Merge pull request #135 from BenjaminHae/statistics

add enhanced feedings statistics

dashboard/templatetags/cards.py

@@ -5,6 +5,8 @@ from django.db.models.functions import TruncDate
 from django.utils import timezone
 from django.utils.translation import gettext as _
 
+from datetime import date, datetime, time
+
 from core import models
 
 
@@ -170,10 +172,11 @@ def card_statistics(child):
         'title': _('Diaper change frequency')})
 
     feedings = _feeding_statistics(child)
-    stats.append({
-        'type': 'duration',
-        'stat': feedings['btwn_average'],
-        'title': _('Feeding frequency')})
+    for item in feedings:
+        stats.append({
+            'type': 'duration',
+            'stat': item['btwn_average'],
+            'title': item['title']})
 
     naps = _nap_statistics(child)
     stats.append({
@@ -235,22 +238,43 @@ def _feeding_statistics(child):
     :param child: an instance of the Child model.
     :returns: a dictionary of statistics.
     """
+    feedings = [
+            {
+                'start': timezone.now()-timezone.timedelta(days=3),
+                'title': _('Feeding frequency (past 3 days)')
+            },
+            {
+                'start': timezone.now()-timezone.timedelta(weeks=2),
+                'title': _('Feeding frequency (past 2 weeks)')
+            },
+            {
+                'start': timezone.make_aware(
+                    datetime.combine(date.min, time(0, 0))
+                    + timezone.timedelta(days=1)),
+                'title': _('Feeding frequency')
+            }
+        ]
+    for timespan in feedings:
+        timespan['btwn_total'] = timezone.timedelta(0)
+        timespan['btwn_count'] = 0
+        timespan['btwn_average'] = 0.0
+
     instances = models.Feeding.objects.filter(child=child).order_by('start')
-    feedings = {
-        'btwn_total': timezone.timedelta(0),
-        'btwn_count': instances.count() - 1,
-        'btwn_average': 0.0}
     last_instance = None
 
     for instance in instances:
         if last_instance:
-            feedings['btwn_total'] += instance.start - last_instance.end
+            for timespan in feedings:
+                if last_instance.start > timespan['start']:
+                    timespan['btwn_total'] += (instance.start
+                                               - last_instance.end)
+                    timespan['btwn_count'] += 1
         last_instance = instance
 
-    if feedings['btwn_count'] > 0:
-        feedings['btwn_average'] = \
-            feedings['btwn_total'] / feedings['btwn_count']
-
+    for timespan in feedings:
+        if timespan['btwn_count'] > 0:
+            timespan['btwn_average'] = \
+                timespan['btwn_total'] / timespan['btwn_count']
     return feedings