RemoveRegions.cs

namespace CommentRemover;

using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using EnvDTE;
using EnvDTE80;
using Microsoft.VisualStudio.Editor;
using Microsoft.VisualStudio.Extensibility;
using Microsoft.VisualStudio.Extensibility.Commands;
using Microsoft.VisualStudio.Extensibility.Shell;
using Microsoft.VisualStudio.Extensibility.VSSdkCompatibility;
using Microsoft.VisualStudio.Shell;
using Microsoft.VisualStudio.Text.Editor;
using Microsoft.VisualStudio.Text.Tagging;
using Microsoft.VisualStudio.TextManager.Interop;

[VisualStudioContribution]
internal class RemoveRegions : CommentRemoverCommand
{
    private const string CommandDescription = "%CommentRemover.RemoveRegions.DisplayName%";

    public RemoveRegions(
        TraceSource traceSource,
        AsyncServiceProviderInjection<DTE, DTE2> dte,
        MefInjection<IBufferTagAggregatorFactoryService> bufferTagAggregatorFactoryService,
        MefInjection<IVsEditorAdaptersFactoryService> editorAdaptersFactoryService,
        AsyncServiceProviderInjection<SVsTextManager, IVsTextManager> textManager)
        : base(traceSource, dte, bufferTagAggregatorFactoryService, editorAdaptersFactoryService, textManager)
    {
    }

    /// <inheritdoc />
    public override CommandConfiguration CommandConfiguration => new(CommandDescription)
    {
        Icon = new(ImageMoniker.Custom("DeleteRegions"), IconSettings.IconAndText),
        EnabledWhen = CommandEnabledWhen,
    };

    public override async Task ExecuteCommandAsync(IClientContext context, CancellationToken cancellationToken)
    {
        if (!await this.Extensibility.Shell().ShowPromptAsync("All regions will be removed from the current document. Are you sure?", PromptOptions.OKCancel, cancellationToken))
        {
            return;
        }

        using var reporter = await this.Extensibility.Shell().StartProgressReportingAsync("Removing comments", options: new(isWorkCancellable: false), cancellationToken);

        await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();

        // Not using context.GetActiveTextViewAsync here because VisualStudio.Extensibility doesn't support classification yet.
        var view = await this.GetCurrentTextViewAsync();
        var dte = await this.Dte.GetServiceAsync();
        try
        {
            dte.UndoContext.Open(CommandDescription);

            this.RemoveRegionsFromBuffer(view);
        }
#pragma warning disable CA1031 // Do not catch general exception types
        catch (Exception ex)
#pragma warning restore CA1031 // Do not catch general exception types
        {
            this.TraceSource.TraceInformation(ex.ToString());
        }
        finally
        {
            dte.UndoContext.Close();
        }
    }

    private void RemoveRegionsFromBuffer(IWpfTextView view)
    {
        using var edit = view.TextBuffer.CreateEdit();
        foreach (var line in view.TextBuffer.CurrentSnapshot.Lines.Reverse())
        {
            if (line.Extent.IsEmpty)
            {
                continue;
            }

            string text = line.GetText()
                              .TrimStart('/', '*')
                              .Replace("<!--", string.Empty)
                              .TrimStart();

            if (text.StartsWith("#region", StringComparison.OrdinalIgnoreCase) ||
                text.StartsWith("#endregion", StringComparison.OrdinalIgnoreCase) ||
                text.StartsWith("#end region", StringComparison.OrdinalIgnoreCase))
            {
                // Strip next line if empty
                if (view.TextBuffer.CurrentSnapshot.LineCount > line.LineNumber + 1)
                {
                    var next = view.TextBuffer.CurrentSnapshot.GetLineFromLineNumber(line.LineNumber + 1);

                    if (IsLineEmpty(next))
                    {
                        edit.Delete(next.Start, next.LengthIncludingLineBreak);
                    }
                }

                edit.Delete(line.Start, line.LengthIncludingLineBreak);
            }
        }

        edit.Apply();
    }
}