// 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 Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Shared.Utilities;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Formatting;
 
internal abstract partial class TreeData
{
    private sealed class Node : TreeData
    {
        public Node(SyntaxNode root)
            : base(root)
        {
            Contract.ThrowIfFalse(root.GetFirstToken(includeZeroWidth: true).RawKind != 0);
        }
 
        public override int GetOriginalColumn(int tabSize, SyntaxToken token)
        {
            Contract.ThrowIfTrue(token.RawKind == 0);
 
            // first find one that has new line text
            var startToken = GetTokenWithLineBreaks(token);
 
            // get last line text from text between them
            var lineText = GetTextBetween(startToken, token).GetLastLineText();
 
            return lineText.GetColumnFromLineOffset(lineText.Length, tabSize);
        }
 
        private static SyntaxToken GetTokenWithLineBreaks(SyntaxToken token)
        {
            var currentToken = token.GetPreviousToken(includeZeroWidth: true);
 
            while (currentToken.RawKind != 0)
            {
                if (currentToken.ToFullString().IndexOf('\n') >= 0)
                {
                    return currentToken;
                }
 
                currentToken = currentToken.GetPreviousToken(includeZeroWidth: true);
            }
 
            return default;
        }
 
        public override string GetTextBetween(SyntaxToken token1, SyntaxToken token2)
        {
            var builder = StringBuilderPool.Allocate();
 
            CommonFormattingHelpers.AppendTextBetween(token1, token2, builder);
 
            return StringBuilderPool.ReturnAndFree(builder);
        }
    }
}