add task solution

src/createServer.js

@@ -1,8 +1,107 @@
 'use strict';
 
+const { formidable } = require('formidable');
+const { createReadStream } = require('fs');
+const http = require('http');
+const zlib = require('node:zlib');
+const { pipeline } = require('stream');
+
 function createServer() {
-  /* Write your code here */
-  // Return instance of http.Server class
+  const server = http.createServer(async (req, res) => {
+    if (req.method === 'GET' && req.url === '/') {
+      const htmlForm =
+        // eslint-disable-next-line max-len
+        '<form action="/compress" method="POST" enctype="multipart/form-data"><input type="file" name="file"><select name="compressionType"><option value="gzip">gzip</option><option value="deflate">deflate</option><option value="br">br</option></select><button type="submit">Compress</button></form>';
+
+      res.writeHead(200, {
+        'Content-Type': 'text/html',
+      });
+      res.end(htmlForm);
+
+      return;
+    }
+
+    if (req.method === 'GET' && req.url === '/compress') {
+      res.statusCode = 400;
+      res.end();
+
+      return;
+    }
+
+    if (req.method === 'POST' && req.url === '/compress') {
+      const form = formidable();
+      let fields;
+      let files;
+
+      try {
+        [fields, files] = await form.parse(req);
+      } catch (err) {
+        res.writeHead(err.httpCode || 400, { 'Content-Type': '' });
+        res.end(String(err));
+
+        return;
+      }
+
+      const compressionType = fields.compressionType?.[0];
+      const uploadedFile = files.file?.[0];
+      let ext;
+
+      if (!compressionType || !uploadedFile) {
+        res.statusCode = 400;
+        res.end();
+
+        return;
+      }
+
+      let compressor;
+
+      switch (compressionType) {
+        case 'gzip':
+          ext = '.gz';
+          compressor = zlib.createGzip();
+          break;
+
+        case 'deflate':
+          ext = '.dfl';
+          compressor = zlib.createDeflate();
+          break;
+
+        case 'br':
+          ext = '.br';
+          compressor = zlib.createBrotliCompress();
+          break;
+
+        default:
+          res.statusCode = 400;
+          res.end();
+
+          return;
+      }
+
+      res.writeHead(200, {
+        'Content-Type': 'application/octet-stream',
+        'Content-Disposition': `attachment; filename=${uploadedFile.originalFilename}${ext}`,
+      });
+
+      pipeline(
+        createReadStream(uploadedFile.filepath),
+        compressor,
+        res,
+        (err) => {
+          if (err) {
+            res.destroy(err);
+          }
+        },
+      );
+
+      return;
+    }
+
+    res.statusCode = 404;
+    res.end();
+  });
+
+  return server;
 }
 
 module.exports = {