Fix backend error handling and model list

src/duckai.ts

@@ -127,6 +127,19 @@ export class DuckAI {
     }
   }
 
+  getAvailableModels(): string[] {
+    return [
+      "gpt-4o-mini",
+      "claude-3-haiku-20240307",
+      "meta-llama/Llama-3.3-70B-Instruct-Turbo",
+      "mistralai/Mistral-Small-24B-Instruct-2501"
+    ];
+  }
+
+  getRateLimitStatus() {
+     return { status: "unknown" };
+  }
+
   async chat(request: any): Promise<string> {
     const ua = new UserAgent({ deviceCategory: 'desktop' }).toString();
     const headers: any = {
@@ -135,33 +148,41 @@ export class DuckAI {
       "x-vqd-accept": "1"
     };
 
-    try {
-      const statusRes = await fetch("https://duckduckgo.com/duckchat/v1/status?q=1", { headers });
-      const hashHeader = statusRes.headers.get("x-vqd-hash-1");
-      if (!hashHeader) throw new Error("Missing x-vqd-hash-1");
+    const statusRes = await fetch("https://duckduckgo.com/duckchat/v1/status?q=1", { headers });
+    const hashHeader = statusRes.headers.get("x-vqd-hash-1");
+    if (!hashHeader) throw new Error("Missing x-vqd-hash-1 - DuckDuckGo might be blocking this IP or Challenge failed.");
 
-      const solvedVqd = await this.solveChallenge(hashHeader, ua);
+    const solvedVqd = await this.solveChallenge(hashHeader, ua);
 
-      const response = await fetch("https://duckduckgo.com/duckchat/v1/chat", {
-        method: "POST",
-        headers: { ...headers, "x-vqd-hash-1": solvedVqd, "Content-Type": "application/json" },
-        body: JSON.stringify(request)
-      });
+    const response = await fetch("https://duckduckgo.com/duckchat/v1/chat", {
+      method: "POST",
+      headers: { ...headers, "x-vqd-hash-1": solvedVqd, "Content-Type": "application/json" },
+      body: JSON.stringify(request)
+    });
 
-      const text = await response.text();
-      let llmResponse = "";
-      const lines = text.split("\n");
-      for (const line of lines) {
-        if (line.startsWith("data: ")) {
-          try {
-            const json = JSON.parse(line.slice(6));
-            if (json.message) llmResponse += json.message;
-          } catch (e) {}
-        }
+    if (!response.ok) {
+        const errorText = await response.text();
+        throw new Error(`DuckDuckGo API Error (${response.status}): ${errorText.substring(0, 100)}`);
+    }
+
+    const text = await response.text();
+    let llmResponse = "";
+    const lines = text.split("\n");
+    for (const line of lines) {
+      if (line.startsWith("data: ")) {
+        try {
+          const chunk = line.slice(6);
+          if (chunk === "[DONE]") break;
+          const json = JSON.parse(chunk);
+          if (json.message) llmResponse += json.message;
+        } catch (e) {}
       }
-      return llmResponse.trim() || "⚠️ Ошибка потока.";
-    } catch (error: any) {
-      return `⚠️ Ошибка бэкенда: ${error.message}`;
     }
+    
+    if (!llmResponse) {
+        throw new Error("Empty response from DuckDuckGo");
+    }
+    
+    return llmResponse.trim();
   }
 }