// 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.Text;
 
namespace Roslyn.Utilities;
 
internal readonly partial struct BKTree
{
    private readonly struct Node(TextSpan wordSpan, int edgeCount, int firstEdgeIndex)
    {
        /// <summary>
        /// The string this node corresponds to.  Specifically, this span is the range of
        /// <see cref="_concatenatedLowerCaseWords"/> for that string.
        /// </summary>
        public readonly TextSpan WordSpan = wordSpan;
 
        ///<summary>How many child edges this node has.</summary>
        public readonly int EdgeCount = edgeCount;
 
        ///<summary>Where the first edge can be found in <see cref="_edges"/>.  The edges 
        ///are in the range _edges[FirstEdgeIndex, FirstEdgeIndex + EdgeCount)
        ///</summary>
        public readonly int FirstEdgeIndex = firstEdgeIndex;
 
        internal void WriteTo(ObjectWriter writer)
        {
            writer.WriteInt32(WordSpan.Start);
            writer.WriteInt32(WordSpan.Length);
            writer.WriteInt32(EdgeCount);
            writer.WriteInt32(FirstEdgeIndex);
        }
 
        internal static Node ReadFrom(ObjectReader reader)
        {
            return new Node(
                new TextSpan(start: reader.ReadInt32(), length: reader.ReadInt32()),
                edgeCount: reader.ReadInt32(), firstEdgeIndex: reader.ReadInt32());
        }
    }
}