package media import ( "fmt" "image" "image/jpeg" "io" "os" "path" "path/filepath" "regexp" "sort" "strconv" "time" // for processing images _ "image/gif" _ "image/png" "github.com/nfnt/resize" "github.com/tajtiattila/metadata" ) type MediaSource struct { StorageDir string ThumbDir string set Set } type Media struct { Type string Name string Size image.Rectangle FullName string metadata *metadata.Metadata } func (ms *MediaSource) LocationOrig(m Media) string { return path.Join(ms.StorageDir, m.Name) } func (ms *MediaSource) ThumbPath(m Media, size image.Rectangle) string { w := size.Dx() h := size.Dy() var ws, hs string if w != 0 { ws = fmt.Sprint(w) } if h != 0 { hs = fmt.Sprint(h) } thumbSlug := filepath.Join(fmt.Sprintf("%sx%s", ws, hs), m.Name) return path.Join("/media", thumbSlug) } func (ms *MediaSource) ThumbFilename(m Media, size image.Rectangle) string { return filepath.Join(ms.ThumbDir, ms.ThumbPath(m, size)) } func (ms *MediaSource) ReceiveNewMedia(name string, r io.Reader) error { ms.set = nil dest := path.Join(ms.StorageDir, name) f, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE, 0644) if err != nil { return err } _, err = io.Copy(f, r) if err != nil { return err } return f.Close() } func (m *Media) Date() time.Time { m.getMetadata() if m.metadata != nil { raw := m.metadata.Get(metadata.DateTimeOriginal) if raw != "" { d, err := time.Parse("2006-01-02T15:04:05", raw) if err == nil { return d } } } fi, err := os.Stat(m.FullName) if err == nil { return fi.ModTime() } return time.Time{} } func (m *Media) getMetadata() error { if m.metadata != nil { return nil } f, err := os.Open(m.FullName) if err != nil { return err } md, err := metadata.Parse(f) if err != nil { return err } m.metadata = md return nil } func (ms *MediaSource) Size(name string) (image.Rectangle, error) { f, err := os.Open(name) if err != nil { return image.ZR, err } defer f.Close() cfg, _, err := image.DecodeConfig(f) if err != nil { return image.ZR, err } width := cfg.Width height := cfg.Height return image.Rect(0, 0, width, height), nil } func (ms *MediaSource) ThumbMax(m Media, maxDim int) (string, image.Rectangle, error) { f, err := os.Open(ms.LocationOrig(m)) if err != nil { return "", image.ZR, err } defer f.Close() cfg, _, err := image.DecodeConfig(f) if err != nil { return "", image.ZR, err } width := cfg.Width height := cfg.Height if width > height { height = height * maxDim / width width = maxDim } else { width = width * maxDim / height height = maxDim } size := image.Rect(0, 0, width, height) if ms.HasThumb(m, size) { return ms.ThumbPath(m, size), size, nil } _, err = f.Seek(0, io.SeekStart) if err != nil { return "", image.ZR, err } src, err := ms.thumbReader(f, m, size) return src, size, err } func (ms *MediaSource) HasThumb(m Media, size image.Rectangle) bool { fi, err := os.Stat(ms.ThumbFilename(m, size)) if err != nil { return false } return m.Date().Before(fi.ModTime()) } func (ms *MediaSource) ByName(name string) *Media { size, _ := ms.Size(path.Join(ms.StorageDir, name)) m := Media{ Type: "image", Name: name, Size: size, } m.FullName = ms.LocationOrig(m) return &m } func (ms *MediaSource) Thumb(m Media, size image.Rectangle) (string, error) { if ms.HasThumb(m, size) { return ms.ThumbPath(m, size), nil } f, err := os.Open(ms.LocationOrig(m)) if err != nil { return "", err } defer f.Close() return ms.thumbReader(f, m, size) } func (ms *MediaSource) thumbReader(r io.Reader, m Media, size image.Rectangle) (string, error) { img, _, err := image.Decode(r) if err != nil { return "", err } return ms.ThumbImage(img, m, size) } func (ms *MediaSource) ThumbImage(img image.Image, m Media, size image.Rectangle) (string, error) { thumbLoc := ms.ThumbFilename(m, size) os.MkdirAll(path.Dir(thumbLoc), 0755) fthumb, err := os.OpenFile(thumbLoc, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0655) if err != nil { return "", err } img = resize.Resize(uint(size.Dx()), uint(size.Dy()), img, resize.Bilinear) err = jpeg.Encode(fthumb, img, nil) if err != nil { return "", err } err = fthumb.Close() if err != nil { return "", err } return ms.ThumbPath(m, size), nil } func (ms *MediaSource) Walk() ([]*Media, error) { if ms.set == nil { var media []*Media err := filepath.Walk(ms.StorageDir, func(name string, fi os.FileInfo, err error) error { if err != nil { return err } if fi.IsDir() { return nil } media = append(media, ms.ByName(path.Base(name))) return nil }) if err != nil { return media, err } ms.set = media } return ms.set, nil } type Set []*Media func (s Set) ByDate() Set { sort.Slice(s, func(i, j int) bool { return s[i].Date().After(s[j].Date()) }) return s } var ( sizeString = regexp.MustCompile(`([0-9]*)(x)?([0-9]*)`) ) func ParseSizeString(str string, actual image.Rectangle) (image.Rectangle, error) { var err = fmt.Errorf("expected a size string {width}x{height}, saw %q", str) strs := sizeString.FindStringSubmatch(str) if len(strs) < 4 { return image.ZR, err } var w, h int var strconvErr error if strs[1] != "" { w, strconvErr = strconv.Atoi(strs[1]) if strconvErr != nil { return image.ZR, err } } if strs[3] != "" { h, strconvErr = strconv.Atoi(strs[3]) if strconvErr != nil { return image.ZR, err } } if strs[2] != "x" { // w was the only dimension given, so set it to the greater dimension // of the actual image size if actual.Dx() > actual.Dy() { h = 0 } else { h = w w = 0 } } return image.Rect(0, 0, w, h), nil } func removeExtension(name string) string { ext := path.Ext(name) return name[:len(name)-len(ext)] }