feat: 新增Client简单对话调用

backend/internal/llm/client.go

@@ -1,8 +1,10 @@
 package llm
 
 import (
+	"context"
 	"fmt"
 	"knowledge-graph-backend/internal/config"
+	"log"
 
 	"github.com/tmc/langchaingo/llms"
 	"github.com/tmc/langchaingo/llms/openai"
@@ -26,4 +28,21 @@ func NewClient(cfg config.LLMConfig) (*Client, error) {
     }
 
 	return &Client{config: cfg, llm: 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)
+
+	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
 }

backend/internal/llm/client_test.go

@@ -1,9 +1,12 @@
 package llm
 
 import (
+	"context"
 	"knowledge-graph-backend/internal/config"
 	"log"
 	"testing"
+
+	"github.com/tmc/langchaingo/llms"
 )
 
 func TestNewClient(t *testing.T) {
@@ -34,4 +37,58 @@ func TestNewClient(t *testing.T) {
 	}
 
 	log.Printf("[INFO] TestNewClient completed successfully")
+}
+
+func TestClient_Chat(t *testing.T) {
+	// 1. 加载配置
+	cfg, err := config.Load()
+	if err != nil {
+		log.Printf("[WARN] config.Load() returned error: %v, using default config", err)
+	} else {
+		log.Printf("[INFO] config loaded successfully, LLM config: %+v", cfg.LLM)
+	}
+
+	// 2. 创建客户端
+	client, err := NewClient(cfg.LLM)
+	if err != nil {
+		log.Printf("[ERROR] NewClient() returned unexpected error: %v", err)
+		t.Fatalf("NewClient() returned unexpected error: %v", err)
+	}
+	log.Printf("[INFO] NewClient() succeeded, client created")
+
+	messages := []llms.MessageContent{
+		{
+			Role: "human",
+			Parts: []llms.ContentPart{
+				llms.TextContent{Text: "你好，请介绍一下你自己"},
+			},
+		},
+	}
+	log.Printf("[INFO] preparing chat request, messages count: %d, content: %q", len(messages), messages[0].Parts[0].(llms.TextContent).Text)
+
+	// 3. 调用被测方法
+	log.Printf("[INFO] calling client.Chat()...")
+	got, err := client.Chat(context.Background(), messages)
+	
+	// 4. 校验结果
+	if err != nil {
+		log.Printf("[ERROR] Chat() returned error: %v", err)
+		t.Errorf("Chat() error = %v, want nil", err)
+		return
+	}
+	log.Printf("[INFO] client.Chat() call completed without error")
+
+	if len(got) == 0 {
+		log.Printf("[ERROR] Chat() returned empty response, got: %v", got)
+		t.Errorf("Chat() returned empty response, want non-empty")
+	} else {
+		// 截取前100个字符打印，防止LLM返回内容过长刷屏，同时方便调试确认内容
+		preview := got
+		if len(preview) > 100 {
+			preview = preview[:100] + "..."
+		}
+		log.Printf("[INFO] Chat() response validation passed, response preview: %q", preview)
+	}
+
+	log.Printf("[INFO] TestClient_Chat completed successfully")
 }