import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/options";
import { NotificationService } from '@/lib/services/notifications/notification-service';

// GET /api/notifications?page=1&limit=20
export async function GET(request: Request) {
  try {
    // Authenticate user
    const session = await getServerSession(authOptions);
    if (!session || !session.user?.id) {
      return NextResponse.json(
        { error: "Not authenticated" },
        { status: 401 }
      );
    }

    const userId = session.user.id;
    const { searchParams } = new URL(request.url);
    const page = parseInt(searchParams.get('page') || '1', 10);
    const limit = parseInt(searchParams.get('limit') || '20', 10);
    
    // Validate parameters
    if (isNaN(page) || page < 1) {
      return NextResponse.json(
        { error: "Invalid page parameter" },
        { status: 400 }
      );
    }
    
    if (isNaN(limit) || limit < 1 || limit > 100) {
      return NextResponse.json(
        { error: "Invalid limit parameter, must be between 1 and 100" },
        { status: 400 }
      );
    }
    
    const notificationService = NotificationService.getInstance();
    const notifications = await notificationService.getNotifications(userId, page, limit);
    
    // Add Cache-Control header to help with client-side caching
    const response = NextResponse.json({
      notifications,
      page,
      limit,
      total: notifications.length
    });
    response.headers.set('Cache-Control', 'private, max-age=30'); // Cache for 30 seconds on client
    return response;
  } catch (error: any) {
    console.error('Error in notifications API:', error);
    return NextResponse.json(
      { error: "Internal server error", message: error.message },
      { status: 500 }
    );
  }
}