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

/**
 * API endpoint to create a specific folder for a user
 * POST /api/storage/init/folder
 */
export async function POST(request: Request) {
  try {
    // Get session
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    // Parse request body
    let reqBody;
    try {
      reqBody = await request.json();
    } catch (error) {
      return NextResponse.json({ error: 'Invalid request body' }, { status: 400 });
    }

    const { folder } = reqBody;
    
    if (!folder || typeof folder !== 'string') {
      return NextResponse.json({ error: 'Missing or invalid folder name' }, { status: 400 });
    }

    // Normalize folder name
    const folderLowercase = folder.toLowerCase();
    const userId = session.user.id;
    
    console.log(`Creating folder ${folderLowercase} for user ${userId}`);
    
    try {
      // Check if folder already exists by listing objects
      const existingFiles = await listUserObjects(userId, folderLowercase);
      
      // If folder already has files, it exists and we don't need to create anything
      if (existingFiles.length > 0) {
        console.log(`Folder ${folderLowercase} already exists with ${existingFiles.length} file(s)`);
        return NextResponse.json({
          success: true,
          message: `Folder ${folderLowercase} already exists`,
          existingFiles: existingFiles.length
        });
      }
      
      // Check if placeholder already exists
      const placeholderKey = `user-${userId}/${folderLowercase}/.placeholder`;
      const placeholderExists = await getObjectContent(placeholderKey);
      
      if (placeholderExists) {
        console.log(`Folder ${folderLowercase} already initialized`);
        return NextResponse.json({
          success: true,
          message: `Folder ${folderLowercase} already initialized`
        });
      }
      
      // Folder is empty and no placeholder exists, create one
      const placeholderContent = `Folder initialized at ${new Date().toISOString()}`;
      await putObject(placeholderKey, placeholderContent, 'text/plain');
      
      console.log(`Successfully initialized folder: user-${userId}/${folderLowercase}/`);
      
      // Return success
      return NextResponse.json({
        success: true,
        message: `Folder ${folderLowercase} initialized successfully`
      });
    } catch (error) {
      console.error(`Error initializing folder ${folderLowercase}:`, error);
      return NextResponse.json({ 
        error: 'Failed to initialize folder',
        details: error instanceof Error ? error.message : String(error)
      }, { status: 500 });
    }
  } catch (error) {
    console.error('Error in folder creation endpoint:', error);
    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
  }
}