// 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;

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);
        }
    }
}