import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/options";
import { getObjectContent } from '@/lib/s3';

// Helper function to check authentication
async function checkAuth(request: Request) {
  const session = await getServerSession(authOptions);
  if (!session?.user?.id) {
    console.error('Unauthorized access attempt:', {
      url: request.url,
      method: request.method,
      headers: Object.fromEntries(request.headers)
    });
    return { authorized: false, userId: null };
  }
  return { authorized: true, userId: session.user.id };
}

export async function GET(request: Request) {
  try {
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { searchParams } = new URL(request.url);
    const path = searchParams.get('path');
    const id = searchParams.get('id');
    
    if (!path && !id) {
      return NextResponse.json({ error: 'Path or ID parameter is required' }, { status: 400 });
    }

    // Determine the key to use
    let key: string;
    
    if (id) {
      // If id is provided directly, use it as the key
      key = id;
      
      // Ensure the user can only access their own files
      if (!key.startsWith(`user-${userId}/`)) {
        console.error('Unauthorized file access attempt:', { userId, fileId: id });
        return NextResponse.json({ error: 'Unauthorized access to file' }, { status: 403 });
      }
    } else if (path) {
      // If a path is provided, ensure it contains the user's ID
      if (!path.includes(`/files/cube-${userId}/`) && !path.includes(`user-${userId}/`)) {
        // For backward compatibility, convert NextCloud path to S3 path
        if (path.startsWith('/files/') || path.includes('/Private/')) {
          // Extract folder and filename from path
          const parts = path.split('/').filter(Boolean);
          const file = parts[parts.length - 1];
          let folder = 'notes'; // Default folder
          
          // Try to determine folder from path
          if (path.includes('/Notes/')) folder = 'notes';
          else if (path.includes('/Diary/')) folder = 'diary';
          else if (path.includes('/Contacts/')) folder = 'contacts';
          else if (path.includes('/Health/')) folder = 'health';
          
          // Use direct user path without pages prefix
          key = `user-${userId}/${folder}/${file}`;
          console.log('Converted NextCloud path to S3 key:', { path, key });
        } else {
          console.error('Unauthorized file access attempt:', { userId, filePath: path });
          return NextResponse.json({ error: 'Unauthorized access to file' }, { status: 403 });
        }
      } else {
        // If it already contains user ID, use the path directly
        key = path;
      }
    } else {
      return NextResponse.json({ error: 'Invalid parameters' }, { status: 400 });
    }

    console.log('Fetching file content from S3:', { key });
    
    // Get the file content
    const content = await getObjectContent(key);
    
    if (!content) {
      return NextResponse.json({ error: 'File not found' }, { status: 404 });
    }
    
    return NextResponse.json({ content });
  } catch (error) {
    console.error('Error fetching file content:', error);
    return NextResponse.json({ error: 'Internal server error', details: error instanceof Error ? error.message : String(error) }, { status: 500 });
  }
}