Refactor: Modularize codebase with separate decision and MCP packages

Architecture improvements:
- Extract AI decision engine to dedicated `decision` package
- Create `mcp` package for Model Context Protocol client
- Separate market data structures into `market/data.go`
- Update trader to use new modular structure

New packages:
- `decision/engine.go` - AI decision logic and prompt building
- `mcp/client.go` - Unified AI API client (DeepSeek/Qwen)
- `market/data.go` - Market data type definitions

Benefits:
- Better separation of concerns
- Improved code organization and maintainability
- Easier to test individual components
- More flexible AI provider integration
- Cleaner dependency management

Updated imports:
- trader/auto_trader.go now uses decision and mcp packages
- Consistent API across different AI providers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

mcp/client.go

@@ -0,0 +1,216 @@
+package mcp
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// Provider AI提供商类型
+type Provider string
+
+const (
+	ProviderDeepSeek Provider = "deepseek"
+	ProviderQwen     Provider = "qwen"
+)
+
+// Config AI API配置
+type Config struct {
+	Provider  Provider
+	APIKey    string
+	SecretKey string // 阿里云需要
+	BaseURL   string
+	Model     string
+	Timeout   time.Duration
+}
+
+// 默认配置
+var defaultConfig = Config{
+	Provider: ProviderDeepSeek,
+	BaseURL:  "https://api.deepseek.com/v1",
+	Model:    "deepseek-chat",
+	Timeout:  120 * time.Second, // 增加到120秒，因为AI需要分析大量数据
+}
+
+// SetDeepSeekAPIKey 设置DeepSeek API密钥
+func SetDeepSeekAPIKey(apiKey string) {
+	defaultConfig.Provider = ProviderDeepSeek
+	defaultConfig.APIKey = apiKey
+	defaultConfig.BaseURL = "https://api.deepseek.com/v1"
+	defaultConfig.Model = "deepseek-chat"
+}
+
+// SetQwenAPIKey 设置阿里云Qwen API密钥
+func SetQwenAPIKey(apiKey, secretKey string) {
+	defaultConfig.Provider = ProviderQwen
+	defaultConfig.APIKey = apiKey
+	defaultConfig.SecretKey = secretKey
+	defaultConfig.BaseURL = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+	defaultConfig.Model = "qwen-plus" // 可选: qwen-turbo, qwen-plus, qwen-max
+}
+
+// SetConfig 设置完整的AI配置（高级用户）
+func SetConfig(config Config) {
+	if config.Timeout == 0 {
+		config.Timeout = 30 * time.Second
+	}
+	defaultConfig = config
+}
+
+// CallWithMessages 使用 system + user prompt 调用AI API（推荐）
+func CallWithMessages(systemPrompt, userPrompt string) (string, error) {
+	if defaultConfig.APIKey == "" {
+		return "", fmt.Errorf("AI API密钥未设置，请先调用 SetDeepSeekAPIKey() 或 SetQwenAPIKey()")
+	}
+
+	// 重试配置
+	maxRetries := 3
+	var lastErr error
+
+	for attempt := 1; attempt <= maxRetries; attempt++ {
+		if attempt > 1 {
+			fmt.Printf("⚠️  AI API调用失败，正在重试 (%d/%d)...\n", attempt, maxRetries)
+		}
+
+		result, err := callOnce(systemPrompt, userPrompt)
+		if err == nil {
+			if attempt > 1 {
+				fmt.Printf("✓ AI API重试成功\n")
+			}
+			return result, nil
+		}
+
+		lastErr = err
+		// 如果不是网络错误，不重试
+		if !isRetryableError(err) {
+			return "", err
+		}
+
+		// 重试前等待
+		if attempt < maxRetries {
+			waitTime := time.Duration(attempt) * 2 * time.Second
+			fmt.Printf("⏳ 等待%v后重试...\n", waitTime)
+			time.Sleep(waitTime)
+		}
+	}
+
+	return "", fmt.Errorf("重试%d次后仍然失败: %w", maxRetries, lastErr)
+}
+
+// callOnce 单次调用AI API（内部使用）
+func callOnce(systemPrompt, userPrompt string) (string, error) {
+	// 构建 messages 数组
+	messages := []map[string]string{}
+
+	// 如果有 system prompt，添加 system message
+	if systemPrompt != "" {
+		messages = append(messages, map[string]string{
+			"role":    "system",
+			"content": systemPrompt,
+		})
+	}
+
+	// 添加 user message
+	messages = append(messages, map[string]string{
+		"role":    "user",
+		"content": userPrompt,
+	})
+
+	// 构建请求体
+	requestBody := map[string]interface{}{
+		"model":       defaultConfig.Model,
+		"messages":    messages,
+		"temperature": 0.5, // 降低temperature以提高JSON格式稳定性
+		"max_tokens":  2000,
+	}
+
+	// 注意：response_format 参数仅 OpenAI 支持，DeepSeek/Qwen 不支持
+	// 我们通过强化 prompt 和后处理来确保 JSON 格式正确
+
+	jsonData, err := json.Marshal(requestBody)
+	if err != nil {
+		return "", fmt.Errorf("序列化请求失败: %w", err)
+	}
+
+	// 创建HTTP请求
+	url := fmt.Sprintf("%s/chat/completions", defaultConfig.BaseURL)
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return "", fmt.Errorf("创建请求失败: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	// 根据不同的Provider设置认证方式
+	switch defaultConfig.Provider {
+	case ProviderDeepSeek:
+		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", defaultConfig.APIKey))
+	case ProviderQwen:
+		// 阿里云Qwen使用API-Key认证
+		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", defaultConfig.APIKey))
+		// 注意：如果使用的不是兼容模式，可能需要不同的认证方式
+	default:
+		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", defaultConfig.APIKey))
+	}
+
+	// 发送请求
+	client := &http.Client{Timeout: defaultConfig.Timeout}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("发送请求失败: %w", err)
+	}
+	defer resp.Body.Close()
+
+	// 读取响应
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("读取响应失败: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("API返回错误 (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	// 解析响应
+	var result struct {
+		Choices []struct {
+			Message struct {
+				Content string `json:"content"`
+			} `json:"message"`
+		} `json:"choices"`
+	}
+
+	if err := json.Unmarshal(body, &result); err != nil {
+		return "", fmt.Errorf("解析响应失败: %w", err)
+	}
+
+	if len(result.Choices) == 0 {
+		return "", fmt.Errorf("API返回空响应")
+	}
+
+	return result.Choices[0].Message.Content, nil
+}
+
+// isRetryableError 判断错误是否可重试
+func isRetryableError(err error) bool {
+	errStr := err.Error()
+	// 网络错误、超时、EOF等可以重试
+	retryableErrors := []string{
+		"EOF",
+		"timeout",
+		"connection reset",
+		"connection refused",
+		"temporary failure",
+		"no such host",
+	}
+	for _, retryable := range retryableErrors {
+		if strings.Contains(errStr, retryable) {
+			return true
+		}
+	}
+	return false
+}