flake: use enum for mode option

README.md

@@ -30,7 +30,8 @@ sudo cp ${GOPATH}/bin/photocatalog /usr/local/bin/photocatalog
 The tool supports the following organization modes:
 
 - **copy** — Copies files to the target directory. If the filesystem supports it, uses Copy-on-Write (COW) for efficiency (via FICLONE ioctl call).
-- **hardlink** — Creates hardlinks to the source files, saving disk space. Ideal if the source and target are on the same partition, though file permissions remain linked to the original.
+- **hardlink** — Creates hardlinks to the source files, saving disk space. Ideal (and usable only) if the source and target are on the same partition, 
+though file permissions remain linked to the original. Fallback to copy on fail.
 - **move** — Moves files from the source to the target directory.
 - **symlink** — Creates symbolic links at the target pointing to the source files.
 

application/application.go

@@ -43,24 +43,24 @@ func (a *Application) Start(ctx context.Context, wg *sync.WaitGroup) error {
 		WithDirMode(os.FileMode(a.config.DirMode)).
 		WithFileMode(os.FileMode(a.config.FileMode)).
 		WithErrLogger(func(err error) {
-			log.Println(err)
+			log.Println("ERROR:", err.Error())
 		})
 
 	if a.config.Overwrite {
 		org = org.WithOverwrite()
 	}
 
-	if !a.config.SkipFullSync {
-		if err := org.FullSync(ctx); err != nil {
-			return fmt.Errorf("full sync: %w", err)
-		}
-	}
-
 	if a.config.Watch {
 		if err := org.Watch(ctx, wg); err != nil {
 			return fmt.Errorf("initialize watch: %w", err)
 		}
 	}
 
+	if !a.config.SkipFullSync {
+		if err := org.FullSync(ctx); err != nil {
+			return fmt.Errorf("full sync: %w", err)
+		}
+	}
+
 	return nil
 }

application/config.go

@@ -14,6 +14,8 @@ const (
 	ModeMove     Mode = "move"
 )
 
+var SupportedModes = []Mode{ModeHardlink, ModeSymlink, ModeMove, ModeCopy}
+
 type Config struct {
 	SourceDir    string
 	TargetDir    string
@@ -34,8 +36,8 @@ func (c *Config) Validate() error {
 		return fmt.Errorf("target dir is required")
 	}
 
-	if !slices.Contains([]Mode{ModeHardlink, ModeSymlink, ModeMove, ModeCopy}, c.Mode) {
+	if !slices.Contains(SupportedModes, c.Mode) {
-		return fmt.Errorf("invalid mode %s", c.Mode)
+		return fmt.Errorf("invalid mode %s, supported modes: %s", c.Mode, SupportedModes)
 	}
 
 	if c.SkipFullSync && !c.Watch {

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1736061677,
+        "narHash": "sha256-DjkQPnkAfd7eB522PwnkGhOMuT9QVCZspDpJJYyOj60=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "cbd8ec4de4469333c82ff40d057350c30e9f7d36",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-24.11",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,128 @@
+{
+  description = "Photo/video organization tool";
+
+  inputs.nixpkgs.url = "nixpkgs/nixos-24.11";
+
+  outputs = { self, nixpkgs }:
+    let
+      lastModifiedDate = self.lastModifiedDate or self.lastModified or "19700101";
+      version = "2.0.4";
+      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+    in
+    {
+      packages = forAllSystems (system:
+        let
+          pkgs = nixpkgsFor.${system};
+        in
+        {
+          photocatalog = pkgs.buildGoModule {
+            pname = "photocatalog";
+            inherit version;
+            src = ./.;
+            vendorHash = "sha256-dj11SRRoB8ZbkcQs75HPI0DpW4c5jzY0N8MD1wKpw+4=";
+          };
+        }
+      );
+
+      nixosModules.photocatalog = { config, lib, pkgs, ... }:
+        with lib;
+      {
+        options.photocatalog = {
+          enable = lib.mkEnableOption "Enable photocatalog";
+
+          syncs = mkOption {
+            default = {};
+            description = ''
+              Organization paths with its own params.
+            '';
+            example = {
+
+            };
+            type = types.attrsOf (types.submodule ({ name, ... }: {
+              options = {
+                source = mkOption {
+                  type = types.str;
+                  default = name;
+                  description = ''
+                    Source folder path.
+                  '';
+                };
+                target = mkOption {
+                  type = types.str;
+                  description = ''
+                    Target folder path.
+                  '';
+                };
+                overwrite = mkOption {
+                  type = types.bool;
+                  default = false;
+                  description = ''
+                    Overwrite files, existing in target.
+                  '';
+                };
+                watch = mkOption {
+                  type = types.bool;
+                  default = true;
+                  description = ''
+                    Watch for new files in source path.
+                  '';
+                };
+                skipFullSync = mkOption {
+                  type = types.bool;
+                  default = false;
+                  description = ''
+                    Do not make full sync.
+                  '';
+                };
+                mode = mkOption {
+                  type = types.enum [ "hardlink" "symlink" "move" "copy" ];
+                  default = "hardlink";
+                  description = ''
+                    Organization mode, one of [ hardlink symlink move copy ].
+                  '';
+                };
+              };
+            }));
+          };
+        };
+
+        config = lib.mkIf config.photocatalog.enable {
+          environment.systemPackages = [ self.packages.${pkgs.system}.photocatalog ];
+          systemd.user.services = lib.mapAttrs' (name: sync: nameValuePair
+            ("photocatalog${lib.replaceStrings ["/"] ["-"] sync.source}")
+            {
+                after = [ "local-fs.target" ];
+                path = [
+                  self.packages.${pkgs.system}.photocatalog
+                ];
+                wantedBy = [
+                  "default.target"
+                ];
+                preStart = if !sync.skipFullSync then (''
+                  mkdir -p ${sync.target}
+                  photocatalog -source ${sync.source} -target ${sync.target} -mode ${sync.mode} ${if sync.overwrite then "-overwrite" else ""}
+                '') else null;
+                script = "photocatalog -source ${sync.source} -target ${sync.target} -skip-full-sync -watch -mode ${sync.mode} ${if sync.overwrite then "-overwrite" else ""}";
+                serviceConfig = {
+                  Type="simple";
+                  Restart="no";
+                };
+            }
+          ) config.photocatalog.syncs;
+        };
+      };
+
+      devShells = forAllSystems (system:
+        let
+          pkgs = nixpkgsFor.${system};
+        in
+        {
+          default = pkgs.mkShell {
+            buildInputs = with pkgs; [ go gopls gotools go-tools ];
+          };
+        });
+      defaultPackage = forAllSystems (system: self.packages.${system}.photocatalog);
+    };
+}

init/systemd/photocatalog.service

@@ -7,5 +7,5 @@ WantedBy=default.target
 [Service]
 Type=simple
 EnvironmentFile=/home/%u/.config/photocatalog
-ExecStart=photocatalog -mode $MODE -target $TARGET -monitor $MONITOR -update_mtime $UPDATECTIME
+ExecStart=photocatalog -mode $MODE -target $TARGET -watch -source $MONITOR -skip-full-sync
-ExecStartPre=photocatalog -mode $MODE -target $TARGET ${MONITOR}
+ExecStartPre=photocatalog -mode $MODE -target $TARGET -source ${MONITOR}

internal/organizer/modes/hardlink.go

@@ -1,21 +1,38 @@
 package modes
 
 import (
-	"fmt"
+	"log"
 	"os"
+	"sync/atomic"
 )
 
+var hardLinkNotSupported = atomic.Bool{}
+
 type HardLink struct {
 }
 
 func (h HardLink) PlaceIt(sourcePath, targetPath string, mode os.FileMode) error {
+	if hardLinkNotSupported.Load() {
+		return h.fallBack(sourcePath, targetPath, mode)
+	}
+
 	if err := os.Link(sourcePath, targetPath); err != nil {
 		if os.IsExist(err) {
 			return nil
 		}
 
-		return fmt.Errorf("create hard link: %w", err)
+		log.Println("Create hardlink failed:", err.Error())
+		hardLinkNotSupported.Store(true)
+
+		return h.fallBack(sourcePath, targetPath, mode)
 	}
 
 	return nil
 }
+
+func (h HardLink) fallBack(sourcePath string, targetPath string, mode os.FileMode) error {
+	if copyErr := (Copy{}).PlaceIt(sourcePath, targetPath, mode); copyErr != nil {
+		return copyErr
+	}
+	return nil
+}

internal/organizer/organizer.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"syscall"
 
 	"github.com/fsnotify/fsnotify"
 
@@ -18,7 +19,7 @@ import (
 )
 
 const (
-	defaultDirMode  = 0o777
+	defaultDirMode  = 0o774
 	defaultFileMode = 0o644
 )
 
@@ -130,6 +131,8 @@ func (o *Organizer) Watch(ctx context.Context, wg *sync.WaitGroup) error {
 		if err := watcher.Close(); err != nil {
 			o.logErr(fmt.Errorf("close watcher: %w", err))
 		}
+
+		syscall.Sync()
 	}()
 
 	go func() {
@@ -149,15 +152,17 @@ func (o *Organizer) Watch(ctx context.Context, wg *sync.WaitGroup) error {
 					// Add new directories to the watcher.
 					if stat.IsDir() {
 						if err := watcher.Add(event.Name); err != nil {
-							o.logErr(fmt.Errorf("watch dir: %w", err))
+							o.logErr(fmt.Errorf("add the directory %s to watcher: %w", event.Name, err))
 						}
 
 						continue
 					}
 
-					if err := o.processFile(event.Name); err != nil {
+					go func() {
-						o.logErr(fmt.Errorf("process file %s: %w", event.Name, err))
+						if err := o.processFile(event.Name); err != nil {
-					}
+							o.logErr(fmt.Errorf("process file %s: %w", event.Name, err))
+						}
+					}()
 				}
 
 			case <-ctx.Done():
@@ -248,7 +253,7 @@ func (o *Organizer) processFile(sourcePath string) error {
 		return fmt.Errorf("build target path: %w", err)
 	}
 
-	if pathExists(targetPath) && !o.overwrite {
+	if o.pathExists(targetPath) && !o.overwrite {
 		return nil
 	}
 
@@ -283,7 +288,7 @@ func (o *Organizer) BuildTargetPath(sourcePath string, meta metadata.Metadata) (
 }
 
 func (o *Organizer) ensureTargetPath(targetPath string) error {
-	if pathExists(targetPath) {
+	if o.pathExists(targetPath) {
 		return nil
 	}
 
@@ -297,21 +302,27 @@ func (o *Organizer) ensureTargetPath(targetPath string) error {
 	for _, part := range strings.Split(relPath, string(filepath.Separator)) {
 		dir = filepath.Join(dir, part)
 
-		if err := os.Mkdir(dir, o.dirMode); err != nil && !os.IsExist(err) {
+		if err := os.Mkdir(dir, os.ModePerm); err != nil && !os.IsExist(err) {
 			return fmt.Errorf("create target directory path at %s: %w", dir, err)
 		}
+
+		if err := os.Chmod(dir, os.ModePerm&o.dirMode); err != nil {
+			return fmt.Errorf("chmod directory %s: %w", dir, err)
+		}
 	}
 
 	return nil
 }
 
-func pathExists(path string) bool {
+func (o *Organizer) pathExists(path string) bool {
 	_, err := os.Stat(path)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return false
 		}
 
+		o.logErr(fmt.Errorf("pathExists stat %s: %w", path, err))
+
 		return true
 	}
 

main.go

@@ -3,8 +3,10 @@ package main
 import (
 	"context"
 	"flag"
+	"fmt"
 	"log"
 	"os/signal"
+	"slices"
 	"strconv"
 	"sync"
 	"syscall"
@@ -33,42 +35,61 @@ func main() {
 }
 
 func loadCfg() application.Config {
-	cfg := application.Config{}
+	cfg := application.Config{
+		DirMode:  0774,
+		FileMode: 0644,
+	}
 
 	flag.StringVar(&cfg.SourceDir, "source", "", "Source directory")
 	flag.StringVar(&cfg.TargetDir, "target", "", "Target directory")
 	flag.BoolVar(&cfg.Overwrite, "overwrite", false, "Overwrite existing files")
-	flag.BoolVar(&cfg.Watch, "watch", true, "Watch for changes in the source directory")
+	flag.BoolVar(&cfg.Watch, "watch", false, "Watch for changes in the source directory")
+	flag.BoolVar(&cfg.Watch, "monitor", false, "Watch for changes in the source directory") // Legacy option
 	flag.BoolVar(&cfg.SkipFullSync, "skip-full-sync", false, "Skip full sync at startup")
 
-	var (
+	flag.Func("dir-mode", "Mode bits for directories can be created while syncing", func(s string) error {
-		dirMode  string
+		var err error
-		fileMode string
-		mode     string
-	)
 
-	flag.StringVar(&dirMode, "dir-mode", "0777", "Mode bits for directories can be created while syncing")
+		cfg.DirMode, err = strconv.ParseUint(s, 8, 32)
-	flag.StringVar(&fileMode, "file-mode", "0644", "Mode bits for files created while syncing (not applicable for hardlink mode)")
+		if err != nil {
-	flag.StringVar(&mode, "mode", "hardlink", "Organizing mode")
+			return err
+		}
+
+		return nil
+	})
+
+	flag.Func("file-mode", "Mode bits for files created while syncing (not applicable for hardlink mode)", func(s string) error {
+		var err error
+
+		cfg.FileMode, err = strconv.ParseUint(s, 8, 32)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+
+	flag.Func("mode", "Organizing mode", func(s string) error {
+		if s == "" {
+			cfg.Mode = application.ModeHardlink
+		}
+
+		cfg.Mode = application.Mode(s)
+
+		if !slices.Contains(application.SupportedModes, cfg.Mode) {
+			return fmt.Errorf("invalid mode, supported modes: %s", application.SupportedModes)
+		}
+
+		return nil
+	})
 
 	flag.Parse()
 
-	cfg.Mode = application.Mode(mode)
+	// Legacy fallback
+	if cfg.SourceDir == "" {
+		log.Println("Source directory not specified. May be using old systemd unit file.")
 
-	var err error
+		cfg.SourceDir = flag.Arg(0)
-
-	cfg.DirMode, err = strconv.ParseUint(dirMode, 8, 32)
-	if err != nil {
-		log.Println("Parse -dir-mode failed:", err)
-
-		cfg.DirMode = 0o777
-	}
-
-	cfg.FileMode, err = strconv.ParseUint(fileMode, 8, 32)
-	if err != nil {
-		log.Println("Parse -file-mode failed:", err)
-
-		cfg.DirMode = 0o644
 	}
 
 	return cfg