release: publish saldo 0.1.0

app/services/comparison_service.py

@@ -0,0 +1,60 @@
+from __future__ import annotations
+
+from decimal import Decimal
+
+from app.models import MonthlyAllocation, MonthlyEntryValue, MonthlyIncome, to_decimal
+
+
+class ComparisonService:
+    def month_delta(self, current_month, previous_month) -> dict:
+        if previous_month is None:
+            zero = Decimal("0.00")
+            return {
+                "income_delta": zero,
+                "cost_delta": zero,
+                "remainder_delta": zero,
+                "allocation_delta": zero,
+            }
+        return {
+            "income_delta": self._total_income(current_month) - self._total_income(previous_month),
+            "cost_delta": self._total_costs(current_month) - self._total_costs(previous_month),
+            "remainder_delta": self._remainder(current_month) - self._remainder(previous_month),
+            "allocation_delta": self._total_allocations(current_month)
+            - self._total_allocations(previous_month),
+        }
+
+    def top_entry_changes(self, current_month, previous_month, limit: int = 6) -> list[dict]:
+        if previous_month is None:
+            return []
+        previous_values = {
+            item.entry_id: to_decimal(item.planned_amount) for item in previous_month.entry_values
+        }
+        changes = []
+        for item in current_month.entry_values:
+            previous_amount = previous_values.get(item.entry_id, Decimal("0.00"))
+            current_amount = to_decimal(item.planned_amount)
+            delta = current_amount - previous_amount
+            if delta:
+                changes.append(
+                    {
+                        "entry_name": item.entry.name,
+                        "category_name": item.entry.category.name,
+                        "delta": delta,
+                        "current_amount": current_amount,
+                        "previous_amount": previous_amount,
+                    }
+                )
+        changes.sort(key=lambda item: abs(item["delta"]), reverse=True)
+        return changes[:limit]
+
+    def _total_income(self, month) -> Decimal:
+        return sum((to_decimal(item.amount) for item in month.incomes), Decimal("0.00"))
+
+    def _total_costs(self, month) -> Decimal:
+        return sum((to_decimal(item.planned_amount) for item in month.entry_values), Decimal("0.00"))
+
+    def _total_allocations(self, month) -> Decimal:
+        return sum((to_decimal(item.amount) for item in month.allocations), Decimal("0.00"))
+
+    def _remainder(self, month) -> Decimal:
+        return self._total_income(month) - self._total_costs(month)