Fix #599 -- Add API to create orders (#911)

* [WIP] Fix #599 -- Add API to create orders

* Add more validation logic

* Add docs and some validation

* Fix test on MySQl

* Validation is fun, let's do more of it!

* Fix live_issues

src/pretix/api/serializers/order.py

@@ -1,16 +1,25 @@
+import json
+from collections import Counter
+from decimal import Decimal
+
+from django_countries.fields import Country
 from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
 from rest_framework.reverse import reverse
 
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.base.models import (
     Checkin, Invoice, InvoiceAddress, InvoiceLine, Order, OrderPosition,
-    QuestionAnswer,
+    Question, QuestionAnswer, Quota,
 )
 from pretix.base.models.orders import OrderFee
 from pretix.base.signals import register_ticket_outputs
 
 
 class CompatibleCountryField(serializers.Field):
+    def to_internal_value(self, data):
+        return {self.field_name: Country(data)}
+
     def to_representation(self, instance: InvoiceAddress):
         if instance.country:
             return str(instance.country)
@@ -25,6 +34,13 @@ class InvoiceAddressSerializer(I18nAwareModelSerializer):
         model = InvoiceAddress
         fields = ('last_modified', 'is_business', 'company', 'name', 'street', 'zipcode', 'city', 'country', 'vat_id',
                   'vat_id_validated', 'internal_reference')
+        read_only_fields = ('last_modified', 'vat_id_validated')
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        for v in self.fields.values():
+            v.required = False
+            v.allow_blank = True
 
 
 class AnswerQuestionIdentifierField(serializers.Field):
@@ -134,6 +150,279 @@ class OrderSerializer(I18nAwareModelSerializer):
                   'checkin_attention', 'last_modified')
 
 
+class AnswerCreateSerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = QuestionAnswer
+        fields = ('question', 'answer', 'options')
+
+    def validate_question(self, q):
+        if q.event != self.context['event']:
+            raise ValidationError(
+                'The specified question does not belong to this event.'
+            )
+        return q
+
+    def validate(self, data):
+        if data.get('question').type == Question.TYPE_FILE:
+            raise ValidationError(
+                'File uploads are currently not supported via the API.'
+            )
+        elif data.get('question').type in (Question.TYPE_CHOICE, Question.TYPE_CHOICE_MULTIPLE):
+            if not data.get('options'):
+                raise ValidationError(
+                    'You need to specify options if the question is of a choice type.'
+                )
+            if data.get('question').type == Question.TYPE_CHOICE and len(data.get('options')) > 1:
+                raise ValidationError(
+                    'You can specify at most one option for this question.'
+                )
+            data['answer'] = ", ".join([str(o) for o in data.get('options')])
+
+        else:
+            if data.get('options'):
+                raise ValidationError(
+                    'You should not specify options if the question is not of a choice type.'
+                )
+
+            if data.get('question').type == Question.TYPE_BOOLEAN:
+                if data.get('answer') in ['true', 'True', '1', 'TRUE']:
+                    data['answer'] = 'True'
+                elif data.get('answer') in ['false', 'False', '0', 'FALSE']:
+                    data['answer'] = 'False'
+                else:
+                    raise ValidationError(
+                        'Please specify "true" or "false" for boolean questions.'
+                    )
+            elif data.get('question').type == Question.TYPE_NUMBER:
+                serializers.DecimalField(
+                    max_digits=50,
+                    decimal_places=25
+                ).to_internal_value(data.get('answer'))
+            elif data.get('question').type == Question.TYPE_DATE:
+                data['answer'] = serializers.DateField().to_internal_value(data.get('answer'))
+            elif data.get('question').type == Question.TYPE_TIME:
+                data['answer'] = serializers.TimeField().to_internal_value(data.get('answer'))
+            elif data.get('question').type == Question.TYPE_DATETIME:
+                data['answer'] = serializers.DateTimeField().to_internal_value(data.get('answer'))
+        return data
+
+
+class OrderFeeCreateSerializer(I18nAwareModelSerializer):
+    class Meta:
+        model = OrderFee
+        fields = ('fee_type', 'value', 'description', 'internal_type', 'tax_rule')
+
+    def validate_tax_rule(self, tr):
+        if tr and tr.event != self.context['event']:
+            raise ValidationError(
+                'The specified tax rate does not belong to this event.'
+            )
+        return tr
+
+
+class OrderPositionCreateSerializer(I18nAwareModelSerializer):
+    answers = AnswerCreateSerializer(many=True, required=False)
+    addon_to = serializers.IntegerField(required=False, allow_null=True)
+    secret = serializers.CharField(required=False)
+
+    class Meta:
+        model = OrderPosition
+        fields = ('positionid', 'item', 'variation', 'price', 'attendee_name', 'attendee_email',
+                  'secret', 'addon_to', 'subevent', 'answers')
+
+    def validate_secret(self, secret):
+        if secret and OrderPosition.objects.filter(order__event=self.context['event'], secret=secret).exists():
+            raise ValidationError(
+                'You cannot assign a position secret that already exists.'
+            )
+        return secret
+
+    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
+
+
+class CompatibleJSONField(serializers.JSONField):
+    def to_internal_value(self, data):
+        try:
+            return json.dumps(data)
+        except (TypeError, ValueError):
+            self.fail('invalid')
+
+    def to_representation(self, value):
+        if value:
+            return json.load(value)
+        return value
+
+
+class OrderCreateSerializer(I18nAwareModelSerializer):
+    invoice_address = InvoiceAddressSerializer(required=False)
+    positions = OrderPositionCreateSerializer(many=True, required=False)
+    fees = OrderFeeCreateSerializer(many=True, required=False)
+    status = serializers.ChoiceField(choices=(
+        ('n', Order.STATUS_PENDING),
+        ('p', Order.STATUS_PAID),
+    ), default='n', required=False)
+    code = serializers.CharField(
+        required=False,
+        max_length=16,
+        min_length=5
+    )
+    comment = serializers.CharField(required=False, allow_blank=True)
+    payment_provider = serializers.CharField(required=True)
+    payment_info = CompatibleJSONField(required=False)
+
+    class Meta:
+        model = Order
+        fields = ('code', 'status', 'email', 'locale', 'payment_provider', 'fees', 'comment',
+                  'invoice_address', 'positions', 'checkin_attention', 'payment_info')
+
+    def validate_payment_provider(self, pp):
+        if pp not in self.context['event'].get_payment_providers():
+            raise ValidationError('The given payment provider is not known.')
+        return pp
+
+    def validate_code(self, code):
+        if code and Order.objects.filter(event__organizer=self.context['event'].organizer, code=code).exists():
+            raise ValidationError(
+                'This order code is already in use.'
+            )
+        if any(c not in 'ABCDEFGHJKLMNPQRSTUVWXYZ1234567890' for c in code):
+            raise ValidationError(
+                'This order code contains invalid characters.'
+            )
+        return code
+
+    def validate_positions(self, data):
+        if not data:
+            raise ValidationError(
+                'An order cannot be empty.'
+            )
+        if any([p.get('positionid') for p in data]):
+            if not all([p.get('positionid') for p in data]):
+                raise ValidationError(
+                    'If you set position IDs manually, you need to do so for all positions.'
+                )
+
+            last_non_add_on = None
+            last_posid = 0
+
+            for p in data:
+                if p['positionid'] != last_posid + 1:
+                    raise ValidationError("Position IDs need to be consecutive.")
+                if p.get('addon_to') and p['addon_to'] != last_non_add_on:
+                    raise ValidationError("If you set addon_to, you need to make sure that the referenced "
+                                          "position ID exists and is transmitted directly before its add-ons.")
+
+                if not p.get('addon_to'):
+                    last_non_add_on = p['positionid']
+                last_posid = p['positionid']
+
+        elif any([p.get('addon_to') for p in data]):
+            raise ValidationError("If you set addon_to, you need to specify position IDs manually.")
+        return data
+
+    def create(self, validated_data):
+        fees_data = validated_data.pop('fees') if 'fees' in validated_data else []
+        positions_data = validated_data.pop('positions') if 'positions' in validated_data else []
+        if 'invoice_address' in validated_data:
+            ia = InvoiceAddress(**validated_data.pop('invoice_address'))
+        else:
+            ia = None
+
+        with self.context['event'].lock():
+            quotadiff = Counter()
+            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():
+                    avail = quota.availability()
+                    if avail[0] != Quota.AVAILABILITY_OK or (avail[1] is not None and avail[1] < diff):
+                        raise ValidationError(
+                            'There is not enough quota available on quota "{}" to perform the operation.'.format(
+                                quota.name
+                            )
+                        )
+
+            order = Order(event=self.context['event'], **validated_data)
+            order.set_expires(subevents=[p['subevent'] for p in positions_data])
+            order.total = sum([p['price'] for p in positions_data]) + sum([f['value'] for f in fees_data], Decimal('0.00'))
+            if order.total == Decimal('0.00') and validated_data.get('status') != Order.STATUS_PAID:
+                order.payment_provider = 'free'
+                order.status = Order.STATUS_PAID
+            elif order.payment_provider == "free" and order.total != Decimal('0.00'):
+                raise ValidationError('You cannot use the "free" payment provider for non-free orders.')
+            order.save()
+            if ia:
+                ia.order = order
+                ia.save()
+            pos_map = {}
+            for pos_data in positions_data:
+                answers_data = pos_data.pop('answers')
+                addon_to = pos_data.pop('addon_to')
+                pos = OrderPosition(**pos_data)
+                pos.order = order
+                pos._calculate_tax()
+                if addon_to:
+                    pos.addon_to = pos_map[addon_to]
+                pos.save()
+                pos_map[pos.positionid] = pos
+                for answ_data in answers_data:
+                    options = answ_data.pop('options')
+                    answ = pos.answers.create(**answ_data)
+                    answ.options.add(*options)
+        for fee_data in fees_data:
+            f = OrderFee(**fee_data)
+            f.order = order
+            f._calculate_tax()
+            f.save()
+
+        return order
+
+
 class InlineInvoiceLineSerializer(I18nAwareModelSerializer):
     class Meta:
         model = InvoiceLine

src/pretix/api/views/order.py

@@ -2,6 +2,7 @@ import datetime
 
 import django_filters
 import pytz
+from django.db import transaction
 from django.db.models import Q
 from django.db.models.functions import Concat
 from django.http import FileResponse
@@ -13,15 +14,18 @@ from rest_framework.exceptions import (
     APIException, NotFound, PermissionDenied, ValidationError,
 )
 from rest_framework.filters import OrderingFilter
+from rest_framework.mixins import CreateModelMixin
 from rest_framework.response import Response
 
 from pretix.api.serializers.order import (
-    InvoiceSerializer, OrderPositionSerializer, OrderSerializer,
+    InvoiceSerializer, OrderCreateSerializer, OrderPositionSerializer,
+    OrderSerializer,
 )
 from pretix.base.models import Invoice, Order, OrderPosition, Quota
 from pretix.base.models.organizer import TeamAPIToken
 from pretix.base.services.invoices import (
-    generate_cancellation, generate_invoice, invoice_pdf, regenerate_invoice,
+    generate_cancellation, generate_invoice, invoice_pdf, invoice_qualified,
+    regenerate_invoice,
 )
 from pretix.base.services.mail import SendMailException
 from pretix.base.services.orders import (
@@ -31,7 +35,7 @@ from pretix.base.services.orders import (
 from pretix.base.services.tickets import (
     get_cachedticket_for_order, get_cachedticket_for_position,
 )
-from pretix.base.signals import register_ticket_outputs
+from pretix.base.signals import order_placed, register_ticket_outputs
 
 
 class OrderFilter(FilterSet):
@@ -45,7 +49,7 @@ class OrderFilter(FilterSet):
         fields = ['code', 'status', 'email', 'locale']
 
 
-class OrderViewSet(viewsets.ReadOnlyModelViewSet):
+class OrderViewSet(CreateModelMixin, viewsets.ReadOnlyModelViewSet):
     serializer_class = OrderSerializer
     queryset = Order.objects.none()
     filter_backends = (DjangoFilterBackend, OrderingFilter)
@@ -56,6 +60,11 @@ class OrderViewSet(viewsets.ReadOnlyModelViewSet):
     permission = 'can_view_orders'
     write_permission = 'can_change_orders'
 
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['event'] = self.request.event
+        return ctx
+
     def get_queryset(self):
         return self.request.event.orders.prefetch_related(
             'positions', 'positions__checkins', 'positions__item', 'positions__answers', 'positions__answers__options',
@@ -226,6 +235,34 @@ class OrderViewSet(viewsets.ReadOnlyModelViewSet):
                 status=status.HTTP_400_BAD_REQUEST
             )
 
+    def create(self, request, *args, **kwargs):
+        serializer = OrderCreateSerializer(data=request.data, context=self.get_serializer_context())
+        serializer.is_valid(raise_exception=True)
+        with transaction.atomic():
+            self.perform_create(serializer)
+            order = serializer.instance
+            serializer = OrderSerializer(order, context=serializer.context)
+
+            order.log_action(
+                'pretix.event.order.placed',
+                user=request.user if request.user.is_authenticated else None,
+                api_token=(request.auth if isinstance(request.auth, TeamAPIToken) else None),
+            )
+        order_placed.send(self.request.event, order=order)
+
+        gen_invoice = invoice_qualified(order) and (
+            (order.event.settings.get('invoice_generate') == 'True') or
+            (order.event.settings.get('invoice_generate') == 'paid' and order.status == Order.STATUS_PAID)
+        ) and not order.invoices.last()
+        if gen_invoice:
+            generate_invoice(order, trigger_pdf=True)
+
+        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()
+
 
 class OrderPositionFilter(FilterSet):
     order = django_filters.CharFilter(name='order', lookup_expr='code__iexact')