check file existant before processing

internal/photos/api/upload.go

@@ -22,6 +22,7 @@ var (
 	ErrUploadNotExists       = errors.New("upload id doesn't exists")
 	ErrUploadPartTooLarge    = fmt.Errorf("upload part too large (> %d B)", MaxUploadPartSize)
 	ErrUploadPartWrongSha256 = errors.New("upload part wrong sha256")
+	ErrFileAlreadExists      = errors.New("file already exists")
 )
 
 // Model
@@ -53,6 +54,8 @@ func (s *Service) UploadCreate(c *gin.Context) {
 	c.JSON(http.StatusCreated, upload)
 }
 
+// Service
+
 type Upload struct {
 	Id string `json:"upload_id" uri:"upload_id" binding:"required,uuid"`
 }
@@ -62,6 +65,12 @@ type UploadPartQuery struct {
 	PartSha256 string `form:"sha256" binding:"required,sha256"`
 }
 
+type UploadCompleteRequest struct {
+	Sha256 string `json:"sha256" binding:"required,sha256"`
+	Name   string `json:"name" binding:"required"`
+	Parts  uint   `json:"parts" binding:"required"`
+}
+
 func (s *Service) UploadPart(c *gin.Context) {
 	var (
 		upload     Upload
@@ -133,12 +142,6 @@ func (s *Service) UploadCancel(c *gin.Context) {
 	c.Status(http.StatusNoContent)
 }
 
-type UploadCompleteRequest struct {
-	Sha256 string `json:"sha256" binding:"required,sha256"`
-	Name   string `json:"name" binding:"required"`
-	Parts  uint   `json:"parts" binding:"required"`
-}
-
 func (s *Service) UploadComplete(c *gin.Context) {
 	var (
 		upload                Upload
@@ -153,6 +156,13 @@ func (s *Service) UploadComplete(c *gin.Context) {
 		return
 	}
 
+	f, err := s.StorageUpload.Stat(uploadCompleteRequest.Sha256[0:1], uploadCompleteRequest.Sha256[1:2], uploadCompleteRequest.Sha256)
+	fmt.Println(err)
+	if err == nil && f.Mode().IsRegular() {
+		c.AbortWithError(http.StatusConflict, ErrFileAlreadExists)
+		return
+	}
+
 	c.Status(http.StatusNoContent)
 }