package photo import ( "bytes" "errors" "fmt" "image" "image/jpeg" "image/png" "io" "os" "git.kirsle.net/apps/gosocial/pkg/config" "git.kirsle.net/apps/gosocial/pkg/log" "git.kirsle.net/apps/gosocial/pkg/models" "github.com/edwvee/exiffix" "golang.org/x/image/draw" ) type UploadConfig struct { User *models.User Extension string // 'jpg' or 'png' only. Data []byte Crop []int // x, y, w, h } // UploadPhoto handles an incoming photo to add to a user's account. // // Returns: // - NewFilename() of the created photo file on disk. // - NewFilename() of the cropped version, or "" if not cropping. // - error on errors func UploadPhoto(cfg UploadConfig) (string, string, error) { // Validate and normalize the extension. var extension = cfg.Extension switch cfg.Extension { case ".jpg": fallthrough case ".jpe": fallthrough case ".jpeg": extension = ".jpg" case ".png": extension = ".png" default: return "", "", errors.New("unsupported image extension, must be jpg or png") } // Decide on a filename for this photo. var ( filename = NewFilename(extension) cropFilename = NewFilename(extension) ) // Decode the image using exiffix, which will auto-rotate jpeg images // based on their EXIF tags. reader := bytes.NewReader(cfg.Data) origImage, _, err := exiffix.Decode(reader) if err != nil { return "", "", err } // Read the config to get the image width. reader.Seek(0, io.SeekStart) var width, height int if decoded, _, err := image.DecodeConfig(reader); err == nil { width, height = decoded.Width, decoded.Height } else { return "", "", err } // Find the longest edge, if it's too large (over 1280px) // cap it to the max and scale the other dimension proportionally. log.Debug("UploadPhoto: taking a %dx%d image to name it %s", width, height, filename) if width >= height { if width > config.MaxPhotoWidth { newWidth := config.MaxPhotoWidth log.Debug("(%d / %d) * %d", width, height, newWidth) height = int((float64(height) / float64(width)) * float64(newWidth)) width = newWidth log.Debug("Its longest is width, scale to %sx%s", width, height) } } else { if height > config.MaxPhotoWidth { newHeight := config.MaxPhotoWidth width = int((float64(width) / float64(height)) * float64(newHeight)) height = newHeight log.Debug("Its longest is height, scale to %sx%s", width, height) } } // Scale the image. scaledImg := Scale(origImage, image.Rect(0, 0, width, height), draw.ApproxBiLinear) // Write the image to disk. if err := ToDisk(filename, extension, scaledImg); err != nil { return "", "", err } // Are we producing a cropped image, too? log.Error("Are we to crop? %+v", cfg.Crop) if cfg.Crop != nil && len(cfg.Crop) >= 4 { log.Debug("Also cropping this image to %+v", cfg.Crop) var ( x = cfg.Crop[0] y = cfg.Crop[1] w = cfg.Crop[2] h = cfg.Crop[3] ) croppedImg := Crop(origImage, image.Rect( x, y, w, h, )) // Write that to disk, too. log.Debug("Writing cropped image to disk: %s", cropFilename) if err := ToDisk(cropFilename, extension, croppedImg); err != nil { return filename, "", err } // Return both filenames! return filename, cropFilename, nil } // Not cropping, return only the first filename. return filename, "", nil } // Scale down an image. Example: // // scaled := Scale(src, image.Rect(0, 0, 200, 200), draw.ApproxBiLinear) func Scale(src image.Image, rect image.Rectangle, scale draw.Scaler) image.Image { dst := image.NewRGBA(rect) scale.Scale(dst, rect, src, src.Bounds(), draw.Over, nil) return dst } // Crop an image, returning the new image. Example: // // cropped := Crop() func Crop(src image.Image, rect image.Rectangle) image.Image { dst := image.NewRGBA(rect) draw.Copy(dst, image.Point{}, src, rect, draw.Over, nil) return dst } // ToDisk commits a photo image to disk in the right file format. // // Filename is like NewFilename() and it goes to e.g. "./web/static/photos/" func ToDisk(filename string, extension string, img image.Image) error { if path, err := EnsurePath(filename); err == nil { fh, err := os.Create(path) if err != nil { return err } defer fh.Close() switch extension { case ".jpg": jpeg.Encode(fh, img, &jpeg.Options{ Quality: config.JpegQuality, }) case ".png": png.Encode(fh, img) } } else { return fmt.Errorf("couldn't EnsurePath: %s", err) } return nil }