server.js

// @ts-nocheck
import express from 'express';
import cors from 'cors';
import multer from 'multer';
import { commit } from '@huggingface/hub'; // Use 'commit' for batch operations
import path from 'path';
import { fileURLToPath } from 'url';

// Fix __dirname for ES Modules
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
// Hugging Face Spaces requires port 7860
const port = process.env.PORT || 7860;

// Middleware
app.use(cors());
app.use(express.json());

// Configure Multer for memory storage
// No limit on file count here, but we limit payload size via express/nginx usually
const storage = multer.memoryStorage();
const upload = multer({ storage: storage });

// SERVER CONFIGURATION
const SERVER_CONFIG = {
  TOKEN: process.env.HF_TOKEN || '',
  REPO: process.env.HF_REPO || 'TwanAPI/DataTwan',
  TYPE: 'dataset'
};

// --- API ROUTES ---

// Batch Upload Endpoint
// Accepts multiple files in the 'files' field
app.post('/api/upload', upload.array('files'), async (req, res) => {
  try {
    const files = req.files;
    // req.body.paths can be a string (if 1 file) or array (if multiple)
    // We normalize it to an array
    const paths = [].concat(req.body.paths || []);

    if (!files || files.length === 0) {
      return res.status(400).json({ error: 'No files provided' });
    }

    if (files.length !== paths.length) {
      return res.status(400).json({ error: 'Mismatch between file count and path count' });
    }

    // Security Check
    if (!SERVER_CONFIG.TOKEN) {
       console.error('[SERVER] Upload Failed: HF_TOKEN missing');
       return res.status(500).json({ error: 'Server misconfiguration: HF_TOKEN secret is missing.' });
    }

    console.log(`[SERVER] Processing batch of ${files.length} files...`);

    // Prepare operations for Hugging Face 'commit'
    const operations = files.map((file, index) => ({
      operation: 'addOrUpdate',
      path: paths[index],
      content: new Blob([file.buffer])
    }));

    // Execute single commit for all files
    const response = await commit({
      credentials: {
        accessToken: SERVER_CONFIG.TOKEN,
      },
      repo: {
        type: SERVER_CONFIG.TYPE,
        name: SERVER_CONFIG.REPO
      },
      operations: operations,
      title: `Upload batch of ${files.length} files via DataTwan`
    });

    const commitHash = response.oid; // 'commit' returns { oid: string, ... }
    const urlPrefix = "https://huggingface.co/datasets";
    
    // Generate public URLs for response
    const urls = paths.map(p => `${urlPrefix}/${SERVER_CONFIG.REPO}/blob/${commitHash}/${p}`);

    console.log(`[SERVER] Batch Success: ${files.length} files committed (Hash: ${commitHash})`);

    res.json({ 
      success: true, 
      count: files.length,
      urls: urls 
    });

  } catch (error) {
    console.error('[SERVER] Batch Upload Error:', error);
    res.status(500).json({ 
      success: false, 
      error: error.message || 'Internal Server Error' 
    });
  }
});

// --- SERVE FRONTEND (Production) ---

app.use(express.static(path.join(__dirname, 'dist')));

app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'dist', 'index.html'));
});

// Start Server
app.listen(port, () => {
  console.log(`--------------------------------------------------`);
  console.log(`✅ Server running on port ${port}`);
  console.log(`   Target Repo: ${SERVER_CONFIG.REPO}`);
  console.log(`--------------------------------------------------`);
});