Implement concurrency queue (max 5) to protect IP from DDG burst bans

src/duckai.ts

@@ -4,9 +4,36 @@ import { Buffer } from "node:buffer";
 import UserAgent from "user-agents";
 
 let activeRequests = 0;
+const MAX_CONCURRENT_CHATS = 5; // Максимум 5 одновременных запросов к DDG
+const requestQueue: (() => void)[] = [];
 
 export class DuckAI {
   
+  // Метод для ожидания своей очереди
+  private async acquireSlot(reqId: string): Promise<void> {
+      if (activeRequests < MAX_CONCURRENT_CHATS) {
+          activeRequests++;
+          return;
+      }
+      
+      console.log(`[${reqId}] [Queue] Space busy (${activeRequests} active). Waiting for slot...`);
+      return new Promise((resolve) => {
+          requestQueue.push(() => {
+              activeRequests++;
+              resolve();
+          });
+      });
+  }
+
+  // Освобождение слота
+  private releaseSlot() {
+      activeRequests--;
+      if (requestQueue.length > 0) {
+          const next = requestQueue.shift();
+          if (next) next();
+      }
+  }
+
   private async solveChallenge(vqdHash: string, reqId: string): Promise<string> {
     const start = Date.now();
     const memBefore = process.memoryUsage().heapUsed / 1024 / 1024;
@@ -79,10 +106,12 @@ export class DuckAI {
 
   async chat(request: any): Promise<string> {
     const reqId = Math.random().toString(36).substring(7).toUpperCase();
-    activeRequests++;
-    const startTime = Date.now();
     
-    console.log(`[${reqId}] [Chat] NEW REQUEST. Parallel active: ${activeRequests}`);
+    // Ждем свободный слот (максимум 5 параллельно)
+    await this.acquireSlot(reqId);
+    
+    const startTime = Date.now();
+    console.log(`[${reqId}] [Chat] STARTING (Active: ${activeRequests}, Queued: ${requestQueue.length})`);
 
     // Добавляем Jitter (случайную задержку 0-500мс), чтобы не долбить DDG пачкой
     await new Promise(r => setTimeout(resolve => r(resolve), Math.random() * 500));
@@ -156,7 +185,7 @@ export class DuckAI {
         console.error(`[${reqId}] [Chat] FAILED: ${error.message}`);
         throw error;
     } finally {
-        activeRequests--;
+        this.releaseSlot();
     }
   }