const express = require('express');
const multer = require('multer');
const path = require('path');
const fs = require('fs');
const mime = require('mime-types');
const router = express.Router();

const uploadDir = path.join(__dirname, '../../uploads');
if (!fs.existsSync(uploadDir)) {
  fs.mkdirSync(uploadDir, { recursive: true });
}

const supportedExtensions = [
  '.jpg', '.jpeg', '.png', '.gif', '.webp',
  '.mp4', '.mov', '.avi', '.mkv', '.webm',
  '.mp3', '.wav', '.ogg', '.m4a'
];

const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, uploadDir);
  },
  filename: (req, file, cb) => {
    const ext = path.extname(file.originalname).toLowerCase();
    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
    cb(null, 'file-' + uniqueSuffix + ext);
  }
});

const fileFilter = (req, file, cb) => {
  const ext = path.extname(file.originalname).toLowerCase();
  if (supportedExtensions.includes(ext)) {
    cb(null, true);
  } else {
    cb(new Error(`Unsupported file type: ${ext}`), false);
  }
};

const upload = multer({
  storage: storage,
  fileFilter: fileFilter,
  limits: {
    fileSize: 100 * 1024 * 1024 // 100MB
  }
});

router.post('/upload', upload.single('file'), (req, res) => {
  if (!req.file) {
    return res.status(400).json({ error: 'No file uploaded or invalid file type' });
  }

  const fileType = mime.lookup(req.file.originalname) || 'application/octet-stream';
  const fileCategory = getFileCategory(fileType);
  const protocol = req.secure || req.headers['x-forwarded-proto'] === 'https' ? 'https' : 'http';
  const host = req.headers.host || `${DOMAIN}:${PORT}`;

  res.json({
    message: 'File uploaded successfully',
    file: {
      originalName: req.file.originalname,
      fileName: req.file.filename,
      size: req.file.size,
      type: fileType,
      category: fileCategory,
      url: `${protocol}://${host}/api/files/${req.file.filename}`
    }
  });
});

router.get('/files/:filename', (req, res) => {
  const filePath = path.join(uploadDir, req.params.filename);
  
  if (!fs.existsSync(filePath)) {
    return res.status(404).json({ 
      error: 'File not found',
      message: `The requested file does not exist on the server`
    });
  }
  
  const contentType = mime.lookup(filePath) || 'application/octet-stream';
  res.setHeader('Content-Type', contentType);
  res.sendFile(filePath);
});

function getFileCategory(mimeType) {
  if (mimeType.startsWith('image/')) return 'image';
  if (mimeType.startsWith('video/')) return 'video';
  if (mimeType.startsWith('audio/')) return 'audio';
  return 'other';
}

module.exports = router;