// 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.
 
#nullable disable
 
using System;
using System.Collections.Immutable;
using System.ComponentModel.Composition;
using System.Threading;
using Microsoft.CodeAnalysis.Editor;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.PooledObjects;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Text;
using Microsoft.VisualStudio.Commanding;
using Microsoft.VisualStudio.Text;
using Microsoft.VisualStudio.Text.Operations;
 
namespace Microsoft.CodeAnalysis.CommentSelection;
 
[Export(typeof(ICommandHandler))]
[VisualStudio.Utilities.ContentType(ContentTypeNames.RoslynContentType)]
[VisualStudio.Utilities.Name(PredefinedCommandHandlerNames.ToggleBlockComment)]
[method: ImportingConstructor]
[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
internal class ToggleBlockCommentCommandHandler(
    ITextUndoHistoryRegistry undoHistoryRegistry,
    IEditorOperationsFactoryService editorOperationsFactoryService,
    ITextStructureNavigatorSelectorService navigatorSelectorService,
    EditorOptionsService editorOptionsService) : AbstractToggleBlockCommentBase(undoHistoryRegistry, editorOperationsFactoryService, navigatorSelectorService, editorOptionsService)
{
 
    /// <summary>
    /// Gets block comments by parsing the text for comment markers.
    /// </summary>
    protected override ImmutableArray<TextSpan> GetBlockCommentsInDocument(Document document, ITextSnapshot snapshot,
        TextSpan linesContainingSelections, CommentSelectionInfo commentInfo, CancellationToken cancellationToken)
    {
        var allText = snapshot.AsText();
        var commentedSpans = ArrayBuilder<TextSpan>.GetInstance();
 
        var openIdx = 0;
        while ((openIdx = allText.IndexOf(commentInfo.BlockCommentStartString, openIdx, caseSensitive: true)) >= 0)
        {
            // Retrieve the first closing marker located after the open index.
            var closeIdx = allText.IndexOf(commentInfo.BlockCommentEndString, openIdx + commentInfo.BlockCommentStartString.Length, caseSensitive: true);
            // If an open marker is found without a close marker, it's an unclosed comment.
            if (closeIdx < 0)
            {
                closeIdx = allText.Length - commentInfo.BlockCommentEndString.Length;
            }
 
            var blockCommentSpan = new TextSpan(openIdx, closeIdx + commentInfo.BlockCommentEndString.Length - openIdx);
            commentedSpans.Add(blockCommentSpan);
            openIdx = closeIdx;
        }
 
        return commentedSpans.ToImmutableAndFree();
    }
}