fix: implement DNS-over-HTTPS (DoH) to bypass local resolver issues

app/bot/bot.js

@@ -4,6 +4,48 @@
  */
 
 const { Telegraf, Markup } = require('telegraf');
+const https = require('https');
+
+// Helper function: Resolve IP via Google DNS-over-HTTPS
+// This bypasses local system DNS (UDP:53) which is often blocked on free hosting.
+async function resolveDoH(hostname) {
+    return new Promise((resolve, reject) => {
+        const options = {
+            hostname: 'dns.google',
+            port: 443,
+            path: `/resolve?name=${hostname}&type=A`,
+            method: 'GET',
+            headers: { 'Accept': 'application/dns-json' }
+        };
+
+        const req = https.request(options, (res) => {
+            let data = '';
+            res.on('data', (chunk) => { data += chunk; });
+            res.on('end', () => {
+                try {
+                    const json = JSON.parse(data);
+                    // Check if Answer exists and has data
+                    if (json.Answer && json.Answer.length > 0) {
+                        // Return the first IP address found
+                        console.log(`[DNS-over-HTTPS] Resolved ${hostname} to ${json.Answer[0].data}`);
+                        resolve(json.Answer[0].data);
+                    } else {
+                        reject(new Error('No DNS Answer found'));
+                    }
+                } catch (e) {
+                    reject(e);
+                }
+            });
+        });
+
+        req.on('error', (e) => {
+            console.error('[DNS-over-HTTPS] Request failed:', e);
+            reject(e);
+        });
+        req.end();
+    });
+}
+
 
 // This function will be called from index.js
 function setupBot(token, webAppUrl) {
@@ -11,28 +53,31 @@ function setupBot(token, webAppUrl) {
         throw new Error('BOT_TOKEN is missing!');
     }
 
-    // --- CUSTOM DNS RESOLUTION FIX ---
-    // Hugging Face Spaces often fails to resolve api.telegram.org via system DNS.
-    // We will manually resolve it using Google DNS (8.8.8.8) and force Telegraf to use the IP.
-
-    const https = require('https');
-    const dns = require('dns');
-
     const botOptions = {};
 
     // Only apply this fix in production (on Hugging Face)
     if (process.env.NODE_ENV === 'production') {
-        console.log('[Bot] Production mode: Forcing custom DNS resolution for Telegram.');
+        console.log('[Bot] Production mode: Configuring DNS-over-HTTPS agent.');
 
         const agent = new https.Agent({
             keepAlive: true,
             family: 4,
-            lookup: (hostname, options, callback) => {
+            lookup: async (hostname, options, callback) => {
+                // Only intercept api.telegram.org
                 if (hostname === 'api.telegram.org') {
-                    // console.log(`[Bot] Resolving ${hostname} to fixed IP.`);
-                    return callback(null, '149.154.167.220', 4);
+                    try {
+                        const ip = await resolveDoH('api.telegram.org');
+                        return callback(null, ip, 4);
+                    } catch (err) {
+                        console.error('[Bot] DoH failed, falling back to system DNS:', err);
+                        // Fallback to system DNS if DoH fails (unlikely if outbound HTTPS works)
+                        const dns = require('dns');
+                        return dns.lookup(hostname, options, callback);
+                    }
                 }
-                dns.lookup(hostname, options, callback);
+                // Default behavior for other domains
+                const dns = require('dns');
+                return dns.lookup(hostname, options, callback);
             }
         });
 
@@ -43,9 +88,6 @@ function setupBot(token, webAppUrl) {
     const bot = new Telegraf(token, botOptions);
 
     // Initial setup for the menu button
-    // Note: setChatMenuButton might need to be called on specific user interaction or globally once logic is decided.
-    // For now, let's put it in the start command to ensure it updates for the user.
-
     bot.start(async (ctx) => {
         const welcomeMessage = `
     Привет! Я AI Post Generator Bot. 🤖
@@ -55,8 +97,6 @@ function setupBot(token, webAppUrl) {
         `;
 
         try {
-            // Set the persistent Menu Button (bottom left of chat input)
-            // This button opens the Web App directly.
             await ctx.setChatMenuButton({
                 type: 'web_app',
                 text: 'Настройки',
@@ -67,7 +107,6 @@ function setupBot(token, webAppUrl) {
             console.error('Failed to set menu button:', e);
         }
 
-        // Send a message with an inline button as well
         await ctx.reply(welcomeMessage, Markup.inlineKeyboard([
             Markup.button.webApp('Открыть настройки ⚙️', `${webAppUrl}/app/index.html`)
         ]));