Initial commit: Kalendartool (Next.js, Prisma, Docker)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/api/calendars/route.ts

@@ -0,0 +1,86 @@
+/**
+ * POST /api/calendars - neuen Kalender erstellen (nur ADMIN).
+ */
+import { NextRequest, NextResponse } from 'next/server';
+import { prisma } from '@/lib/db/client';
+import { requireDbUser } from '@/lib/api/context';
+import { createCalendarSchema } from '@/lib/validation';
+import { errorResponse, forbiddenResponse } from '@/lib/api/responses';
+
+export async function POST(request: NextRequest): Promise<NextResponse> {
+  try {
+    const user = await requireDbUser();
+    if (user.role !== 'ADMIN') {
+      return forbiddenResponse();
+    }
+
+    const body = createCalendarSchema.parse(await request.json());
+
+    const calendar = await prisma.calendar.create({
+      data: {
+        ownerId: user.id,
+        title: body.title,
+        description: body.description ?? null,
+        timezone: body.timezone,
+      },
+      select: { id: true, title: true, description: true, timezone: true },
+    });
+
+    return NextResponse.json({ calendar }, { status: 201 });
+  } catch (error) {
+    return errorResponse(error);
+  }
+}
+
+/**
+ * GET /api/calendars - Kalender des angemeldeten Benutzers.
+ *
+ * Admin: alle Kalender (Verwaltungsrolle, konsistent mit canManageCalendar
+ * und den Server-Komponenten in Dashboard/Verwaltung). User: genau der
+ * eine Kalender, in dem er Mitglied ist (plan.md Abschnitt 14: Dashboard).
+ */
+export async function GET(): Promise<NextResponse> {
+  try {
+    const user = await requireDbUser();
+
+    if (user.role === 'ADMIN') {
+      const calendars = await prisma.calendar.findMany({
+        orderBy: { createdAt: 'desc' },
+        select: {
+          id: true,
+          title: true,
+          description: true,
+          timezone: true,
+          isActive: true,
+          createdAt: true,
+          _count: { select: { reservations: true, members: true } },
+        },
+      });
+      return NextResponse.json({ calendars });
+    }
+
+    // User: genau ein Kalender (durch unique auf userId garantiert).
+    const membership = await prisma.calendarMember.findUnique({
+      where: { userId: user.id },
+      include: {
+        calendar: {
+          select: {
+            id: true,
+            title: true,
+            description: true,
+            timezone: true,
+            isActive: true,
+            createdAt: true,
+            _count: { select: { reservations: true, members: true } },
+          },
+        },
+      },
+    });
+
+    return NextResponse.json({
+      calendars: membership?.calendar ? [membership.calendar] : [],
+    });
+  } catch (error) {
+    return errorResponse(error);
+  }
+}