Implement compression app solution

src/createServer.js

@@ -1,8 +1,108 @@
 'use strict';
 
+const http = require('http');
+const { IncomingForm } = require('formidable');
+const zlib = require('zlib');
+const fs = require('fs');
+
 function createServer() {
-  /* Write your code here */
-  // Return instance of http.Server class
+  return http.createServer((req, res) => {
+    if (req.method === 'POST' && req.url === '/compress') {
+      const form = new IncomingForm({ multiples: false });
+
+      form.parse(req, (err, fields, files) => {
+        if (err) {
+          res.statusCode = 500;
+
+          return res.end('Parsing form error');
+        }
+
+        const compressionType = Array.isArray(fields.compressionType)
+          ? fields.compressionType[0]
+          : fields.compressionType;
+        const file = files.file;
+
+        if (!file) {
+          res.statusCode = 400;
+
+          return res.end('Missing file');
+        }
+
+        if (!compressionType) {
+          res.statusCode = 400;
+
+          return res.end('Missing compression type');
+        }
+
+        const originalFileName = file[0].originalFilename;
+        const filePath = file[0].filepath.replace(/\\/g, '/');
+
+        let compressor;
+        let ext;
+
+        switch (compressionType) {
+          case 'gzip':
+            compressor = zlib.createGzip();
+            ext = '.gzip';
+            break;
+
+          case 'deflate':
+            compressor = zlib.createDeflate();
+            ext = '.deflate';
+            break;
+
+          case 'br':
+            compressor = zlib.createBrotliCompress();
+            ext = '.br';
+            break;
+
+          default:
+            res.statusCode = 400;
+            res.end('Unsupported compression type');
+
+            return;
+        }
+
+        const compressedFileName = originalFileName + ext;
+
+        if (file && compressor) {
+          res.statusCode = 200;
+          res.setHeader('Content-Type', 'application/octet-stream');
+
+          res.setHeader(
+            'Content-Disposition',
+            `attachment; filename=${compressedFileName}`,
+          );
+
+          const readStream = fs.createReadStream(filePath);
+
+          readStream.pipe(compressor).pipe(res);
+        } else {
+          res.statusCode = 500;
+          res.end('Error processing file or compressor');
+        }
+      });
+    } else if (req.method === 'GET' && req.url === '/') {
+      res.statusCode = 200;
+      res.setHeader('Content-type', 'text/html');
+
+      res.end(`<form method="POST" action="/compress" enctype="multipart/form-data">
+        <input name="file" type="file">
+        <select name="compressionType">
+          <option value="gzip">gzip</option>
+          <option value="deflate">deflate</option>
+          <option value="br">br</option>
+        </select>
+        <button type="submit">Submit</button>
+      </form>`);
+    } else if (req.method === 'GET' && req.url === '/compress') {
+      res.statusCode = 400;
+      res.end('GET not allowed');
+    } else {
+      res.statusCode = 404;
+      res.end('Not found');
+    }
+  });
 }
 
 module.exports = {