From 525d7e6709f159b519e6aaf5b1d90c8faf8ed711 Mon Sep 17 00:00:00 2001
From: Skia <skia@libskia.so>
Date: Fri, 22 Jul 2016 01:19:04 +0200
Subject: [PATCH] Add atomic transaction in counters

---
 counter/templates/counter/user_account.jinja |  1 +
 counter/views.py                             | 50 +++++++++++---------
 2 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/counter/templates/counter/user_account.jinja b/counter/templates/counter/user_account.jinja
index 7d96d872..294e6bf2 100644
--- a/counter/templates/counter/user_account.jinja
+++ b/counter/templates/counter/user_account.jinja
@@ -6,6 +6,7 @@
 
 {% block infos %}
 <h3>{% trans %}User account{% endtrans %}</h3>
+<p>{% trans %}Amount: {% endtrans %}{{ customer.amount }} €</p>
 <p>{{ customer.refillings.all() }}</p>
 <p>{{ customer.buyings.all() }}</p>
 {% endblock %}
diff --git a/counter/views.py b/counter/views.py
index 899a90a4..c06632e8 100644
--- a/counter/views.py
+++ b/counter/views.py
@@ -10,6 +10,7 @@ from django.utils import timezone
 from django import forms
 from django.utils.translation import ugettext_lazy as _
 from django.conf import settings
+from django.db import DataError, transaction
 
 import re
 
@@ -218,31 +219,34 @@ class CounterClick(DetailView):
 
     def finish(self, request):
         """ Finish the click session, and validate the basket """
-        if self.is_barman_price():
-            seller = self.customer.user
-        else:
-            seller = Counter.get_random_barman(self.object.id)
-        request.session['last_basket'] = []
-        for pid,infos in request.session['basket'].items():
-            # This duplicates code for DB optimization (prevent to load many times the same object)
-            p = Product.objects.filter(pk=pid).first()
+        with transaction.atomic():
             if self.is_barman_price():
-                uprice = p.special_selling_price
+                seller = self.customer.user
             else:
-                uprice = p.selling_price
-            request.session['last_basket'].append("%d x %s" % (infos['qty'], p.name))
-            s = Selling(product=p, counter=self.object, unit_price=uprice,
-                   quantity=infos['qty'], seller=seller, customer=self.customer)
-            s.save()
-        request.session['last_customer'] = self.customer.user.get_display_name()
-        request.session['last_total'] = "%0.2f" % self.sum_basket(request)
-        request.session['new_customer_amount'] = str(self.customer.amount)
-        del request.session['basket']
-        request.session.modified = True
-        kwargs = {
-                'counter_id': self.object.id,
-                }
-        return HttpResponseRedirect(reverse_lazy('counter:details', args=self.args, kwargs=kwargs))
+                seller = Counter.get_random_barman(self.object.id)
+            request.session['last_basket'] = []
+            for pid,infos in request.session['basket'].items():
+                # This duplicates code for DB optimization (prevent to load many times the same object)
+                p = Product.objects.filter(pk=pid).first()
+                if self.is_barman_price():
+                    uprice = p.special_selling_price
+                else:
+                    uprice = p.selling_price
+                if uprice * infos['qty'] > self.customer.amount:
+                    raise DataError(_("You have not enough money to buy all the basket"))
+                request.session['last_basket'].append("%d x %s" % (infos['qty'], p.name))
+                s = Selling(product=p, counter=self.object, unit_price=uprice,
+                       quantity=infos['qty'], seller=seller, customer=self.customer)
+                s.save()
+            request.session['last_customer'] = self.customer.user.get_display_name()
+            request.session['last_total'] = "%0.2f" % self.sum_basket(request)
+            request.session['new_customer_amount'] = str(self.customer.amount)
+            del request.session['basket']
+            request.session.modified = True
+            kwargs = {
+                    'counter_id': self.object.id,
+                    }
+            return HttpResponseRedirect(reverse_lazy('counter:details', args=self.args, kwargs=kwargs))
 
     def cancel(self, request):
         """ Cancel the click session """