From 0c4aa86f853702b5956ba31d4da5b38b9f47ff4c Mon Sep 17 00:00:00 2001
From: Michael Mayer <michael@photoprism.app>
Date: Tue, 14 Feb 2023 11:37:22 +0100
Subject: [PATCH] CLI: Create thumbs and convert files in deterministic order
 #3194

This also adds support for specifying a path to the thumbs command.

Signed-off-by: Michael Mayer <michael@photoprism.app>
---
 internal/api/import.go                |  2 +-
 internal/commands/backup.go           |  2 +-
 internal/commands/cleanup.go          |  2 +-
 internal/commands/convert.go          |  4 +-
 internal/commands/copy.go             |  2 +-
 internal/commands/faces.go            |  4 +-
 internal/commands/import.go           |  2 +-
 internal/commands/index.go            |  2 +-
 internal/commands/moments.go          |  2 +-
 internal/commands/optimize.go         |  2 +-
 internal/commands/places.go           |  2 +-
 internal/commands/purge.go            |  2 +-
 internal/commands/reset.go            |  2 +-
 internal/commands/restore.go          |  2 +-
 internal/commands/show.go             |  2 +-
 internal/commands/start.go            |  2 +-
 internal/commands/status.go           |  2 +-
 internal/commands/stop.go             |  2 +-
 internal/commands/thumbs.go           | 49 +++++++++++----
 internal/commands/users.go            |  2 +-
 internal/commands/version.go          |  2 +-
 internal/photoprism/convert.go        | 10 +--
 internal/photoprism/import.go         |  2 +-
 internal/photoprism/index.go          |  2 +-
 internal/photoprism/mediafile.go      | 89 +++++++++++++++++++--------
 internal/photoprism/mediafile_test.go |  9 ++-
 internal/photoprism/thumbs.go         | 31 ++++++----
 internal/photoprism/thumbs_test.go    |  2 +-
 internal/query/folders.go             |  2 +-
 pkg/fs/mime.go                        |  4 ++
 30 files changed, 161 insertions(+), 83 deletions(-)

diff --git a/internal/api/import.go b/internal/api/import.go
index 5a3fd7fbd..e44a1e8fc 100644
--- a/internal/api/import.go
+++ b/internal/api/import.go
@@ -57,7 +57,7 @@ func StartImport(router *gin.RouterGroup) {
 		srcFolder := ""
 		importPath := conf.ImportPath()
 
-		// Import from sub-folder?
+		// Import from subfolder?
 		if srcFolder = c.Param("path"); srcFolder != "" && srcFolder != "/" {
 			srcFolder = clean.UserPath(srcFolder)
 		} else if f.Path != "" {
diff --git a/internal/commands/backup.go b/internal/commands/backup.go
index 6075d94f0..295ffb1e7 100644
--- a/internal/commands/backup.go
+++ b/internal/commands/backup.go
@@ -24,7 +24,7 @@ const backupDescription = "A user-defined SQL dump FILENAME or - for stdout can
 	"   Make sure to run the command with exec -T when using Docker to prevent log messages from being sent to stdout.\n" +
 	"   The index backup and album file paths are automatically detected if not specified explicitly."
 
-// BackupCommand configures the backup cli command.
+// BackupCommand configures the command name, flags, and action.
 var BackupCommand = cli.Command{
 	Name:        "backup",
 	Description: backupDescription,
diff --git a/internal/commands/cleanup.go b/internal/commands/cleanup.go
index d43323dff..21fd8d922 100644
--- a/internal/commands/cleanup.go
+++ b/internal/commands/cleanup.go
@@ -11,7 +11,7 @@ import (
 	"github.com/photoprism/photoprism/internal/photoprism"
 )
 
-// CleanUpCommand registers the cleanup command.
+// CleanUpCommand configures the command name, flags, and action.
 var CleanUpCommand = cli.Command{
 	Name:   "cleanup",
 	Usage:  "Removes orphaned index entries, sidecar and thumbnail files",
diff --git a/internal/commands/convert.go b/internal/commands/convert.go
index 3528332b1..b187d271b 100644
--- a/internal/commands/convert.go
+++ b/internal/commands/convert.go
@@ -13,11 +13,11 @@ import (
 	"github.com/photoprism/photoprism/pkg/clean"
 )
 
-// ConvertCommand registers the convert cli command.
+// ConvertCommand configures the command name, flags, and action.
 var ConvertCommand = cli.Command{
 	Name:      "convert",
 	Usage:     "Converts files in other formats to JPEG and AVC as needed",
-	ArgsUsage: "[sub-folder]",
+	ArgsUsage: "[subfolder]",
 	Flags: []cli.Flag{
 		cli.StringSliceFlag{
 			Name:  "ext, e",
diff --git a/internal/commands/copy.go b/internal/commands/copy.go
index d68ad427b..b7089226a 100644
--- a/internal/commands/copy.go
+++ b/internal/commands/copy.go
@@ -15,7 +15,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/clean"
 )
 
-// CopyCommand registers the copy cli command.
+// CopyCommand configures the command name, flags, and action.
 var CopyCommand = cli.Command{
 	Name:      "cp",
 	Aliases:   []string{"copy"},
diff --git a/internal/commands/faces.go b/internal/commands/faces.go
index b27834189..6f8a6df27 100644
--- a/internal/commands/faces.go
+++ b/internal/commands/faces.go
@@ -18,7 +18,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
-// FacesCommand registers the face recognition subcommands.
+// FacesCommand configures the command name, flags, and action.
 var FacesCommand = cli.Command{
 	Name:  "faces",
 	Usage: "Face recognition subcommands",
@@ -53,7 +53,7 @@ var FacesCommand = cli.Command{
 		{
 			Name:      "index",
 			Usage:     "Searches originals for faces",
-			ArgsUsage: "[sub-folder]",
+			ArgsUsage: "[subfolder]",
 			Action:    facesIndexAction,
 		},
 		{
diff --git a/internal/commands/import.go b/internal/commands/import.go
index e1d74e5df..069f754fc 100644
--- a/internal/commands/import.go
+++ b/internal/commands/import.go
@@ -15,7 +15,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/clean"
 )
 
-// ImportCommand registers the import cli command.
+// ImportCommand configures the command name, flags, and action.
 var ImportCommand = cli.Command{
 	Name:      "mv",
 	Aliases:   []string{"import"},
diff --git a/internal/commands/index.go b/internal/commands/index.go
index f766ad7a2..6de43fcc9 100644
--- a/internal/commands/index.go
+++ b/internal/commands/index.go
@@ -19,7 +19,7 @@ import (
 var IndexCommand = cli.Command{
 	Name:      "index",
 	Usage:     "Indexes original media files",
-	ArgsUsage: "[sub-folder]",
+	ArgsUsage: "[subfolder]",
 	Flags:     indexFlags,
 	Action:    indexAction,
 }
diff --git a/internal/commands/moments.go b/internal/commands/moments.go
index a967b4ea5..7565d4ea3 100644
--- a/internal/commands/moments.go
+++ b/internal/commands/moments.go
@@ -9,7 +9,7 @@ import (
 	"github.com/photoprism/photoprism/internal/get"
 )
 
-// MomentsCommand registers the moments command.
+// MomentsCommand configures the command name, flags, and action.
 var MomentsCommand = cli.Command{
 	Name:   "moments",
 	Usage:  "Creates albums of special moments, trips, and places",
diff --git a/internal/commands/optimize.go b/internal/commands/optimize.go
index bcd3815b8..54a7a9013 100644
--- a/internal/commands/optimize.go
+++ b/internal/commands/optimize.go
@@ -10,7 +10,7 @@ import (
 	"github.com/photoprism/photoprism/internal/workers"
 )
 
-// OptimizeCommand registers the index cli command.
+// OptimizeCommand configures the command name, flags, and action.
 var OptimizeCommand = cli.Command{
 	Name:  "optimize",
 	Usage: "Maintains titles, estimates, and other metadata",
diff --git a/internal/commands/places.go b/internal/commands/places.go
index 57f6092e8..f44d400df 100644
--- a/internal/commands/places.go
+++ b/internal/commands/places.go
@@ -13,7 +13,7 @@ import (
 	"github.com/photoprism/photoprism/internal/query"
 )
 
-// PlacesCommand registers the places subcommands.
+// PlacesCommand configures the command name, flags, and action.
 var PlacesCommand = cli.Command{
 	Name:  "places",
 	Usage: "Maps and location details subcommands",
diff --git a/internal/commands/purge.go b/internal/commands/purge.go
index fdffe03fc..cd9cd182e 100644
--- a/internal/commands/purge.go
+++ b/internal/commands/purge.go
@@ -15,7 +15,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
-// PurgeCommand registers the index cli command.
+// PurgeCommand configures the command name, flags, and action.
 var PurgeCommand = cli.Command{
 	Name:   "purge",
 	Usage:  "Updates missing files, photo counts, and album covers",
diff --git a/internal/commands/reset.go b/internal/commands/reset.go
index f9449f537..dea75e12d 100644
--- a/internal/commands/reset.go
+++ b/internal/commands/reset.go
@@ -18,7 +18,7 @@ import (
 	"github.com/photoprism/photoprism/internal/entity"
 )
 
-// ResetCommand resets the index, clears the cache, and removes sidecar files after confirmation.
+// ResetCommand configures the command name, flags, and action.
 var ResetCommand = cli.Command{
 	Name:  "reset",
 	Usage: "Resets the index, clears the cache, and removes sidecar files",
diff --git a/internal/commands/restore.go b/internal/commands/restore.go
index a9b56f2d7..5ff82d6b1 100644
--- a/internal/commands/restore.go
+++ b/internal/commands/restore.go
@@ -26,7 +26,7 @@ const restoreDescription = "A user-defined SQL dump FILENAME can be passed as th
 	"The -i parameter can be omitted in this case.\n" +
 	"   The index backup and album file paths are automatically detected if not specified explicitly."
 
-// RestoreCommand configures the backup cli command.
+// RestoreCommand configures the command name, flags, and action.
 var RestoreCommand = cli.Command{
 	Name:        "restore",
 	Description: restoreDescription,
diff --git a/internal/commands/show.go b/internal/commands/show.go
index b947a43c6..e9d768cac 100644
--- a/internal/commands/show.go
+++ b/internal/commands/show.go
@@ -4,7 +4,7 @@ import (
 	"github.com/urfave/cli"
 )
 
-// ShowCommand registers the show subcommands.
+// ShowCommand configures the show subcommands.
 var ShowCommand = cli.Command{
 	Name:  "show",
 	Usage: "Shows supported formats, features, and config options",
diff --git a/internal/commands/start.go b/internal/commands/start.go
index 0c82d765a..01ac1fd9a 100644
--- a/internal/commands/start.go
+++ b/internal/commands/start.go
@@ -24,7 +24,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
-// StartCommand registers the start cli command.
+// StartCommand configures the command name, flags, and action.
 var StartCommand = cli.Command{
 	Name:    "start",
 	Aliases: []string{"up"},
diff --git a/internal/commands/status.go b/internal/commands/status.go
index 1fa883cc7..f5ffbc031 100644
--- a/internal/commands/status.go
+++ b/internal/commands/status.go
@@ -12,7 +12,7 @@ import (
 	"github.com/photoprism/photoprism/internal/config"
 )
 
-// StatusCommand registers the status command.
+// StatusCommand configures the command name, flags, and action.
 var StatusCommand = cli.Command{
 	Name:   "status",
 	Usage:  "Checks if the Web server is running",
diff --git a/internal/commands/stop.go b/internal/commands/stop.go
index a2f87f966..11fd290ac 100644
--- a/internal/commands/stop.go
+++ b/internal/commands/stop.go
@@ -9,7 +9,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/clean"
 )
 
-// StopCommand registers the stop cli command.
+// StopCommand configures the command name, flags, and action.
 var StopCommand = cli.Command{
 	Name:    "stop",
 	Aliases: []string{"down"},
diff --git a/internal/commands/thumbs.go b/internal/commands/thumbs.go
index b02a065c1..4938779f4 100644
--- a/internal/commands/thumbs.go
+++ b/internal/commands/thumbs.go
@@ -2,6 +2,7 @@ package commands
 
 import (
 	"context"
+	"strings"
 	"time"
 
 	"github.com/urfave/cli"
@@ -10,24 +11,25 @@ import (
 	"github.com/photoprism/photoprism/pkg/clean"
 )
 
-// ThumbsCommand registers the resample cli command.
+// ThumbsCommand configures the command name, flags, and action.
 var ThumbsCommand = cli.Command{
-	Name:  "thumbs",
-	Usage: "Generates thumbnails using the current settings",
+	Name:      "thumbs",
+	Usage:     "Generates thumbnails using the current settings",
+	ArgsUsage: "[subfolder]",
 	Flags: []cli.Flag{
 		cli.BoolFlag{
 			Name:  "force, f",
-			Usage: "replace existing thumbnails",
+			Usage: "replace existing thumbnail files",
 		},
 		cli.BoolFlag{
 			Name:  "originals, o",
-			Usage: "originals only, skip sidecar files",
+			Usage: "scan originals only, skip sidecar folder",
 		},
 	},
 	Action: thumbsAction,
 }
 
-// thumbsAction pre-renders thumbnail images.
+// thumbsAction generates thumbnails using the current settings.
 func thumbsAction(ctx *cli.Context) error {
 	start := time.Now()
 
@@ -43,16 +45,41 @@ func thumbsAction(ctx *cli.Context) error {
 	conf.RegisterDb()
 	defer conf.Shutdown()
 
-	log.Infof("creating thumbs in %s", clean.Log(conf.ThumbCachePath()))
+	dir := strings.TrimSpace(ctx.Args().First())
+	force := ctx.Bool("force")
+	originals := ctx.Bool("originals")
 
-	rs := get.Thumbs()
+	var action, ack string
+	if force {
+		action = "replacing"
+		ack = "replaced"
+	} else {
+		action = "creating"
+		ack = "created"
+	}
 
-	if err := rs.Start(ctx.Bool("force"), ctx.Bool("originals")); err != nil {
-		log.Error(err)
+	// Display info.
+	if dir == "" {
+		if originals {
+			log.Infof("%s thumbnails for originals only", action)
+		} else {
+			log.Infof("%s thumbnails for originals and sidecar files", action)
+		}
+	} else {
+		if originals {
+			log.Infof("%s thumbnails for originals in %s", action, clean.LogQuote(dir))
+		} else {
+			log.Infof("%s thumbnails for originals and sidecar files in %s", action, clean.LogQuote(dir))
+		}
+	}
+
+	w := get.Thumbs()
+
+	if err = w.Start(dir, ctx.Bool("force"), ctx.Bool("originals")); err != nil {
 		return err
 	}
 
-	log.Infof("thumbs created in %s", time.Since(start))
+	log.Infof("thumbnails %s in %s", ack, time.Since(start))
 
 	return nil
 }
diff --git a/internal/commands/users.go b/internal/commands/users.go
index 793d40ae7..f36cd154d 100644
--- a/internal/commands/users.go
+++ b/internal/commands/users.go
@@ -18,7 +18,7 @@ const (
 	UserWebDAVUsage   = "allow to sync files via WebDAV"
 )
 
-// UsersCommand registers the user management subcommands.
+// UsersCommand configures the user management subcommands.
 var UsersCommand = cli.Command{
 	Name:    "users",
 	Aliases: []string{"user"},
diff --git a/internal/commands/version.go b/internal/commands/version.go
index 14791d999..a625817c5 100644
--- a/internal/commands/version.go
+++ b/internal/commands/version.go
@@ -8,7 +8,7 @@ import (
 	"github.com/photoprism/photoprism/internal/config"
 )
 
-// VersionCommand registers the version cli command.
+// VersionCommand configures the command name, flags, and action.
 var VersionCommand = cli.Command{
 	Name:   "version",
 	Usage:  "Shows version information",
diff --git a/internal/photoprism/convert.go b/internal/photoprism/convert.go
index b0a40e64c..fd3dc6c9e 100644
--- a/internal/photoprism/convert.go
+++ b/internal/photoprism/convert.go
@@ -40,7 +40,7 @@ func NewConvert(conf *config.Config) *Convert {
 }
 
 // Start converts all files in a directory to JPEG if possible.
-func (c *Convert) Start(path string, ext []string, force bool) (err error) {
+func (c *Convert) Start(dir string, ext []string, force bool) (err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			err = fmt.Errorf("convert: %s (panic)\nstack: %s", r, debug.Stack())
@@ -48,7 +48,7 @@ func (c *Convert) Start(path string, ext []string, force bool) (err error) {
 		}
 	}()
 
-	if err := mutex.MainWorker.Start(); err != nil {
+	if err = mutex.MainWorker.Start(); err != nil {
 		return err
 	}
 
@@ -70,7 +70,7 @@ func (c *Convert) Start(path string, ext []string, force bool) (err error) {
 	done := make(fs.Done)
 	ignore := fs.NewIgnoreList(fs.IgnoreFile, true, false)
 
-	if err := ignore.Dir(path); err != nil {
+	if err = ignore.Dir(dir); err != nil {
 		log.Infof("convert: %s", err)
 	}
 
@@ -78,7 +78,7 @@ func (c *Convert) Start(path string, ext []string, force bool) (err error) {
 		log.Infof("convert: ignoring %s", clean.Log(filepath.Base(fileName)))
 	}
 
-	err = godirwalk.Walk(path, &godirwalk.Options{
+	err = godirwalk.Walk(dir, &godirwalk.Options{
 		ErrorCallback: func(fileName string, err error) godirwalk.ErrorAction {
 			return godirwalk.SkipNode
 		},
@@ -122,7 +122,7 @@ func (c *Convert) Start(path string, ext []string, force bool) (err error) {
 
 			return nil
 		},
-		Unsorted:            true,
+		Unsorted:            false,
 		FollowSymbolicLinks: true,
 	})
 
diff --git a/internal/photoprism/import.go b/internal/photoprism/import.go
index a784120ef..4c45d0e23 100644
--- a/internal/photoprism/import.go
+++ b/internal/photoprism/import.go
@@ -70,7 +70,7 @@ func (imp *Import) Start(opt ImportOptions) fs.Done {
 
 	// Check if the import folder exists.
 	if !fs.PathExists(importPath) {
-		event.Error(fmt.Sprintf("import: %s does not exist", importPath))
+		event.Error(fmt.Sprintf("import: directory %s not found", importPath))
 		return done
 	}
 
diff --git a/internal/photoprism/index.go b/internal/photoprism/index.go
index feb51998d..3dd90ab0c 100644
--- a/internal/photoprism/index.go
+++ b/internal/photoprism/index.go
@@ -90,7 +90,7 @@ func (ind *Index) Start(o IndexOptions) fs.Done {
 	optionsPath := filepath.Join(originalsPath, o.Path)
 
 	if !fs.PathExists(optionsPath) {
-		event.Error(fmt.Sprintf("%s does not exist", clean.Log(optionsPath)))
+		event.Error(fmt.Sprintf("index: directory %s not found", clean.Log(optionsPath)))
 		return done
 	} else if fs.DirIsEmpty(originalsPath) {
 		event.InfoMsg(i18n.ErrOriginalsEmpty)
diff --git a/internal/photoprism/mediafile.go b/internal/photoprism/mediafile.go
index 84a015756..f452b1e79 100644
--- a/internal/photoprism/mediafile.go
+++ b/internal/photoprism/mediafile.go
@@ -721,53 +721,96 @@ func (m *MediaFile) IsPreviewImage() bool {
 	return m.IsJpeg() || m.IsPng()
 }
 
-// IsJpeg return true if this media file is a JPEG image.
+// IsJpeg checks if the file is a JPEG image with a supported file type extension.
 func (m *MediaFile) IsJpeg() bool {
-	// Don't import/use existing thumbnail files (we create our own)
 	if m.Extension() == fs.ExtTHM {
+		// Ignore .thm files, as some cameras automatically
+		// create them as thumbnails.
+		return false
+	} else if fs.FileType(m.fileName) != fs.ImageJPEG {
+		// Files with an incorrect file extension are no longer
+		// recognized as JPEG to improve indexing performance.
 		return false
 	}
 
+	// Since mime type detection is expensive, it is only
+	// performed after other checks have passed.
 	return m.MimeType() == fs.MimeTypeJpeg
 }
 
-// IsPng returns true if this is a PNG image.
+// IsPng checks if the file is a PNG image with a supported file type extension.
 func (m *MediaFile) IsPng() bool {
+	if fs.FileType(m.fileName) != fs.ImagePNG {
+		// Files with an incorrect file extension are no longer
+		// recognized as PNG to improve indexing performance.
+		return false
+	}
+
+	// Since mime type detection is expensive, it is only
+	// performed after other checks have passed.
 	return m.MimeType() == fs.MimeTypePng
 }
 
-// IsGif returns true if this is a GIF image.
+// IsGif checks if the file is a GIF image with a supported file type extension.
 func (m *MediaFile) IsGif() bool {
+	if fs.FileType(m.fileName) != fs.ImageGIF {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeGif
 }
 
-// IsTiff returns true if this is a TIFF image.
+// IsTiff checks if the file is a TIFF image with a supported file type extension.
 func (m *MediaFile) IsTiff() bool {
-	return m.HasFileType(fs.ImageTIFF) && m.MimeType() == fs.MimeTypeTiff
+	if fs.FileType(m.fileName) != fs.ImageTIFF {
+		return false
+	}
+
+	return m.MimeType() == fs.MimeTypeTiff
 }
 
-// IsDNG returns true if this is a Adobe Digital Negative image.
+// IsDNG checks if the file is a Adobe Digital Negative (DNG) image with a supported file type extension.
 func (m *MediaFile) IsDNG() bool {
+	if fs.FileType(m.fileName) != fs.ImageDNG {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeDNG
 }
 
-// IsHEIC returns true if this is a High Efficiency Image File Format image.
+// IsHEIC checks if the file is a High Efficiency Image File Format (HEIC/HEIF) image with a supported file type extension.
 func (m *MediaFile) IsHEIC() bool {
+	if t := fs.FileType(m.fileName); t != fs.ImageHEIC && t != fs.ImageHEIF {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeHEIC
 }
 
-// IsAVIF returns true if this is an AV1 Image File Format image.
+// IsAVIF checks if the file is an AV1 Image File Format image with a supported file type extension.
 func (m *MediaFile) IsAVIF() bool {
+	if fs.FileType(m.fileName) != fs.ImageAVIF {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeAVIF
 }
 
-// IsBitmap returns true if this is a bitmap image.
+// IsBitmap checks if the file is a bitmap image with a supported file type extension.
 func (m *MediaFile) IsBitmap() bool {
+	if fs.FileType(m.fileName) != fs.ImageBMP {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeBitmap
 }
 
-// IsWebP returns true if this is a WebP image file.
+// IsWebP checks if the file is a WebP image file with a supported file type extension.
 func (m *MediaFile) IsWebP() bool {
+	if fs.FileType(m.fileName) != fs.ImageWebP {
+		return false
+	}
+
 	return m.MimeType() == fs.MimeTypeWebP
 }
 
@@ -780,12 +823,12 @@ func (m *MediaFile) Duration() time.Duration {
 	return m.MetaData().Duration
 }
 
-// IsAnimatedGif returns true if it is an animated GIF.
+// IsAnimatedGif checks if the file is an animated GIF with a supported file type extension.
 func (m *MediaFile) IsAnimatedGif() bool {
 	return m.IsGif() && m.MetaData().Frames > 1
 }
 
-// IsJson return true if this media file is a json sidecar file.
+// IsJson checks if the file is a JSON sidecar file with a supported file type extension.
 func (m *MediaFile) IsJson() bool {
 	return m.HasFileType(fs.SidecarJSON)
 }
@@ -848,7 +891,7 @@ func (m *MediaFile) IsAnimated() bool {
 
 // IsVideo returns true if this is a video file.
 func (m *MediaFile) IsVideo() bool {
-	return strings.HasPrefix(m.MimeType(), "video/") || m.Media() == media.Video
+	return m.HasMediaType(media.Video)
 }
 
 // IsVector returns true if this is a vector graphics.
@@ -863,7 +906,7 @@ func (m *MediaFile) IsSidecar() bool {
 
 // IsSVG returns true if this is a SVG vector graphics.
 func (m *MediaFile) IsSVG() bool {
-	return m.HasFileType(fs.VectorSVG)
+	return m.FileType() == fs.VectorSVG
 }
 
 // IsXMP returns true if this is a XMP sidecar file.
@@ -964,25 +1007,17 @@ func (m *MediaFile) HasPreviewImage() bool {
 
 	jpegName := fs.ImageJPEG.FindFirst(m.FileName(), []string{Config().SidecarPath(), fs.HiddenPath}, Config().OriginalsPath(), false)
 
-	if jpegName == "" {
-		m.hasPreviewImage = false
-	} else {
-		m.hasPreviewImage = fs.MimeType(jpegName) == fs.MimeTypeJpeg
-	}
-
-	if m.hasPreviewImage {
+	if m.hasPreviewImage = fs.MimeType(jpegName) == fs.MimeTypeJpeg; m.hasPreviewImage {
 		return true
 	}
 
 	pngName := fs.ImagePNG.FindFirst(m.FileName(), []string{Config().SidecarPath(), fs.HiddenPath}, Config().OriginalsPath(), false)
 
-	if pngName == "" {
-		m.hasPreviewImage = false
-	} else {
-		m.hasPreviewImage = fs.MimeType(pngName) == fs.MimeTypePng
+	if m.hasPreviewImage = fs.MimeType(pngName) == fs.MimeTypePng; m.hasPreviewImage {
+		return true
 	}
 
-	return m.hasPreviewImage
+	return false
 }
 
 func (m *MediaFile) decodeDimensions() error {
diff --git a/internal/photoprism/mediafile_test.go b/internal/photoprism/mediafile_test.go
index 9da6f2624..c8c76e62a 100644
--- a/internal/photoprism/mediafile_test.go
+++ b/internal/photoprism/mediafile_test.go
@@ -2139,9 +2139,12 @@ func TestMediaFile_FileType(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	assert.True(t, m.IsJpeg())
-	assert.Equal(t, "jpg", string(m.FileType()))
-	assert.Equal(t, fs.ImageJPEG, m.FileType())
+	// No longer recognized as JPEG to improve indexing performance (skips mime type detection).
+	assert.False(t, m.IsJpeg())
+	assert.False(t, m.IsPng())
+	assert.Equal(t, "png", string(m.FileType()))
+	assert.Equal(t, "image/jpeg", m.MimeType())
+	assert.Equal(t, fs.ImagePNG, m.FileType())
 	assert.Equal(t, ".png", m.Extension())
 }
 
diff --git a/internal/photoprism/thumbs.go b/internal/photoprism/thumbs.go
index 0728de8a7..c7edf88c4 100644
--- a/internal/photoprism/thumbs.go
+++ b/internal/photoprism/thumbs.go
@@ -26,8 +26,8 @@ func NewThumbs(conf *config.Config) *Thumbs {
 	return &Thumbs{conf: conf}
 }
 
-// Start creates thumbnail images for all files found in the originals and sidecar folders.
-func (w *Thumbs) Start(force, originalsOnly bool) (err error) {
+// Start creates thumbnails for files in the originals and sidecar folders.
+func (w *Thumbs) Start(dir string, force, originalsOnly bool) (err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			err = fmt.Errorf("thumbs: %s (panic)\nstack: %s", r, debug.Stack())
@@ -36,13 +36,22 @@ func (w *Thumbs) Start(force, originalsOnly bool) (err error) {
 	}()
 
 	originalsPath := w.conf.OriginalsPath()
+	originalsDir := filepath.Join(originalsPath, dir)
 	sidecarPath := w.conf.SidecarPath()
+	sidecarDir := filepath.Join(sidecarPath, dir)
 
-	originalsOnly = originalsOnly || sidecarPath == "" || sidecarPath == originalsPath
+	// Valid path provided?
+	if !fs.PathExists(originalsDir) {
+		return fmt.Errorf("thumbs: directory %s not found", clean.Log(originalsDir))
+	}
 
-	if _, err = w.Dir(originalsPath, force); err != nil || originalsOnly {
+	// Scan sidecar folder?
+	originalsOnly = originalsOnly || sidecarPath == "" || sidecarPath == originalsPath || !fs.PathExists(sidecarDir)
+
+	// Start creating thumbnails.
+	if _, err = w.Dir(originalsDir, force); err != nil || originalsOnly {
 		return err
-	} else if _, err = w.Dir(sidecarPath, force); err != nil {
+	} else if _, err = w.Dir(sidecarDir, force); err != nil {
 		return err
 	}
 
@@ -50,10 +59,10 @@ func (w *Thumbs) Start(force, originalsOnly bool) (err error) {
 }
 
 // Dir creates thumbnail images for files found in a given path.
-func (w *Thumbs) Dir(dir string, force bool) (done fs.Done, err error) {
-	done = make(fs.Done)
+func (w *Thumbs) Dir(dir string, force bool) (fs.Done, error) {
+	done := make(fs.Done)
 
-	if err = mutex.MainWorker.Start(); err != nil {
+	if err := mutex.MainWorker.Start(); err != nil {
 		return done, err
 	}
 
@@ -123,18 +132,18 @@ func (w *Thumbs) Dir(dir string, force bool) (done fs.Done, err error) {
 		return nil
 	}
 
-	log.Infof("thumbs: processing files in %s folder", clean.Log(filepath.Base(dir)))
+	log.Infof("thumbs: processing %s", clean.Log(dir))
 
 	if err := ignore.Dir(dir); err != nil {
 		log.Infof("thumbs: %s", err)
 	}
 
-	err = godirwalk.Walk(dir, &godirwalk.Options{
+	err := godirwalk.Walk(dir, &godirwalk.Options{
 		ErrorCallback: func(fileName string, err error) godirwalk.ErrorAction {
 			return godirwalk.SkipNode
 		},
 		Callback:            handler,
-		Unsorted:            true,
+		Unsorted:            false,
 		FollowSymbolicLinks: true,
 	})
 
diff --git a/internal/photoprism/thumbs_test.go b/internal/photoprism/thumbs_test.go
index 90d94ad36..78b9ef824 100644
--- a/internal/photoprism/thumbs_test.go
+++ b/internal/photoprism/thumbs_test.go
@@ -44,7 +44,7 @@ func TestResample_Start(t *testing.T) {
 
 	rs := NewThumbs(conf)
 
-	err := rs.Start(true, false)
+	err := rs.Start("", true, false)
 
 	if err != nil {
 		t.Fatal(err)
diff --git a/internal/query/folders.go b/internal/query/folders.go
index 68d0c95a8..2b6c32909 100644
--- a/internal/query/folders.go
+++ b/internal/query/folders.go
@@ -9,7 +9,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/media"
 )
 
-// FoldersByPath returns a slice of folders in a given directory incl sub-folders in recursive mode.
+// FoldersByPath returns a slice of folders in a given directory incl subfolders in recursive mode.
 func FoldersByPath(rootName, rootPath, path string, recursive bool) (folders entity.Folders, err error) {
 	dirs, err := fs.Dirs(filepath.Join(rootPath, path), recursive, true)
 
diff --git a/pkg/fs/mime.go b/pkg/fs/mime.go
index 1eb23ad41..098bd143e 100644
--- a/pkg/fs/mime.go
+++ b/pkg/fs/mime.go
@@ -30,6 +30,10 @@ const (
 
 // MimeType returns the mime type of a file, or an empty string if it could not be detected.
 func MimeType(filename string) (mimeType string) {
+	if filename == "" {
+		return MimeTypeUnknown
+	}
+
 	// Workaround for types that cannot be reliably detected.
 	switch Extensions[strings.ToLower(filepath.Ext(filename))] {
 	case ImageDNG: