better code completion apply

src/SharpIDE.Application/Features/Analysis/IdeCompletionService.cs

@@ -0,0 +1,17 @@
+using Microsoft.CodeAnalysis.Completion;
+using SharpIDE.Application.Features.FileWatching;
+using SharpIDE.Application.Features.SolutionDiscovery;
+
+namespace SharpIDE.Application.Features.Analysis;
+
+public class IdeCompletionService(RoslynAnalysis roslynAnalysis, FileChangedService fileChangedService)
+{
+	private readonly RoslynAnalysis _roslynAnalysis = roslynAnalysis;
+	private readonly FileChangedService _fileChangedService = fileChangedService;
+
+	public async Task ApplyCompletion(SharpIdeFile file, CompletionItem completionItem)
+	{
+		var (updatedDocumentText, newLinePosition) = await _roslynAnalysis.GetCompletionApplyChanges(file, completionItem);
+		await _fileChangedService.SharpIdeFileChanged(file, updatedDocumentText, FileChangeType.CompletionChange, newLinePosition);
+	}
+}

src/SharpIDE.Application/Features/Analysis/RoslynAnalysis.cs

@@ -575,6 +575,37 @@ public class RoslynAnalysis
 		return completions;
 	}
 
+	public async Task<(string updatedText, SharpIdeFileLinePosition sharpIdeFileLinePosition)> GetCompletionApplyChanges(SharpIdeFile file, CompletionItem completionItem, CancellationToken cancellationToken = default)
+	{
+		var documentId = _workspace!.CurrentSolution.GetDocumentIdsWithFilePath(file.Path).Single();
+		var document = _workspace.CurrentSolution.GetRequiredDocument(documentId);
+		var completionService = CompletionService.GetService(document) ?? throw new InvalidOperationException("Completion service is not available for the document.");
+
+		var completionChange = await completionService.GetChangeAsync(document, completionItem, commitCharacter: '.', cancellationToken: cancellationToken);
+		var sourceText = await document.GetTextAsync(cancellationToken);
+		var newText = sourceText.WithChanges(completionChange.TextChange);
+		var newCaretPosition = completionChange.NewPosition ?? NewCaretPosition();
+		var linePosition = newText.Lines.GetLinePosition(newCaretPosition);
+		var sharpIdeFileLinePosition = new SharpIdeFileLinePosition
+		{
+			Line = linePosition.Line,
+			Column = linePosition.Character
+		};
+
+		return (newText.ToString(), sharpIdeFileLinePosition);
+
+		int NewCaretPosition()
+		{
+			var caretPosition = completionChange.TextChange.Span.Start + completionChange.TextChange.NewText!.Length;
+			// if change ends with (), place caret between the parentheses
+			if (completionChange.TextChange.NewText!.EndsWith("()"))
+			{
+				caretPosition -= 1;
+			}
+			return caretPosition;
+		}
+	}
+
 	/// Returns the list of files that would be modified by applying the code action. Does not apply the changes to the workspace sln
 	public async Task<List<(SharpIdeFile File, string UpdatedText)>> GetCodeActionApplyChanges(CodeAction codeAction)
 	{

src/SharpIDE.Application/Features/FileWatching/FileChangedService.cs

@@ -13,7 +13,8 @@ public enum FileChangeType
 	IdeSaveToDisk, // Apply to disk
 	IdeUnsavedChange, // Apply only in memory
 	ExternalChange, // Apply to disk, as well as in memory
-	CodeActionChange // Apply to disk, as well as in memory
+	CodeActionChange, // Apply to disk, as well as in memory
+	CompletionChange // Apply only in memory, as well as notify tabs of new content
 }
 
 public class FileChangedService(RoslynAnalysis roslynAnalysis, IdeOpenTabsFileManager openTabsFileManager)
@@ -59,7 +60,7 @@ public class FileChangedService(RoslynAnalysis roslynAnalysis, IdeOpenTabsFileMa
 	}
 
 	// All file changes should go via this service
-	public async Task SharpIdeFileChanged(SharpIdeFile file, string newContents, FileChangeType changeType)
+	public async Task SharpIdeFileChanged(SharpIdeFile file, string newContents, FileChangeType changeType, SharpIdeFileLinePosition? linePosition = null)
 	{
 		if (changeType is FileChangeType.ExternalChange)
 		{
@@ -67,13 +68,19 @@ public class FileChangedService(RoslynAnalysis roslynAnalysis, IdeOpenTabsFileMa
 			// Update any open tabs
 			// update in memory
 			await _openTabsFileManager.UpdateFileTextInMemory(file, newContents);
-			file.FileContentsChangedExternally.InvokeParallelFireAndForget();
+			file.FileContentsChangedExternally.InvokeParallelFireAndForget(linePosition);
 		}
 		else if (changeType is FileChangeType.CodeActionChange)
 		{
 			// update in memory, tabs and save to disk
 			await _openTabsFileManager.UpdateInMemoryIfOpenAndSaveAsync(file, newContents);
-			file.FileContentsChangedExternally.InvokeParallelFireAndForget();
+			file.FileContentsChangedExternally.InvokeParallelFireAndForget(linePosition);
+		}
+		else if (changeType is FileChangeType.CompletionChange)
+		{
+			// update in memory, tabs
+			await _openTabsFileManager.UpdateFileTextInMemory(file, newContents);
+			file.FileContentsChangedExternally.InvokeParallelFireAndForget(linePosition);
 		}
 		else if (changeType is FileChangeType.IdeSaveToDisk)
 		{

src/SharpIDE.Application/Features/SolutionDiscovery/SharpIdeFile.cs

@@ -1,6 +1,7 @@
 using System.Collections.Concurrent;
 using System.Diagnostics.CodeAnalysis;
 using R3;
+using SharpIDE.Application.Features.Analysis;
 using SharpIDE.Application.Features.Events;
 using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
 
@@ -19,7 +20,7 @@ public class SharpIdeFile : ISharpIdeNode, IChildSharpIdeNode, IFileOrFolder
 	public required ReactiveProperty<bool> IsDirty { get; init; }
 	public required bool SuppressDiskChangeEvents { get; set; } // probably has concurrency issues
 	public required DateTimeOffset? LastIdeWriteTime { get; set; }
-	public EventWrapper<Task> FileContentsChangedExternally { get; } = new(() => Task.CompletedTask);
+	public EventWrapper<SharpIdeFileLinePosition?, Task> FileContentsChangedExternally { get; } = new((_) => Task.CompletedTask);
 
 	[SetsRequiredMembers]
 	internal SharpIdeFile(string fullPath, string name, IExpandableSharpIdeNode parent, ConcurrentBag<SharpIdeFile> allFiles)

src/SharpIDE.Godot/DiAutoload.cs

@@ -26,6 +26,7 @@ public partial class DiAutoload : Node
         services.AddScoped<RunService>();
         services.AddScoped<IdeFileExternalChangeHandler>();
         services.AddScoped<CodeActionService>();
+        services.AddScoped<IdeCompletionService>();
         services.AddScoped<FileChangedService>();
         services.AddScoped<IdeFileWatcher>();
         services.AddScoped<IdeOpenTabsFileManager>();

src/SharpIDE.Godot/Features/CodeEditor/SharpIdeCodeEdit.cs

@@ -1,8 +1,8 @@
 using System.Collections.Immutable;
 using Godot;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.Classification;
 using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.Completion;
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
 using SharpIDE.Application;
@@ -14,6 +14,7 @@ using SharpIDE.Application.Features.FileWatching;
 using SharpIDE.Application.Features.Run;
 using SharpIDE.Application.Features.SolutionDiscovery;
 using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+using SharpIDE.Godot.Features.Problems;
 using SharpIDE.RazorAccess;
 using Task = System.Threading.Tasks.Task;
 using Timer = Godot.Timer;
@@ -47,6 +48,7 @@ public partial class SharpIdeCodeEdit : CodeEdit
     [Inject] private readonly RoslynAnalysis _roslynAnalysis = null!;
     [Inject] private readonly CodeActionService _codeActionService = null!;
     [Inject] private readonly FileChangedService _fileChangedService = null!;
+    [Inject] private readonly IdeCompletionService _ideCompletionService = null!;
 	
 	public override void _Ready()
 	{
@@ -299,12 +301,12 @@ public partial class SharpIdeCodeEdit : CodeEdit
 		});
 	}
 
-	private async Task OnFileChangedExternally()
+	private async Task OnFileChangedExternally(SharpIdeFileLinePosition? linePosition)
 	{
 		var fileContents = await _openTabsFileManager.GetFileTextAsync(_currentFile);
 		Callable.From(() =>
 		{
-			var currentCaretPosition = GetCaretPosition();
+			(int line, int col) currentCaretPosition = linePosition is null ? GetCaretPosition() : (linePosition.Value.Line, linePosition.Value.Column);
 			var vScroll = GetVScroll();
 			BeginComplexOperation();
 			SetText(fileContents);
@@ -317,8 +319,8 @@ public partial class SharpIdeCodeEdit : CodeEdit
 
 	public void SetFileLinePosition(SharpIdeFileLinePosition fileLinePosition)
 	{
-		var line = fileLinePosition.Line - 1;
+		var line = fileLinePosition.Line;
-		var column = fileLinePosition.Column - 1;
+		var column = fileLinePosition.Column;
 		SetCaretLine(line);
 		SetCaretColumn(column);
 		CenterViewportToCaret();
@@ -498,6 +500,20 @@ public partial class SharpIdeCodeEdit : CodeEdit
 		});
 	}
 
+	public override void _ConfirmCodeCompletion(bool replace)
+	{
+		GD.Print("Code completion confirmed");
+		var selectedIndex = GetCodeCompletionSelectedIndex();
+		var selectedText = GetCodeCompletionOption(selectedIndex);
+		if (selectedText is null) return;
+		var completionItem = selectedText["default_value"].As<RefCountedContainer<CompletionItem>>().Item;
+		_ = Task.GodotRun(async () =>
+		{
+			await _ideCompletionService.ApplyCompletion(_currentFile, completionItem);
+		});
+		CancelCodeCompletion();
+	}
+
 	private void OnCodeCompletionRequested()
 	{
 		var (caretLine, caretColumn) = GetCaretPosition();
@@ -510,9 +526,20 @@ public partial class SharpIdeCodeEdit : CodeEdit
 			var completions = await _roslynAnalysis.GetCodeCompletionsForDocumentAtPosition(_currentFile, linePos);
 			await this.InvokeAsync(() =>
 			{
-				foreach (var completionItem in completions.ItemsList)
+				foreach (var (index, completionItem) in completions.ItemsList.Take(100).Index())
 				{
-					AddCodeCompletionOption(CodeCompletionKind.Class, completionItem.DisplayText, completionItem.DisplayText);
+					var symbolKindString = CollectionExtensions.GetValueOrDefault(completionItem.Properties, "SymbolKind");
+					var symbolKind = symbolKindString is null ? null : (SymbolKind?)int.Parse(symbolKindString);
+					var godotCompletionType = symbolKind switch
+					{
+						SymbolKind.Method => CodeCompletionKind.Function,
+						SymbolKind.NamedType => CodeCompletionKind.Class,
+						SymbolKind.Local => CodeCompletionKind.Variable,
+						SymbolKind.Property => CodeCompletionKind.Member,
+						SymbolKind.Field => CodeCompletionKind.Member,
+						_ => CodeCompletionKind.PlainText
+					};
+					AddCodeCompletionOption(godotCompletionType, completionItem.DisplayText, completionItem.DisplayText, value: new RefCountedContainer<CompletionItem>(completionItem));
 				}
 				// partially working - displays menu only when caret is what CodeEdit determines as valid
 				UpdateCodeCompletionOptions(true);

src/SharpIDE.Godot/Features/Search/SearchInFiles/SearchResultComponent.cs

@@ -26,7 +26,7 @@ public partial class SearchResultComponent : MarginContainer
 
     private void OnButtonPressed()
     {
-        var fileLinePosition = new SharpIdeFileLinePosition { Line = Result.Line, Column = Result.StartColumn };
+        var fileLinePosition = new SharpIdeFileLinePosition { Line = Result.Line - 1, Column = Result.StartColumn - 1 };
         GodotGlobalEvents.Instance.FileExternallySelected.InvokeParallelFireAndForget(Result.File, fileLinePosition);
         ParentSearchWindow.Hide();
     }