated_data.get('subevent'))
+                          if validated_data.get('variation')
+                          else validated_data.get('item').quotas.filter(subevent=validated_data.get('subevent')))
+            for quota in new_quotas:
+                avail = quota.availability()
+                if avail[0] != Quota.AVAILABILITY_OK or (avail[1] is not None and avail[1] < 1):
+                    raise ValidationError(
+                        ugettext_lazy('There is not enough quota available on quota "{}" to perform '
+                                      'the operation.').format(
+                            quota.name
+                        )
+                    )
+            cp = CartPosition.objects.create(event=self.context['event'], **validated_data)
+
+        for answ_data in answers_data:
+            options = answ_data.pop('options')
+            answ = cp.answers.create(**answ_data)
+            answ.options.add(*options)
+        return cp
+
+    def validate_cart_id(self, cid):
+        if cid and not cid.endswith('@api'):
+            raise ValidationError('Cart ID should end in @api or be empty.')
+
+    def validate_item(self, item):
+        if item.event != self.context['event']:
+            raise ValidationError(
+                'The specified item does not belong to this event.'
+            )
+        if not item.active:
+            raise ValidationError(
+                'The specified item is not active.'
+            )
+        return item
+
+    def validate_subevent(self, subevent):
+        if self.context['event'].has_subevents:
+            if not subevent:
+                raise ValidationError(
+                    'You need to set a subevent.'
+                )
+            if subevent.event != self.context['event']:
+                raise ValidationError(
+                    'The specified subevent does not belong to this event.'
+                )
+        elif subevent:
+            raise ValidationError(
+                'You cannot set a subevent for this event.'
+            )
+        return subevent
+
+    def validate(self, data):
+        if data.get('item'):
+            if data.get('item').has_variations:
+                if not data.get('variation'):
+                    raise ValidationError('You should specify a variation for this item.')
+                else:
+                    if data.get('variation').item != data.get('item'):
+                        raise ValidationError(
+                            'The specified variation does not belong to the specified item.'
+                        )
+            elif data.get('variation'):
+                raise ValidationError(
+                    'You cannot specify a variation for this item.'
+                )
+        return data

src/pretix/api/serializers/order.py

@@ -13,7 +13,7 @@ from pretix.base.models import (
     Checkin, Invoice, InvoiceAddress, InvoiceLine, Order, OrderPosition,
     Question, QuestionAnswer, Quota,
 )
-from pretix.base.models.orders import OrderFee
+from pretix.base.models.orders import CartPosition, OrderFee
 from pretix.base.pdf import get_variables
 from pretix.base.signals import register_ticket_outputs
 
@@ -340,11 +340,12 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
     comment = serializers.CharField(required=False, allow_blank=True)
     payment_provider = serializers.CharField(required=True)
     payment_info = CompatibleJSONField(required=False)
+    consume_carts = serializers.ListField(child=serializers.CharField(), required=False)
 
     class Meta:
         model = Order
         fields = ('code', 'status', 'email', 'locale', 'payment_provider', 'fees', 'comment',
-                  'invoice_address', 'positions', 'checkin_attention', 'payment_info')
+                  'invoice_address', 'positions', 'checkin_attention', 'payment_info', 'consume_carts')
 
     def validate_payment_provider(self, pp):
         if pp not in self.context['event'].get_payment_providers():
@@ -399,15 +400,27 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
         else:
             ia = None
 
-        with self.context['event'].lock():
+        with self.context['event'].lock() as now_dt:
             quotadiff = Counter()
+
+            consume_carts = validated_data.pop('consume_carts', [])
+            delete_cps = []
+            if consume_carts:
+                for cp in CartPosition.objects.filter(event=self.context['event'], cart_id__in=consume_carts):
+                    quotas = (cp.variation.quotas.filter(subevent=cp.subevent)
+                              if cp.variation else cp.item.quotas.filter(subevent=cp.subevent))
+                    if cp.expires > now_dt:
+                        quotadiff.subtract(quotas)
+                    delete_cps.append(cp)
+
             for pos_data in positions_data:
                 new_quotas = (pos_data.get('variation').quotas.filter(subevent=pos_data.get('subevent'))
                               if pos_data.get('variation')
                               else pos_data.get('item').quotas.filter(subevent=pos_data.get('subevent')))
                 quotadiff.update(new_quotas)
 
-                for quota, diff in quotadiff.items():
+            for quota, diff in quotadiff.items():
+                if diff > 0:
                     avail = quota.availability()
                     if avail[0] != Quota.AVAILABILITY_OK or (avail[1] is not None and avail[1] < diff):
                         raise ValidationError(
@@ -445,6 +458,9 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                     options = answ_data.pop('options')
                     answ = pos.answers.create(**answ_data)
                     answ.options.add(*options)
+
+            for cp in delete_cps:
+                cp.delete()
         for fee_data in fees_data:
             f = OrderFee(**fee_data)
             f.order = order

src/pretix/api/urls.py

@@ -4,6 +4,8 @@ from django.apps import apps
 from django.conf.urls import include, url
 from rest_framework import routers
 
+from pretix.api.views import cart
+
 from .views import (
     checkin, event, item, oauth, order, organizer, voucher, waitinglist,
 )
@@ -28,6 +30,7 @@ event_router.register(r'invoices', order.InvoiceViewSet)
 event_router.register(r'taxrules', event.TaxRuleViewSet)
 event_router.register(r'waitinglistentries', waitinglist.WaitingListViewSet)
 event_router.register(r'checkinlists', checkin.CheckinListViewSet)
+event_router.register(r'cartpositions', cart.CartPositionViewSet)
 
 checkinlist_router = routers.DefaultRouter()
 checkinlist_router.register(r'positions', checkin.CheckinListPositionViewSet)

src/pretix/api/views/cart.py

@@ -0,0 +1,46 @@
+from django.db import transaction
+from rest_framework import status, viewsets
+from rest_framework.filters import OrderingFilter
+from rest_framework.mixins import CreateModelMixin, DestroyModelMixin
+from rest_framework.response import Response
+
+from pretix.api.serializers.cart import (
+    CartPositionCreateSerializer, CartPositionSerializer,
+)
+from pretix.base.models import CartPosition
+
+
+class CartPositionViewSet(CreateModelMixin, DestroyModelMixin, viewsets.ReadOnlyModelViewSet):
+    serializer_class = CartPositionSerializer
+    queryset = CartPosition.objects.none()
+    filter_backends = (OrderingFilter,)
+    ordering = ('datetime',)
+    ordering_fields = ('datetime', 'cart_id')
+    lookup_field = 'id'
+    permission = 'can_view_orders'
+    write_permission = 'can_change_orders'
+
+    def get_queryset(self):
+        return CartPosition.objects.filter(
+            event=self.request.event,
+            cart_id__endswith="@api"
+        )
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['event'] = self.request.event
+        return ctx
+
+    def create(self, request, *args, **kwargs):
+        serializer = CartPositionCreateSerializer(data=request.data, context=self.get_serializer_context())
+        serializer.is_valid(raise_exception=True)
+        with transaction.atomic():
+            self.perform_create(serializer)
+            cp = serializer.instance
+            serializer = CartPositionSerializer(cp, context=serializer.context)
+
+        headers = self.get_success_headers(serializer.data)
+        return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
+
+    def perform_create(self, serializer):
+        serializer.save()