feat: return 400 error when no available provider in pool

src/common.js

@@ -402,9 +402,24 @@ export async function handleContentGenerationRequest(req, res, service, endpoint
 
     // 2.5. 如果使用了提供商池，根据模型重新选择提供商
     if (providerPoolManager && CONFIG.providerPools && CONFIG.providerPools[CONFIG.MODEL_PROVIDER]) {
-        const { getApiService } = await import('./service-manager.js');
+        const { getApiService, NoAvailableProviderError } = await import('./service-manager.js');
-        service = await getApiService(CONFIG, model);
+        try {
-        console.log(`[Content Generation] Re-selected service adapter based on model: ${model}`);
+            service = await getApiService(CONFIG, model);
+            console.log(`[Content Generation] Re-selected service adapter based on model: ${model}`);
+        } catch (error) {
+            if (error instanceof NoAvailableProviderError) {
+                // 号池无可用账号，返回 400 错误
+                res.writeHead(400, { 'Content-Type': 'application/json' });
+                res.end(JSON.stringify({
+                    error: {
+                        type: 'no_available_provider',
+                        message: error.message
+                    }
+                }));
+                return;
+            }
+            throw error;
+        }
     }
 
     // 3. Apply system prompt from file if configured.

src/service-manager.js

@@ -56,11 +56,28 @@ export async function initApiService(config) {
     return serviceInstances; // Return the collection of initialized service instances
 }
 
+/**
+ * Custom error class for no available provider in pool
+ */
+export class NoAvailableProviderError extends Error {
+    constructor(providerType, requestedModel = null) {
+        const message = requestedModel 
+            ? `号池无可用账号: ${providerType} (model: ${requestedModel})`
+            : `号池无可用账号: ${providerType}`;
+        super(message);
+        this.name = 'NoAvailableProviderError';
+        this.providerType = providerType;
+        this.requestedModel = requestedModel;
+        this.statusCode = 400;
+    }
+}
+
 /**
  * Get API service adapter, considering provider pools
  * @param {Object} config - The current request configuration
  * @param {string} [requestedModel] - Optional. The model name to filter providers by.
  * @returns {Promise<Object>} The API service adapter
+ * @throws {NoAvailableProviderError} If no healthy provider is available in the pool
  */
 export async function getApiService(config, requestedModel = null) {
     let serviceConfig = config;
@@ -74,7 +91,9 @@ export async function getApiService(config, requestedModel = null) {
             config.uuid = serviceConfig.uuid;
             console.log(`[API Service] Using pooled configuration for ${config.MODEL_PROVIDER}: ${serviceConfig.uuid}${requestedModel ? ` (model: ${requestedModel})` : ''}`);
         } else {
-            console.warn(`[API Service] No healthy provider found in pool for ${config.MODEL_PROVIDER}${requestedModel ? ` supporting model: ${requestedModel}` : ''}. Falling back to main config.`);
+            // 号池没有可用账号，抛出错误
+            console.error(`[API Service] 号池无可用账号: ${config.MODEL_PROVIDER}${requestedModel ? ` (model: ${requestedModel})` : ''}`);
+            throw new NoAvailableProviderError(config.MODEL_PROVIDER, requestedModel);
         }
     }
     return getServiceAdapter(serviceConfig);