Avatar(file) upload from form data in go

avatarupload.go

/*
  Takes a valid file(png/jpg) from form data,
  creates a unique user directory to store file
  and lastly re-size the file to passed in dimmensions
  and copies the filebytes to the directory
*/

// AvatarUpload handle uploading of a users profile avatar
func (p *Profiles) AvatarUpload(c *gin.Context) {

	// get uploaded file
	fHeader, _ := c.FormFile("avatar")
	ext := strings.ToLower((filepath.Ext(fHeader.Filename)))

	// check ext
	if !(ext == ".jpg" || ext == ".png") {
		response.RespondWithError(
			c, 
			http.StatusInternalServerError, 
			"Only files of type JPG or PNG are allowed.",
		)
		return
	}

	file, err := fHeader.Open()
	if err != nil {
		uploadAvatarErr(c)
		return
	}
	defer file.Close()

	// create dir path for avatar
	avatarPath := fmt.Sprintf("images/avatars/%v/", parser.GetIDFromCTX(c))
	err = os.MkdirAll(avatarPath, 0755)
	if err != nil {
		uploadAvatarErr(c)
		return
	}

	// create destination file
	dst, err := os.Create(avatarPath + "avatar.jpg")
	if err != nil {
		uploadAvatarErr(c)
		return
	}
	defer dst.Close()


	// rezise and store avatar in users path
	err = jpeg.Encode(dst, resizeImg(150, 150, file), nil)
	if err != nil {
		uploadAvatarErr(c)
		return
	}

	// notify user that upload wa successfull
	response.RespondWithSuccess(
		c,
		http.StatusCreated,
		"Avatar successfully uploaded!")
}

// resize image file to passed inn demensions
// using Lanczos resampling and preserve aspect ratio
func resizeImg(width uint, height uint, file multipart.File) image.Image {
	img, _, err := image.Decode(file)
	defer file.Close()

	if err != nil {
		fmt.Println(err)
		panic(err)
	}

	new := resize.Resize(height, width, img, resize.Lanczos3)
	return new
}

// helper func to send error message releated to avatar upload
func uploadAvatarErr(c *gin.Context) {
	response.RespondWithError(
		c, 
		http.StatusInternalServerError, 
		"Something went wrong when uploading image. Please try again.",
	)
}