♻️ refactor OpenAI client options and unify custom headers parsing

Use OpenAI.ClientOptions for stronger typing and clarity
Extract custom headers parsing into parseCustomHeaders util
Simplify getEngine by delegating header parsing to helper
Improve maintainability and reduce code duplication

Author: EmilienMottet

src/engine/openAi.ts

@@ -14,21 +14,17 @@ export class OpenAiEngine implements AiEngine {
   constructor(config: OpenAiConfig) {
     this.config = config;
 
-    // Configuration options for the OpenAI client
-    const clientOptions: any = {
+    const clientOptions: OpenAI.ClientOptions = {
       apiKey: config.apiKey
     };
 
-    // Add baseURL if present
     if (config.baseURL) {
       clientOptions.baseURL = config.baseURL;
     }
 
-    // Add custom headers if present
     if (config.customHeaders) {
       try {
         let headers = config.customHeaders;
-        // If the headers are a string, try to parse them as JSON
         if (typeof config.customHeaders === 'string') {
           headers = JSON.parse(config.customHeaders);
         }
@@ -37,7 +33,6 @@ export class OpenAiEngine implements AiEngine {
           clientOptions.defaultHeaders = headers;
         }
       } catch (error) {
-        // Silently ignore parsing errors
       }
     }
 

src/utils/engine.ts

@@ -12,33 +12,39 @@ import { GroqEngine } from '../engine/groq';
 import { MLXEngine } from '../engine/mlx';
 import { DeepseekEngine } from '../engine/deepseek';
 
+function parseCustomHeaders(headers: any): Record<string, string> {
+  let parsedHeaders = {};
+  
+  if (!headers) {
+    return parsedHeaders;
+  }
+  
+  try {
+    if (typeof headers === 'object' && !Array.isArray(headers)) {
+      parsedHeaders = headers;
+    } else {
+      parsedHeaders = JSON.parse(headers);
+    }
+  } catch (error) {
+    console.warn('Invalid OCO_API_CUSTOM_HEADERS format, ignoring custom headers');
+  }
+  
+  return parsedHeaders;
+}
+
 export function getEngine(): AiEngine {
   const config = getConfig();
   const provider = config.OCO_AI_PROVIDER;
 
-  // Parse custom headers if provided
-  let customHeaders = {};
-  if (config.OCO_API_CUSTOM_HEADERS) {
-    try {
-      // If it's already an object, no need to parse it
-      if (typeof config.OCO_API_CUSTOM_HEADERS === 'object' && !Array.isArray(config.OCO_API_CUSTOM_HEADERS)) {
-        customHeaders = config.OCO_API_CUSTOM_HEADERS;
-      } else {
-        // Try to parse as JSON
-        customHeaders = JSON.parse(config.OCO_API_CUSTOM_HEADERS);
-      }
-    } catch (error) {
-      console.warn('Invalid OCO_API_CUSTOM_HEADERS format, ignoring custom headers');
-    }
-  }
+  const customHeaders = parseCustomHeaders(config.OCO_API_CUSTOM_HEADERS);
 
   const DEFAULT_CONFIG = {
     model: config.OCO_MODEL!,
     maxTokensOutput: config.OCO_TOKENS_MAX_OUTPUT!,
     maxTokensInput: config.OCO_TOKENS_MAX_INPUT!,
     baseURL: config.OCO_API_URL!,
     apiKey: config.OCO_API_KEY!,
-    customHeaders // Add custom headers to the configuration
+    customHeaders
   };
 
   switch (provider) {