feat: add function for calculating daily_spending_allowance

app/apps/monthly_overview/utils/daily_spending_allowance.py

@@ -0,0 +1,65 @@
+from decimal import Decimal
+from django.utils import timezone
+from calendar import monthrange
+
+from apps.common.functions.dates import remaining_days_in_month
+
+
+def calculate_daily_allowance_currency(currency_totals, month=None, year=None):
+    """
+    Calculate daily spending allowance based on currency totals.
+
+    Args:
+        currency_totals (dict): Result from calculate_currency_totals function
+        month (int, optional): Month to calculate for. Defaults to current month.
+        year (int, optional): Year to calculate for. Defaults to current year.
+
+    Returns:
+        dict: Daily allowance per currency, or empty dict if not current month
+    """
+    print(currency_totals)
+    # If month/year not provided, use current date
+    current_date = timezone.localdate(timezone.now())
+    if month is None:
+        month = current_date.month
+    if year is None:
+        year = current_date.year
+
+    # Only calculate if we're looking at the current month
+    if current_date.month != month or current_date.year != year:
+        return {}
+
+    # Calculate remaining days in month
+    _, days_in_month = monthrange(year, month)
+    remaining_days = remaining_days_in_month(
+        current_date=current_date, month=month, year=year
+    )
+
+    # Calculate daily allowance for each currency
+    result = {}
+
+    for currency_id, data in currency_totals.items():
+        # Get the total_final value, skip if not present
+        total_final = data.get("total_final")
+        if total_final is None:
+            continue
+
+        # Calculate daily allowance
+        daily_amount = (
+            total_final / remaining_days if remaining_days > 0 else Decimal("0")
+        )
+
+        # Only include positive amounts
+        if daily_amount > 0:
+            result[currency_id] = {"currency": data["currency"], "amount": daily_amount}
+
+            # Include exchanged amount if available
+            if "exchanged" in data and "total_final" in data["exchanged"]:
+                exchanged_daily = data["exchanged"]["total_final"] / remaining_days
+                if exchanged_daily > 0:
+                    result[currency_id]["exchanged"] = {
+                        "currency": data["exchanged"]["currency"],
+                        "amount": exchanged_daily,
+                    }
+
+    return result