in between commit

Signed-off-by: Nico Schottelius <nico@nico-notebook.schottelius.org>

uncloud_django_based/uncloud/uncloud_net/models.py

@@ -23,30 +23,96 @@ class VPNPool(UncloudModel):
     network_size = models.IntegerField(validators=[MinValueValidator(0),
                                                    MaxValueValidator(128)])
 
-    subnetwork_size = models.IntegerField(validators=[MinValueValidator(0),
-                                                   MaxValueValidator(128)])
+    subnetwork_size = models.IntegerField(validators=[
+                                              MinValueValidator(0),
+                                              MaxValueValidator(128)
+                                          ])
 
     vpn_hostname = models.CharField(max_length=256)
 
     wireguard_private_key = models.CharField(max_length=48)
 
+    @property
+    def num_maximum_networks(self):
+        """
+        sample:
+        network_size = 40
+        subnetwork_size = 48
+        maximum_networks = 2^(48-40)
+
+        2nd sample:
+        network_size = 8
+        subnetwork_size = 24
+        maximum_networks = 2^(24-8)
+        """
+
+        return 2**(subnetwork_size - network_size)
+
+    @property
+    def used_networks(self):
+        return self.vpnnetworkreservation_set.objects.filter(vpnpool=self, status='used')
+
+    @property
+    def num_used_networks(self):
+        return len(self.used_networks)
+
+    @property
+    def num_free_networks(self):
+        return self.num_maximum_networks - self.num_used_networks
+
+    @property
+    def next_free_network(self):
+        free_net = self.vpnnetworkreservation_set.objects.filter(vpnpool=self,
+                                                                 status='free')
+
+        last_net = self.vpnnetworkreservation_set.objects.filter(vpnpool=self,
+                                                                 status='used')
+
+        if num_free_networks == 0:
+            raise Exception("No free networks")
+
+        if len(free_net) > 0:
+            return free_net[0].address
+
+        if len(used_net) > 0:
+            """
+            sample:
+
+            pool = 2a0a:e5c1:200::/40
+            last_used = 2a0a:e5c1:204::/48
+
+            next:
+            """
+
+            last_ip = last_net.address
+#            next_ip =
+
+
+
+
 
 class VPNNetworkReservation(UncloudModel):
     """
-    This class tracks the used VPN networks. It will be deleted, when the product is cancelled.
-    """
+     This class tracks the used VPN networks. It will be deleted, when the product is cancelled.
+     """
     vpnpool = models.ForeignKey(VPNPool,
-                                  on_delete=models.CASCADE)
-
+                                 on_delete=models.CASCADE)
     address = models.GenericIPAddressField(primary_key=True)
 
+    status = models.CharField(max_length=256,
+                              choices = (
+                                  ('used', 'used'),
+                                  ('free', 'free')
+                              )
+    )
+
 
 class VPNNetwork(Product):
     """
     A selected network. Used for tracking reservations / used networks
     """
     network = models.ForeignKey(VPNNetworkReservation,
-                                on_delete=models.CASCADE,
-                                editable=False)
+                               on_delete=models.CASCADE,
+                               editable=False)
 
     wireguard_public_key = models.CharField(max_length=48)