Refactor navigation structure and API routes

- Centralize user menu, sidebar items, and breadcrumb logic.
- Map consistent API endpoints in `customerRoutes`.
- Replace inline route definitions with reusable constants.
- Refactor auth configuration file location.
- Improve `<Link>` usage to replace static `<a>` elements.
- Adjust sidebar and dropdown components to use dynamic navigation configurations.

internal_frontend/app/api/auth/[...nextauth]/route.ts

@@ -1,5 +1,5 @@
 import NextAuth from "next-auth";
-import {authOptions} from "@/lib/auth/authOptions";
+import {authOptions} from "@/lib/api/auth/authOptions";
 
 const handler = NextAuth(authOptions);
 export {handler as GET, handler as POST};

internal_frontend/app/api/customers/[id]/route.ts

@@ -1,9 +1,10 @@
 import {NextRequest, NextResponse} from "next/server";
 import {serverCall} from "@/lib/api/serverCall";
+import {customerRoutes} from "@/app/api/customers/customerRoutes";
 
 export async function GET(request: NextRequest) {
     const id = request.url.split('/').pop();
-    const response = await serverCall(`/customers/${id}`, "GET");
+    const response = await serverCall(customerRoutes.getById(id!), "GET");
 
     if (!response.ok) {
         return NextResponse.json({error: "Customer not found"}, {status: 404});

internal_frontend/app/api/customers/customerRoutes.ts

@@ -1,4 +1,5 @@
 export const customerRoutes = {
     create: "/customers",
     validate: "/customers/validate",
+    getById: (id: string) => `/customers/${id}`,
 };

internal_frontend/app/api/customers/route.ts

@@ -1,14 +1,15 @@
 import {NextRequest, NextResponse} from "next/server";
 import {serverCall} from "@/lib/api/serverCall";
+import {customerRoutes} from "@/app/api/customers/customerRoutes";
 
 export async function GET() {
-    const data = await serverCall("/customers", "GET");
+    const data = await serverCall(customerRoutes.create, "GET");
     const customers = await data.json();
     return NextResponse.json(customers);
 }
 
 export async function POST(req: NextRequest) {
     const body = await req.json()
-    const result = await serverCall("/customers", "POST", body);
+    const result = await serverCall(customerRoutes.create, "POST", body);
     return NextResponse.json(result.json());
 }

internal_frontend/app/customers/page.tsx

@@ -1,7 +1,6 @@
 "use client";
 
 import {useState, useEffect, useMemo} from "react";
-import {useRouter} from "next/navigation";
 import {Button} from "@/components/ui/button";
 import {Input} from "@/components/ui/input";
 import {Card, CardContent} from "@/components/ui/card";
@@ -25,9 +24,9 @@ import {ArrowRight} from "lucide-react";
 import {NewCustomerModal} from "@/components/customers/modal/NewCustomerModal";
 import axios from "axios";
 import {Customer} from "@/services/customers/entities/customer";
+import Link from "next/link";
 
 export default function CustomersPage() {
-    const router = useRouter();
     const [customers, setCustomers] = useState<Customer[]>([]);
     const [search, setSearch] = useState("");
     const [loading, setLoading] = useState(true);
@@ -143,13 +142,11 @@ export default function CustomersPage() {
                                                 <TableCell>{customer.city}</TableCell>
                                                 <TableCell>{new Date(customer.createdAt).toLocaleString()}</TableCell>
                                                 <TableCell>
-                                                    <Button
-                                                        variant="ghost"
-                                                        size="icon"
-                                                        onClick={() => router.push(`/customers/${customer.id}`)}
-                                                    >
+                                                    <Link href={`/customers/${customer.id}`}>
+                                                        <Button variant="ghost" size="icon">
                                                             <ArrowRight className="w-4 h-4"/>
                                                         </Button>
+                                                    </Link>
                                                 </TableCell>
                                             </TableRow>
                                         ))}

internal_frontend/app/layout.tsx

@@ -8,7 +8,7 @@ import {Separator} from "@/components/ui/separator";
 import {DynamicBreadcrumb} from "@/components/dynamic-breadcrumb";
 import {getServerSession} from "next-auth";
 import LoginScreen from "@/components/login-screen";
-import {authOptions} from "@/lib/auth/authOptions";
+import {authOptions} from "@/lib/api/auth/authOptions";
 
 export const metadata: Metadata = {
     title: "Internal | Rhein Software",

internal_frontend/components/app-sidebar.tsx

@@ -1,13 +1,11 @@
+import Link from 'next/link';
 import {
-    AppWindowIcon,
     ChevronUp,
     ChevronRight,
-    Home,
     Scale,
     User2,
-    Settings, LayoutDashboard
+    Settings,
 } from "lucide-react";
-
 import {
     Sidebar,
     SidebarContent,
@@ -23,40 +21,20 @@ import {
     SidebarMenuSubItem,
     SidebarMenuSubButton,
 } from "@/components/ui/sidebar";
-
 import {
     DropdownMenu,
     DropdownMenuContent,
     DropdownMenuItem,
     DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
-
 import {
     Collapsible,
     CollapsibleTrigger,
     CollapsibleContent,
 } from "@/components/ui/collapsible";
+import {rheinItems, customerItems, kanzleiItems} from "@/lib/navigation/sidebar-items";
+import {userMenuItems} from "@/lib/navigation/user-menu-items";
 
-const rheinItems = [
-    {
-        title: "Dashboard",
-        url: "/",
-        icon: Home,
-    },
-    {
-        title: "Apps",
-        url: "/apps",
-        icon: AppWindowIcon,
-    },
-];
-
-const customerItems = [
-    {
-        title: "Kundenübersicht",
-        url: "/customers",
-        icon: LayoutDashboard,
-    },
-];
 
 export function AppSidebar() {
     return (
@@ -74,10 +52,10 @@ export function AppSidebar() {
                                         asChild
                                         className="hover:bg-accent hover:text-accent-foreground"
                                     >
-                                        <a href={item.url}>
+                                        <Link href={item.url}>
                                             <item.icon/>
                                             <span>{item.title}</span>
-                                        </a>
+                                        </Link>
                                     </SidebarMenuButton>
                                 </SidebarMenuItem>
                             ))}
@@ -95,10 +73,10 @@ export function AppSidebar() {
                                         asChild
                                         className="hover:bg-accent hover:text-accent-foreground"
                                     >
-                                        <a href={item.url}>
+                                        <Link href={item.url}>
                                             <item.icon/>
                                             <span>{item.title}</span>
-                                        </a>
+                                        </Link>
                                     </SidebarMenuButton>
                                 </SidebarMenuItem>
                             ))}
@@ -117,11 +95,10 @@ export function AppSidebar() {
                                         asChild
                                         className="hover:bg-accent hover:text-accent-foreground"
                                     >
-
-                                        <a href="/demo/settings">
+                                        <Link href="/demo/settings">
                                             <Settings/>
                                             <span>Demo Settings</span>
-                                        </a>
+                                        </Link>
                                     </SidebarMenuButton>
                                 </SidebarMenuItem>
                             </SidebarMenu>
@@ -144,21 +121,15 @@ export function AppSidebar() {
 
                                 <CollapsibleContent>
                                     <SidebarMenuSub className="ml-4 border-l border-border pl-4 flex flex-col gap-y-1">
-                                        <SidebarMenuSubItem>
-                                            <SidebarMenuSubButton href="/demo/kanzlei/steuer">
-                                                Steuer
-                                            </SidebarMenuSubButton>
-                                        </SidebarMenuSubItem>
-                                        <SidebarMenuSubItem>
-                                            <SidebarMenuSubButton href="/demo/kanzlei/rechtsanwalt">
-                                                Rechtsanwalt
-                                            </SidebarMenuSubButton>
-                                        </SidebarMenuSubItem>
-                                        <SidebarMenuSubItem>
-                                            <SidebarMenuSubButton href="/demo/kanzlei/bilanzbuchhalter">
-                                                Bilanzbuchhalter
+                                        {kanzleiItems.map((item) => (
+                                            <SidebarMenuSubItem key={item.title}>
+                                                <SidebarMenuSubButton asChild>
+                                                    <Link href={item.url}>
+                                                        {item.title}
+                                                    </Link>
                                                 </SidebarMenuSubButton>
                                             </SidebarMenuSubItem>
+                                        ))}
                                     </SidebarMenuSub>
                                 </CollapsibleContent>
                             </Collapsible>
@@ -183,15 +154,14 @@ export function AppSidebar() {
                                 side="top"
                                 className="w-[--radix-popper-anchor-width]"
                             >
-                                <DropdownMenuItem>
-                                    <span>Account</span>
-                                </DropdownMenuItem>
-                                <DropdownMenuItem>
-                                    <span>Billing</span>
-                                </DropdownMenuItem>
-                                <DropdownMenuItem>
-                                    <span>Sign out</span>
+                                {userMenuItems.map((item) => (
+                                    <DropdownMenuItem key={item.title} asChild>
+                                        <Link href={item.url}>
+                                            {item.icon && <item.icon className="mr-2 h-4 w-4"/>}
+                                            <span>{item.title}</span>
+                                        </Link>
                                     </DropdownMenuItem>
+                                ))}
                             </DropdownMenuContent>
                         </DropdownMenu>
                     </SidebarMenuItem>

internal_frontend/components/dynamic-breadcrumb.tsx

@@ -11,8 +11,8 @@ import {
 } from '@/components/ui/breadcrumb';
 import {Skeleton} from "@/components/ui/skeleton";
 import React, {useEffect, useState} from 'react';
-import {getBreadcrumbs} from '@/utils/BreadcrumbUtils';
-import {breadcrumbResolvers} from "@/lib/breadcrumb-map";
+import {getBreadcrumbs} from '@/services/navigation/breadcrumb-utils';
+import {breadcrumbResolvers} from "@/lib/navigation/breadcrumb-map";
 
 interface ResolvedBreadcrumb {
     href: string;

internal_frontend/lib/api/auth/authOptions.ts

@@ -15,10 +15,10 @@ const {
     NEXTAUTH_SECRET,
 } = process.env;
 
-// if (!KEYCLOAK_CLIENT_ID) throw new Error("Missing KEYCLOAK_CLIENT_ID");
-// if (!KEYCLOAK_CLIENT_SECRET) throw new Error("Missing KEYCLOAK_CLIENT_SECRET");
-// if (!KEYCLOAK_ISSUER) throw new Error("Missing KEYCLOAK_ISSUER");
-// if (!NEXTAUTH_SECRET) throw new Error("Missing NEXTAUTH_SECRET");
+if (!KEYCLOAK_CLIENT_ID) throw new Error("Missing KEYCLOAK_CLIENT_ID");
+if (!KEYCLOAK_CLIENT_SECRET) throw new Error("Missing KEYCLOAK_CLIENT_SECRET");
+if (!KEYCLOAK_ISSUER) throw new Error("Missing KEYCLOAK_ISSUER");
+if (!NEXTAUTH_SECRET) throw new Error("Missing NEXTAUTH_SECRET");
 
 console.log("[auth] Using Keycloak provider:");
 console.log("  - Client ID:", KEYCLOAK_CLIENT_ID);
@@ -42,8 +42,8 @@ async function isTokenValid(token: string): Promise<boolean> {
 export const authOptions: NextAuthOptions = {
     providers: [
         KeycloakProvider({
-            clientId: KEYCLOAK_CLIENT_ID as string,
-            clientSecret: KEYCLOAK_CLIENT_SECRET as string,
+            clientId: KEYCLOAK_CLIENT_ID,
+            clientSecret: KEYCLOAK_CLIENT_SECRET,
             issuer: KEYCLOAK_ISSUER,
         }),
     ],

internal_frontend/lib/api/serverCall.ts

@@ -1,6 +1,6 @@
 // lib/callBackendApi.ts
 import {getServerSession} from "next-auth";
-import {authOptions} from "@/lib/auth/authOptions";
+import {authOptions} from "@/lib/api/auth/authOptions";
 
 export async function serverCall(
     path: string,

internal_frontend/lib/navigation/breadcrumb-map.ts

@@ -1,20 +1,19 @@
-// lib/breadcrumb-map.ts
+import {customerRoutes} from "@/app/api/customers/customerRoutes";
+
 export const breadcrumbMap: Record<string, string> = {
     'dashboard': 'Dashboard',
     'settings': 'Settings',
     'demo': 'Demo',
     'users': 'User Management',
     'customers': 'Kundenübersicht',
-    // Add more mappings as needed
 };
 
 export const breadcrumbResolvers: Record<string, (id: string) => Promise<string>> = {
     "customers": async (id: string) => {
-        const res = await fetch(`/api/customers/${id}`, {cache: "no-store"});
+        const res = await fetch(`/api${customerRoutes.getById(id)}`, {cache: "no-store"});
         const customer = await res.json();
         if (customer.companyName) return `Firma: ${customer.companyName}`;
         if (customer.name) return `Name: ${customer.name}`;
         return `ID: ${id}`;
     },
-    // Add more mappings as needed
 };

internal_frontend/lib/navigation/sidebar-items.ts

@@ -0,0 +1,38 @@
+import {AppWindowIcon, Home, LayoutDashboard} from "lucide-react";
+import {MenuItem, SubMenuItem} from "@/types/navigation/sidebar";
+
+export const rheinItems: MenuItem[] = [
+    {
+        title: "Dashboard",
+        url: "/",
+        icon: Home,
+    },
+    {
+        title: "Apps",
+        url: "/apps",
+        icon: AppWindowIcon,
+    },
+];
+
+export const customerItems: MenuItem[] = [
+    {
+        title: "Kundenübersicht",
+        url: "/customers",
+        icon: LayoutDashboard,
+    },
+];
+
+export const kanzleiItems: SubMenuItem[] = [
+    {
+        title: "Steuer",
+        url: "/demo/kanzlei/steuer",
+    },
+    {
+        title: "Rechtsanwalt",
+        url: "/demo/kanzlei/rechtsanwalt",
+    },
+    {
+        title: "Bilanzbuchhalter",
+        url: "/demo/kanzlei/bilanzbuchhalter",
+    },
+];

internal_frontend/lib/navigation/user-menu-items.ts

@@ -0,0 +1,20 @@
+import {LogOut, Settings} from "lucide-react";
+
+export interface UserMenuItem {
+    title: string;
+    url: string;
+    icon?: typeof Settings;
+}
+
+export const userMenuItems: UserMenuItem[] = [
+    {
+        title: "Settings",
+        url: "/settings",
+        icon: Settings,
+    },
+    {
+        title: "Ausloggen",
+        url: "/api/auth/signout",
+        icon: LogOut,
+    },
+];

internal_frontend/services/navigation/breadcrumb-utils.ts

@@ -1,4 +1,4 @@
-import {breadcrumbMap} from "@/lib/breadcrumb-map";
+import {breadcrumbMap} from "@/lib/navigation/breadcrumb-map";
 
 export interface Breadcrumb {
     href: string;

internal_frontend/types/navigation/sidebar.ts

@@ -0,0 +1,12 @@
+import {LucideIcon} from "lucide-react";
+
+export interface MenuItem {
+    title: string;
+    url: string;
+    icon: LucideIcon;
+}
+
+export interface SubMenuItem {
+    title: string;
+    url: string;
+}