store: refactor playlist BeforeSave Error handling

api/v1/utils.go

@@ -48,6 +48,8 @@ func statusCodeFromError(err error) (code int, response ErrorResponse) {
 		response.Detail = err
 	case store.ErrInvalidMetadataField:
 		code = http.StatusBadRequest
+	case store.ErrInvalidPlaylistEntry:
+		code = http.StatusBadRequest
 	case *importer.JobSourceResult:
 		response.Detail = err.(*importer.JobSourceResult).Log
 	default:

store/playlists.go

@@ -33,29 +33,36 @@ import (
 	"github.com/jinzhu/gorm"
 )
 
+func generateFileURI(file *File) string {
+	uri := url.URL{Scheme: FileURIScheme, Host: file.ShowName, Path: strconv.FormatUint(file.ID, 10)}
+	return uri.String()
+}
+
 func (p *Playlist) BeforeSave() error {
 	for idx := range p.Entries {
 		p.Entries[idx].LineNum = uint(idx)
 		if p.Entries[idx].File != nil {
-			p.Entries[idx].URI = "" // this will be regenerated in AfterFind()
+			if p.Entries[idx].URI != "" && p.Entries[idx].URI != generateFileURI(p.Entries[idx].File) {
+				return ErrInvalidPlaylistEntry{idx, "File and Uri Parameter mismatch"}
+			}
 		} else if p.Entries[idx].URI != "" {
 			uri, err := url.Parse(p.Entries[idx].URI)
 			if err != nil {
-				return fmt.Errorf("playlist entry #%d is invalid: %v", idx, err)
+				return ErrInvalidPlaylistEntry{idx, err.Error()}
 			}
 			if uri.Scheme == FileURIScheme {
 				if uri.Host == "" || uri.Path == "" {
-					return fmt.Errorf("playlist entry #%d is invalid: uri must be in the format %s://<show>/<file-id>", idx, FileURIScheme)
+					return ErrInvalidPlaylistEntry{idx, "uri must be in the format " + FileURIScheme + "://<show>/<file-id>"}
 				}
 				fileID, err := strconv.ParseUint(strings.TrimPrefix(uri.Path, "/"), 10, 64)
 				if err != nil {
-					return fmt.Errorf("playlist entry #%d is invalid: %v", idx, err)
+					return ErrInvalidPlaylistEntry{idx, err.Error()}
 				}
 				p.Entries[idx].File = &File{ID: fileID, ShowName: uri.Host}
 				p.Entries[idx].URI = "" // this will be regenerated in AfterFind()
 			}
 		} else {
-			return fmt.Errorf("playlist entry #%d is invalid, entries must either contain a File or have a URI set", idx)
+			return ErrInvalidPlaylistEntry{idx, "entries must either contain a File or have a URI set"}
 		}
 	}
 	return nil
@@ -68,10 +75,7 @@ func (p *Playlist) AfterSave(tx *gorm.DB) error {
 func (p *Playlist) AfterFind() error {
 	for idx := range p.Entries {
 		if p.Entries[idx].File != nil {
-			urihost := p.Entries[idx].File.ShowName
-			uripath := strconv.FormatUint(p.Entries[idx].File.ID, 10)
-			uri := url.URL{Scheme: FileURIScheme, Host: urihost, Path: uripath}
-			p.Entries[idx].URI = uri.String()
+			p.Entries[idx].URI = generateFileURI(p.Entries[idx].File)
 		}
 	}
 	return nil

store/types.go

@@ -64,6 +64,15 @@ func (e ErrInvalidMetadataField) Error() string {
 	return "invalid metadata field: " + string(e)
 }
 
+type ErrInvalidPlaylistEntry struct {
+	idx     int
+	message string
+}
+
+func (e ErrInvalidPlaylistEntry) Error() string {
+	return fmt.Sprintf("playlist entry #%d is invalid: %s", e.idx, e.message)
+}
+
 //******* Logs
 
 type LogLine struct {