// 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.Formatting
{
    // the default provider that will be called by the engine at the end of provider's chain.
    // there is no way for a user to be remove this provider.
    //
    // to reduce number of unnecessary heap allocations, most of them just return null.
    internal sealed class DefaultOperationProvider : AbstractFormattingRule
    {
        public static readonly DefaultOperationProvider Instance = new();
 
        private DefaultOperationProvider()
        {
        }
 
        public override void AddSuppressOperations(List<SuppressOperation> list, SyntaxNode node, in NextSuppressOperationAction nextOperation)
        {
        }
 
        public override void AddAnchorIndentationOperations(List<AnchorIndentationOperation> list, SyntaxNode node, in NextAnchorIndentationOperationAction nextOperation)
        {
        }
 
        public override void AddIndentBlockOperations(List<IndentBlockOperation> list, SyntaxNode node, in NextIndentBlockOperationAction nextOperation)
        {
        }
 
        public override void AddAlignTokensOperations(List<AlignTokensOperation> list, SyntaxNode node, in NextAlignTokensOperationAction nextOperation)
        {
        }
 
        public override AdjustNewLinesOperation? GetAdjustNewLinesOperation(in SyntaxToken previousToken, in SyntaxToken currentToken, in NextGetAdjustNewLinesOperation nextOperation)
            => null;
 
        // return 1 space for every token pairs as a default operation
        public override AdjustSpacesOperation GetAdjustSpacesOperation(in SyntaxToken previousToken, in SyntaxToken currentToken, in NextGetAdjustSpacesOperation nextOperation)
        {
            var space = currentToken.Kind() == SyntaxKind.EndOfFileToken ? 0 : 1;
            return FormattingOperations.CreateAdjustSpacesOperation(space, AdjustSpacesOption.DefaultSpacesIfOnSingleLine);
        }
    }
}