feat: 新增Model管理模块

- 添加 Model 实体定义
- 实现 Model CRUD 接口
- 添加 Model 仓储层和服务层

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/internal/service/model_service.go

@@ -0,0 +1,166 @@
+package service
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"x-agents/server/internal/model"
+	"x-agents/server/internal/repository"
+
+	"github.com/google/uuid"
+)
+
+// ModelService 模型服务
+type ModelService struct {
+	repo *repository.ModelRepository
+}
+
+func NewModelService(repo *repository.ModelRepository) *ModelService {
+	return &ModelService{repo: repo}
+}
+
+// List 获取模型列表
+func (s *ModelService) List() ([]model.ModelInfo, error) {
+	return s.repo.FindAll()
+}
+
+// GetByID 根据 ID 获取模型
+func (s *ModelService) GetByID(id string) (*model.ModelInfo, error) {
+	return s.repo.FindByID(id)
+}
+
+// Create 创建模型
+func (s *ModelService) Create(req model.CreateModelRequest) (*model.ModelInfo, error) {
+	info := &model.ModelInfo{
+		ID:          uuid.New().String(),
+		Name:        req.Name,
+		ModelType:   req.ModelType,
+		Provider:    req.Provider,
+		Model:       req.Model,
+		APIKey:      req.APIKey,
+		BaseURL:     req.BaseURL,
+		APIEndpoint: req.APIEndpoint,
+		Status:      "active",
+	}
+
+	if err := s.repo.Create(info); err != nil {
+		return nil, err
+	}
+	return info, nil
+}
+
+// Update 更新模型
+func (s *ModelService) Update(id string, req model.UpdateModelRequest) (*model.ModelInfo, error) {
+	// 检查是否存在
+	_, err := s.repo.FindByID(id)
+	if err != nil {
+		return nil, fmt.Errorf("model not found")
+	}
+
+	// 构建更新字段
+	fields := make(map[string]interface{})
+	if req.Name != "" {
+		fields["name"] = req.Name
+	}
+	if req.ModelType != "" {
+		fields["model_type"] = req.ModelType
+	}
+	if req.Provider != "" {
+		fields["provider"] = req.Provider
+	}
+	if req.Model != "" {
+		fields["model"] = req.Model
+	}
+	if req.APIKey != "" {
+		fields["api_key"] = req.APIKey
+	}
+	if req.BaseURL != "" {
+		fields["base_url"] = req.BaseURL
+	}
+	if req.APIEndpoint != "" {
+		fields["api_endpoint"] = req.APIEndpoint
+	}
+	if req.Status != "" {
+		fields["status"] = req.Status
+	}
+
+	if err := s.repo.UpdateFields(id, fields); err != nil {
+		return nil, err
+	}
+
+	return s.repo.FindByID(id)
+}
+
+// Delete 删除模型
+func (s *ModelService) Delete(id string) error {
+	// 检查是否存在
+	_, err := s.repo.FindByID(id)
+	if err != nil {
+		return fmt.Errorf("model not found")
+	}
+	return s.repo.Delete(id)
+}
+
+// TestConnection 测试模型连接
+func (s *ModelService) TestConnection(req model.TestModelRequest) (*model.TestModelResponse, error) {
+	// 构建请求 URL
+	baseURL := req.BaseURL
+	if req.APIEndpoint != "" {
+		baseURL = baseURL + req.APIEndpoint
+	} else {
+		// 默认端点
+		switch req.Provider {
+		case "OpenAI":
+			baseURL = baseURL + "/v1/chat/completions"
+		case "Ollama":
+			baseURL = baseURL + "/api/chat"
+		}
+	}
+
+	// 构建请求体
+	requestBody := map[string]interface{}{
+		"model": req.Model,
+		"messages": []map[string]string{
+			{"role": "user", "content": "Hello"},
+		},
+		"max_tokens": 10,
+	}
+
+	body, err := json.Marshal(requestBody)
+	if err != nil {
+		return &model.TestModelResponse{Success: false, Message: err.Error()}, nil
+	}
+
+	// 创建 HTTP 请求
+	httpReq, err := http.NewRequest("POST", baseURL, bytes.NewBuffer(body))
+	if err != nil {
+		return &model.TestModelResponse{Success: false, Message: err.Error()}, nil
+	}
+
+	httpReq.Header.Set("Content-Type", "application/json")
+	if req.APIKey != "" {
+		httpReq.Header.Set("Authorization", "Bearer "+req.APIKey)
+	}
+
+	// 发送请求
+	client := &http.Client{}
+	resp, err := client.Do(httpReq)
+	if err != nil {
+		return &model.TestModelResponse{Success: false, Message: err.Error()}, nil
+	}
+	defer resp.Body.Close()
+
+	// 读取响应
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return &model.TestModelResponse{Success: false, Message: err.Error()}, nil
+	}
+
+	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+		return &model.TestModelResponse{Success: true, Message: "Connection successful"}, nil
+	}
+
+	return &model.TestModelResponse{Success: false, Message: fmt.Sprintf("HTTP %d: %s", resp.StatusCode, string(respBody))}, nil
+}