import { NextResponse } from "next/server";
import type { NextRequest } from "next/server";
import { getSessionClientId } from "@/lib/auth";
import { isAdminSession, getAllPermissions } from "@/lib/adminAuth";
import { getCalendarMonthData } from "@/lib/calendarMonth";
import { corsHeaders, corsPreflight } from "@/lib/teamApiCors";

export async function OPTIONS(request: NextRequest) {
  return corsPreflight(request);
}

export async function GET(request: NextRequest) {
  const headers = corsHeaders(request);
  const clientId = await getSessionClientId();
  if (!clientId || !(await isAdminSession())) {
    return NextResponse.json({ error: "Nicht angemeldet." }, { status: 401, headers });
  }
  const permissions = await getAllPermissions();
  if (!permissions.orders_view && !permissions.calendars_view) {
    return NextResponse.json({ error: "Keine Berechtigung." }, { status: 403, headers });
  }

  const monthParam = request.nextUrl.searchParams.get("month") || "";
  const now = new Date();
  let year = now.getFullYear();
  let monthIndex = now.getMonth();
  if (/^\d{4}-\d{2}$/.test(monthParam)) {
    const [y, m] = monthParam.split("-").map(Number);
    if (m >= 1 && m <= 12) {
      year = y;
      monthIndex = m - 1;
    }
  }

  const data = await getCalendarMonthData(clientId, permissions, year, monthIndex);
  return NextResponse.json(data, { headers });
}