Improve subscription and add it to admin app

subscription/models.py

@@ -0,0 +1,128 @@
+from datetime import date, timedelta
+from django.db import models
+from django.utils import timezone
+from django.utils.translation import ugettext_lazy as _
+from django.conf import settings
+
+from core.models import User
+
+def validate_type(value):
+    if value not in settings.AE_SUBSCRIPTIONS.keys():
+        raise ValidationError(_('Bad subscription type'))
+
+def validate_payment(value):
+    if value not in settings.AE_PAYMENT_METHOD:
+        raise ValidationError(_('Bad payment method'))
+
+class Member(models.Model):
+    user = models.OneToOneField(User, primary_key=True)
+
+    def is_subscribed(self):
+        return self.subscriptions.last().is_valid_now()
+
+    def __str__(self):
+        return self.user.username
+
+class Subscription(models.Model):
+    member = models.ForeignKey(Member, related_name='subscriptions')
+    subscription_type = models.CharField(_('subscription type'),
+                                         max_length=255,
+                                         choices=((k, v['name']) for k,v in sorted(settings.AE_SUBSCRIPTIONS.items())))
+    subscription_start = models.DateField(_('subscription start'))
+    subscription_end = models.DateField(_('subscription end'))
+    payment_method = models.CharField(_('payment method'), max_length=255, choices=settings.AE_PAYMENT_METHOD)
+
+    def save(self, *args, **kwargs):
+        """
+        This makes the Subscription to be updated with right dates with respect to date.today() each time you save the
+        Subscription object.
+        It means that you must be careful when modifying old Subscription, because you could make
+        someone that had no more valid subscription to get one again!
+
+        TODO: FIXME by putting it in the right function that would be triggered only when using the right Form!!!!
+        """
+        self.subscription_start = self.compute_start()
+        self.subscription_end = self.compute_end(
+                duration=settings.AE_SUBSCRIPTIONS[self.subscription_type]['duration'],
+                start=self.subscription_start)
+        super(Subscription, self).save(*args, **kwargs)
+
+    class Meta:
+        ordering = ['subscription_start',]
+
+    def __str__(self):
+        return self.member.user.username+' - '+str(self.pk)
+
+    @staticmethod
+    def compute_start(d=date.today()):
+        """
+        This function computes the start date of the subscription with respect to the given date (default is today),
+        and the start date given in settings.AE_START_DATE.
+        It takes the nearest past start date.
+        Exemples: with AE_START_DATE = (8, 15)
+            Today      -> Start date
+            2015-03-17 -> 2015-02-15
+            2015-01-11 -> 2014-08-15
+        """
+        today = d
+        year = today.year
+        start = date(year, settings.AE_START_DATE[0], settings.AE_START_DATE[1])
+        start2 = start.replace(month=(start.month+6)%12)
+        if start > start2:
+            start, start2 = start2, start
+        if today < start:
+            return start2.replace(year=year-1)
+        elif today < start2:
+            return start
+        else:
+            return start2
+
+    @staticmethod
+    def compute_end(duration, start=None):
+        """
+        This function compute the end date of the subscription given a start date and a duration in number of semestre
+        Exemple:
+            Start - Duration -> End date
+            2015-09-18 - 1 -> 2016-03-18
+            2015-09-18 - 2 -> 2016-09-18
+            2015-09-18 - 3 -> 2017-03-18
+            2015-09-18 - 4 -> 2017-09-18
+        """
+        if start is None:
+            start = Subscription.compute_start()
+        # This can certainly be simplified, but it works like this
+        return start.replace(month=(start.month+6*duration)%12,
+                             year=start.year+int(duration/2)+(1 if start.month > 6 and duration%2 == 1 else 0))
+
+    def is_valid_now(self):
+        return self.subscription_start <= date.today() and date.today() <= self.subscription_end
+
+def guy_test(date):
+    print(str(date)+" -> "+str(Subscription.compute_start(date)))
+def bibou_test(duration, date=None):
+    print(str(date)+" - "+str(duration)+" -> "+str(Subscription.compute_end(duration, date)))
+def guy():
+    guy_test(date(2015, 7, 11))
+    guy_test(date(2015, 8, 11))
+    guy_test(date(2015, 2, 17))
+    guy_test(date(2015, 3, 17))
+    guy_test(date(2015, 1, 11))
+    guy_test(date(2015, 2, 11))
+    guy_test(date(2015, 8, 17))
+    guy_test(date(2015, 9, 17))
+    print('='*80)
+    bibou_test(1, date(2015, 2, 18))
+    bibou_test(2, date(2015, 2, 18))
+    bibou_test(3, date(2015, 2, 18))
+    bibou_test(4, date(2015, 2, 18))
+    bibou_test(1, date(2015, 9, 18))
+    bibou_test(2, date(2015, 9, 18))
+    bibou_test(3, date(2015, 9, 18))
+    bibou_test(4, date(2015, 9, 18))
+    bibou_test(1)
+    bibou_test(2)
+    bibou_test(3)
+    bibou_test(4)
+
+if __name__ == "__main__":
+    guy()