MangaConverter.cs

using Extensions;
using System;
using System.IO;
using System.IO.Compression;
using System.Linq;

namespace unicon {
    class MangaConverter : IConverter {

        readonly FileInfo[] fileInfos;

        string OutputFileExtension { get; } = ".zip";

        public MangaConverter(string path) {
            //scan
            DirectoryInfo di = new(path);
            fileInfos = di.EnumerateFiles("*.*", SearchOption.AllDirectories).ToArray();
        }
        public void Convert() {
            if (!fileInfos.Any()) return;

            long deltaSum = 0;
            for (int i = 0; i < fileInfos.Length; i++) {

                Console.WriteLine($"Processing {fileInfos[i].Name} ... {i} of {fileInfos.Length}");

                Console.WriteLine("step 1 : extract");


                string inFile = fileInfos[i].FullName;
                string outFile = Path.ChangeExtension(inFile, OutputFileExtension);
                string tmpDir = "$TMP";
                string tmpFile = Path.ChangeExtension(tmpDir, OutputFileExtension);

                if (Directory.Exists(tmpDir)) throw new IOException($"{tmpDir} exsists");
                if (File.Exists(tmpFile)) throw new IOException($"{tmpFile} exsists");

                ZipFile.ExtractToDirectory(inFile, tmpDir);



                Console.WriteLine("step 2 : optimize");

                //optimize
                Preset[] presets = new Preset[] { new MozjpegPreset(), new CwebpPreset() };
                new GeneralFileConverter(presets, tmpDir).Convert();

                //repack
                Console.WriteLine("step 3 : compress");
                ZipFile.CreateFromDirectory(tmpDir, tmpFile);
                Directory.Delete(tmpDir, true);

                //replace
                Console.WriteLine("step 4 : replace");
                FileInfo fi = new(inFile);
                FileInfo fi_out = new(tmpFile);

                long old_size = fi.Length;
                long new_size = fi_out.Length;

                fi.IsReadOnly = false;
                fi.Delete();
                fi_out.MoveTo(outFile);
                fi_out.IsReadOnly = true;

                long delta = old_size - new_size;
                deltaSum += delta;
                Console.WriteLine($"done ... {delta.ToSizeSuffix()} decresead\n");

            }

            Console.WriteLine($"\ncomplete!\n{fileInfos.Length} files processed\n{deltaSum.ToSizeSuffix()} decreased");
        }
    }
}