// 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.Generic;
using Microsoft.CodeAnalysis.Formatting.Rules;
 
namespace Microsoft.CodeAnalysis.CSharp.ExtractMethod;
 
internal sealed partial class CSharpMethodExtractor
{
    private sealed class FormattingRule : AbstractFormattingRule
    {
        public static readonly FormattingRule Instance = new();
 
        private FormattingRule()
        {
        }
 
        public override AdjustNewLinesOperation? GetAdjustNewLinesOperation(in SyntaxToken previousToken, in SyntaxToken currentToken, in NextGetAdjustNewLinesOperation nextOperation)
        {
            // for extract method case, for a hybrid case, don't force rule, but preserve user style
            var operation = base.GetAdjustNewLinesOperation(in previousToken, in currentToken, in nextOperation);
            if (operation == null)
            {
                return null;
            }
 
            if (operation.Option == AdjustNewLinesOption.ForceLinesIfOnSingleLine)
            {
                return FormattingOperations.CreateAdjustNewLinesOperation(operation.Line, AdjustNewLinesOption.PreserveLines);
            }
 
            if (operation.Option != AdjustNewLinesOption.ForceLines)
            {
                return operation;
            }
 
            if (previousToken.RawKind == (int)SyntaxKind.OpenBraceToken)
            {
                return operation;
            }
 
            if (previousToken.BetweenFieldAndNonFieldMember(currentToken))
            {
                // make sure to have at least 2 line breaks between field and other members except field
                return FormattingOperations.CreateAdjustNewLinesOperation(2, AdjustNewLinesOption.PreserveLines);
            }
 
            if (previousToken.HasHybridTriviaBetween(currentToken))
            {
                return FormattingOperations.CreateAdjustNewLinesOperation(operation.Line, AdjustNewLinesOption.PreserveLines);
            }
 
            return operation;
        }
 
        public override void AddAnchorIndentationOperations(List<AnchorIndentationOperation> list, SyntaxNode node, in NextAnchorIndentationOperationAction nextOperation)
        {
            if (node.Kind() is SyntaxKind.SimpleLambdaExpression or SyntaxKind.ParenthesizedLambdaExpression or SyntaxKind.AnonymousMethodExpression)
            {
                return;
            }
 
            nextOperation.Invoke();
        }
    }
}