Feat: Kündigung blockt Erneuerungsentwurf; Upgrade storniert alte Rechnungen + legt neuen Entwurf an

backend/routes/admin.py

@@ -1150,7 +1150,7 @@ async def list_upgrade_requests(user=Depends(require_admin)):
 async def fulfill_upgrade_request(req_id: int, user=Depends(require_admin)):
     with db() as conn:
         req = conn.execute(
-            "SELECT r.*, u.name, u.email FROM upgrade_requests r JOIN users u ON u.id=r.user_id WHERE r.id=?",
+            "SELECT r.*, u.name, u.email, u.subscription_tier AS old_tier FROM upgrade_requests r JOIN users u ON u.id=r.user_id WHERE r.id=?",
             (req_id,)
         ).fetchone()
         if not req:
@@ -1259,9 +1259,70 @@ async def fulfill_upgrade_request(req_id: int, user=Depends(require_admin)):
         import logging
         logging.getLogger(__name__).warning(f"Bestätigungsmail fehlgeschlagen: {e}")
 
+    # Offene Rechnungen (sent/draft) des alten Tiers stornieren + neuen Entwurf anlegen
+    try:
+        await _handle_upgrade_invoices(req, tier_label)
+    except Exception as e:
+        logger.warning(f"Upgrade-Rechnungslogik fehlgeschlagen für {req['name']}: {e}")
+
     return {"ok": True, "tier": req["tier"], "user": req["name"]}
 
 
+async def _handle_upgrade_invoices(req: dict, new_tier_label: str):
+    """Storniert offene Rechnungen des alten Tiers und legt neuen Entwurf an."""
+    from routes.invoices import _next_invoice_number
+    from datetime import timedelta
+
+    with db() as conn:
+        # Offene Rechnungen (draft + sent) dieses Users finden
+        open_invoices = conn.execute(
+            "SELECT * FROM invoices WHERE user_id=? AND status IN ('draft','sent')",
+            (req["user_id"],)
+        ).fetchall()
+
+        for inv in open_invoices:
+            cancel_num = _next_invoice_number(conn, "ST")
+            conn.execute(
+                """UPDATE invoices SET status='cancelled', cancelled_at=strftime('%Y-%m-%dT%H:%M:%SZ','now'),
+                   cancellation_reason=?, cancellation_number=? WHERE id=?""",
+                (f"Tarif-Upgrade auf {new_tier_label}", cancel_num, inv["id"])
+            )
+            logger.info(f"Rechnung {inv['invoice_number']} storniert ({cancel_num}) — Upgrade auf {new_tier_label}")
+
+        # Neuen Entwurf für den neuen Tier anlegen
+        tier       = req["tier"]
+        price      = {"pro": 29.00, "breeder": 49.00}.get(tier, 29.00)
+        today      = datetime.now(_TZ).date()
+        end_date   = today.replace(year=today.year + 1) - timedelta(days=1)
+        period     = f"{today.strftime('%d.%m.%Y')} – {end_date.strftime('%d.%m.%Y')}"
+        description = f"{new_tier_label} Jahresabo"
+
+        billing = conn.execute(
+            "SELECT billing_address FROM users WHERE id=?", (req["user_id"],)
+        ).fetchone()
+        billing_address = billing["billing_address"] if billing else None
+
+        inv_number = _next_invoice_number(conn)
+        conn.execute("""
+            INSERT INTO invoices
+                (invoice_number, user_id, recipient_name, recipient_email, recipient_address,
+                 description, service_period, amount_net, discount_pct, discount_amount,
+                 amount_after_discount, tax_rate, tax_amount, amount_gross, notes)
+            VALUES (?,?,?,?,?,?,?,?,0,0,?,0,0,?,?)
+        """, (
+            inv_number, req["user_id"], req["name"], req["email"], billing_address,
+            description, period, price, price, price,
+            f"Automatisch bei Upgrade von {req.get('old_tier','Standard')} auf {new_tier_label}.",
+        ))
+        invoice_id = conn.execute("SELECT last_insert_rowid()").fetchone()[0]
+        conn.execute(
+            "INSERT INTO invoice_items (invoice_id, description, quantity, unit_price, total) VALUES (?,?,1,?,?)",
+            (invoice_id, description, price, price)
+        )
+
+    logger.info(f"Neuer Rechnungsentwurf {inv_number} für {req['email']} nach Upgrade auf {new_tier_label}")
+
+
 # ------------------------------------------------------------------
 # Helpers: Quartalsdaten
 # ------------------------------------------------------------------