package llm

import (
	"context"
	"knowledge-graph-backend/internal/config"
	"log"
	"testing"

	"github.com/tmc/langchaingo/llms"
)

func TestNewClient(t *testing.T) {
	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)
	}

	client, err := NewClient(cfg.LLM)
	if err != nil {
		t.Fatalf("NewClient() returned unexpected error: %v", err)
	}
	log.Printf("[INFO] NewClient() succeeded, client created")

	// 验证返回的 Client 实例不为 nil
	if client == nil {
		t.Fatal("NewClient() returned nil client")
	}
	log.Printf("[INFO] client instance is non-nil, validation passed")

	// 验证 llm 实例被成功创建（不调用，只检查非 nil）
	if client.llm == nil {
		t.Error("client.llm is nil, expected a non-nil llms.Model")
	} else {
		log.Printf("[INFO] client.llm is non-nil, llms.Model created successfully")
	}

	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")
}

func TestClient_ChatWithSystemPrompt(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")

	// 3. 构造系统提示词与消息列表
	systemPrompt := "你是一个专业的知识图谱助手，请用简洁的中文回答问题。"
	messages := []llms.MessageContent{
		{
			Role: "human",
			Parts: []llms.ContentPart{
				llms.TextContent{Text: "请简要介绍一下知识图谱的概念"},
			},
		},
	}
	log.Printf("[INFO] preparing chat with system prompt request, system prompt: %q, messages count: %d, content: %q", systemPrompt, len(messages), messages[0].Parts[0].(llms.TextContent).Text)

	// 4. 调用被测方法
	log.Printf("[INFO] calling client.ChatWithSystemPrompt()...")
	got, err := client.ChatWithSystemPrompt(context.Background(), systemPrompt, messages)
	
	// 5. 校验结果
	if err != nil {
		log.Printf("[ERROR] ChatWithSystemPrompt() returned error: %v", err)
		t.Errorf("ChatWithSystemPrompt() error = %v, want nil", err)
		return
	}
	log.Printf("[INFO] client.ChatWithSystemPrompt() call completed without error")

	if len(got) == 0 {
		log.Printf("[ERROR] ChatWithSystemPrompt() returned empty response, got: %v", got)
		t.Errorf("ChatWithSystemPrompt() 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] ChatWithSystemPrompt() response validation passed, response preview: %q", preview)
	}

	log.Printf("[INFO] TestClient_ChatWithSystemPrompt completed successfully")
}