// app/api/notifications/stream/route.ts
import { NextRequest } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/[...nextauth]/route"
import realtimeNotificationService from '@/lib/realtime/RealtimeNotificationService';


export async function GET(request: NextRequest) {
    try {
      const session = await getServerSession(authOptions);
      if (!session?.user?.id) {
        return new Response('Unauthorized', { status: 401 });
      }
  
      const userId = session.user.id;
      const encoder = new TextEncoder();
  
      const stream = new ReadableStream({
        start(controller) {
          // 클라이언트 등록
          const clientId = realtimeNotificationService.addClient(userId, controller);
          
          console.log(`SSE stream started for user ${userId} (${clientId})`);
  
          // 초기 연결 확인 메시지
          controller.enqueue(encoder.encode("data: {\"type\":\"connected\"}\n\n"));
  
          // 연결 해제 처리
          request.signal.addEventListener('abort', () => {
            console.log(`SSE stream ended for user ${userId} (${clientId})`);
            realtimeNotificationService.removeClient(userId, controller);
            controller.close();
          });
        },
        
        cancel() {
          console.log(`SSE stream cancelled for user ${userId}`);
          realtimeNotificationService.removeClient(userId, controller);
        }
      });
  
      return new Response(stream, {
        headers: {
          'Content-Type': 'text/event-stream',
          'Cache-Control': 'no-cache, no-transform',
          'Connection': 'keep-alive',
          'X-Accel-Buffering': 'no', // Nginx 버퍼링 비활성화
        },
      });
    } catch (error) {
      console.error('Error creating SSE stream:', error);
      return new Response('Internal Server Error', { status: 500 });
    }
  }