refactor: rewrite amend behaviour (#300)

* toggle amend will show changes in HEAD commit
* since discard is not compatible with staged changes in `amend` mode, we only allows user to discard unstaged changes

src/Commands/Discard.cs

@@ -11,7 +11,7 @@ namespace SourceGit.Commands
             new Clean(repo).Exec();
         }
 
-        public static void ChangesInWorkTree(string repo, List<Models.Change> changes)
+        public static void Changes(string repo, List<Models.Change> changes)
         {
             var needClean = new List<string>();
             var needCheckout = new List<string>();
@@ -19,14 +19,10 @@ namespace SourceGit.Commands
             foreach (var c in changes)
             {
                 if (c.WorkTree == Models.ChangeState.Untracked || c.WorkTree == Models.ChangeState.Added)
-                {
                     needClean.Add(c.Path);
-                }
                 else
-                {
                     needCheckout.Add(c.Path);
             }
-            }
 
             for (int i = 0; i < needClean.Count; i += 10)
             {
@@ -40,17 +36,5 @@ namespace SourceGit.Commands
                 new Restore(repo, needCheckout.GetRange(i, count), "--worktree --recurse-submodules").Exec();
             }
         }
-
-        public static void ChangesInStaged(string repo, List<Models.Change> changes)
-        {
-            for (int i = 0; i < changes.Count; i += 10)
-            {
-                var count = Math.Min(10, changes.Count - i);
-                var files = new List<string>();
-                for (int j = 0; j < count; j++)
-                    files.Add(changes[i + j].Path);
-                new Restore(repo, files, "--staged --worktree --recurse-submodules").Exec();
-            }
-        }
     }
 }

src/Commands/QueryStagedChangesWithAmend.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace SourceGit.Commands
+{
+    public partial class QueryStagedChangesWithAmend : Command
+    {
+        [GeneratedRegex(@"^:[\d]{6} ([\d]{6}) ([0-9a-f]{40}) [0-9a-f]{40} ([ACDMTUX])\d{0,6}\t(.*)$")]
+        private static partial Regex REG_FORMAT1();
+        [GeneratedRegex(@"^:[\d]{6} ([\d]{6}) ([0-9a-f]{40}) [0-9a-f]{40} R\d{0,6}\t(.*\t.*)$")]
+        private static partial Regex REG_FORMAT2();
+
+        public QueryStagedChangesWithAmend(string repo)
+        {
+            WorkingDirectory = repo;
+            Context = repo;
+            Args = "diff-index --cached -M HEAD^";
+        }
+
+        public List<Models.Change> Result()
+        {
+            var rs = ReadToEnd();
+            if (rs.IsSuccess)
+            {
+                var changes = new List<Models.Change>();
+                var lines = rs.StdOut.Split('\n', StringSplitOptions.RemoveEmptyEntries);
+                foreach (var line in lines)
+                {
+                    var match = REG_FORMAT2().Match(line);
+                    if (match.Success)
+                    {
+                        var change = new Models.Change() { 
+                            Path = match.Groups[3].Value,
+                            DataForAmend = new Models.ChangeDataForAmend()
+                            {
+                                FileMode = match.Groups[1].Value,
+                                ObjectHash = match.Groups[2].Value,
+                            },
+                        };
+                        change.Set(Models.ChangeState.Renamed);
+                        changes.Add(change);
+                        continue;
+                    }
+
+                    match = REG_FORMAT1().Match(line);
+                    if (match.Success)
+                    {
+                        var change = new Models.Change() { 
+                            Path = match.Groups[4].Value,
+                            DataForAmend = new Models.ChangeDataForAmend()
+                            {
+                                FileMode = match.Groups[1].Value,
+                                ObjectHash = match.Groups[2].Value,
+                            },
+                        };
+
+                        var type = match.Groups[3].Value;
+                        switch (type)
+                        {
+                            case "A":
+                                change.Set(Models.ChangeState.Added);
+                                break;
+                            case "C":
+                                change.Set(Models.ChangeState.Copied);
+                                break;
+                            case "D":
+                                change.Set(Models.ChangeState.Deleted);
+                                break;
+                            case "M":
+                                change.Set(Models.ChangeState.Modified);
+                                break;
+                            case "T":
+                                change.Set(Models.ChangeState.TypeChanged);
+                                break;
+                            case "U":
+                                change.Set(Models.ChangeState.Unmerged);
+                                break;
+                        }
+                        changes.Add(change);
+                    }
+                }
+
+                return changes;
+            }
+
+            return [];
+        }
+    }
+}

src/Commands/UnstageChangesForAmend.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Text;
+
+using Avalonia.Threading;
+
+namespace SourceGit.Commands
+{
+    public class UnstageChangesForAmend
+    {
+        public UnstageChangesForAmend(string repo, List<Models.Change> changes)
+        {
+            _repo = repo;
+
+            foreach (var c in changes)
+            {
+                if (c.Index == Models.ChangeState.Renamed)
+                {
+                    _patchBuilder.Append("0 0000000000000000000000000000000000000000\t");
+                    _patchBuilder.Append(c.Path);
+                    _patchBuilder.Append("\0100644 ");
+                    _patchBuilder.Append(c.DataForAmend.ObjectHash);
+                    _patchBuilder.Append("\t");
+                    _patchBuilder.Append(c.OriginalPath);
+                    _patchBuilder.Append("\n");
+                }
+                else if (c.Index == Models.ChangeState.Added)
+                {
+                    _patchBuilder.Append("0 0000000000000000000000000000000000000000\t");
+                    _patchBuilder.Append(c.Path);
+                    _patchBuilder.Append("\n");
+                }
+                else if (c.Index == Models.ChangeState.Deleted)
+                {
+                    _patchBuilder.Append("100644 ");
+                    _patchBuilder.Append(c.DataForAmend.ObjectHash);
+                    _patchBuilder.Append("\t");
+                    _patchBuilder.Append(c.Path);
+                    _patchBuilder.Append("\n");
+                }
+                else
+                {
+                    _patchBuilder.Append(c.DataForAmend.FileMode);
+                    _patchBuilder.Append(" ");
+                    _patchBuilder.Append(c.DataForAmend.ObjectHash);
+                    _patchBuilder.Append("\t");
+                    _patchBuilder.Append(c.Path);
+                    _patchBuilder.Append("\n");
+                }
+            }
+        }
+
+        public bool Exec()
+        {
+            var starter = new ProcessStartInfo();
+            starter.WorkingDirectory = _repo;
+            starter.FileName = Native.OS.GitExecutable;
+            starter.Arguments = "-c core.editor=true update-index --index-info";
+            starter.UseShellExecute = false;
+            starter.CreateNoWindow = true;
+            starter.WindowStyle = ProcessWindowStyle.Hidden;
+            starter.RedirectStandardInput = true;
+            starter.RedirectStandardOutput = false;
+            starter.RedirectStandardError = true;
+
+            try
+            {
+                var proc = new Process() { StartInfo = starter };
+                proc.Start();
+                proc.StandardInput.Write(_patchBuilder.ToString());
+                proc.StandardInput.Close();
+
+                var err = proc.StandardError.ReadToEnd();
+                proc.WaitForExit();
+                var rs = proc.ExitCode == 0;
+                proc.Close();
+
+                if (!rs)
+                    Dispatcher.UIThread.Invoke(() => App.RaiseException(_repo, err));
+
+                return rs;
+            }
+            catch (Exception e)
+            {
+                Dispatcher.UIThread.Invoke(() =>
+                {
+                    App.RaiseException(_repo, "Failed to unstage changes: " + e.Message);
+                });
+                return false;
+            }
+        }
+
+        private string _repo = "";
+        private StringBuilder _patchBuilder = new StringBuilder();
+    }
+}

src/Models/Change.cs

@@ -22,12 +22,19 @@ namespace SourceGit.Models
         Untracked
     }
 
+    public class ChangeDataForAmend
+    {
+        public string FileMode { get; set; } = "";
+        public string ObjectHash { get; set; } = "";
+    }
+
     public class Change
     {
-        public ChangeState Index { get; set; }
+        public ChangeState Index { get; set; } = ChangeState.None;
         public ChangeState WorkTree { get; set; } = ChangeState.None;
         public string Path { get; set; } = "";
         public string OriginalPath { get; set; } = "";
+        public ChangeDataForAmend DataForAmend { get; set; } = null;
 
         public bool IsConflit
         {

src/Models/DiffOption.cs

@@ -39,7 +39,11 @@ namespace SourceGit.Models
             }
             else
             {
+                if (change.DataForAmend != null)
+                    _extra = "--cached HEAD^";
+                else
                     _extra = "--cached";
+
                 _path = change.Path;
                 _orgPath = change.OriginalPath;
             }

src/ViewModels/Discard.cs

@@ -19,11 +19,10 @@ namespace SourceGit.ViewModels
             View = new Views.Discard { DataContext = this };
         }
 
-        public Discard(Repository repo, List<Models.Change> changes, bool isUnstaged)
+        public Discard(Repository repo, List<Models.Change> changes)
         {
             _repo = repo;
             _changes = changes;
-            _isUnstaged = isUnstaged;
 
             if (_changes == null)
                 Mode = new Models.Null();
@@ -44,10 +43,8 @@ namespace SourceGit.ViewModels
             {
                 if (_changes == null)
                     Commands.Discard.All(_repo.FullPath);
-                else if (_isUnstaged)
-                    Commands.Discard.ChangesInWorkTree(_repo.FullPath, _changes);
                 else
-                    Commands.Discard.ChangesInStaged(_repo.FullPath, _changes);
+                    Commands.Discard.Changes(_repo.FullPath, _changes);
 
                 CallUIThread(() =>
                 {
@@ -61,6 +58,5 @@ namespace SourceGit.ViewModels
 
         private readonly Repository _repo = null;
         private readonly List<Models.Change> _changes = null;
-        private readonly bool _isUnstaged = true;
     }
 }

src/ViewModels/WorkingCopy.cs

@@ -88,7 +88,9 @@ namespace SourceGit.ViewModels
             get => _useAmend;
             set
             {
-                if (SetProperty(ref _useAmend, value) && value)
+                if (SetProperty(ref _useAmend, value))
+                {
+                    if (value)
                     {
                         var currentBranch = _repo.CurrentBranch;
                         if (currentBranch == null)
@@ -102,9 +104,12 @@ namespace SourceGit.ViewModels
                         CommitMessage = new Commands.QueryCommitFullMessage(_repo.FullPath, currentBranch.Head).Result();
                     }
 
+                    Staged = GetStagedChanges();
+                    SelectedStaged = [];
                     OnPropertyChanged(nameof(IsCommitWithPushVisible));
                 }
             }
+        }
 
         public bool IsCommitWithPushVisible
         {
@@ -216,6 +221,8 @@ namespace SourceGit.ViewModels
 
         public bool SetData(List<Models.Change> changes)
         {
+            _cached = changes;
+
             var unstaged = new List<Models.Change>();
             var staged = new List<Models.Change>();
             var selectedUnstaged = new List<Models.Change>();
@@ -237,17 +244,6 @@ namespace SourceGit.ViewModels
             var hasConflict = false;
             foreach (var c in changes)
             {
-                if (c.Index == Models.ChangeState.Modified
-                    || c.Index == Models.ChangeState.Added
-                    || c.Index == Models.ChangeState.Deleted
-                    || c.Index == Models.ChangeState.Renamed)
-                {
-                    staged.Add(c);
-
-                    if (lastSelectedStaged.Contains(c.Path))
-                        selectedStaged.Add(c);
-                }
-
                 if (c.WorkTree != Models.ChangeState.None)
                 {
                     unstaged.Add(c);
@@ -258,6 +254,13 @@ namespace SourceGit.ViewModels
                 }
             }
 
+            staged = GetStagedChanges();
+            foreach (var c in staged)
+            {
+                if (lastSelectedStaged.Contains(c.Path))
+                    selectedStaged.Add(c);
+            }
+
             _count = changes.Count;
 
             Dispatcher.UIThread.Invoke(() =>
@@ -358,7 +361,11 @@ namespace SourceGit.ViewModels
             SetDetail(null);
             IsUnstaging = true;
             _repo.SetWatcherEnabled(false);
-            if (changes.Count == _staged.Count)
+            if (_useAmend)
+            {
+                await Task.Run(() => new Commands.UnstageChangesForAmend(_repo.FullPath, changes).Exec());
+            }
+            else if (changes.Count == _staged.Count)
             {
                 await Task.Run(() => new Commands.Reset(_repo.FullPath).Exec());
             }
@@ -376,24 +383,14 @@ namespace SourceGit.ViewModels
             IsUnstaging = false;
         }
 
-        public void Discard(List<Models.Change> changes, bool isUnstaged)
+        public void Discard(List<Models.Change> changes)
         {
             if (PopupHost.CanCreatePopup())
-            {
-                if (isUnstaged)
             {
                 if (changes.Count == _unstaged.Count && _staged.Count == 0)
                     PopupHost.ShowPopup(new Discard(_repo));
                 else
-                        PopupHost.ShowPopup(new Discard(_repo, changes, true));
+                    PopupHost.ShowPopup(new Discard(_repo, changes));
-                }
-                else
-                {
-                    if (changes.Count == _staged.Count && _unstaged.Count == 0)
-                        PopupHost.ShowPopup(new Discard(_repo));
-                    else
-                        PopupHost.ShowPopup(new Discard(_repo, changes, false));
-                }
             }
         }
 
@@ -491,7 +488,7 @@ namespace SourceGit.ViewModels
                     discard.Icon = App.CreateMenuIcon("Icons.Undo");
                     discard.Click += (_, e) =>
                     {
-                        Discard(_selectedUnstaged, true);
+                        Discard(_selectedUnstaged);
                         e.Handled = true;
                     };
 
@@ -815,7 +812,7 @@ namespace SourceGit.ViewModels
                 discard.Icon = App.CreateMenuIcon("Icons.Undo");
                 discard.Click += (_, e) =>
                 {
-                    Discard(_selectedUnstaged, true);
+                    Discard(_selectedUnstaged);
                     e.Handled = true;
                 };
 
@@ -904,15 +901,6 @@ namespace SourceGit.ViewModels
                     e.Handled = true;
                 };
 
-                var discard = new MenuItem();
-                discard.Header = App.Text("FileCM.Discard");
-                discard.Icon = App.CreateMenuIcon("Icons.Undo");
-                discard.Click += (_, e) =>
-                {
-                    Discard(_selectedStaged, false);
-                    e.Handled = true;
-                };
-
                 var stash = new MenuItem();
                 stash.Header = App.Text("FileCM.Stash");
                 stash.Icon = App.CreateMenuIcon("Icons.Stashes");
@@ -971,7 +959,6 @@ namespace SourceGit.ViewModels
                 menu.Items.Add(openWith);
                 menu.Items.Add(new MenuItem() { Header = "-" });
                 menu.Items.Add(unstage);
-                menu.Items.Add(discard);
                 menu.Items.Add(stash);
                 menu.Items.Add(patch);
                 menu.Items.Add(new MenuItem() { Header = "-" });
@@ -1071,15 +1058,6 @@ namespace SourceGit.ViewModels
                     e.Handled = true;
                 };
 
-                var discard = new MenuItem();
-                discard.Header = App.Text("FileCM.DiscardMulti", _selectedStaged.Count);
-                discard.Icon = App.CreateMenuIcon("Icons.Undo");
-                discard.Click += (_, e) =>
-                {
-                    Discard(_selectedStaged, false);
-                    e.Handled = true;
-                };
-
                 var stash = new MenuItem();
                 stash.Header = App.Text("FileCM.StashMulti", _selectedStaged.Count);
                 stash.Icon = App.CreateMenuIcon("Icons.Stashes");
@@ -1118,7 +1096,6 @@ namespace SourceGit.ViewModels
                 };
 
                 menu.Items.Add(unstage);
-                menu.Items.Add(discard);
                 menu.Items.Add(stash);
                 menu.Items.Add(patch);
             }
@@ -1162,6 +1139,25 @@ namespace SourceGit.ViewModels
             return menu;
         }
 
+        private List<Models.Change> GetStagedChanges()
+        {
+            if (_useAmend)
+            {
+                return new Commands.QueryStagedChangesWithAmend(_repo.FullPath).Result();
+            }
+            else
+            {
+                var rs = new List<Models.Change>();
+                foreach (var c in _cached)
+                {
+                    if (c.Index != Models.ChangeState.None &&
+                        c.Index != Models.ChangeState.Untracked)
+                        rs.Add(c);
+                }
+                return rs;
+            }
+        }
+
         private void SetDetail(Models.Change change)
         {
             if (_isLoadingData)
@@ -1287,6 +1283,7 @@ namespace SourceGit.ViewModels
         private bool _isCommitting = false;
         private bool _useAmend = false;
         private bool _canCommitWithPush = false;
+        private List<Models.Change> _cached = [];
         private List<Models.Change> _unstaged = [];
         private List<Models.Change> _staged = [];
         private List<Models.Change> _selectedUnstaged = [];

src/Views/TextDiffView.axaml

@@ -77,7 +77,7 @@
     <StackPanel x:Name="Popup" IsVisible="False" Orientation="Horizontal" VerticalAlignment="Top" HorizontalAlignment="Right" Effect="drop-shadow(0 0 6 #40000000)">
       <Button Classes="flat" Content="{DynamicResource Text.Hunk.Stage}" Click="OnStageChunk" IsVisible="{Binding #ThisControl.IsUnstagedChange}"/>
       <Button Classes="flat" Content="{DynamicResource Text.Hunk.Unstage}" Click="OnUnstageChunk" IsVisible="{Binding #ThisControl.IsUnstagedChange, Converter={x:Static BoolConverters.Not}}"/>
-      <Button Classes="flat" Content="{DynamicResource Text.Hunk.Discard}" Margin="8,0,0,0" Click="OnDiscardChunk"/>
+      <Button Classes="flat" Content="{DynamicResource Text.Hunk.Discard}" Margin="8,0,0,0" Click="OnDiscardChunk" IsVisible="{Binding #ThisControl.IsUnstagedChange}"/>
     </StackPanel>
   </Grid>
 </UserControl>

src/Views/TextDiffView.axaml.cs

@@ -1273,7 +1273,7 @@ namespace SourceGit.Views
                     return;
 
                 var workcopy = workcopyView.DataContext as ViewModels.WorkingCopy;
-                workcopy?.Discard(new List<Models.Change> { change }, diff.Option.IsUnstaged);
+                workcopy?.Discard(new List<Models.Change> { change });
             }
             else
             {
@@ -1303,7 +1303,7 @@ namespace SourceGit.Views
                     diff.GeneratePatchFromSelectionSingleSide(change, treeGuid, selection, true, chunk.IsOldSide, tmpFile);
                 }
 
-                new Commands.Apply(diff.Repo, tmpFile, true, "nowarn", diff.Option.IsUnstaged ? "--reverse" : "--index --reverse").Exec();
+                new Commands.Apply(diff.Repo, tmpFile, true, "nowarn", "--reverse").Exec();
                 File.Delete(tmpFile);
 
                 repo.MarkWorkingCopyDirtyManually();