Adds option for duplicating an existing purchase order (#3567)

* Adds option for duplicating an existing purchase order

- Copy line items across

* Update API version

* JS linting

* Adds option for duplication of extra lines

* Decimal point rounding fix

* Unit tests for PO duplication via the API

InvenTree/order/api.py

@@ -1,10 +1,13 @@
 """JSON API for the Order app."""
 
+from django.db import transaction
 from django.db.models import F, Q
 from django.urls import include, path, re_path
+from django.utils.translation import gettext_lazy as _
 
 from django_filters import rest_framework as rest_filters
 from rest_framework import filters, status
+from rest_framework.exceptions import ValidationError
 from rest_framework.response import Response
 
 import order.models as models
@@ -116,12 +119,48 @@ class PurchaseOrderList(APIDownloadMixin, ListCreateAPI):
 
     def create(self, request, *args, **kwargs):
         """Save user information on create."""
-        serializer = self.get_serializer(data=self.clean_data(request.data))
+
+        data = self.clean_data(request.data)
+
+        duplicate_order = data.pop('duplicate_order', None)
+        duplicate_line_items = str2bool(data.pop('duplicate_line_items', False))
+        duplicate_extra_lines = str2bool(data.pop('duplicate_extra_lines', False))
+
+        if duplicate_order is not None:
+            try:
+                duplicate_order = models.PurchaseOrder.objects.get(pk=duplicate_order)
+            except (ValueError, models.PurchaseOrder.DoesNotExist):
+                raise ValidationError({
+                    'duplicate_order': [_('No matching purchase order found')],
+                })
+
+        serializer = self.get_serializer(data=data)
         serializer.is_valid(raise_exception=True)
 
-        item = serializer.save()
-        item.created_by = request.user
-        item.save()
+        with transaction.atomic():
+            order = serializer.save()
+            order.created_by = request.user
+            order.save()
+
+            # Duplicate line items from other order if required
+            if duplicate_order is not None:
+
+                if duplicate_line_items:
+                    for line in duplicate_order.lines.all():
+                        # Copy the line across to the new order
+                        line.pk = None
+                        line.order = order
+                        line.received = 0
+
+                        line.save()
+
+                if duplicate_extra_lines:
+                    for line in duplicate_order.extra_lines.all():
+                        # Copy the line across to the new order
+                        line.pk = None
+                        line.order = order
+
+                        line.save()
 
         headers = self.get_success_headers(serializer.data)
         return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)