// 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;
using System.ComponentModel.Composition;
using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.Text.Shared.Extensions;
using Microsoft.VisualStudio.Commanding;
using Microsoft.VisualStudio.Text.Editor.Commanding.Commands;
using Microsoft.VisualStudio.Utilities;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.BlockCommentEditing;
 
[Export(typeof(ICommandHandler))]
[ContentType(ContentTypeNames.CSharpContentType)]
[Name(nameof(CloseBlockCommentCommandHandler))]
[Order(After = nameof(BlockCommentEditingCommandHandler))]
[method: ImportingConstructor]
[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
internal sealed class CloseBlockCommentCommandHandler(EditorOptionsService editorOptionsService) : ICommandHandler<TypeCharCommandArgs>
{
    private readonly EditorOptionsService _editorOptionsService = editorOptionsService;
 
    public string DisplayName => EditorFeaturesResources.Block_Comment_Editing;
 
    public bool ExecuteCommand(TypeCharCommandArgs args, CommandExecutionContext executionContext)
    {
        if (args.TypedChar == '/')
        {
            var caret = args.TextView.GetCaretPoint(args.SubjectBuffer);
            if (caret != null)
            {
                var (snapshot, position) = caret.Value;
 
                // Check that the line is all whitespace ending with an asterisk and a single space (| marks caret position):
                // * |
                if (position >= 2 &&
                    snapshot[position - 1] == ' ' &&
                    snapshot[position - 2] == '*')
                {
                    var line = snapshot.GetLineFromPosition(position);
                    if (line.End == position &&
                        line.IsEmptyOrWhitespace(0, line.Length - 2))
                    {
                        if (_editorOptionsService.GlobalOptions.GetOption(BlockCommentEditingOptionsStorage.AutoInsertBlockCommentStartString, LanguageNames.CSharp) &&
                            BlockCommentEditingCommandHandler.IsCaretInsideBlockCommentSyntax(caret.Value, args.SubjectBuffer, _editorOptionsService, out _, out _, executionContext.OperationContext.UserCancellationToken))
                        {
                            args.SubjectBuffer.Replace(new VisualStudio.Text.Span(position - 1, 1), "/");
                            return true;
                        }
                    }
                }
            }
        }
 
        return false;
    }
 
    public CommandState GetCommandState(TypeCharCommandArgs args)
        => CommandState.Unspecified;
}