feat: 当用gpt-4的API 时增加可用的 Max Tokens (Chanzhaoyu#729)

* fix: 用GPT-4 API时增加max token

* style: eslint fix

---------

Co-authored-by: Redon <790348264@qq.com>

service/src/chatgpt/index.ts

@@ -42,10 +42,22 @@ let api: ChatGPTAPI | ChatGPTUnofficialProxyAPI
     const options: ChatGPTAPIOptions = {
       apiKey: process.env.OPENAI_API_KEY,
       completionParams: { model },
-      maxModelTokens: 32768,
       debug: true,
     }
 
+    // increase max token limit if use gpt-4
+    if (model.toLowerCase().includes('gpt-4')) {
+      // if use 32k model
+      if (model.toLowerCase().includes('32k')) {
+        options.maxModelTokens = 32768
+        options.maxResponseTokens = 8192
+      }
+      else {
+        options.maxModelTokens = 8192
+        options.maxResponseTokens = 2048
+      }
+    }
+
     if (isNotEmptyString(process.env.SYSTEM_MESSAGE)) {
       let now = new Date()
       now = new Date(now.getTime() - (now.getTimezoneOffset()*60*1000))