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app/main/api/internal/logic/upload/serveuploadedfilelogic.go

@@ -0,0 +1,66 @@
+package upload
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"tyc-server/app/main/api/internal/svc"
+	"tyc-server/app/main/api/internal/types"
+	"tyc-server/common/xerr"
+
+	"github.com/pkg/errors"
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type ServeUploadedFileLogic struct {
+	logx.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+func NewServeUploadedFileLogic(ctx context.Context, svcCtx *svc.ServiceContext) *ServeUploadedFileLogic {
+	return &ServeUploadedFileLogic{
+		Logger: logx.WithContext(ctx),
+		ctx:    ctx,
+		svcCtx: svcCtx,
+	}
+}
+
+func (l *ServeUploadedFileLogic) ServeUploadedFile(req *types.ServeUploadedFileReq) (resp *types.ServeUploadedFileResp, err error) {
+	fileName := strings.TrimSpace(req.FileName)
+	if fileName == "" {
+		return nil, errors.Wrap(xerr.NewErrMsg("缺少文件名"), "fileName empty")
+	}
+	// 只允许文件名，禁止路径穿越
+	if strings.Contains(fileName, "..") || filepath.Base(fileName) != fileName {
+		return nil, errors.Wrap(xerr.NewErrMsg("非法文件名"), fileName)
+	}
+
+	candidates := []string{
+		"data/uploads",
+		"../data/uploads",
+		"../../data/uploads",
+		"../../../data/uploads",
+	}
+	for _, c := range candidates {
+		abs, _ := filepath.Abs(c)
+		fullPath := filepath.Join(abs, fileName)
+		if info, err := os.Stat(fullPath); err == nil && !info.IsDir() {
+			contentType := "image/jpeg"
+			if strings.HasSuffix(strings.ToLower(fileName), ".png") {
+				contentType = "image/png"
+			} else if strings.HasSuffix(strings.ToLower(fileName), ".gif") {
+				contentType = "image/gif"
+			} else if strings.HasSuffix(strings.ToLower(fileName), ".webp") {
+				contentType = "image/webp"
+			}
+			return &types.ServeUploadedFileResp{
+				FilePath:    fullPath,
+				ContentType: contentType,
+			}, nil
+		}
+	}
+	return nil, errors.Wrapf(xerr.NewErrMsg("文件不存在"), "fileName=%s", fileName)
+}