import { NextResponse } from 'next/server';
import { scheduleDisconnectRoomChat } from '@/lib/chzzk/chat-session';
import {
  getRoom,
  getRoomViewerCount,
  removeRoomViewer,
  toPublicRoom,
} from '@/lib/rooms/store';

export const runtime = 'nodejs';

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

/**
 * 탭/창 종료·페이지 이탈 시 호출.
 * 마지막 시청자면 치지직 채팅 웹소켓을 유예 후 끊는다 (빠른 재입장 대비).
 */
export async function POST(request: Request, { params }: Params) {
  const { roomId } = await params;
  const room = getRoom(roomId);
  if (!room) {
    return NextResponse.json({ ok: true, emptied: true });
  }

  let clientId = '';
  const contentType = request.headers.get('content-type') || '';
  try {
    if (contentType.includes('application/json')) {
      const body = (await request.json()) as { clientId?: string };
      clientId = body.clientId?.trim() || '';
    } else {
      const text = await request.text();
      if (text.startsWith('{')) {
        const body = JSON.parse(text) as { clientId?: string };
        clientId = body.clientId?.trim() || '';
      } else {
        clientId = new URLSearchParams(text).get('clientId')?.trim() || '';
      }
    }
  } catch {
    clientId = '';
  }

  if (!clientId) {
    return NextResponse.json({ ok: true, viewers: getRoomViewerCount(roomId) });
  }

  const { viewers, emptied } = removeRoomViewer(roomId, clientId);
  if (emptied) {
    scheduleDisconnectRoomChat(roomId);
  }

  return NextResponse.json({
    ok: true,
    viewers,
    emptied,
    room: toPublicRoom(getRoom(roomId) ?? room),
  });
}