import { NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";
import { requireRole } from "@/lib/auth";

type Params = { params: Promise<{ id: string }> };

export async function PATCH(req: Request, { params }: Params) {
  const session = await requireRole("INSTITUTION_ADMIN");
  if (!session || !session.institutionId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  const { id } = await params;
  const body = await req.json().catch(() => ({}));

  const data: { name?: string; nameBn?: string | null; isActive?: boolean } = {};
  if (body.name !== undefined) {
    const name = String(body.name).trim();
    if (!name) return NextResponse.json({ error: "Name is required" }, { status: 400 });
    const exists = await prisma.accountHead.findFirst({
      where: { institutionId: session.institutionId, name, NOT: { id: Number(id) } },
    });
    if (exists) return NextResponse.json({ error: "NAME_EXISTS" }, { status: 409 });
    data.name = name;
  }
  if (body.nameBn !== undefined) data.nameBn = String(body.nameBn).trim() || null;
  if (body.isActive !== undefined) data.isActive = Boolean(body.isActive);

  try {
    const head = await prisma.accountHead.update({
      where: { id: Number(id) },
      data,
    });
    return NextResponse.json({ head });
  } catch {
    return NextResponse.json({ error: "Could not update head" }, { status: 500 });
  }
}

export async function DELETE(_req: Request, { params }: Params) {
  const session = await requireRole("INSTITUTION_ADMIN");
  if (!session || !session.institutionId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  const { id } = await params;
  const head = await prisma.accountHead.findFirst({
    where: { id: Number(id), institutionId: session.institutionId },
    include: { _count: { select: { entries: true } } },
  });
  if (!head) return NextResponse.json({ error: "Not found" }, { status: 404 });
  if (head._count.entries > 0) {
    return NextResponse.json({ error: "HEAD_IN_USE" }, { status: 409 });
  }

  try {
    await prisma.accountHead.delete({ where: { id: head.id } });
    return NextResponse.json({ ok: true });
  } catch {
    return NextResponse.json({ error: "Could not delete head" }, { status: 500 });
  }
}