Fix booking slots order

apps/booking/views.py

@@ -14,6 +14,12 @@ class CheckWhetherBookingAvailable(generics.GenericAPIView):
     """ Checks which service to use if establishmend is managed by any """
 
     _VALID_GUESTONLINE_PERIODS = {'lunch', 'dinner', 'afternoon', 'breakfast'}
+    _GUESTONLINE_PERIODS_TO_PRIOR = {
+        'breakfast': 1,
+        'lunch': 2,
+        'afternoon': 3,
+        'dinner': 4,
+    }
 
     permission_classes = (permissions.AllowAny,)
     serializer_class = CheckBookingSerializer
@@ -32,7 +38,7 @@ class CheckWhetherBookingAvailable(generics.GenericAPIView):
 
         period_template = iter(periods_by_name.values()).__next__().copy()
         period_template.pop('total_left_seats')
-        period_template.pop('hours')
+        period_template['hours'] = []
         period_template.pop('period')
 
         processed_periods = [
@@ -46,7 +52,8 @@ class CheckWhetherBookingAvailable(generics.GenericAPIView):
         for unnamed_period in unnamed_periods:
             processed_periods.append(unnamed_period)
 
-        response['periods'] = processed_periods
+        response['periods'] = sorted(processed_periods,
+                                     key=lambda x: self._GUESTONLINE_PERIODS_TO_PRIOR[x.get('period', 'lunch')])
 
         return response