Added container copy function

container/views.py

@@ -36,6 +36,42 @@ class ContainerCreateView(LoginRequiredMixin, generic.CreateView):
         return super().form_valid(form)
 
 
+def suggest_named_id(existing_id):
+    result = re.search(r'\d{0,9}$', existing_id)
+    number_part = int(result.group()) + 1
+    number_digits = result.span()[1] - result.span()[0]
+    prefix_part = existing_id[0:result.span()[0]]
+    id_candidate = prefix_part + str(number_part).zfill(number_digits)
+    while Container.objects.filter(named_id=id_candidate).exists():
+        number_part = number_part + 1
+        id_candidate = prefix_part + str(number_part).zfill(number_digits)
+
+    return id_candidate
+
+
+class ContainerCopyView(LoginRequiredMixin, generic.CreateView):
+    model = Container
+    fields = ['named_id', 'description', 'color', 'container_type']
+    success_url = '/container/'
+
+    def form_valid(self, form):
+        if not form.instance.named_id.startswith('C-'):
+            form.instance.named_id = 'C-' + form.instance.named_id
+        form.instance.changed_by = self.request.user
+        form.instance.created_by = self.request.user
+        return super().form_valid(form)
+
+    def get_initial(self, *args, **kwargs):
+        initial = super(ContainerCopyView, self).get_initial(**kwargs)
+        copy_source = Container.objects.get(pk=self.kwargs['pk'])
+        initial['container_type'] = copy_source.container_type
+        initial['color'] = copy_source.color
+        initial['description'] = copy_source.description
+        # strategy to find a new named_id by using the numbers at the end and trying to increment
+        initial['named_id'] = suggest_named_id(existing_id=copy_source.named_id)
+        return initial
+
+
 class ContainerImportView(LoginRequiredMixin, generic.TemplateView):
     template_name = 'container_import.html'