Full application rewrite

application/config.go

@@ -0,0 +1,41 @@
+package application
+
+import (
+	"fmt"
+	"slices"
+)
+
+type Mode string
+
+const (
+	ModeCopy     Mode = "copy"
+	ModeHardlink Mode = "hardlink"
+	ModeSymlink  Mode = "symlink"
+	ModeMove     Mode = "move"
+)
+
+type Config struct {
+	SourceDir string
+	TargetDir string
+	Mode      Mode
+	Overwrite bool
+	DirMode   uint64
+	FileMode  uint64
+	Watch     bool
+}
+
+func (c *Config) Validate() error {
+	if c.SourceDir == "" {
+		return fmt.Errorf("source dir is required")
+	}
+
+	if c.TargetDir == "" {
+		return fmt.Errorf("target dir is required")
+	}
+
+	if !slices.Contains([]Mode{ModeHardlink, ModeSymlink, ModeMove, ModeSymlink}, c.Mode) {
+		return fmt.Errorf("invalid mode %s", c.Mode)
+	}
+
+	return nil
+}