import fs from 'fs';
import path from 'path';
import multer from 'multer';

const uploadDir = path.join(process.cwd(), 'uploads', 'projects');
fs.mkdirSync(uploadDir, { recursive: true });

const storage = multer.diskStorage({
  destination: (_req, _file, cb) => cb(null, uploadDir),
  filename: (req, file, cb) => {
    const ext = path.extname(file.originalname);
    cb(null, `project-${req.params.id}-${Date.now()}-${Math.round(Math.random() * 1e9)}${ext}`);
  },
});

const ALLOWED_MIME_TYPES = new Set([
  'application/pdf',
  'application/msword',
  'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  'image/png',
  'image/jpeg',
]);

function fileFilter(_req: unknown, file: Express.Multer.File, cb: multer.FileFilterCallback) {
  if (!ALLOWED_MIME_TYPES.has(file.mimetype)) {
    return cb(new Error('Only PDF, Word, or image files are allowed'));
  }
  cb(null, true);
}

export const uploadProjectDocument = multer({
  storage,
  fileFilter,
  limits: { fileSize: 10 * 1024 * 1024 },
}).single('file');