// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Collections.Immutable;
using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
using Microsoft.CodeAnalysis.Editor.Undo;
using Microsoft.CodeAnalysis.Text;
using Microsoft.VisualStudio.Text;
 
namespace Microsoft.CodeAnalysis.Editor;
 
internal static class TextEditApplication
{
    internal static void UpdateText(SourceText newText, ITextBuffer buffer, EditOptions options)
    {
        var oldSnapshot = buffer.CurrentSnapshot;
        var oldText = oldSnapshot.AsText();
        var changes = newText.GetTextChanges(oldText);
        UpdateText([.. changes], buffer, oldSnapshot, oldText, options);
    }
 
    public static void UpdateText(ImmutableArray<TextChange> textChanges, ITextBuffer buffer, EditOptions options)
    {
        var oldSnapshot = buffer.CurrentSnapshot;
        var oldText = oldSnapshot.AsText();
 
        UpdateText(textChanges, buffer, oldSnapshot, oldText, options);
    }
 
    private static void UpdateText(ImmutableArray<TextChange> textChanges, ITextBuffer buffer, ITextSnapshot oldSnapshot, SourceText oldText, EditOptions options)
    {
        using var edit = buffer.CreateEdit(options, reiteratedVersionNumber: null, editTag: null);
        if (Workspace.TryGetWorkspace(oldText.Container, out var workspace))
        {
            var undoService = workspace.Services.GetRequiredService<ISourceTextUndoService>();
            undoService.BeginUndoTransaction(oldSnapshot);
        }
 
        foreach (var change in textChanges)
        {
            edit.Replace(change.Span.Start, change.Span.Length, change.NewText);
        }
 
        edit.ApplyAndLogExceptions();
    }
}