From aeecfa63e395008a78d4df054ba61869968484d7 Mon Sep 17 00:00:00 2001
From: Mariia Hula <maria.gula0307@gmail.com>
Date: Wed, 7 Jan 2026 16:10:03 +0200
Subject: [PATCH 1/3] Solution

---
 src/createServer.js | 148 +++++++++++++++++++++++++++++++++++++++++++-
 src/index.html      |  35 +++++++++++
 src/script.js       |  96 ++++++++++++++++++++++++++++
 src/styles.css      | 135 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 412 insertions(+), 2 deletions(-)
 create mode 100644 src/index.html
 create mode 100644 src/script.js
 create mode 100644 src/styles.css

diff --git a/src/createServer.js b/src/createServer.js
index 1cf1dda..fc6b1e3 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -1,8 +1,152 @@
 'use strict';
 
+const fs = require('node:fs');
+const http = require('node:http');
+const path = require('node:path');
+const { pipeline } = require('node:stream');
+const zlib = require('node:zlib');
+const { IncomingForm } = require('formidable');
+
+const SUPPORTED_COMPRESSION_TYPES = ['gzip', 'deflate', 'br'];
+const CONTENT_TYPES = {
+  html: 'text/html',
+  css: 'text/css',
+  js: 'application/javascript',
+  plain: 'text/plain',
+};
+
+function encodeFilename(filename) {
+  const cleaned = filename
+    .replace(/[\r\n\t]/g, '')
+    .replace(/["\\]/g, '')
+    .trim();
+
+  const hasNonASCII = [...cleaned].some((char) => char.charCodeAt(0) > 127);
+  const hasSpaces = cleaned.includes(' ');
+
+  if (hasNonASCII || hasSpaces) {
+    const encoded = encodeURIComponent(cleaned);
+
+    return `filename*=UTF-8''${encoded}`;
+  }
+
+  return `filename=${cleaned}`;
+}
+
+function createCompressionStream(type) {
+  const streams = {
+    gzip: () => zlib.createGzip(),
+    deflate: () => zlib.createDeflate(),
+    br: () => zlib.createBrotliCompress(),
+  };
+
+  return streams[type]();
+}
+
+function serveStaticFile(res, filepath, contentType) {
+  res.statusCode = 200;
+  res.setHeader('Content-Type', contentType);
+  res.end(fs.readFileSync(path.join(__dirname, filepath)));
+}
+
+function sendError(res, statusCode, message) {
+  res.statusCode = statusCode;
+  res.setHeader('Content-Type', CONTENT_TYPES.plain);
+  res.end(message);
+}
+
+function handleCompressRequest(req, res) {
+  if (req.method !== 'POST') {
+    sendError(res, 400, 'Bad Request');
+
+    return;
+  }
+
+  const form = new IncomingForm();
+  let file = null;
+  let compressionType = null;
+  let filename = null;
+
+  form.on('file', (name, fileData) => {
+    if (name === 'file') {
+      file = fileData;
+      filename = fileData.originalFilename || 'file.txt';
+    }
+  });
+
+  form.on('field', (name, value) => {
+    if (name === 'compressionType') {
+      compressionType = value;
+    }
+  });
+
+  form.on('end', () => {
+    if (
+      !file ||
+      !compressionType ||
+      !SUPPORTED_COMPRESSION_TYPES.includes(compressionType)
+    ) {
+      sendError(res, 400, 'Bad Request');
+
+      return;
+    }
+
+    const compressStream = createCompressionStream(compressionType);
+    const encodedFilename = encodeFilename(`${filename}.${compressionType}`);
+    const fileStream = fs.createReadStream(file.filepath);
+    const tempFilePath = file.filepath;
+
+    res.statusCode = 200;
+    res.setHeader('Content-Disposition', `attachment; ${encodedFilename}`);
+
+    pipeline(fileStream, compressStream, res, (err) => {
+      if (err && !res.headersSent) {
+        sendError(res, 500, 'Internal Server Error');
+      }
+
+      fs.unlink(tempFilePath, () => {});
+    });
+  });
+
+  form.on('error', () => {
+    sendError(res, 400, 'Bad Request');
+  });
+
+  form.parse(req);
+}
+
 function createServer() {
-  /* Write your code here */
-  // Return instance of http.Server class
+  const server = new http.Server();
+
+  server.on('request', (req, res) => {
+    if (req.url === '/') {
+      serveStaticFile(res, 'index.html', CONTENT_TYPES.html);
+
+      return;
+    }
+
+    if (req.url === '/styles.css') {
+      serveStaticFile(res, 'styles.css', CONTENT_TYPES.css);
+
+      return;
+    }
+
+    if (req.url === '/script.js') {
+      serveStaticFile(res, 'script.js', CONTENT_TYPES.js);
+
+      return;
+    }
+
+    if (req.url === '/compress') {
+      handleCompressRequest(req, res);
+
+      return;
+    }
+
+    sendError(res, 404, 'Not Found');
+  });
+
+  return server;
 }
 
 module.exports = {
diff --git a/src/index.html b/src/index.html
new file mode 100644
index 0000000..8bd83dd
--- /dev/null
+++ b/src/index.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>File Compression Tool</title>
+  <link rel="stylesheet" href="/styles.css">
+</head>
+<body>
+  <div class="container">
+    <h1 class="title">File Compression Tool</h1>
+
+    <form action="/compress" enctype="multipart/form-data" method="post" id="compressForm">
+      <div class="form-group">
+        <label for="file" class="label">Select File</label>
+        <input type="file" name="file" id="file" class="file-input" required>
+        <div class="file-info" id="fileInfo"></div>
+      </div>
+
+      <div class="form-group">
+        <label for="compressionType" class="label">Compression Type</label>
+        <select name="compressionType" id="compressionType" class="select" required>
+          <option value="gzip">Gzip</option>
+          <option value="deflate">Deflate</option>
+          <option value="br">Brotli</option>
+        </select>
+      </div>
+
+      <button type="submit" id="submitBtn" class="submit-btn">Compress File</button>
+    </form>
+  </div>
+
+  <script src="/script.js"></script>
+</body>
+</html>
diff --git a/src/script.js b/src/script.js
new file mode 100644
index 0000000..0e12a4d
--- /dev/null
+++ b/src/script.js
@@ -0,0 +1,96 @@
+const fileInput = document.getElementById('file');
+const fileInfo = document.getElementById('fileInfo');
+const submitBtn = document.getElementById('submitBtn');
+const form = document.getElementById('compressForm');
+
+function formatFileSize(bytes) {
+  return `${(bytes / 1024).toFixed(2)} KB`;
+}
+
+function extractFilename(contentDisposition) {
+  if (!contentDisposition) {
+    return 'compressed-file';
+  }
+
+  const rfc5987Match = contentDisposition.match(/filename\*=UTF-8''([^;]+)/);
+
+  if (rfc5987Match && rfc5987Match[1]) {
+    return decodeURIComponent(rfc5987Match[1]);
+  }
+
+  const filenameMatch = contentDisposition.match(
+    /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/,
+  );
+
+  if (filenameMatch && filenameMatch[1]) {
+    return filenameMatch[1].replace(/['"]/g, '');
+  }
+
+  return 'compressed-file';
+}
+
+function downloadFile(blob, filename) {
+  const url = window.URL.createObjectURL(blob);
+  const link = document.createElement('a');
+
+  link.href = url;
+  link.download = filename;
+  document.body.appendChild(link);
+  link.click();
+  window.URL.revokeObjectURL(url);
+  document.body.removeChild(link);
+}
+
+function resetButton(originalText) {
+  submitBtn.disabled = false;
+  submitBtn.textContent = originalText;
+}
+
+function clearFileInfo() {
+  fileInfo.textContent = '';
+  fileInfo.classList.remove('show');
+}
+
+fileInput.addEventListener('change', (e) => {
+  const file = e.target.files[0];
+
+  if (file) {
+    fileInfo.textContent = `Selected: ${file.name} (${formatFileSize(file.size)})`;
+    fileInfo.classList.add('show');
+  } else {
+    clearFileInfo();
+  }
+});
+
+form.addEventListener('submit', async (e) => {
+  e.preventDefault();
+
+  const formData = new FormData(form);
+  const originalText = submitBtn.textContent;
+
+  submitBtn.disabled = true;
+  submitBtn.textContent = 'Compressing...';
+
+  try {
+    const response = await fetch('/compress', {
+      method: 'POST',
+      body: formData,
+    });
+
+    if (!response.ok) {
+      throw new Error(`Server error: ${response.status}`);
+    }
+
+    const blob = await response.blob();
+    const contentDisposition = response.headers.get('content-disposition');
+    const filename = extractFilename(contentDisposition);
+
+    downloadFile(blob, filename);
+    resetButton(originalText);
+    form.reset();
+    clearFileInfo();
+  } catch (error) {
+    window.alert(`Error: ${error.message}`);
+    resetButton(originalText);
+  }
+});
diff --git a/src/styles.css b/src/styles.css
new file mode 100644
index 0000000..c0a6eb5
--- /dev/null
+++ b/src/styles.css
@@ -0,0 +1,135 @@
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+body {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+
+  padding: 20px;
+  min-height: 100vh;
+
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
+    Ubuntu, Cantarell, sans-serif;
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+}
+
+.container {
+  padding: 40px;
+
+  width: 100%;
+  max-width: 500px;
+
+  background: white;
+  border-radius: 12px;
+  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+}
+
+.title {
+  margin-bottom: 30px;
+
+  font-size: 28px;
+  text-align: center;
+  color: #333;
+}
+
+.form-group {
+  margin-bottom: 20px;
+}
+
+.label {
+  display: block;
+  margin-bottom: 8px;
+
+  font-size: 14px;
+  font-weight: 500;
+  color: #555;
+}
+
+.file-input {
+  width: 100%;
+  padding: 12px;
+
+  font-size: 14px;
+
+  border: 2px dashed #ddd;
+  border-radius: 8px;
+  background: #f9f9f9;
+  cursor: pointer;
+  transition: all 0.3s ease;
+}
+
+.file-input:hover {
+  border-color: #667eea;
+  background: #f0f0ff;
+}
+
+.file-info {
+  display: none;
+  margin-top: 10px;
+  padding: 10px;
+
+  font-size: 13px;
+  color: #555;
+
+  background: #f0f0ff;
+  border-radius: 6px;
+}
+
+.file-info.show {
+  display: block;
+}
+
+.select {
+  padding: 12px;
+  width: 100%;
+
+  font-size: 14px;
+
+  border: 2px solid #ddd;
+  border-radius: 8px;
+  background: white;
+  cursor: pointer;
+  transition: border-color 0.3s ease;
+}
+
+.select:focus {
+  outline: none;
+  border-color: #667eea;
+}
+
+.submit-btn {
+  width: 100%;
+  padding: 14px;
+  margin-top: 10px;
+
+  font-size: 16px;
+  font-weight: 600;
+  color: white;
+
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+  border: none;
+  border-radius: 8px;
+  cursor: pointer;
+  transition:
+    transform 0.2s ease,
+    box-shadow 0.2s ease;
+}
+
+.submit-btn:hover {
+  transform: translateY(-2px);
+  box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
+}
+
+.submit-btn:active {
+  transform: translateY(0);
+}
+
+.submit-btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+  transform: none;
+}

From b317f703a8543a33cf8e9fdafc366790a205d65c Mon Sep 17 00:00:00 2001
From: Mariia Hula <maria.gula0307@gmail.com>
Date: Wed, 7 Jan 2026 17:06:29 +0200
Subject: [PATCH 2/3] use streams to read static files

---
 src/createServer.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/createServer.js b/src/createServer.js
index fc6b1e3..0449d7e 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -44,9 +44,16 @@ function createCompressionStream(type) {
 }
 
 function serveStaticFile(res, filepath, contentType) {
+  const fileStream = fs.createReadStream(path.join(__dirname, filepath));
+
   res.statusCode = 200;
   res.setHeader('Content-Type', contentType);
-  res.end(fs.readFileSync(path.join(__dirname, filepath)));
+
+  pipeline(fileStream, res, (err) => {
+    if (err && !res.headersSent) {
+      sendError(res, 500, 'Internal Server Error');
+    }
+  });
 }
 
 function sendError(res, statusCode, message) {

From 0eeb96e7f6a47a35e791bcb5e978a74e97789e59 Mon Sep 17 00:00:00 2001
From: Mariia Hula <maria.gula0307@gmail.com>
Date: Wed, 7 Jan 2026 17:16:33 +0200
Subject: [PATCH 3/3] change compression type extension

---
 src/createServer.js        | 6 +++---
 src/index.html             | 4 ++--
 tests/createServer.test.js | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/createServer.js b/src/createServer.js
index 0449d7e..da9c2ff 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -7,7 +7,7 @@ const { pipeline } = require('node:stream');
 const zlib = require('node:zlib');
 const { IncomingForm } = require('formidable');
 
-const SUPPORTED_COMPRESSION_TYPES = ['gzip', 'deflate', 'br'];
+const SUPPORTED_COMPRESSION_TYPES = ['gz', 'dfl', 'br'];
 const CONTENT_TYPES = {
   html: 'text/html',
   css: 'text/css',
@@ -35,8 +35,8 @@ function encodeFilename(filename) {
 
 function createCompressionStream(type) {
   const streams = {
-    gzip: () => zlib.createGzip(),
-    deflate: () => zlib.createDeflate(),
+    gz: () => zlib.createGzip(),
+    dfl: () => zlib.createDeflate(),
     br: () => zlib.createBrotliCompress(),
   };
 
diff --git a/src/index.html b/src/index.html
index 8bd83dd..f6af7dd 100644
--- a/src/index.html
+++ b/src/index.html
@@ -20,8 +20,8 @@ <h1 class="title">File Compression Tool</h1>
       <div class="form-group">
         <label for="compressionType" class="label">Compression Type</label>
         <select name="compressionType" id="compressionType" class="select" required>
-          <option value="gzip">Gzip</option>
-          <option value="deflate">Deflate</option>
+          <option value="gz">Gzip</option>
+          <option value="dfl">Deflate</option>
           <option value="br">Brotli</option>
         </select>
       </div>
diff --git a/tests/createServer.test.js b/tests/createServer.test.js
index b53ef15..4773075 100644
--- a/tests/createServer.test.js
+++ b/tests/createServer.test.js
@@ -27,10 +27,10 @@ function stringToStream(str) {
 }
 
 const compressionTypes = {
-  gzip: {
+  gz: {
     decompress: util.promisify(zlib.gunzip),
   },
-  deflate: {
+  dfl: {
     decompress: util.promisify(zlib.inflate),
   },
   br: {