import { NextResponse } from "next/server";
import { getPayload } from "payload";
import config from "@payload-config";
import { calendarFeedUrl, generateCalendarFeedToken, hashCalendarFeedToken } from "@/lib/calendar/feedToken";

export const dynamic = "force-dynamic";

/**
 * POST /api/admin/calendar-feed/regenerate — (re)generates Anna's personal
 * ICS feed link. Only the new token's hash is stored; the plaintext URL is
 * returned exactly once in this response and can never be retrieved again
 * — generating a new one immediately invalidates whichever link was issued
 * before (see collections/Users.ts).
 */
export async function POST(request: Request) {
  try {
    const payload = await getPayload({ config });
    const { user } = await payload.auth({ headers: request.headers });
    if (!user || user.collection !== "users") {
      return NextResponse.json({ error: "Nicht autorisiert." }, { status: 401 });
    }

    const token = generateCalendarFeedToken();
    await payload.update({
      collection: "users",
      id: user.id,
      data: { calendarFeedTokenHash: hashCalendarFeedToken(token) },
    });

    return NextResponse.json({ url: calendarFeedUrl(token) });
  } catch (error) {
    console.error("calendar feed regenerate failed", error);
    return NextResponse.json({ error: "Der Kalender-Link konnte nicht erzeugt werden." }, { status: 500 });
  }
}