Initial commit: FPT Financial Planning Tool

src/app/api/plans/[planId]/phases/route.ts

@@ -0,0 +1,50 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { prisma } from "@/lib/db";
+import { phaseInclude } from "@/lib/queries";
+
+const createPhaseSchema = z.object({
+  name: z.string().min(1).max(120),
+  durationYears: z.number().int().min(1).max(80),
+  inflationRate: z.number().min(-20).max(50).nullable().optional(),
+  incomeMode: z.enum(["PER_PERSON", "HOUSEHOLD"]).default("HOUSEHOLD"),
+});
+
+// Fuegt eine neue Lebensabschnittsphase am Ende der Phasenkette eines Plans an
+// (TDD Kapitel 3: Phasen werden chronologisch aneinandergereiht).
+export async function POST(
+  request: NextRequest,
+  { params }: { params: Promise<{ planId: string }> }
+) {
+  const { planId } = await params;
+  const body = await request.json();
+  const parsed = createPhaseSchema.safeParse(body);
+  if (!parsed.success) {
+    return NextResponse.json({ error: parsed.error.flatten() }, { status: 400 });
+  }
+
+  const plan = await prisma.plan.findUnique({ where: { id: planId } });
+  if (!plan) {
+    return NextResponse.json({ error: "Plan nicht gefunden." }, { status: 404 });
+  }
+
+  const lastPhase = await prisma.phase.findFirst({
+    where: { planId },
+    orderBy: { sequenceNumber: "desc" },
+  });
+  const nextSequence = (lastPhase?.sequenceNumber ?? 0) + 1;
+
+  const phase = await prisma.phase.create({
+    data: {
+      planId,
+      sequenceNumber: nextSequence,
+      name: parsed.data.name,
+      durationYears: parsed.data.durationYears,
+      inflationRate: parsed.data.inflationRate ?? null,
+      incomeMode: parsed.data.incomeMode,
+    },
+    include: phaseInclude,
+  });
+
+  return NextResponse.json({ phase }, { status: 201 });
+}