feat: implement word-by-word streaming typing effect

src/bot/message-sender.js

@@ -45,36 +45,48 @@ export async function sendFormatted(ctx, text) {
 export async function sendStreamingMessage(ctx, text, options = {}) {
   if (!text) return;
 
-  const { delay = 50, maxChunkSize = 1000 } = options;
+  const { 
+    delay = 100, 
+    minDelay = 50, 
+    maxDelay = 250,
+    charMode = false // Set to true for character-by-character, false for word-by-word
+  } = options;
 
   try {
-    // Stream chunks with typing indicator
-    const chunks = splitMessage(text);
-    let delayTimer = null;
-
-    for (const chunk of chunks) {
-      // Clear previous typing indicator
-      if (delayTimer) {
-        clearTimeout(delayTimer);
-        delayTimer = null;
+    // Send initial "typing..." indicator
+    const sendTyping = () => ctx.api.sendChatAction(ctx.chat.id, 'typing').catch(() => {});
+    
+    if (charMode) {
+      // Character-by-character streaming
+      let sentText = '';
+      const chars = text.split('');
+      
+      for (const char of chars) {
+        sentText += char;
+        
+        // Send message with the accumulated text
+        await ctx.reply(sentText, { parse_mode: 'Markdown' });
+        
+        // Random delay between min and max
+        const delayMs = minDelay + Math.random() * (maxDelay - minDelay);
+        await new Promise(resolve => setTimeout(resolve, delayMs));
       }
-
-      // Send chunk with minimal delay for real-time effect
-      await ctx.reply(chunk, { parse_mode: 'Markdown' });
-
-      // Show typing indicator between chunks
-      if (chunks.length > 1) {
-        delayTimer = setTimeout(() => {
-          ctx.api.sendChatAction(ctx.chat.id, 'typing').catch(() => {});
-        }, delay);
+    } else {
+      // Word-by-word streaming (default)
+      const words = text.split(' ');
+      let sentText = '';
+      
+      for (let i = 0; i < words.length; i++) {
+        sentText += (i > 0 ? ' ' : '') + words[i];
+        
+        // Send accumulated text
+        await ctx.reply(sentText, { parse_mode: 'Markdown' });
+        
+        // Variable delay based on word length
+        const wordDelay = Math.max(minDelay, Math.min(maxDelay, delay + words[i].length * 10));
+        await new Promise(resolve => setTimeout(resolve, wordDelay));
       }
     }
-
-    // Clear typing indicator
-    if (delayTimer) {
-      clearTimeout(delayTimer);
-      delayTimer = null;
-    }
   } catch (error) {
     logger.error('Streaming send failed:', error);
     // Fallback to non-streaming