feat: allow to specify output dir; process dir recursively

main.go

@@ -10,13 +10,19 @@ import (
 	flag "github.com/spf13/pflag"
 )
 
-func processFile(filePath string) error {
+func processFile(filePath string, outputDir string) error {
+	// skip if the extension is not .ncm
+	if filePath[len(filePath)-4:] != ".ncm" {
+		return nil
+	}
+
+	// process the file
 	currentFile, err := ncmcrypt.NewNeteaseCloudMusic(filePath)
 	if err != nil {
 		utils.ErrorPrintfln("Reading '%s' failed: %s", filePath, err.Error())
 		return err
 	}
-	dump, err := currentFile.Dump(filepath.Dir(filePath))
+	dump, err := currentFile.Dump(outputDir)
 	if err != nil {
 		utils.ErrorPrintfln("Processing '%s' failed: %s", filePath, err.Error())
 		return err
@@ -33,10 +39,13 @@ func processFile(filePath string) error {
 }
 
 func main() {
-	var folderPath string
+	var sourceDir string
+	var outputDir string
 	showHelp := flag.BoolP("help", "h", false, "Display help message")
 	showVersion := flag.BoolP("version", "v", false, "Display version information")
-	flag.StringVarP(&folderPath, "dir", "d", "", "Process all files in the directory")
+	processRecursive := flag.BoolP("recursive", "r", false, "Process all files in the directory recursively")
+	flag.StringVarP(&outputDir, "output", "o", "", "Output directory for the dump files")
+	flag.StringVarP(&sourceDir, "dir", "d", "", "Process all files in the directory")
 	flag.Parse()
 
 	if len(os.Args) == 1 {
@@ -54,51 +63,82 @@ func main() {
 		os.Exit(0)
 	}
 
-	if folderPath != "" {
-		// check if the folder exists
-		info, err := os.Stat(folderPath)
-		if err != nil {
-			utils.ErrorPrintfln("Unable to access directory: '%s'", folderPath)
-			os.Exit(1)
-		}
+	if !flag.Lookup("dir").Changed && sourceDir == "" && len(flag.Args()) == 0 {
+		flag.Usage()
+		os.Exit(1)
+	}
 
-		if !info.IsDir() {
-			utils.ErrorPrintfln("Not a directory: %s", folderPath)
-			os.Exit(1)
-		}
+	if flag.Lookup("recursive").Changed && !flag.Lookup("dir").Changed {
+		utils.ErrorPrintfln("The -r option can only be used with the -d option")
+		os.Exit(1)
+	}
 
-		// dump files in the folder
-		files, err := os.ReadDir(folderPath)
-		if err != nil {
-			utils.ErrorPrintfln("Unable to read directory: '%s'", folderPath)
-			os.Exit(1)
-		}
+	outputDirSpecified := flag.Lookup("output").Changed
 
-		for _, file := range files {
-			if file.IsDir() {
-				continue
+	if outputDirSpecified {
+		if utils.PathExists(outputDir) {
+			if !utils.IsDir(outputDir) {
+				utils.ErrorPrintfln("Output directory '%s' is not valid.", outputDir)
+				os.Exit(1)
 			}
+		} else {
+			_ = os.MkdirAll(outputDir, os.ModePerm)
+		}
+	}
 
-			filePath := filepath.Join(folderPath, file.Name())
-			// skip if the extension is not .ncm
-			if filePath[len(filePath)-4:] != ".ncm" {
-				continue
-			}
-			err = processFile(filePath)
+	if sourceDir != "" {
+		if !utils.IsDir(sourceDir) {
+			utils.ErrorPrintfln("The source directory '%s' is not valid.", sourceDir)
+			os.Exit(1)
+		}
+
+		if *processRecursive {
+			_ = filepath.WalkDir(sourceDir, func(p string, d os.DirEntry, err_ error) error {
+				if !outputDirSpecified {
+					outputDir = sourceDir
+				}
+				relativePath := utils.GetRelativePath(sourceDir, p)
+				destinationPath := filepath.Join(outputDir, relativePath)
+
+				if utils.IsRegularFile(p) {
+					parentDir := filepath.Dir(destinationPath)
+					_ = os.MkdirAll(parentDir, os.ModePerm)
+					_ = processFile(p, parentDir)
+				}
+				return nil
+			})
+		} else {
+			// dump files in the folder
+			files, err := os.ReadDir(sourceDir)
 			if err != nil {
-				continue
+				utils.ErrorPrintfln("Unable to read directory: '%s'", sourceDir)
+				os.Exit(1)
+			}
+
+			for _, file := range files {
+				if file.IsDir() {
+					continue
+				}
+
+				filePath := filepath.Join(sourceDir, file.Name())
+				if outputDirSpecified {
+					_ = processFile(filePath, outputDir)
+				} else {
+					_ = processFile(filePath, sourceDir)
+				}
 			}
 		}
 	} else {
-		// dump file from args
+		// process files from args
 		for _, filePath := range flag.Args() {
 			// skip if the extension is not .ncm
 			if filePath[len(filePath)-4:] != ".ncm" {
 				continue
 			}
-			err := processFile(filePath)
-			if err != nil {
-				continue
+			if outputDirSpecified {
+				_ = processFile(filePath, outputDir)
+			} else {
+				_ = processFile(filePath, sourceDir)
 			}
 		}
 	}

utils/file.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"os"
 	"path/filepath"
 	"strings"
 )
@@ -9,3 +10,39 @@ func ReplaceExtension(filepathStr, newExt string) string {
 	ext := filepath.Ext(filepathStr)
 	return strings.TrimSuffix(filepathStr, ext) + newExt
 }
+
+func PathExists(path string) bool {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true
+	}
+	if os.IsNotExist(err) {
+		return false
+	}
+	return false
+}
+
+func IsDir(path string) bool {
+	s, err := os.Stat(path)
+	if err != nil {
+
+		return false
+	}
+	return s.IsDir()
+}
+
+func GetRelativePath(from, to string) string {
+	rel, err := filepath.Rel(from, to)
+	if err != nil {
+		return ""
+	}
+	return rel
+}
+
+func IsRegularFile(path string) bool {
+	s, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+	return s.Mode().IsRegular()
+}