// 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.Collections.Generic;
using System.Threading;
using Microsoft.CodeAnalysis.Text;
 
namespace Microsoft.CodeAnalysis.Formatting;
 
internal abstract partial class AbstractTriviaDataFactory
{
    protected sealed class FormattedWhitespace : TriviaData
    {
        private readonly string _newString;
 
        public FormattedWhitespace(LineFormattingOptions options, int lineBreaks, int indentation)
            : base(options)
        {
            this.LineBreaks = Math.Max(0, lineBreaks);
            this.Spaces = Math.Max(0, indentation);
 
            _newString = CreateString(Options.NewLine);
        }
 
        private string CreateString(string newLine)
        {
            if (this.SecondTokenIsFirstTokenOnLine)
            {
                var builder = StringBuilderPool.Allocate();
                for (var i = 0; i < LineBreaks; i++)
                {
                    builder.Append(newLine);
                }
 
                builder.AppendIndentationString(Spaces, Options.UseTabs, Options.TabSize);
                return StringBuilderPool.ReturnAndFree(builder);
            }
 
            // space case. always use space
            return new string(' ', Spaces);
        }
 
        public override bool TreatAsElastic => false;
 
        public override bool IsWhitespaceOnlyTrivia => true;
 
        public override bool ContainsChanges => true;
 
        public override IEnumerable<TextChange> GetTextChanges(TextSpan textSpan)
            => [new TextChange(textSpan, _newString)];
 
        public override TriviaData WithSpace(int space, FormattingContext context, ChainedFormattingRules formattingRules)
            => throw new NotImplementedException();
 
        public override TriviaData WithLine(int line, int indentation, FormattingContext context, ChainedFormattingRules formattingRules, CancellationToken cancellationToken)
            => throw new NotImplementedException();
 
        public override TriviaData WithIndentation(int indentation, FormattingContext context, ChainedFormattingRules formattingRules, CancellationToken cancellationToken)
            => throw new NotImplementedException();
 
        public override void Format(
            FormattingContext context, ChainedFormattingRules formattingRules, Action<int, TokenStream, TriviaData> formattingResultApplier, CancellationToken cancellationToken, int tokenPairIndex = TokenPairIndexNotNeeded)
        {
            throw new NotImplementedException();
        }
    }
}