chore: optimize code (Chanzhaoyu#1328)

Author: shunyue1320

service/src/chatgpt/index.ts

@@ -27,7 +27,7 @@ const timeoutMs: number = !isNaN(+process.env.TIMEOUT_MS) ? +process.env.TIMEOUT
 const disableDebug: boolean = process.env.OPENAI_API_DISABLE_DEBUG === 'true'
 
 let apiModel: ApiModel
-let model = 'gpt-3.5-turbo'
+const model = isNotEmptyString(process.env.OPENAI_API_MODEL) ? process.env.OPENAI_API_MODEL : 'gpt-3.5-turbo'
 
 if (!isNotEmptyString(process.env.OPENAI_API_KEY) && !isNotEmptyString(process.env.OPENAI_ACCESS_TOKEN))
   throw new Error('Missing OPENAI_API_KEY or OPENAI_ACCESS_TOKEN environment variable')
@@ -39,8 +39,6 @@ let api: ChatGPTAPI | ChatGPTUnofficialProxyAPI
 
   if (isNotEmptyString(process.env.OPENAI_API_KEY)) {
     const OPENAI_API_BASE_URL = process.env.OPENAI_API_BASE_URL
-    const OPENAI_API_MODEL = process.env.OPENAI_API_MODEL
-    model = isNotEmptyString(OPENAI_API_MODEL) ? OPENAI_API_MODEL : 'gpt-3.5-turbo'
 
     const options: ChatGPTAPIOptions = {
       apiKey: process.env.OPENAI_API_KEY,
@@ -70,19 +68,13 @@ let api: ChatGPTAPI | ChatGPTUnofficialProxyAPI
     apiModel = 'ChatGPTAPI'
   }
   else {
-    const OPENAI_API_MODEL = process.env.OPENAI_API_MODEL
     const options: ChatGPTUnofficialProxyAPIOptions = {
       accessToken: process.env.OPENAI_ACCESS_TOKEN,
+      apiReverseProxyUrl: isNotEmptyString(process.env.API_REVERSE_PROXY) ? process.env.API_REVERSE_PROXY : 'https://bypass.churchless.tech/api/conversation',
+      model,
       debug: !disableDebug,
     }
 
-    if (isNotEmptyString(OPENAI_API_MODEL))
-      options.model = OPENAI_API_MODEL
-
-    options.apiReverseProxyUrl = isNotEmptyString(process.env.API_REVERSE_PROXY)
-      ? process.env.API_REVERSE_PROXY
-      : 'https://bypass.churchless.tech/api/conversation'
-
     setupProxy(options)
 
     api = new ChatGPTUnofficialProxyAPI({ ...options })