import { NextResponse } from "next/server";
import { getPayload } from "payload";
import config from "@payload-config";
import { createLiveKitToken, getLiveKitClientUrl } from "@/lib/meeting/livekit";
import { isMeetingParticipantKicked } from "@/lib/meeting/kicks";
import { verifyMeetingToken } from "@/lib/meeting/token";
import { authorizeMeeting } from "@/lib/meeting/access";

export const dynamic = "force-dynamic";

type Args = { params: Promise<{ slug: string }> };

/** Exchanges the app's short-lived meeting credential for a LiveKit token. */
export async function POST(request: Request, { params }: Args) {
  const { slug } = await params;
  const authorization = request.headers.get("authorization") ?? "";
  const appToken = authorization.startsWith("Bearer ") ? authorization.slice(7) : "";
  const meetingToken = verifyMeetingToken(appToken);
  if (!meetingToken || meetingToken.eventSlug !== slug) {
    return NextResponse.json({ error: "Die Meeting-Sitzung ist ungültig." }, { status: 401 });
  }
  if (isMeetingParticipantKicked(slug, meetingToken.participantId, meetingToken.clientId)) {
    return NextResponse.json({ error: "Du wurdest aus diesem Meeting entfernt." }, { status: 403 });
  }

  try {
    let expiresAt = meetingToken.exp;
    const isAdminTestRoom = meetingToken.role === "host" && meetingToken.testRoom === true && slug.startsWith("test-");
    if (!isAdminTestRoom) {
      const payload = await getPayload({ config });
      const { docs } = await payload.find({ collection: "events", where: { slug: { equals: slug } }, limit: 1 });
      if (!docs[0]?.isOnline) return NextResponse.json({ error: "Dieser Online-Termin wurde nicht gefunden." }, { status: 404 });
      const access = await authorizeMeeting(payload, docs[0], meetingToken.role);
      if (!access || access.accessVersion !== meetingToken.accessVersion) {
        return NextResponse.json({ error: "Dieser Meeting-Zugang ist nicht mehr gültig. Bitte tritt erneut bei." }, { status: 403 });
      }
      expiresAt = Math.min(expiresAt, access.expiresAt);
    }

    const participantToken = await createLiveKitToken({
      eventSlug: slug,
      participantId: meetingToken.participantId,
      name: meetingToken.name,
      role: meetingToken.role,
      clientId: meetingToken.clientId,
      accessVersion: meetingToken.accessVersion,
      expiresAt,
    });
    return NextResponse.json({ serverUrl: getLiveKitClientUrl(), participantToken });
  } catch (error) {
    console.error("meeting LiveKit connect failed", error);
    return NextResponse.json({ error: "Der Video-Server ist gerade nicht erreichbar." }, { status: 503 });
  }
}