Radioo_LincleLINK/WPFLinkTool/ViewModel/Commands/MakeHardLinksCommand.cs

using System;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows.Forms;
using static WPFLinkTool.Global;

namespace WPFLinkTool
{
    public class MakeHardLinksCommand : AsyncCommandBase
    {
        private readonly MainWindowViewModel vm;
        private bool delet = false;
        private string target;

        public MakeHardLinksCommand(MainWindowViewModel viewmodel, Action<Exception> onException) : base(onException)
        {
            vm = viewmodel;
        }

        protected override async Task ExecuteAsync(object parameter)
        {
            IsExecuting = true;
            vm.UIEnabled = false;
            vm.LinkButtonEnabled = false;

            var prompt = MessageBox.Show($"Creating hard links from {vm.SelectedInstance.InstanceName}.\nProceed to link target selection?", "Make hard links", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (prompt == DialogResult.Yes)
            {
                FolderBrowserDialog dialog = new();
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    target = dialog.SelectedPath;

                    vm.Loggerr.Log("Checking for duplicates...");

                    bool proceed = await Task.Run(() => CheckDupes());

                    if (delet)
                    {
                        foreach (var file in vm.SelectedInstance.InstanceFiles)
                        {
                            if (File.Exists(target + file.Location + @"\" + file.OriginalFileName))
                            {
                                //vm.Loggerr.Log(@$"Deleting {target + file.Location + @"\" + file.OriginalFileName}");
                                File.Delete(target + file.Location + @"\" + file.OriginalFileName);
                            }
                        }
                    }

                    vm.Loggerr.Log("Linking...");

                    if (proceed)
                    {
                        var uniqueFolders = (from folders in vm.SelectedInstance.InstanceFiles
                                             where folders.Location != string.Empty
                                             select folders.Location).Distinct();

                        double progressStep = 100D / (vm.SelectedInstance.InstanceFiles.Count + uniqueFolders.Count());

                        foreach (var folder in uniqueFolders)
                        {
                            if (!Directory.Exists(target + folder))
                            {
                                //vm.Loggerr.Log($@"Creating directory {target + folder}");
                                await Task.Run(() => Directory.CreateDirectory(target + folder));
                            }
                            vm.Progress += progressStep;
                        }

                        foreach (var file in vm.SelectedInstance.InstanceFiles)
                        {
                            if (!File.Exists(target + file.Location + @"\" + file.OriginalFileName))
                            {
                                //vm.Loggerr.Log($@"Linking {target + file.Location + @"\" + file.OriginalFileName}");
                                await Task.Run(() => CreateHardLink(target + file.Location + @"\" + file.OriginalFileName,
                                    dbDir + @"\" + file.HashedFileName, IntPtr.Zero));
                            }
                            vm.Progress += progressStep;
                        }
                    }
                }

            }

            vm.Progress = 0;

            vm.Loggerr.Log("Link operation finished");

            vm.UIEnabled = true;
            vm.LinkButtonEnabled = true;
            IsExecuting = false;
        }

        bool CheckDupes()
        {
            foreach (var file in vm.SelectedInstance.InstanceFiles)
            {
                if (File.Exists(target + file.Location + @"\" + file.OriginalFileName))
                {
                    var prompt2 = MessageBox.Show(@$"{file.Location}\{file.OriginalFileName} already exists in the target directory!" + "\n"
                        + "Do you want to delete all encountered dupes before making hard links? (If you didn't know or forgot, overwriting hard linked files changes the originals). Nothing was linked yet. 'No' cancels the whole operation.", "Duplicate files detected!", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);

                    if (prompt2 == DialogResult.Yes)
                    {
                        delet = true;
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                }
            }
            return true;
        }


        [DllImport("Kernel32.dll", CharSet = CharSet.Unicode)]
        static extern bool CreateHardLink(
        string lpFileName,
        string lpExistingFileName,
        IntPtr lpSecurityAttributes
        );
    }
}