import { NextResponse, type NextRequest } from "next/server";
import { asSystem } from "@/lib/db";
import { callFunction } from "@/lib/db/rpc";

// Applies effective-dated changes (Versetzung/Beförderung/Karenz/Reorg/Daten
// ändern with a future "Wirksam ab" date) once their date has arrived — see
// apply_due_pending_changes() in supabase/migrations. Runs as a Vercel Cron
// job (see vercel.json), not on behalf of any HR user, so it authenticates
// via a shared secret rather than a Supabase session and uses the
// service-role client (the one legitimate server-only use case for it).
export async function GET(request: NextRequest) {
  const authHeader = request.headers.get("authorization");
  if (!process.env.CRON_SECRET || authHeader !== `Bearer ${process.env.CRON_SECRET}`) {
    return NextResponse.json({ error: "Nicht autorisiert." }, { status: 401 });
  }

  // Kein privilegierter Zugang mehr: derselbe Datenbankbenutzer ohne
  // BYPASSRLS wie überall. apply_due_pending_changes ist SECURITY DEFINER
  // und prüft selbst, was sie tut — der Dienstschlüssel, der RLS aushebelte,
  // ist damit entfallen.
  try {
    const applied = await asSystem((tx) => callFunction(tx, "apply_due_pending_changes"));
    return NextResponse.json({ applied });
  } catch (err) {
    console.error("apply_due_pending_changes failed:", err);
    return NextResponse.json({ error: "Interner Fehler." }, { status: 500 });
  }
}