update invoice

package-lock.json

@@ -14,6 +14,7 @@
         "bcryptjs": "^3.0.2",
         "next": "15.3.2",
         "next-auth": "^4.24.11",
+        "nodemailer": "^6.10.1",
         "react": "^19.0.0",
         "react-dom": "^19.0.0"
       },
@@ -21,6 +22,7 @@
         "@eslint/eslintrc": "^3",
         "@tailwindcss/postcss": "^4",
         "@types/node": "^20",
+        "@types/nodemailer": "^6.4.17",
         "@types/react": "^19",
         "@types/react-dom": "^19",
         "eslint": "^9",
@@ -1599,6 +1601,16 @@
         "undici-types": "~6.19.2"
       }
     },
+    "node_modules/@types/nodemailer": {
+      "version": "6.4.17",
+      "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-6.4.17.tgz",
+      "integrity": "sha512-I9CCaIp6DTldEg7vyUTZi8+9Vo0hi1/T8gv3C89yk1rSAAzoKQ8H8ki/jBYJSFoH/BisgLP8tkZMlQ91CIquww==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/react": {
       "version": "19.1.4",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.1.4.tgz",
@@ -5023,6 +5035,15 @@
         "node": "^10 || ^12 || >=14"
       }
     },
+    "node_modules/nodemailer": {
+      "version": "6.10.1",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.10.1.tgz",
+      "integrity": "sha512-Z+iLaBGVaSjbIzQ4pX6XV41HrooLsQ10ZWPUehGmuantvzWoDVBnmsdUcOIDM1t+yPor5pDhVlDESgOMEGxhHA==",
+      "license": "MIT-0",
+      "engines": {
+        "node": ">=6.0.0"
+      }
+    },
     "node_modules/oauth": {
       "version": "0.9.15",
       "resolved": "https://registry.npmjs.org/oauth/-/oauth-0.9.15.tgz",

package.json

@@ -15,6 +15,7 @@
     "bcryptjs": "^3.0.2",
     "next": "15.3.2",
     "next-auth": "^4.24.11",
+    "nodemailer": "^6.10.1",
     "react": "^19.0.0",
     "react-dom": "^19.0.0"
   },
@@ -22,6 +23,7 @@
     "@eslint/eslintrc": "^3",
     "@tailwindcss/postcss": "^4",
     "@types/node": "^20",
+    "@types/nodemailer": "^6.4.17",
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^9",

prisma/schema.prisma

@@ -12,24 +12,24 @@ datasource db {
 model Account {
   id                String  @id @default(cuid())
   userId            String
-  type              String
-  provider          String
-  providerAccountId String
+  type              String // z.B. "oauth", "oidc"
+  provider          String // z.B. "keycloak", "credentials"
+  providerAccountId String // Die ID des Benutzers beim Provider (z.B. Keycloak 'sub')
   refresh_token     String? @db.Text
   access_token      String? @db.Text
-  expires_at        Int? // Üblicherweise für access_token Ablauf (in Sekunden seit Unix-Epoche)
-  token_type        String?
+  expires_at        Int? // Unix-Timestamp (in Sekunden) für den Ablauf des access_token
+  token_type        String? // z.B. "Bearer"
   scope             String?
   id_token          String? @db.Text
   session_state     String?
 
-  refresh_expires_in Int? // NEU: Lebensdauer des Refresh Tokens in Sekunden
-  not_before_policy  Int? // NEU: Keycloak "Not Before Policy" Wert (Unix-Timestamp)
+  refresh_expires_in Int? // Lebensdauer des Refresh Tokens in Sekunden
+  not_before_policy  Int? // NEU: Keycloak "Not Before Policy" Wert (oft ein Timestamp)
 
   user User @relation(fields: [userId], references: [id], onDelete: Cascade)
 
   @@unique([provider, providerAccountId])
-  @@index([userId]) // Index für userId hinzugefügt für bessere Abfrageleistung
+  @@index([userId])
 }
 
 model Session {

src/pages/admin/index.tsx

@@ -4,7 +4,6 @@ import { useSession, signOut } from 'next-auth/react';
 import { useRouter } from 'next/router';
 import { useEffect, useState, Fragment } from 'react';
 import { Dialog, Transition } from '@headlessui/react';
-// import { useTheme } from '../../context/ThemeContext'; // Entfernt
 
 // Typen für die Admin-Seite (Frontend)
 interface AdminUser {
@@ -58,6 +57,13 @@ interface SetApprovalStatusApiResponse {
     approvedAt: Date | null;
 }
 
+interface SendInvoicesApiResponse {
+    message: string;
+    sentToCount: number;
+    errors: { userId: string; error: string }[];
+}
+
+
 const AdminPanelPage: NextPage = () => {
     const { data: session, status } = useSession();
     const router = useRouter();
@@ -79,6 +85,17 @@ const AdminPanelPage: NextPage = () => {
     const [isLoadingUserTransactions, setIsLoadingUserTransactions] = useState(false);
     const [isTransactionsModalOpen, setIsTransactionsModalOpen] = useState(false);
 
+    const [isInvoiceModalOpen, setIsInvoiceModalOpen] = useState(false);
+    const [invoiceDeadline, setInvoiceDeadline] = useState<string>(() => {
+        const today = new Date();
+        today.setDate(today.getDate() + 14);
+        return today.toISOString().split('T')[0];
+    });
+    // paypalEmail und cashPaymentContacts States entfernt, da sie jetzt fest im Backend sind
+    const [isSendingInvoices, setIsSendingInvoices] = useState(false);
+    const [selectedUserIdsForInvoice, setSelectedUserIdsForInvoice] = useState<string[]>([]);
+
+
     useEffect(() => {
         if (status === 'loading') return;
 
@@ -249,6 +266,60 @@ const AdminPanelPage: NextPage = () => {
         }
     };
 
+    const openInvoiceModal = (userIds: string[] = []) => {
+        setSelectedUserIdsForInvoice(userIds);
+        setIsInvoiceModalOpen(true);
+    };
+
+    const handleSendInvoices = async (e: React.FormEvent<HTMLFormElement>) => {
+        e.preventDefault();
+        setIsSendingInvoices(true);
+        setError(null);
+        setSuccessMessage(null);
+
+        const payload: { deadline: string; userIds?: string[] } = { // paypalEmail und cashPaymentContacts entfernt
+            deadline: invoiceDeadline,
+        };
+
+        if (selectedUserIdsForInvoice.length > 0) {
+            payload.userIds = selectedUserIdsForInvoice;
+        }
+
+        try {
+            const response = await fetch('/api/admin/invoices/send-bulk', { // API-Route bleibt gleich
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify(payload),
+            });
+            const data: SendInvoicesApiResponse = await response.json();
+            if (!response.ok) {
+                throw new Error(data.message || 'Fehler beim Senden der Rechnungs-E-Mails.');
+            }
+            setSuccessMessage(`${data.message} Fehler beim Senden an ${data.errors.length} Benutzer (Details in Konsole).`);
+            if (data.errors.length > 0) {
+                console.error("Fehler beim E-Mail-Versand für folgende Benutzer:", data.errors);
+            }
+            setIsInvoiceModalOpen(false);
+        } catch (err: unknown) {
+            if (err instanceof Error) {
+                setError(err.message);
+            } else {
+                setError('Ein unbekannter Fehler beim Senden der Rechnungs-E-Mails ist aufgetreten.');
+            }
+            console.error("Fehler Rechnungsversand:", err);
+        } finally {
+            setIsSendingInvoices(false);
+        }
+    };
+
+    const handleUserSelectionForInvoice = (userId: string, isSelected: boolean) => {
+        if (isSelected) {
+            setSelectedUserIdsForInvoice(prev => [...prev, userId]);
+        } else {
+            setSelectedUserIdsForInvoice(prev => prev.filter(id => id !== userId));
+        }
+    };
+
 
     if (status === 'loading' || (status === 'authenticated' && session?.user?.role !== 'admin' && !isLoadingUsers) ) {
         return (
@@ -268,13 +339,12 @@ const AdminPanelPage: NextPage = () => {
 
     return (
         <div className="min-h-screen bg-gray-100 dark:bg-slate-900 p-4 sm:p-6 lg:p-8 transition-colors duration-300">
-            {/* Header angepasst für mobile Ansicht */}
             <header className="mb-8 flex flex-col sm:flex-row sm:justify-between sm:items-center">
-                <div className="mb-4 sm:mb-0"> {/* Div für Admin Panel Text */}
+                <div className="mb-4 sm:mb-0">
                     <h1 className="text-3xl font-bold text-gray-800 dark:text-gray-100">Admin Panel</h1>
                     <p className="text-gray-600 dark:text-gray-400">Benutzerverwaltung & Übersicht</p>
                 </div>
-                <div className="flex flex-col space-y-2 sm:flex-row sm:space-y-0 sm:space-x-4"> {/* Container für Buttons */}
+                <div className="flex flex-col space-y-2 sm:flex-row sm:space-y-0 sm:space-x-4">
                     <button
                         onClick={() => router.push('/dashboard')}
                         className="w-full sm:w-auto px-4 py-2 bg-blue-500 text-white rounded-md hover:bg-blue-600 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2"
@@ -293,7 +363,6 @@ const AdminPanelPage: NextPage = () => {
             {error && <div className="mb-4 p-3 bg-red-100 text-red-700 border border-red-300 rounded-md dark:bg-red-900 dark:text-red-200 dark:border-red-700">{error}</div>}
             {successMessage && <div className="mb-4 p-3 bg-green-100 text-green-700 border border-green-300 rounded-md dark:bg-green-900 dark:text-green-200 dark:border-green-700">{successMessage}</div>}
 
-            {/* Gesamtübersicht Sektion */}
             <section className="mb-8 p-6 bg-white dark:bg-slate-800 shadow-lg rounded-lg">
                 <h2 className="text-2xl font-semibold text-gray-700 dark:text-gray-200 mb-4">Gesamtübersicht</h2>
                 <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
@@ -314,7 +383,31 @@ const AdminPanelPage: NextPage = () => {
                 </div>
             </section>
 
-            {/* Benutzerliste */}
+            <section className="mb-8 p-6 bg-white dark:bg-slate-800 shadow-lg rounded-lg">
+                <h2 className="text-2xl font-semibold text-gray-700 dark:text-gray-200 mb-4">Rechnungsversand</h2>
+                <div className="space-y-3 sm:space-y-0 sm:flex sm:space-x-3">
+                    <button
+                        onClick={() => openInvoiceModal()}
+                        className="w-full sm:w-auto px-4 py-2 border border-transparent text-sm font-medium rounded-md shadow-sm text-white bg-orange-600 hover:bg-orange-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-orange-500 dark:bg-orange-500 dark:hover:bg-orange-600"
+                    >
+                        Rechnung an alle (positiver Saldo)
+                    </button>
+                    <button
+                        onClick={() => {
+                            if (selectedUserIdsForInvoice.length === 0) {
+                                setError("Bitte wähle zuerst Benutzer aus der Liste unten aus.");
+                                return;
+                            }
+                            openInvoiceModal(selectedUserIdsForInvoice);
+                        }}
+                        disabled={selectedUserIdsForInvoice.length === 0}
+                        className="w-full sm:w-auto px-4 py-2 border border-transparent text-sm font-medium rounded-md shadow-sm text-white bg-cyan-600 hover:bg-cyan-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-cyan-500 disabled:opacity-50 dark:bg-cyan-500 dark:hover:bg-cyan-600"
+                    >
+                        Rechnung an Ausgewählte ({selectedUserIdsForInvoice.length})
+                    </button>
+                </div>
+            </section>
+
             <section className="p-6 bg-white dark:bg-slate-800 shadow-lg rounded-lg">
                 <h2 className="text-2xl font-semibold text-gray-700 dark:text-gray-200 mb-4">Benutzerübersicht</h2>
                 {isLoadingUsers ? (
@@ -324,6 +417,9 @@ const AdminPanelPage: NextPage = () => {
                         <table className="min-w-full divide-y divide-gray-200 dark:divide-gray-700">
                             <thead className="bg-gray-50 dark:bg-slate-700">
                                 <tr>
+                                    <th className="px-1 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
+                                        <span className="sr-only">Alle auswählen</span>
+                                    </th>
                                     <th className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">Name</th>
                                     <th className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">E-Mail</th>
                                     <th className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">Saldo</th>
@@ -334,7 +430,17 @@ const AdminPanelPage: NextPage = () => {
                             </thead>
                             <tbody className="bg-white dark:bg-slate-800 divide-y divide-gray-200 dark:divide-gray-700">
                                 {users.map((user) => (
-                                    <tr key={user.id} className="dark:hover:bg-slate-700/50">
+                                    <tr key={user.id} className={`dark:hover:bg-slate-700/50 ${selectedUserIdsForInvoice.includes(user.id) ? 'bg-blue-50 dark:bg-blue-900/30' : ''}`}>
+                                        <td className="px-1 py-4 whitespace-nowrap">
+                                            {parseFloat(user.balance || "0") > 0 && (
+                                                <input
+                                                    type="checkbox"
+                                                    className="h-4 w-4 text-indigo-600 border-gray-300 dark:border-gray-600 rounded focus:ring-indigo-500 dark:bg-slate-700 dark:focus:ring-indigo-600"
+                                                    checked={selectedUserIdsForInvoice.includes(user.id)}
+                                                    onChange={(e) => handleUserSelectionForInvoice(user.id, e.target.checked)}
+                                                />
+                                            )}
+                                        </td>
                                         <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-900 dark:text-gray-100">{user.name || 'N/A'}</td>
                                         <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-700 dark:text-gray-300">{user.email || 'N/A'}</td>
                                         <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-700 dark:text-gray-300 font-medium">{user.balance ? `${user.balance} €` : '0.00 €'}</td>
@@ -379,7 +485,74 @@ const AdminPanelPage: NextPage = () => {
                 )}
             </section>
 
-            {/* Modal für Saldo anpassen */}
+            {/* Modal für Rechnungsversand */}
+            <Transition appear show={isInvoiceModalOpen} as={Fragment}>
+                <Dialog as="div" className="relative z-20" onClose={() => setIsInvoiceModalOpen(false)}>
+                    <Transition.Child
+                        as="div" className="fixed inset-0"
+                        enter="ease-out duration-300" enterFrom="opacity-0" enterTo="opacity-100"
+                        leave="ease-in duration-200" leaveFrom="opacity-100" leaveTo="opacity-0"
+                    >
+                        <div className="absolute inset-0 bg-black/30 backdrop-blur-sm dark:bg-slate-900/80" />
+                    </Transition.Child>
+                    <div className="fixed inset-0 overflow-y-auto">
+                        <div className="flex min-h-full items-center justify-center p-4 text-center">
+                            <Transition.Child
+                                as="div"
+                                className="w-full max-w-lg transform overflow-hidden rounded-2xl bg-white dark:bg-slate-800 p-6 text-left align-middle shadow-xl transition-all"
+                                enter="ease-out duration-300" enterFrom="opacity-0 scale-95" enterTo="opacity-100 scale-100"
+                                leave="ease-in duration-200" leaveFrom="opacity-100 scale-100" leaveTo="opacity-0 scale-95"
+                            >
+                                <Dialog.Panel>
+                                    <Dialog.Title as="h3" className="text-lg font-medium leading-6 text-gray-900 dark:text-gray-100">
+                                        Rechnungs-E-Mails senden
+                                    </Dialog.Title>
+                                    <Dialog.Description className="mt-2 text-sm text-gray-500 dark:text-gray-400">
+                                        {selectedUserIdsForInvoice.length > 0
+                                            ? `E-Mail wird an ${selectedUserIdsForInvoice.length} ausgewählte Benutzer gesendet.`
+                                            : "E-Mail wird an alle Benutzer mit positivem Saldo gesendet."
+                                        }
+                                        <br/>Die PayPal-Adresse und Barzahlungskontakte sind fest hinterlegt.
+                                    </Dialog.Description>
+                                    <form onSubmit={handleSendInvoices} className="mt-4 space-y-4">
+                                        <div>
+                                            <label htmlFor="invoiceDeadline" className="block text-sm font-medium text-gray-700 dark:text-gray-300">Zahlungsfrist</label>
+                                            <input
+                                                type="date"
+                                                id="invoiceDeadline"
+                                                value={invoiceDeadline}
+                                                onChange={(e) => setInvoiceDeadline(e.target.value)}
+                                                required
+                                                className="mt-1 block w-full px-3 py-2 border border-gray-400 dark:border-gray-600 rounded-md shadow-sm focus:ring-indigo-500 focus:border-indigo-500 sm:text-sm text-gray-900 dark:text-gray-100 bg-white dark:bg-slate-700"
+                                            />
+                                        </div>
+                                        {/* Eingabefelder für PayPal E-Mail und Barzahlungskontakte entfernt */}
+                                        <div className="mt-6 flex justify-end space-x-3">
+                                            <button
+                                                type="button"
+                                                className="inline-flex justify-center rounded-md border border-transparent bg-gray-200 dark:bg-slate-700 px-4 py-2 text-sm font-medium text-gray-800 dark:text-gray-100 hover:bg-gray-300 dark:hover:bg-slate-600 focus:outline-none focus-visible:ring-2 focus-visible:ring-gray-500 focus-visible:ring-offset-2"
+                                                onClick={() => setIsInvoiceModalOpen(false)}
+                                            >
+                                                Abbrechen
+                                            </button>
+                                            <button
+                                                type="submit"
+                                                disabled={isSendingInvoices}
+                                                className="inline-flex justify-center rounded-md border border-transparent bg-green-600 px-4 py-2 text-sm font-medium text-white hover:bg-green-700 focus:outline-none focus-visible:ring-2 focus-visible:ring-green-500 focus-visible:ring-offset-2 disabled:opacity-50 dark:bg-green-500 dark:hover:bg-green-600"
+                                            >
+                                                {isSendingInvoices ? 'Senden...' : 'E-Mails senden'}
+                                            </button>
+                                        </div>
+                                    </form>
+                                </Dialog.Panel>
+                            </Transition.Child>
+                        </div>
+                    </div>
+                </Dialog>
+            </Transition>
+
+            {/* Andere Modals (Saldo anpassen, Transaktionsverlauf) bleiben unverändert */}
+            {/* ... Code für AdjustModal und TransactionsModal ... */}
             <Transition appear show={isAdjustModalOpen} as={Fragment}>
                 <Dialog as="div" className="relative z-10" onClose={() => setIsAdjustModalOpen(false)}>
                     <Transition.Child
@@ -472,7 +645,6 @@ const AdminPanelPage: NextPage = () => {
                 </Dialog>
             </Transition>
 
-            {/* Modal für Transaktionsverlauf */}
             <Transition appear show={isTransactionsModalOpen} as={Fragment}>
                 <Dialog as="div" className="relative z-10" onClose={() => setIsTransactionsModalOpen(false)}>
                     <Transition.Child

src/pages/api/admin/invoices/send-bulk.ts

@@ -0,0 +1,241 @@
+// Datei: pages/api/admin/invoices/send-bulk.ts
+import type { NextApiRequest, NextApiResponse } from 'next';
+import { getServerSession } from 'next-auth/next';
+import { Decimal } from '@prisma/client/runtime/library';
+import nodemailer from 'nodemailer';
+import {authOptions} from "@/pages/api/auth/[...nextauth]";
+import prisma from "@/lib/prisma"
+
+// FESTE KONSTANTEN
+const FIXED_CASH_PAYMENT_CONTACTS = "Thomas, Elias oder Paul"; // <-- HIER DEINE KONTAKTE EINTRAGEN
+
+interface SendBulkInvoicesRequestBody {
+    deadline: string;
+    // paypalEmail: string; // Entfernt
+    // cashPaymentContacts: string; // Entfernt
+    userIds?: string[];
+}
+
+interface SuccessResponse {
+    message: string;
+    sentToCount: number;
+    errors: { userId: string; error: string }[];
+}
+
+interface ErrorResponse {
+    message: string;
+}
+
+// HTML E-Mail Vorlage
+function createInvoiceHtml(
+    userName: string | null,
+    balance: Decimal,
+    deadline: string // ISO String
+    // paypalEmailText und cashPaymentContacts werden jetzt durch Konstanten ersetzt
+): string {
+    const formattedDeadline = new Date(deadline).toLocaleDateString('de-DE', {
+        year: 'numeric', month: 'long', day: 'numeric'
+    });
+    const formattedBalance = balance.toFixed(2);
+    const paypalMeLink = `http://paypal.me/thomasqst/${formattedBalance}`;
+
+    return `
+    <!DOCTYPE html>
+    <html lang="de">
+    <head>
+      <meta charset="UTF-8">
+      <meta name="viewport" content="width=device-width, initial-scale=1.0">
+      <title>Deine Strichlisten-Rechnung</title>
+      <style>
+        body { font-family: Arial, sans-serif; line-height: 1.6; color: #333; margin: 0; padding: 20px; background-color: #f4f4f4; }
+        .container { background-color: #fff; padding: 20px; border-radius: 8px; box-shadow: 0 0 10px rgba(0,0,0,0.1); max-width: 600px; margin: auto; }
+        h1 { color: #333; }
+        p { margin-bottom: 10px; }
+        .highlight { font-weight: bold; color: #d9534f; }
+        .footer { margin-top: 20px; font-size: 0.9em; color: #777; text-align: center; }
+        ul { list-style-type: none; padding: 0; }
+        li { margin-bottom: 8px; }
+        a { color: #007bff; text-decoration: none; }
+        a:hover { text-decoration: underline; }
+      </style>
+    </head>
+    <body>
+      <div class="container">
+        <h1>Hallo ${userName || 'Benutzer'},</h1>
+        <p>dein aktueller Saldo auf der Strichliste beträgt: <span class="highlight">${formattedBalance} €</span>.</p>
+        <p>Bitte begleiche diesen Betrag bis zum <strong>${formattedDeadline}</strong>.</p>
+        <h2>Zahlungsmöglichkeiten:</h2>
+        <ul>
+          <li><strong>PayPal:</strong> <a href="${paypalMeLink}" target="_blank">${paypalMeLink}</a></li>
+          <li><strong>Bar an:</strong> ${FIXED_CASH_PAYMENT_CONTACTS}</li>
+        </ul>
+        <p>Vielen Dank!</p>
+        <p>Dein Strichlisten-Team</p>
+        <div class="footer">
+          <p>Dies ist eine automatisch generierte E-Mail.</p>
+        </div>
+      </div>
+    </body>
+    </html>
+  `;
+}
+
+// Nodemailer Transporter erstellen
+const transporter = nodemailer.createTransport({
+    host: process.env.SMTP_HOST,
+    port: parseInt(process.env.SMTP_PORT || "587"),
+    secure: process.env.SMTP_SECURE === 'true',
+    auth: {
+        user: process.env.SMTP_USER,
+        pass: process.env.SMTP_PASS,
+    },
+    tls: {
+        rejectUnauthorized: true,
+    }
+});
+
+
+async function sendInvoiceEmail(
+    userName: string | null,
+    userEmail: string | null,
+    balance: Decimal,
+    deadline: string
+    // paypalEmailText und cashPaymentContacts entfernt, da Konstanten verwendet werden
+): Promise<{ success: boolean; error?: string }> {
+    if (!userEmail) {
+        return { success: false, error: "Keine E-Mail-Adresse für den Benutzer vorhanden." };
+    }
+    if (!process.env.SMTP_HOST || !process.env.SMTP_USER || !process.env.SMTP_PASS || !process.env.SMTP_FROM_EMAIL) {
+        console.error("SMTP-Konfiguration unvollständig. E-Mail-Versand übersprungen (simuliert).");
+        const formattedDeadlineSim = new Date(deadline).toLocaleDateString('de-DE', { year: 'numeric', month: '2-digit', day: '2-digit' });
+        const formattedBalanceSim = balance.toFixed(2);
+        const paypalMeLinkSim = `http://paypal.me/thomasqst/${formattedBalanceSim}`;
+        console.log("----------------------------------------------------");
+        console.log(`SIMULIERTER E-Mail-Versand an: ${userEmail}`);
+        console.log(`Betreff: Deine Strichlisten-Rechnung - Saldo: ${formattedBalanceSim}€`);
+        console.log(`Inhalt: Saldo ${formattedBalanceSim}€, Frist ${formattedDeadlineSim}, PayPal Link ${paypalMeLinkSim}, Bar bei ${FIXED_CASH_PAYMENT_CONTACTS}`);
+        console.log("----------------------------------------------------");
+        return { success: true };
+    }
+
+
+    const htmlContent = createInvoiceHtml(userName, balance, deadline); // Parameter entfernt
+    const mailOptions = {
+        from: `"${process.env.SMTP_FROM_NAME || 'Strichlisten Team'}" <${process.env.SMTP_FROM_EMAIL}>`,
+        to: userEmail,
+        subject: `Deine Strichlisten-Rechnung - Saldo: ${balance.toFixed(2)}€`,
+        html: htmlContent,
+        text: `Hallo ${userName || ''},\n\n` +
+            `dein aktueller Saldo auf der Strichliste beträgt: ${balance.toFixed(2)} €.\n` +
+            `Bitte begleiche diesen Betrag bis zum ${new Date(deadline).toLocaleDateString('de-DE', { year: 'numeric', month: 'long', day: 'numeric' })}.\n\n` +
+            `Zahlungsmöglichkeiten:\n` +
+            `- PayPal: http://paypal.me/thomasqst/${balance.toFixed(2)}\n` +
+            `- Bar an: ${FIXED_CASH_PAYMENT_CONTACTS}\n\n` +
+            `Vielen Dank!\n` +
+            `Dein Strichlisten-Team`
+    };
+
+    try {
+        await transporter.sendMail(mailOptions);
+        console.log(`Rechnungs-E-Mail erfolgreich gesendet an: ${userEmail}`);
+        return { success: true };
+    } catch (e: unknown) {
+        console.error(`Fehler beim Senden der E-Mail an ${userEmail}:`, e);
+        if (!(e instanceof Error)) return { success: false, error: 'Unbekannter Fehler beim E-Mail-Versand' };
+        return { success: false, error: e.message || 'Unbekannter Fehler beim E-Mail-Versand' };
+    }
+}
+
+
+export default async function handler(
+    req: NextApiRequest,
+    res: NextApiResponse<SuccessResponse | ErrorResponse>
+) {
+    if (req.method !== 'POST') {
+        res.setHeader('Allow', ['POST']);
+        return res.status(405).json({ message: `Method ${req.method} Not Allowed` });
+    }
+
+    const session = await getServerSession(req, res, authOptions);
+    if (!session || !session.user || session.user.role !== 'admin') {
+        return res.status(403).json({ message: 'Zugriff verweigert. Nur für Administratoren.' });
+    }
+
+    const { deadline, userIds } = req.body as SendBulkInvoicesRequestBody; // paypalEmail und cashPaymentContacts entfernt
+
+    if (!deadline) { // Prüfung auf cashPaymentContacts entfernt
+        return res.status(400).json({ message: 'Frist ist erforderlich.' });
+    }
+    try {
+        new Date(deadline);
+    } catch (e) {
+        console.error('Ungültiges Datumsformat für die Frist:', e);
+        return res.status(400).json({ message: 'Ungültiges Datumsformat für die Frist.' });
+    }
+
+    try {
+        let usersToInvoice;
+        if (userIds && userIds.length > 0) {
+            usersToInvoice = await prisma.user.findMany({
+                where: {
+                    id: { in: userIds },
+                    balance: { gt: 0 },
+                    isApproved: true,
+                },
+                select: { id: true, name: true, email: true, balance: true },
+            });
+        } else {
+            usersToInvoice = await prisma.user.findMany({
+                where: {
+                    balance: { gt: 0 },
+                    isApproved: true,
+                },
+                select: { id: true, name: true, email: true, balance: true },
+            });
+        }
+
+
+        if (usersToInvoice.length === 0) {
+            return res.status(200).json({ message: 'Keine passenden Benutzer für den Rechnungsversand gefunden.', sentToCount: 0, errors: [] });
+        }
+
+        let sentCount = 0;
+        const emailErrors: { userId: string; error: string }[] = [];
+
+        for (const user of usersToInvoice) {
+            if (user.balance) {
+                const result = await sendInvoiceEmail(
+                    user.name,
+                    user.email,
+                    user.balance,
+                    deadline
+                    // Parameter für PayPal und Kontakte entfernt
+                );
+                if (result.success) {
+                    sentCount++;
+                } else {
+                    emailErrors.push({ userId: user.id, error: result.error || 'Unbekannter Fehler beim E-Mail-Versand' });
+                }
+            }
+        }
+
+        const targetAudience = userIds && userIds.length > 0 ? `${userIds.length} ausgewählte(n)` : "allen";
+        const finalMessage = emailErrors.length === 0
+            ? `Rechnungs-E-Mails wurden erfolgreich an ${sentCount} von ${usersToInvoice.length} (${targetAudience}) Benutzer(n) gesendet.`
+            : `Rechnungs-E-Mails wurden an ${sentCount} von ${usersToInvoice.length} (${targetAudience}) Benutzer(n) gesendet. ${emailErrors.length} Fehler sind aufgetreten.`;
+
+
+        return res.status(200).json({
+            message: finalMessage,
+            sentToCount: sentCount,
+            errors: emailErrors,
+        });
+
+    } catch (error: unknown) {
+        console.error('Fehler beim Senden der Rechnungs-E-Mails:', error);
+        if (error instanceof Error) {
+            return res.status(500).json({ message: `Interner Serverfehler: ${error.message}` });
+        }
+        return res.status(500).json({ message: 'Ein unbekannter interner Serverfehler ist aufgetreten.' });
+    }
+}

src/pages/api/auth/[...nextauth].ts

@@ -1,21 +1,21 @@
 // Datei: pages/api/auth/[...nextauth].ts
 
 import NextAuth, {AuthOptions, TokenSet} from "next-auth";
-import CredentialsProvider from "next-auth/providers/credentials";
+import CredentialsProvider, {CredentialInput} from "next-auth/providers/credentials";
 import KeycloakProvider, { KeycloakProfile } from "next-auth/providers/keycloak";
 import { PrismaAdapter } from "@next-auth/prisma-adapter";
 import prisma from "../../../lib/prisma";
 import bcrypt from "bcryptjs";
 
-import type { User } from "next-auth";
+import type { User, Account, Profile } from "next-auth";
+import {AdapterUser} from "next-auth/adapters"; // Account und Profile importieren für den signIn Callback
 
 export const authOptions: AuthOptions = {
     adapter: PrismaAdapter(prisma),
     session: {
         strategy: "jwt",
     },
-    // Debug-Modus für ausführlichere Logs von NextAuth.js aktivieren
-    debug: true, // process.env.NODE_ENV === 'development',
+    debug: process.env.NODE_ENV === 'development',
     providers: [
         KeycloakProvider({
             clientId: process.env.KEYCLOAK_CLIENT_ID as string,
@@ -23,14 +23,11 @@ export const authOptions: AuthOptions = {
             issuer: process.env.KEYCLOAK_ISSUER as string,
             allowDangerousEmailAccountLinking: true,
             profile(profile: KeycloakProfile, tokens: TokenSet): User | Promise<User> {
-                // Detailliertes Logging des empfangenen Keycloak-Profils und der Tokens
                 console.log("[NextAuth.js] Keycloak Profile Received:", JSON.stringify(profile, null, 2));
-                // Vorsicht beim Loggen von Tokens in der Produktion, hier nur ein Snippet des ID-Tokens
                 if (tokens.id_token) {
                     console.log("[NextAuth.js] Keycloak ID Token Snippet:", tokens.id_token.substring(0, 50) + "...");
                 }
 
-
                 let userRole = 'user';
                 if (profile.realm_access?.roles && Array.isArray(profile.realm_access.roles) && profile.realm_access.roles.includes('admin')) {
                     userRole = 'admin';
@@ -38,22 +35,20 @@ export const authOptions: AuthOptions = {
                     userRole = 'admin';
                 }
 
-                const emailFromProvider = profile.email?.toLowerCase(); // E-Mail normalisieren (zu Kleinbuchstaben)
+                const emailFromProvider = profile.email?.toLowerCase();
 
                 if (!emailFromProvider) {
                     console.error("[NextAuth.js] Email not provided by Keycloak profile. Profile data:", profile);
-                    // Du könntest hier entscheiden, einen Fehler zu werfen oder einen Fallback zu implementieren,
-                    // aber für die Kontoverknüpfung ist eine E-Mail essentiell.
                     throw new Error("E-Mail wurde nicht vom Identitätsprovider (Keycloak) bereitgestellt.");
                 }
 
                 const userToReturn: User = {
                     id: profile.sub,
                     name: profile.name || profile.preferred_username,
-                    email: emailFromProvider, // Normalisierte E-Mail verwenden
+                    email: emailFromProvider,
                     image: profile.picture,
                     role: userRole,
-                    isApproved: true, // Annahme: OIDC-Benutzer sind standardmäßig freigegeben
+                    isApproved: true,
                 };
 
                 console.log("[NextAuth.js] User object to be processed by adapter/callbacks:", JSON.stringify(userToReturn, null, 2));
@@ -95,6 +90,27 @@ export const authOptions: AuthOptions = {
         }),
     ],
     callbacks: {
+        async signIn({account}: { user: User | AdapterUser, account: Account | null, profile?: Profile | KeycloakProfile, email?: { verificationRequest?: boolean }, credentials?: Record<string, CredentialInput> }) {
+            if (account && account.provider === "keycloak") {
+                // Das 'account'-Objekt hier enthält die rohen Daten vom Token-Endpunkt des Providers.
+                // Wir verwenden eine Typ-Assertion, um TypeScript mitzuteilen, dass wir zusätzliche,
+                // provider-spezifische Felder erwarten könnten.
+                const keycloakAccount = account as Account & {
+                    'not-before-policy'?: unknown; // Geändert von any zu unknown
+                    not_before_policy?: unknown;   // Geändert von any zu unknown
+                    // Füge hier weitere provider-spezifische Felder hinzu, falls nötig
+                };
+
+                if (keycloakAccount['not-before-policy'] !== undefined) {
+                    console.log(`[NextAuth.js] signIn callback: Renaming 'not-before-policy' to 'not_before_policy' for account: ${account.providerAccountId}`);
+                    // Der Wert wird einfach kopiert. Die Typüberprüfung für den Wert selbst ist hier weniger kritisch
+                    // als die Vermeidung von 'any' in der Typdefinition.
+                    keycloakAccount.not_before_policy = keycloakAccount['not-before-policy'];
+                    delete keycloakAccount['not-before-policy'];
+                }
+            }
+            return true; // Erlaube den Anmeldevorgang
+        },
         async jwt({ token, user, account }) {
             if (account && user) {
                 token.id = user.id;