refactor: prepare the ground for watch command

utils/file_utils.go

@@ -0,0 +1,12 @@
+package utils
+
+import "os"
+
+// IsValidFolder checks if the provided path is a valid directory
+func IsValidFolder(path string) bool {
+	info, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+	return info.IsDir()
+}

utils/optimize.go

@@ -0,0 +1,47 @@
+package utils
+
+import (
+	"fmt"
+	"github.com/belphemur/CBZOptimizer/cbz"
+	"github.com/belphemur/CBZOptimizer/converter"
+	"strings"
+)
+
+// Optimize optimizes a CBZ file using the specified converter.
+func Optimize(chapterConverter converter.Converter, path string, quality uint8, override bool) error {
+	fmt.Printf("Processing file: %s\n", path)
+
+	// Load the chapter
+	chapter, err := cbz.LoadChapter(path)
+	if err != nil {
+		return fmt.Errorf("failed to load chapter: %v", err)
+	}
+
+	if chapter.IsConverted {
+		fmt.Printf("Chapter already converted: %s\n", path)
+		return nil
+	}
+
+	// Convert the chapter
+	convertedChapter, err := chapterConverter.ConvertChapter(chapter, quality, func(msg string) {
+		fmt.Println(msg)
+	})
+	if err != nil {
+		return fmt.Errorf("failed to convert chapter: %v", err)
+	}
+	convertedChapter.SetConverted()
+
+	// Write the converted chapter back to a CBZ file
+	outputPath := path
+	if !override {
+		outputPath = strings.TrimSuffix(path, ".cbz") + "_converted.cbz"
+	}
+	err = cbz.WriteChapterToCBZ(convertedChapter, outputPath)
+	if err != nil {
+		return fmt.Errorf("failed to write converted chapter: %v", err)
+	}
+
+	fmt.Printf("Converted file written to: %s\n", outputPath)
+	return nil
+
+}