(experimental) add running totals functionality

Author: PetrDlouhy

hordak/admin.py

@@ -18,16 +18,18 @@
 
 
 @admin.register(models.Account)
-class AccountAdmin(MPTTModelAdmin):
+class AccountAdmin(admin.ModelAdmin):
     list_display = (
         "name",
         "code_",
         "type_",
         "currencies",
         "balance_sum",
         "income",
+        # "running_totals",
+        # "running_incomes",
     )
-    readonly_fields = ("balance",)
+    readonly_fields = ("balance", "balance_sum", "income")
     raw_id_fields = ("parent",)
     search_fields = (
         "code",

hordak/defaults.py

@@ -5,7 +5,7 @@
 
 DEFAULT_CURRENCY = getattr(settings, "DEFAULT_CURRENCY", "EUR")
 
-CURRENCIES = getattr(settings, "CURRENCIES", [])
+CURRENCIES = getattr(settings, "CURRENCIES", list)
 
 DECIMAL_PLACES = getattr(settings, "HORDAK_DECIMAL_PLACES", 2)
 

hordak/management/commands/recalculate_running_totals.py

@@ -0,0 +1,37 @@
+from django.core.management.base import BaseCommand
+from django.db.models import Q
+from hordak.models import Account
+from moneyed import Money
+
+
+try:  # SubquerySum is quicker, but django-sql-utils can remain as optional dependency.
+    from sql_util.utils import SubquerySum as Sum
+
+    legs_filter = Q(amount__lt=0)
+except ImportError:
+    from django.db.models import Sum
+
+    legs_filter = Q(legs__amount__lt=0)
+
+
+class Command(BaseCommand):
+    help = "Recalculate running totals for all accounts"
+
+    def handle(self, *args, **options):
+        print("Recalculating running totals for all accounts")
+        # queryset = Account.objects.filter(id__in=[1]).values("legs__amount_currency")
+        # .annotate(
+        #     total=Sum("legs__amount"),
+        #     # income=Sum("legs__amount", filter=legs_filter),
+        # )
+        queryset = Account.objects.all()
+        for account in queryset[:1000]:
+            total = account.balance()
+            print(total, account.name)
+            account.running_totals = [total[c] for c in total.currencies()]
+            print(account.running_totals)
+            # account.running_totals = [Money(r["total"], r["amount_currency"]) for r in account]
+            # account.running_incomes = [Money(r["income"], r["amount_currency"]) for r in account]
+            account.save()
+            if total:
+                import pudb; pudb.set_trace()

hordak/models/core.py

@@ -23,6 +23,8 @@
 
 from django.contrib.postgres.fields.array import ArrayField
 from django.db import models
+from django.db.models.signals import post_save, post_delete
+from django.dispatch import receiver
 from django.db import transaction as db_transaction
 from django.db.models import JSONField
 from django.utils import timezone
@@ -138,6 +140,27 @@ class Account(MPTTModel):
         default=defaults.CURRENCIES,
         verbose_name=_("currencies"),
     )
+        running_totals = ArrayField(
+        MoneyField(
+            max_digits=MAX_DIGITS,
+            decimal_places=DECIMAL_PLACES,
+            default_currency=defaults.INTERNAL_CURRENCY,
+        ),
+        default=list,
+        help_text="Running totals for each currency. This field should be considered an estimated value calculated for performance reasons. It is not guaranteed to be accurate.",
+        verbose_name=_("running totals"),
+    )
+    running_incomes = ArrayField(
+        MoneyField(
+            max_digits=MAX_DIGITS,
+            decimal_places=DECIMAL_PLACES,
+            help_text="Record debits as positive, credits as negative",
+            default_currency=defaults.INTERNAL_CURRENCY,
+        ),
+        default=list,
+        help_text="Running incomes for each currency. This field should be considered an estimated value calculated for performance reasons. It is not guaranteed to be accurate.",
+        verbose_name=_("running incomes"),
+    )
 
     objects = AccountManager.from_queryset(AccountQuerySet)()
 
@@ -549,6 +572,45 @@ class Meta:
         verbose_name = _("Leg")
 
 
+@receiver(post_save, sender=Leg)
+def update_running_totals(sender, instance, created, **kwargs):
+    """Update the running total of the account associated with the leg"""
+    if created:
+        instance.account.running_totals[instance.amount.currency] += instance.amount
+    else:
+        # We are updating the leg, so we need to get the old amount
+        old_amount = sender.objects.get(pk=instance.pk).amount
+        instance.account.running_totals[instance.amount.currency] += instance.amount - old_amount
+
+
+@receiver(post_save, sender=Leg)
+def update_running_incomes(sender, instance, created, **kwargs):
+    """Update the running income of the account associated with the leg"""
+    if created:
+        if instance.is_credit():
+            instance.account.running_income += instance.amount
+    else:
+        # We are updating the leg, so we need to get the old amount
+        old_amount = sender.objects.get(pk=instance.pk).amount
+        if instance.is_credit():
+            instance.account.running_income += instance.amount - old_amount
+        elif old_amount.amount < 0:
+            instance.account.running_income += old_amount
+
+
+@receiver(post_delete, sender=Leg)
+def update_running_totals_on_delete(sender, instance, **kwargs):
+    """Update the running total of the account associated with the leg"""
+    instance.account.running_totals[instance.amount.currency] -= instance.amount
+
+
+@receiver(post_delete, sender=Leg)
+def update_running_incomes_on_delete(sender, instance, **kwargs):
+    """Update the running income of the account associated with the leg"""
+    if instance.is_credit():
+        instance.account.running_income -= instance.amount
+
+
 class StatementImportManager(models.Manager):
     def get_by_natural_key(self, uuid):
         return self.get(uuid=uuid)