Eco Account deduction

* adds deductable_surface to EcoAccount model to provide an easy way to change the deductable amount from an account -> depends on external funding e.g. with AktionBlau or similar
* adds overview of deducted and deductable volume to detail view
* adds check to eco account model, so the deductable_surface can never be larger than the total amount of after_state surface sum
* adds german formating for python logic based number formating
* adds/updates translations

compensation/models.py

@@ -9,6 +9,7 @@ import shutil
 
 from django.contrib.auth.models import User
 from django.contrib.gis.db import models
+from django.core.exceptions import ValidationError
 from django.core.validators import MinValueValidator
 from django.db.models import Sum, QuerySet
 from django.utils.translation import gettext_lazy as _
@@ -281,9 +282,22 @@ class EcoAccount(AbstractCompensation):
         related_name="+"
     )
 
+    deductable_surface = models.FloatField(
+        blank=True,
+        null=True,
+        help_text="Amount of deductable surface - can be lower than the total surface due to deduction limitations",
+        default=0,
+    )
+
     def __str__(self):
         return "{}".format(self.identifier)
 
+    def clean(self):
+        # Deductable surface can not be larger than added states after surface
+        after_state_sum = self.get_state_after_surface_sum()
+        if self.deductable_surface > after_state_sum:
+            raise ValidationError(_("Deductable surface can not be larger than existing surfaces in after states"))
+
     def save(self, *args, **kwargs):
         if self.identifier is None or len(self.identifier) == 0:
             # Create new identifier
@@ -293,15 +307,34 @@ class EcoAccount(AbstractCompensation):
             self.identifier = new_id
         super().save(*args, **kwargs)
 
+    @property
+    def deductions_surface_sum(self) -> float:
+        """ Shortcut for get_deductions_surface.
+
+        Can be used in templates
+
+        Returns:
+            sum_surface (float)
+        """
+        return self.get_deductions_surface()
+
     def get_deductions_surface(self) -> float:
-        """ Calculates the account's deductions sum surface
+        """ Calculates the account's deductions surface sum
 
         Returns:
             sum_surface (float)
         """
         return self.deductions.all().aggregate(Sum("surface"))["surface__sum"] or 0
 
-    def get_available_rest(self, as_percentage: bool = False):
+    def get_state_after_surface_sum(self) -> float:
+        """ Calculates the account's after state surface sum
+
+        Returns:
+            sum_surface (float)
+        """
+        return self.after_states.all().aggregate(Sum("surface"))["surface__sum"] or 0
+
+    def get_available_rest(self, as_percentage: bool = False) -> float:
         """ Calculates available rest surface of the eco account
 
         Args:
@@ -310,17 +343,16 @@ class EcoAccount(AbstractCompensation):
         Returns:
 
         """
-        ret_val = 0
         deductions = self.deductions.filter(
             intervention__deleted=None,
         )
         deductions_surfaces = deductions.aggregate(Sum("surface"))["surface__sum"] or 0
-        after_states_surfaces = self.after_states.all().aggregate(Sum("surface"))["surface__sum"] or deductions_surfaces ## no division by zero
-        ret_val = after_states_surfaces - deductions_surfaces
+        available_surfaces = self.deductable_surface or deductions_surfaces ## no division by zero
+        ret_val = available_surfaces - deductions_surfaces
 
         if as_percentage:
-            if after_states_surfaces > 0:
-                ret_val = int((ret_val / after_states_surfaces) * 100)
+            if available_surfaces > 0:
+                ret_val = int((ret_val / available_surfaces) * 100)
             else:
                 ret_val = 0
         return ret_val

compensation/templates/compensation/detail/eco_account/view.html

@@ -33,6 +33,7 @@
                     <tr>
                         <th scope="row">{% trans 'Available' %}</th>
                         <td class="align-middle">
+                            {{obj.deductions_surface_sum|floatformat:2}} / {{obj.deductable_surface|floatformat:2}} m²
                             {% with available as value %}
                                 {% include 'konova/custom_widgets/progressbar.html' %}
                             {% endwith %}