feat: 新增文件上传服务

- 添加 UploadHandler 处理文件上传
- 添加 UploadService 实现文件存储
- 配置上传文件大小限制和存储路径

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

server/internal/service/upload_service.go

@@ -0,0 +1,166 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/v7"
+	"github.com/minio/minio-go/v7/pkg/credentials"
+	"github.com/google/uuid"
+	"x-agents/server/internal/config"
+)
+
+type UploadService struct {
+	cfg *config.Config
+	minioClient *minio.Client
+}
+
+// UploadResponse 上传响应
+type UploadResponse struct {
+	Success bool   `json:"success"`
+	URL     string `json:"url"`
+	FileKey string `json:"fileKey"` // 文件标识，用于删除等操作
+	Message string `json:"message"`
+}
+
+func NewUploadService(cfg *config.Config) (*UploadService, error) {
+	s := &UploadService{cfg: cfg}
+
+	// 如果是 MinIO 模式，初始化 MinIO 客户端
+	if cfg.UploadMode == "minio" {
+		if cfg.MinIOEndpoint == "" || cfg.MinIOAccessKey == "" || cfg.MinIOSecretKey == "" {
+			return nil, fmt.Errorf("MinIO configuration is incomplete")
+		}
+
+		client, err := minio.New(cfg.MinIOEndpoint, &minio.Options{
+			Creds:  credentials.NewStaticV4(cfg.MinIOAccessKey, cfg.MinIOSecretKey, ""),
+			Secure: cfg.MinIOUseSSL,
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to create MinIO client: %w", err)
+		}
+
+		// 检查 bucket 是否存在，不存在则创建
+		exists, err := client.BucketExists(context.Background(), cfg.MinIOBucket)
+		if err != nil {
+			return nil, fmt.Errorf("failed to check MinIO bucket: %w", err)
+		}
+		if !exists {
+			if err := client.MakeBucket(context.Background(), cfg.MinIOBucket, minio.MakeBucketOptions{}); err != nil {
+				return nil, fmt.Errorf("failed to create MinIO bucket: %w", err)
+			}
+		}
+
+		s.minioClient = client
+	}
+
+	return s, nil
+}
+
+// Upload 上传文件
+func (s *UploadService) Upload(file *multipart.FileHeader) (*UploadResponse, error) {
+	// 打开文件
+	f, err := file.Open()
+	if err != nil {
+		return &UploadResponse{Success: false, Message: err.Error()}, nil
+	}
+	defer f.Close()
+
+	// 生成唯一文件名
+	ext := filepath.Ext(file.Filename)
+	filename := fmt.Sprintf("%s%s", uuid.New().String(), ext)
+	fileKey := strings.TrimSuffix(filename, ext)
+
+	// 根据模式选择存储方式
+	if s.cfg.UploadMode == "minio" {
+		return s.uploadToMinIO(f, filename, fileKey, file.Size)
+	}
+	return s.uploadToLocal(f, filename, fileKey)
+}
+
+// uploadToMinIO 上传到 MinIO
+func (s *UploadService) uploadToMinIO(f multipart.File, filename, fileKey string, size int64) (*UploadResponse, error) {
+	_, err := s.minioClient.PutObject(context.Background(), s.cfg.MinIOBucket, filename, f, size, minio.PutObjectOptions{
+		ContentType: "application/octet-stream",
+	})
+	if err != nil {
+		return &UploadResponse{Success: false, Message: fmt.Sprintf("MinIO upload failed: %v", err)}, nil
+	}
+
+	// 生成预签名 URL（有效期 24 小时）
+	presignedURL, err := s.minioClient.PresignedGetObject(context.Background(), s.cfg.MinIOBucket, filename, 24*time.Hour, nil)
+	if err != nil {
+		return &UploadResponse{Success: false, Message: fmt.Sprintf("failed to generate URL: %v", err)}, nil
+	}
+
+	return &UploadResponse{
+		Success: true,
+		URL:     presignedURL.String(),
+		FileKey: fileKey,
+		Message: "Upload successful",
+	}, nil
+}
+
+// uploadToLocal 上传到本地
+func (s *UploadService) uploadToLocal(f multipart.File, filename, fileKey string) (*UploadResponse, error) {
+	// 确保目录存在
+	uploadPath := s.cfg.UploadLocalPath
+	if err := os.MkdirAll(uploadPath, 0755); err != nil {
+		return &UploadResponse{Success: false, Message: fmt.Sprintf("failed to create directory: %v", err)}, nil
+	}
+
+	// 创建文件
+	dst, err := os.Create(filepath.Join(uploadPath, filename))
+	if err != nil {
+		return &UploadResponse{Success: false, Message: err.Error()}, nil
+	}
+	defer dst.Close()
+
+	// 复制内容
+	if _, err := io.Copy(dst, f); err != nil {
+		return &UploadResponse{Success: false, Message: err.Error()}, nil
+	}
+
+	// 生成 URL
+	fileURL := fmt.Sprintf("%s/files/%s", s.cfg.ServerBaseURL, filename)
+
+	return &UploadResponse{
+		Success: true,
+		URL:     fileURL,
+		FileKey: fileKey,
+		Message: "Upload successful",
+	}, nil
+}
+
+// DeleteFile 删除文件
+func (s *UploadService) DeleteFile(filename string) error {
+	if s.cfg.UploadMode == "minio" {
+		return s.minioClient.RemoveObject(context.Background(), s.cfg.MinIOBucket, filename, minio.RemoveObjectOptions{})
+	}
+
+	// 本地删除
+	path := filepath.Join(s.cfg.UploadLocalPath, filename)
+	return os.Remove(path)
+}
+
+// GetFileURL 获取文件 URL（用于已存在的文件）
+func (s *UploadService) GetFileURL(filename string) (string, error) {
+	if s.cfg.UploadMode == "minio" {
+		presignedURL, err := s.minioClient.PresignedGetObject(context.Background(), s.cfg.MinIOBucket, filename, 24*time.Hour, nil)
+		if err != nil {
+			return "", err
+		}
+		return presignedURL.String(), nil
+	}
+
+	// 本地文件
+	escaped := url.PathEscape(filename)
+	return fmt.Sprintf("%s/files/%s", s.cfg.ServerBaseURL, escaped), nil
+}