Add update_pending_customer() for custorder batch handler

and perhaps more importantly, `validate_pending_customer_data()`

this was needed for sake of unique email address checks

rattail/batch/custorder.py

@@ -265,6 +265,47 @@ class CustomerOrderBatchHandler(BatchHandler):
         session.flush()
         session.refresh(batch)
 
+    def validate_pending_customer_data(self, batch, user, data):
+        pass
+
+    def update_pending_customer(self, batch, user, data):
+        model = self.model
+        people = self.app.get_people_handler()
+
+        # first validate all data
+        self.validate_pending_customer_data(batch, user, data)
+
+        # clear out any contact it may have
+        self.unassign_contact(batch)
+
+        # create pending customer if needed
+        pending = batch.pending_customer
+        if not pending:
+            pending = model.PendingCustomer()
+            pending.user = user
+            pending.status_code = self.enum.PENDING_CUSTOMER_STATUS_PENDING
+            batch.pending_customer = pending
+
+        # update pending customer info
+        if 'first_name' in data:
+            pending.first_name = data['first_name']
+        if 'last_name' in data:
+            pending.last_name = data['last_name']
+        if 'display_name' in data:
+            pending.display_name = data['display_name']
+        else:
+            pending.display_name = people.normalize_full_name(pending.first_name,
+                                                              pending.last_name)
+        if 'phone_number' in data:
+            pending.phone_number = self.app.format_phone_number(data['phone_number'])
+        if 'email_address' in data:
+            pending.email_address = data['email_address']
+
+        # also update the batch w/ contact info
+        batch.contact_name = pending.display_name
+        batch.phone_number = pending.phone_number
+        batch.email_address = pending.email_address
+
     def get_case_size_for_product(self, product):
         if product.case_size:
             return product.case_size