feat: enhance file transfer and improve user experience

- Standardized quote style across all files to be consistent
- Added functionality to generate TURN credentials dynamically
- Improved UI feedback for upload and download processes
- Introduced a copy URL button for easier sharing
- Implemented progress feedback during file download
- Disabled buttons during ongoing operations to prevent duplicate actions
- Ensured default mnemonic handling for smoother user interaction

These changes enhance the reliability and usability of file transfers.

app.js

@@ -1,39 +1,39 @@
-import express from 'express';
+import express from "express";
-import path from 'path';
+import path from "path";
-import { fileURLToPath } from 'url';
+import { fileURLToPath } from "url";
-import bip39 from 'bip39';
+import bip39 from "bip39";
-import crypto from 'crypto';
+import crypto from "crypto";
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
 const app = express();
-const trackerUrl = process.env.TRACKER_URL || 'ws://localhost:8106';
+const trackerUrl = process.env.TRACKER_URL || "ws://localhost:8106";
 const stunServerUrl = process.env.STUN_SERVER_URL;
 const turnServerUrl = process.env.TURN_SERVER_URL;
 const turnSecret = process.env.TURN_SECRET;
 const turnTTL = 86400;
 
-app.set('view engine', 'ejs');
+app.set("view engine", "ejs");
-app.use(express.static(path.join(__dirname, 'public')));
+app.use(express.static(path.join(__dirname, "public")));
 
-app.get('/', (req, res) => {
+app.get("/", (req, res) => {
-    res.render('index', { trackerUrl });
+  res.render("index", { trackerUrl });
 });
 
-app.get('/generate-mnemonic/:infoHash', (req, res) => {
+app.get("/generate-mnemonic/:infoHash", (req, res) => {
   const infoHash = req.params.infoHash;
   const mnemonic = bip39.entropyToMnemonic(infoHash);
   res.json({ mnemonic });
 });
 
-app.get('/get-infohash/:mnemonic', (req, res) => {
+app.get("/get-infohash/:mnemonic", (req, res) => {
   const mnemonic = req.params.mnemonic;
   const infoHash = bip39.mnemonicToEntropy(mnemonic);
   res.json({ infoHash });
 });
 
-app.get('/turn-credentials', (req, res) => {
+app.get("/turn-credentials", (req, res) => {
   const iceServers = [];
 
   if (stunServerUrl) {
@@ -43,20 +43,34 @@ app.get('/turn-credentials', (req, res) => {
   if (turnServerUrl && turnSecret) {
     const unixTimeStamp = Math.floor(Date.now() / 1000) + turnTTL;
     const username = `${unixTimeStamp}:transfercoffee`;
-        const hmac = crypto.createHmac('sha1', turnSecret);
+    const hmac = crypto.createHmac("sha1", turnSecret);
     hmac.update(username);
-        const credential = hmac.digest('base64');
+    const credential = hmac.digest("base64");
 
     iceServers.push({
       urls: turnServerUrl,
       username: username,
-            credential: credential
+      credential: credential,
     });
   }
 
   res.json({ iceServers });
 });
 
+app.get("/:mnemonic?", (req, res) => {
+  var mnemonic = req.params.mnemonic || "";
+
+  if (mnemonic) {
+    mnemonic = mnemonic.replaceAll(".", " ").trim();
+
+    if (!bip39.validateMnemonic(mnemonic)) {
+      return res.status(400).send("Invalid mnemonic");
+    }
+  }
+
+  res.render("index", { trackerUrl, mnemonic });
+});
+
 const PORT = process.env.PORT || 8105;
 app.listen(PORT, () => {
   console.log(`Server is running on port ${PORT}`);

public/css/style.css

@@ -37,6 +37,10 @@ body {
   button:hover {
     background-color: #218838;
   }
+  button:disabled {
+    background-color: #ccc;
+    cursor: not-allowed;
+  }
   .progress {
     width: 100%;
     background-color: #f3f3f3;

public/js/index.js

@@ -10,12 +10,20 @@ async function uploadFile() {
   const fileInput = document.getElementById("fileInput");
   const file = fileInput.files[0];
   const uploadStats = document.getElementById("uploadStats");
+  const uploadSection = document.getElementById("uploadSection");
+  const downloadSection = document.getElementById("downloadSection");
+  const copyButton = document.getElementById("copyButton");
+  const uploadButton = document.getElementById("uploadButton");
 
   if (!file) {
     alert("Please select a file to upload.");
     return;
   }
 
+  downloadSection.style.display = "none";
+  uploadSection.style.display = "block";
+  uploadButton.disabled = true;
+
   const rtcConfig = {
     iceServers: await getRTCIceServers(),
   };
@@ -26,14 +34,17 @@ async function uploadFile() {
   };
 
   client.seed(file, opts, async (torrent) => {
-    downloadSection.style.display = 'none';
-    uploadSection.style.display = 'block';
-
     fetch(`/generate-mnemonic/${torrent.infoHash}`)
       .then((response) => response.json())
       .then((data) => {
         const uploadResult = document.getElementById("uploadResult");
-        uploadResult.innerHTML = `File uploaded. Share this mnemonic: <strong>${data.mnemonic}</strong>`;
+        const downloadUrl = `${
+          window.location.origin
+        }/${data.mnemonic.replaceAll(" ", ".")}`;
+        uploadResult.innerHTML = `Seeding file. Share this mnemonic: <strong>${data.mnemonic}</strong>
+        <br>Note that the file will be available for download only as long as you keep this page open.`;
+        copyButton.style.display = "inline-block";
+        copyButton.setAttribute("data-url", downloadUrl);
       });
 
     let totalPeers = 0;
@@ -60,6 +71,19 @@ async function uploadFile() {
   });
 }
 
+function copyToClipboard() {
+  const copyButton = document.getElementById("copyButton");
+  const url = copyButton.getAttribute("data-url");
+  navigator.clipboard
+    .writeText(url)
+    .then(() => {
+      alert("URL copied to clipboard");
+    })
+    .catch((err) => {
+      console.error("Failed to copy: ", err);
+    });
+}
+
 async function sha256(str) {
   const buffer = new TextEncoder().encode(str);
   const hash = await crypto.subtle.digest("SHA-256", buffer);
@@ -71,12 +95,19 @@ async function sha256(str) {
 async function downloadFile() {
   const mnemonicInput = document.getElementById("mnemonicInput").value;
   const downloadProgressBar = document.getElementById("downloadProgressBar");
+  const downloadButton = document.getElementById("downloadButton");
 
   if (!mnemonicInput) {
     alert("Please enter a mnemonic.");
     return;
   }
 
+  downloadSection.style.display = "block";
+  uploadSection.style.display = "none";
+  downloadButton.disabled = true;
+
+  downloadResult.innerHTML = "Preparing incoming file transfer, please wait...";
+
   const rtcConfig = {
     iceServers: await getRTCIceServers(),
   };
@@ -92,9 +123,6 @@ async function downloadFile() {
       };
 
       client.add(torrentId, opts, (torrent) => {
-        downloadSection.style.display = 'block';
-        uploadSection.style.display = 'none';
-
         torrent.files[0].getBlob((err, blob) => {
           if (err) {
             const downloadResult = document.getElementById("downloadResult");
@@ -120,5 +148,51 @@ async function downloadFile() {
           downloadProgressBar.textContent = `${progress}%`;
         });
       });
+
+      setInterval(() => {
+        const downloadResult = document.getElementById("downloadResult");
+
+        if (client.get(torrentId)) {
+          const torrent = client.get(torrentId);
+          const progress = Math.round(
+            (torrent.downloaded / torrent.length) * 100
+          );
+          downloadResult.innerHTML = `Downloading:
+          <strong>${torrent.files[0].name}</strong>
+          <br>
+          <br><strong>Status:</strong> ${
+            torrent.done ? "Completed, seeding" : "Downloading"
+          }
+          <br><strong>Peers:</strong> ${torrent.numPeers}
+          <br><strong>Downloaded:</strong> ${(
+            torrent.downloaded /
+            (1024 * 1024)
+          ).toFixed(2)} MB / ${(torrent.length / (1024 * 1024)).toFixed(
+            2
+          )} MB (${progress}%)
+          <br><strong>Speed:</strong> ${(
+            torrent.downloadSpeed /
+            (1024 * 1024)
+          ).toFixed(2)} MB/s
+          <br><strong>ETA:</strong> ${torrent.timeRemaining} seconds
+          <br><strong>Uploaded:</strong> ${(
+            torrent.uploaded /
+            (1024 * 1024)
+          ).toFixed(2)} MB
+          <br><strong>Ratio:</strong> ${torrent.ratio.toFixed(2)}`;
+          return;
+        }
+
+        downloadResult.innerHTML = "File not found. Please check the mnemonic.";
+      }, 1000);
     });
 }
+
+document.addEventListener("DOMContentLoaded", () => {
+  if (mnemonic) {
+    const mnemonicInput = document.getElementById("mnemonicInput");
+    const downloadButton = document.getElementById("downloadButton");
+    mnemonicInput.value = mnemonic;
+    downloadButton.click();
+  }
+});

views/index.ejs

@@ -14,19 +14,25 @@
         <button onclick="uploadFile()">Share</button>
         <div class="result" id="uploadResult"></div>
         <div class="result" id="uploadStats"></div>
+        <button id="copyButton" style="display: none;" onclick="copyToClipboard()">Copy URL</button>
       </div>
       <div class="section" id="downloadSection">
         <h2>Receive File</h2>
         <input type="text" id="mnemonicInput" placeholder="Enter mnemonic" />
-        <button onclick="downloadFile()">Receive</button>
+        <button id="downloadButton" onclick="downloadFile()">Receive</button>
         <div class="progress" id="downloadProgress">
           <div class="progress-bar" id="downloadProgressBar">0%</div>
         </div>
         <div class="result" id="downloadResult"></div>
+        <div class="result" id="downloadStats"></div>
+
       </div>
     </div>
     <script>
       const trackerUrl = "<%= trackerUrl %>";
+      <% if (typeof mnemonic !== 'undefined') { %>
+        const mnemonic = "<%= mnemonic %>";
+      <% } %>
     </script>
     <script src="/js/index.js"></script>
   </body>