// 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 Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.Formatting.Rules;
 
namespace Microsoft.VisualStudio.LanguageServices.CSharp.CodeModel;
 
internal sealed class EndRegionFormattingRule : AbstractFormattingRule
{
    public static readonly EndRegionFormattingRule Instance = new();
 
    private EndRegionFormattingRule()
    {
    }
 
    private static bool IsAfterEndRegionBeforeMethodDeclaration(SyntaxToken previousToken)
    {
        if (previousToken.Kind() == SyntaxKind.EndOfDirectiveToken)
        {
            var previousPreviousToken = previousToken.GetPreviousToken();
            return previousPreviousToken.Kind() == SyntaxKind.EndRegionKeyword;
        }
 
        return false;
    }
 
    public override AdjustNewLinesOperation GetAdjustNewLinesOperation(in SyntaxToken previousToken, in SyntaxToken currentToken, in NextGetAdjustNewLinesOperation nextOperation)
    {
        if (IsAfterEndRegionBeforeMethodDeclaration(previousToken))
        {
            return FormattingOperations.CreateAdjustNewLinesOperation(2, AdjustNewLinesOption.ForceLines);
        }
 
        return nextOperation.Invoke(in previousToken, in currentToken);
    }
}