package filesystem import ( "crypto/rand" "fmt" "io" "os" "path/filepath" "regexp" "strconv" "strings" "github.com/knadh/listmonk/internal/media" ) const tmpFilePrefix = "listmonk" // Opts represents filesystem params type Opts struct { UploadPath string `koanf:"upload_path"` UploadURI string `koanf:"upload_uri"` } // Client implements `media.Store` type Client struct { opts Opts } // NewDiskStore initialises store for Filesystem provider. func NewDiskStore(opts Opts) (media.Store, error) { return &Client{ opts: opts, }, nil } // Put accepts the filename, the content type and file object itself and stores the file in disk. func (e *Client) Put(filename string, cType string, src io.ReadSeeker) (string, error) { var out *os.File // There's no explicit name. Use the one posted in the HTTP request. if filename == "" { filename = strings.TrimSpace(filename) if filename == "" { filename, _ = generateRandomString(10) } } // Get the directory path dir := getDir(e.opts.UploadPath) filename = assertUniqueFilename(dir, filename) o, err := os.OpenFile(filepath.Join(dir, filename), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0664) if err != nil { return "", err } out = o defer out.Close() if _, err := io.Copy(out, src); err != nil { return "", err } return filename, nil } // Get accepts a filename and retrieves the full path from disk. func (e *Client) Get(name string) string { return fmt.Sprintf("%s/%s", e.opts.UploadURI, name) } // Delete accepts a filename and removes it from disk. func (e *Client) Delete(file string) error { dir := getDir(e.opts.UploadPath) err := os.Remove(filepath.Join(dir, file)) if err != nil { return err } return nil } // This matches filenames, sans extensions, of the format // filename_(number). The number is incremented in case // new file uploads conflict with existing filenames // on the filesystem. var fnameRegexp = regexp.MustCompile(`(.+?)_([0-9]+)$`) // assertUniqueFilename takes a file path and check if it exists on the disk. If it doesn't, // it returns the same name and if it does, it adds a small random hash to the filename // and returns that. func assertUniqueFilename(dir, fileName string) string { var ( ext = filepath.Ext(fileName) base = fileName[0 : len(fileName)-len(ext)] num = 0 ) for { // There's no name conflict. if _, err := os.Stat(filepath.Join(dir, fileName)); os.IsNotExist(err) { return fileName } // Does the name match the _(num) syntax? r := fnameRegexp.FindAllStringSubmatch(fileName, -1) if len(r) == 1 && len(r[0]) == 3 { num, _ = strconv.Atoi(r[0][2]) } num++ fileName = fmt.Sprintf("%s_%d%s", base, num, ext) } } // generateRandomString generates a cryptographically random, alphanumeric string of length n. func generateRandomString(n int) (string, error) { const dictionary = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" var bytes = make([]byte, n) if _, err := rand.Read(bytes); err != nil { return "", err } for k, v := range bytes { bytes[k] = dictionary[v%byte(len(dictionary))] } return string(bytes), nil } // getDir returns the current working directory path if no directory is specified, // else returns the directory path specified itself. func getDir(dir string) string { if dir == "" { dir, _ = os.Getwd() } return dir }