refactor: Modifikator-Helfer öffentlich, load_scenario_inputs aus run_projection (A13-T1)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

finance/app/engine/scenario.py

@@ -37,7 +37,7 @@ class PlainModifier:
     end_date: date | None = None
 
 
-def _modified(amount: Decimal, category_id: int | None, recurring_id: int | None,
+def modified_amount(amount: Decimal, category_id: int | None, recurring_id: int | None,
                     modifiers: list[PlainModifier]) -> Decimal | None:
     for m in modifiers:
         hit = ((m.target_type == "category" and category_id == m.target_id)
@@ -56,7 +56,7 @@ def _modified(amount: Decimal, category_id: int | None, recurring_id: int | None
     return amount
 
 
-def _effective_end(r: PlainRecurring, modifiers: list[PlainModifier]) -> date | None:
+def effective_end(r: PlainRecurring, modifiers: list[PlainModifier]) -> date | None:
     """Fruehestes Ende aus eigenem end_date und allen treffenden ende-Modifikatoren."""
     end = r.end_date
     for m in modifiers:
@@ -76,14 +76,14 @@ def build_cashflows(recurring: list[PlainRecurring], planned: list[PlainPlanned]
                     window_start: date, window_end: date) -> list[tuple[date, Decimal]]:
     flows: list[tuple[date, Decimal]] = []
     for r in recurring:
-        amount = _modified(r.amount, r.category_id, r.id, modifiers)
+        amount = modified_amount(r.amount, r.category_id, r.id, modifiers)
         if amount is None:
             continue
         for d in occurrences(r.rhythm, r.due_day, window_start, window_end,
-                             r.start_date, _effective_end(r, modifiers)):
+                             r.start_date, effective_end(r, modifiers)):
             flows.append((d, amount))
     for p in planned:
-        amount = _modified(p.amount, p.category_id, None, modifiers)
+        amount = modified_amount(p.amount, p.category_id, None, modifiers)
         if amount is not None and window_start <= p.due <= window_end:
             flows.append((p.due, amount))
     for d, payout in loan_payouts:

finance/app/services/projection_service.py

@@ -1,3 +1,4 @@
+from dataclasses import dataclass
 from datetime import date, timedelta
 from datetime import datetime, timezone
 from decimal import Decimal
@@ -18,36 +19,61 @@ from app.models.tables import (Loan, PlannedItem, ProjectionPoint,
 from app.services.balances import total_balance
 
 
-def run_projection(session: Session, scenario: Scenario, horizon_days: int,
-                   start_date: date) -> ProjectionResult:
-    end = start_date + timedelta(days=horizon_days)
+@dataclass(frozen=True)
+class ScenarioInputs:
+    """Eingaben einer Szenario-Rechnung (Projektion wie Aufteilung)."""
+    recurring: list[PlainRecurring]
+    planned: list[PlainPlanned]
+    loans: list[Loan]
+    modifiers: list[PlainModifier]
+
+
+def load_scenario_inputs(session: Session, scenario: Scenario | None) -> ScenarioInputs:
+    """Lädt die Eingaben eines Szenarios. scenario=None ist die reine
+    Planung („System-Plan"): alle Fixposten, alle globalen Einmalposten,
+    alle Kredite, keine Modifikatoren, keine Szenario-Einmalposten."""
     recurring = []
-    if scenario.include_recurring:
+    if scenario is None or scenario.include_recurring:
         recurring = [PlainRecurring(r.id, r.name, Decimal(r.amount), r.rhythm,
                                     r.due_day, r.start_date, r.end_date, r.category_id)
-                     for r in session.execute(select(RecurringItem)).scalars()]
+                     for r in session.execute(
+                         select(RecurringItem).order_by(RecurringItem.id)).scalars()]
     planned = []
-    if scenario.include_planned:
+    if scenario is None or scenario.include_planned:
         planned = [PlainPlanned(p.name, Decimal(p.amount), p.due, p.category_id)
-                   for p in session.execute(select(PlannedItem)).scalars()]
+                   for p in session.execute(
+                       select(PlannedItem).order_by(PlannedItem.id)).scalars()]
+    if scenario is None:
+        loans = list(session.execute(select(Loan).order_by(Loan.id)).scalars())
+        return ScenarioInputs(recurring, planned, loans, [])
     # Szenario-eigene Einmalzahlungen zaehlen IMMER fuer dieses Szenario -
     # include_planned steuert nur die globalen PlannedItems.
     planned += [PlainPlanned(p.name, Decimal(p.amount), p.due, None)
                 for p in session.execute(select(ScenarioPlannedItem).where(
-                    ScenarioPlannedItem.scenario_id == scenario.id)).scalars()]
-    loans = session.execute(
+                    ScenarioPlannedItem.scenario_id == scenario.id)
+                    .order_by(ScenarioPlannedItem.id)).scalars()]
+    loans = list(session.execute(
         select(Loan).join(ScenarioLoan, ScenarioLoan.loan_id == Loan.id)
-        .where(ScenarioLoan.scenario_id == scenario.id)).scalars().all()
-    schedules = [loan_schedule(Decimal(l.principal), Decimal(l.annual_rate_pct),
-                               l.term_months, l.payout_date, l.repayment_type)
-                 for l in loans]
-    payouts = [(l.payout_date, Decimal(l.principal)) for l in loans]
+        .where(ScenarioLoan.scenario_id == scenario.id)
+        .order_by(Loan.id)).scalars())
     modifiers = [PlainModifier(m.target_type, m.target_id, m.kind,
                                Decimal(m.value), m.end_date)
                  for m in session.execute(select(ScenarioModifier).where(
-                     ScenarioModifier.scenario_id == scenario.id)).scalars()]
-    flows = build_cashflows(recurring, planned, schedules, payouts, modifiers,
-                            start_date, end)
+                     ScenarioModifier.scenario_id == scenario.id)
+                     .order_by(ScenarioModifier.id)).scalars()]
+    return ScenarioInputs(recurring, planned, loans, modifiers)
+
+
+def run_projection(session: Session, scenario: Scenario, horizon_days: int,
+                   start_date: date) -> ProjectionResult:
+    end = start_date + timedelta(days=horizon_days)
+    inputs = load_scenario_inputs(session, scenario)
+    schedules = [loan_schedule(Decimal(l.principal), Decimal(l.annual_rate_pct),
+                               l.term_months, l.payout_date, l.repayment_type)
+                 for l in inputs.loans]
+    payouts = [(l.payout_date, Decimal(l.principal)) for l in inputs.loans]
+    flows = build_cashflows(inputs.recurring, inputs.planned, schedules, payouts,
+                            inputs.modifiers, start_date, end)
     proj = project(total_balance(session), start_date, flows, horizon_days,
                    threshold=get_settings().warn_threshold)
     session.execute(delete(ProjectionPoint).where(

finance/tests/test_scenario_inputs.py

@@ -0,0 +1,68 @@
+from datetime import date
+from decimal import Decimal
+
+from app.engine.scenario import (PlainModifier, PlainRecurring, effective_end,
+                                 modified_amount)
+from app.models.tables import (Loan, PlannedItem, RecurringItem, Scenario,
+                               ScenarioLoan, ScenarioModifier,
+                               ScenarioPlannedItem)
+from app.services.projection_service import load_scenario_inputs
+
+
+def test_modifikator_helfer_oeffentlich():
+    mods = [PlainModifier("recurring", 1, "percent", Decimal("10")),
+            PlainModifier("recurring", 1, "ende", Decimal("0"), date(2030, 6, 30))]
+    assert modified_amount(Decimal("-100.00"), None, 1, mods) == Decimal("-90.00")
+    assert modified_amount(Decimal("-100.00"), None, 2, mods) == Decimal("-100.00")
+    r = PlainRecurring(1, "R", Decimal("-100.00"), "monthly", 1, None,
+                       date(2030, 12, 31), None)
+    assert effective_end(r, mods) == date(2030, 6, 30)
+
+
+def _daten(db):
+    rec = RecurringItem(name="R", amount=Decimal("-10.00"), rhythm="monthly", due_day=1)
+    pln = PlannedItem(name="P", amount=Decimal("-20.00"), due=date(2030, 1, 1))
+    k1 = Loan(name="K1", principal=Decimal("100.00"), annual_rate_pct=Decimal("0"),
+              term_months=2, payout_date=date(2030, 1, 1), repayment_type="annuity")
+    k2 = Loan(name="K2", principal=Decimal("200.00"), annual_rate_pct=Decimal("0"),
+              term_months=2, payout_date=date(2030, 1, 1), repayment_type="annuity")
+    sc = Scenario(name="S", description="", include_recurring=True,
+                  include_planned=False)
+    db.add_all([rec, pln, k1, k2, sc])
+    db.flush()
+    db.add_all([
+        ScenarioLoan(scenario_id=sc.id, loan_id=k1.id),
+        ScenarioModifier(scenario_id=sc.id, target_type="recurring",
+                         target_id=rec.id, kind="percent", value=Decimal("50")),
+        ScenarioPlannedItem(scenario_id=sc.id, name="SP", amount=Decimal("-5.00"),
+                            due=date(2030, 2, 1)),
+    ])
+    db.commit()
+    return sc
+
+
+def test_load_scenario_inputs_szenario(db):
+    sc = _daten(db)
+    inp = load_scenario_inputs(db, sc)
+    assert [r.name for r in inp.recurring] == ["R"]
+    # include_planned=False: globale Einmalposten fehlen, Szenario-eigene zählen immer.
+    assert [p.name for p in inp.planned] == ["SP"]
+    assert inp.planned[0].category_id is None
+    assert [l.name for l in inp.loans] == ["K1"]
+    assert [(m.kind, m.value) for m in inp.modifiers] == [("percent", Decimal("50"))]
+
+
+def test_load_scenario_inputs_ohne_fixposten(db):
+    sc = _daten(db)
+    sc.include_recurring = False
+    db.commit()
+    assert load_scenario_inputs(db, sc).recurring == []
+
+
+def test_load_scenario_inputs_system_plan(db):
+    _daten(db)
+    inp = load_scenario_inputs(db, None)
+    assert [r.name for r in inp.recurring] == ["R"]
+    assert [p.name for p in inp.planned] == ["P"]
+    assert [l.name for l in inp.loans] == ["K1", "K2"]
+    assert inp.modifiers == []