From f7274fe967f7d1976b7bec3fc2adb2af8efd9edb Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Thu, 3 Sep 2020 16:38:51 +0200
Subject: [PATCH] Adding logic to order to find out whether its closed

---
 uncloud_pay/models.py | 73 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 5 deletions(-)

diff --git a/uncloud_pay/models.py b/uncloud_pay/models.py
index e8e7ac2..d1cf6a3 100644
--- a/uncloud_pay/models.py
+++ b/uncloud_pay/models.py
@@ -290,6 +290,22 @@ class Order(models.Model):
     """
     Order are assumed IMMUTABLE and used as SOURCE OF TRUST for generating
     bills. Do **NOT** mutate then!
+
+
+    An one time order is "closed" (does not need to be billed anymore)
+    if it has one bill record. Having more than one is a programming
+    error.
+
+    A recurring order is closed if it has been replaced
+    (replaces__isnull=False) AND the ending_date is set AND it was
+    billed the last time it needed to be billed (how to check the last
+    item?)
+
+    BOTH are closed, if they are ended/closed AND have been fully
+    charged.
+
+    Fully charged == fully billed: sum_of_order_usage == sum_of_bill_records
+
     """
 
     owner = models.ForeignKey(get_user_model(),
@@ -365,6 +381,34 @@ class Order(models.Model):
 
         return sum([ br.quantity for br in self.bill_records.all() ])
 
+    @property
+    def count_used(self, when=None):
+        """
+        How many times this order was billed so far.
+        This logic is mainly thought to be for recurring bills, but also works for one time bills
+        """
+
+        if self.is_one_time:
+            return 1
+
+        if not when:
+            when = timezone.now()
+
+        # Cannot be used after it ended
+        if self.ending_date and when > self.ending_date:
+            when = self.ending_date
+
+        return (when - self.starting_date) / self.default_recurring_period
+
+    @property
+    def fully_billed(self, when=None):
+        """
+        Returns true if this order does not need any further billing
+        ever. In other words: is this order "closed"?
+        """
+
+        if self.count_billed ==
+
     @property
     def is_recurring(self):
         return not self.recurring_period == RecurringPeriod.ONE_TIME
@@ -375,10 +419,9 @@ class Order(models.Model):
 
     def replace_with(self, new_order):
         new_order.replaces = self
-        self.ending_date = new_order.starting_date - datetime.timedelta(seconds=1)
+        self.ending_date = end_before(new_order.starting_date)
         self.save()
 
-
     def save(self, *args, **kwargs):
         if self.ending_date and self.ending_date < self.starting_date:
             raise ValidationError("End date cannot be before starting date")
@@ -445,6 +488,28 @@ class Bill(models.Model):
         for owner in get_user_model().objects.all():
             cls.create_next_bills_for_user(owner)
 
+    @classmethod
+    def create_next_bill_for_user_address(cls,
+                                          owner,
+                                          billing_address,
+                                          ending_date=None):
+
+        """
+        Check the existing orders  of the billing address
+        and generate a bill if there is at least one active order
+        """
+
+        all_orders = Order.objects.filter(owner=owner,
+                                          billing_address=billing_address).order_by('id')
+
+
+        # a bill. If there
+        # for order in all_orders:
+        #     if order.is_one_time:
+        #         cls.create_one_time_record
+
+        # pass
+
     @classmethod
     def create_next_bills_for_user(cls, owner, ending_date=None):
         """
@@ -534,8 +599,6 @@ class Bill(models.Model):
     def get_bill_record_ending_date(order, bill):
         """
         Determine the ending date of the billing record
-
-
         """
 
         # If the order is quit, charge the final amount (?)
@@ -550,7 +613,7 @@ class Bill(models.Model):
         return this_ending_date
 
     @classmethod
-    def create_next_bill_for_user_address(cls,
+    def create_next_bill_for_user_address_old(cls,
                                           owner,
                                           billing_address,
                                           ending_date=None):