import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { prisma } from "@/lib/db";
import { getOwnedPlan } from "@/lib/queries";
import { getCurrentUserId } from "@/lib/session";
import { PERSON_ONLY_CATEGORIES } from "@/lib/elements";

const createSchema = z.object({
  category: z.enum([
    "INCOME",
    "EXPENSE",
    "AHV",
    "PENSION_FUND",
    "PILLAR_3A",
    "REAL_ESTATE",
    "OTHER_ASSET",
    "OTHER_DEBT",
  ]),
  name: z.string().min(1).max(120),
  ownerRole: z.enum(["PERSON_A", "PERSON_B", "HOUSEHOLD"]).nullable().optional(),
});

// Legt ein neues finanzielles Element (plan-weit) an. Personen-Pflicht je Kategorie.
export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ planId: string }> }
) {
  const userId = await getCurrentUserId();
  if (!userId) return NextResponse.json({ error: "Nicht authentifiziert." }, { status: 401 });
  const { planId } = await params;

  const plan = await getOwnedPlan(planId, userId);
  if (!plan) return NextResponse.json({ error: "Plan nicht gefunden." }, { status: 404 });

  const body = await request.json();
  const parsed = createSchema.safeParse(body);
  if (!parsed.success) return NextResponse.json({ error: "Ungueltige Eingabe." }, { status: 400 });

  const { category, name } = parsed.data;
  let ownerRole = parsed.data.ownerRole ?? null;

  if (PERSON_ONLY_CATEGORIES.includes(category)) {
    if (ownerRole !== "PERSON_A" && ownerRole !== "PERSON_B") {
      return NextResponse.json(
        { error: "Diese Kategorie muss einer Person zugeordnet werden." },
        { status: 400 }
      );
    }
  } else if (ownerRole == null) {
    ownerRole = "HOUSEHOLD";
  }

  const maxOrder = await prisma.financialElement.aggregate({
    where: { planId: plan.id },
    _max: { orderIndex: true },
  });

  const element = await prisma.financialElement.create({
    data: {
      planId: plan.id,
      category,
      name,
      ownerRole,
      orderIndex: (maxOrder._max.orderIndex ?? 0) + 1,
    },
  });

  return NextResponse.json({ element: { id: element.id } }, { status: 201 });
}