refactor: 重构llm包

backend/internal/llm/client.go

@@ -11,11 +11,10 @@ import (
 )
 
 type Client struct {
-	llm llms.Model
+	model  llms.Model
 	config config.LLMConfig
 }
 
-// 创建 LLM 实例
 func NewClient(cfg config.LLMConfig) (*Client, error) {
 	model, err := openai.New(
 		openai.WithToken(cfg.APIKey),
@@ -24,47 +23,44 @@ func NewClient(cfg config.LLMConfig) (*Client, error) {
 	)
 
 	if err != nil {
-        return nil, fmt.Errorf("failed to create llm client: %w", err)
-    }
+		return nil, fmt.Errorf("failed to create llm client: %w", err)
+	}
 
-	return &Client{config: cfg, llm: model}, nil
+	return &Client{config: cfg, model: model}, nil
 }
 
-// Client简单对话调用
-func (c *Client) Chat(ctx context.Context, messages []llms.MessageContent) (string, error) {
-	resp, err := c.llm.GenerateContent(ctx, messages)
-
+func (c *Client) Generate(ctx context.Context, messages []llms.MessageContent, opts ...llms.CallOption) (*llms.ContentResponse, error) {
+	resp, err := c.model.GenerateContent(ctx, messages, opts...)
 	if err != nil {
-        log.Printf("[ERROR] GenerateContent failed: %v", err)
-        return "", fmt.Errorf("generate content error: %w", err)
-    }
-    if resp == nil || len(resp.Choices) == 0 {
-        log.Printf("[WARN] Response is empty or has no choices")
-        return "", fmt.Errorf("no content choices returned")
-    }
-    log.Printf("[INFO] Chat completed successfully, choice length: %d", len(resp.Choices[0].Content))
-
-	return resp.Choices[0].Content, nil
-}
-
-// Client包含系统提示词的调用
-func (c *Client) ChatWithSystemPrompt(ctx context.Context, systemPrompt string, messages []llms.MessageContent) (string, error) {
-	// 构造系统提示词消息
-	systemMessage := llms.TextParts(llms.ChatMessageTypeSystem, systemPrompt)
-	
-	// 将系统提示词插入到消息列表头部
-	allMessages := append([]llms.MessageContent{systemMessage}, messages...)
-
-	resp, err := c.llm.GenerateContent(ctx, allMessages)
-	if err != nil {
-		log.Printf("[ERROR] GenerateContent with system prompt failed: %v", err)
-		return "", fmt.Errorf("generate content error: %w", err)
+		log.Printf("[ERROR] GenerateContent failed: %v", err)
+		return nil, fmt.Errorf("generate content error: %w", err)
 	}
 	if resp == nil || len(resp.Choices) == 0 {
-		log.Printf("[WARN] Response with system prompt is empty or has no choices")
-		return "", fmt.Errorf("no content choices returned")
+		log.Printf("[WARN] Response is empty or has no choices")
+		return nil, fmt.Errorf("no content choices returned")
+	}
+	return resp, nil
+}
+
+func (c *Client) Chat(ctx context.Context, messages []llms.MessageContent) (string, error) {
+	resp, err := c.Generate(ctx, messages)
+	if err != nil {
+		return "", err
+	}
+	log.Printf("[INFO] Chat completed successfully, choice length: %d", len(resp.Choices[0].Content))
+	return resp.Choices[0].Content, nil
+}
+
+func (c *Client) ChatWithSystemPrompt(ctx context.Context, systemPrompt string, messages []llms.MessageContent) (string, error) {
+	allMessages := NewMessageBuilder().
+		WithSystemPrompt(systemPrompt).
+		WithMessages(messages).
+		Build()
+
+	resp, err := c.Generate(ctx, allMessages)
+	if err != nil {
+		return "", err
 	}
 	log.Printf("[INFO] Chat with system prompt completed successfully, choice length: %d", len(resp.Choices[0].Content))
-
 	return resp.Choices[0].Content, nil
-}
+}