feat: Salden-Seite mit Stichtag und Monatsuebersicht

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

finance/app/routers/gui.py

@@ -3,15 +3,16 @@ from decimal import Decimal
 
 from fastapi import APIRouter, Depends, HTTPException, Request
 from fastapi.templating import Jinja2Templates
-from sqlalchemy import select
+from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
 from app.auth import COOKIE, session_valid
 from app.db import get_session
+from app.engine.loans import add_months
 from app.engine.recurrence import occurrences
 from app.models.tables import (Account, Category, PlannedItem,
                                ProjectionResult, RecurringItem,
-                               ScenarioLoan, ScenarioModifier)
+                               ScenarioLoan, ScenarioModifier, Transaction)
 from app.routers.imports import list_imports as _list_imports
 from app.routers.imports import preview as _preview_import
 from app.routers.planning import list_loans as _list_loans
@@ -84,6 +85,25 @@ def _opt_date(value: str | None) -> date | None:
         return None
 
 
+def _month_starts_desc(session: Session, today: date) -> list[date]:
+    """Liefert die Monatsersten von "heute" rueckwaerts bis zum Monat der
+    fruehesten bestaetigten Buchung, absteigend sortiert (heute zuerst).
+    Ohne bestaetigte Buchungen: leere Liste."""
+    earliest = session.execute(
+        select(func.min(Transaction.booking_date)).where(Transaction.status == "confirmed")
+    ).scalar_one_or_none()
+    if earliest is None:
+        return []
+    start = date(earliest.year, earliest.month, 1)
+    current = date(today.year, today.month, 1)
+    months = []
+    m = current
+    while m >= start:
+        months.append(m)
+        m = add_months(m, -1)
+    return months
+
+
 @router.get("/", dependencies=[Depends(gui_session)])
 def index(request: Request, session: Session = Depends(get_session)):
     accounts = session.execute(select(Account)).scalars().all()
@@ -158,6 +178,50 @@ def buchungen(
     })
 
 
+@router.get("/salden", dependencies=[Depends(gui_session)])
+def salden_page(
+    request: Request,
+    stichtag: str | None = None,
+    session: Session = Depends(get_session),
+):
+    # Lenient wie die Filter auf /buchungen: ein leerer oder kaputter
+    # stichtag-Parameter fuehrt nie zu 422, sondern faellt auf "heute" zurueck.
+    today = date.today()
+    parsed_stichtag = _opt_date(stichtag) or today
+
+    accounts = session.execute(select(Account)).scalars().all()
+    balances = [(a, account_balance(session, a, at=parsed_stichtag)) for a in accounts]
+    total = sum((b for _, b in balances), Decimal("0"))
+
+    month_rows = []
+    for month in _month_starts_desc(session, today):
+        # Saldo am Monatsanfang = Stand am ENDE DES VORTAGS (letzter Tag des
+        # Vormonats), NICHT account_balance(at=month) - sonst wuerden
+        # Buchungen AM 1. bereits in den "Anfangs"-Saldo einfliessen und den
+        # Ausweis verzerren. Siehe Fussnote im Template ("Stand: Ende des
+        # Vortags").
+        vortag = month - timedelta(days=1)
+        values = [(a, account_balance(session, a, at=vortag)) for a in accounts]
+        month_rows.append({
+            "month": month,
+            "values": values,
+            "total": sum((v for _, v in values), Decimal("0")),
+        })
+
+    accounts_without_anchor = [
+        a for a in accounts if a.anchor_date is None or a.anchor_balance is None
+    ]
+
+    return templates.TemplateResponse(request, "salden.html", {
+        "stichtag": parsed_stichtag,
+        "balances": balances,
+        "total": total,
+        "accounts": accounts,
+        "months": month_rows,
+        "accounts_without_anchor": accounts_without_anchor,
+    })
+
+
 @router.get("/import", dependencies=[Depends(gui_session)])
 def import_page(request: Request, session: Session = Depends(get_session)):
     return templates.TemplateResponse(request, "import.html", {