// 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.
 
#nullable disable
 
using System.Collections.Immutable;
using Microsoft.VisualStudio.Shell.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.Library.VsNavInfo;
 
internal class NavInfoNodeEnum : IVsEnumNavInfoNodes
{
    private readonly ImmutableArray<NavInfoNode> _nodes;
    private int _index;
 
    public NavInfoNodeEnum(ImmutableArray<NavInfoNode> nodes)
        => _nodes = nodes;
 
    public int Clone(out IVsEnumNavInfoNodes ppEnum)
    {
        ppEnum = new NavInfoNodeEnum(_nodes);
        return VSConstants.S_OK;
    }
 
    public int Next(uint celt, IVsNavInfoNode[] rgelt, out uint pceltFetched)
    {
        var i = 0;
        for (; i < celt && _index < _nodes.Length; i++, _index++)
        {
            rgelt[i] = _nodes[_index];
        }
 
        pceltFetched = (uint)i;
 
        return i < celt
            ? VSConstants.S_FALSE
            : VSConstants.S_OK;
    }
 
    public int Reset()
    {
        _index = 0;
        return VSConstants.S_OK;
    }
 
    public int Skip(uint celt)
    {
        _index += (int)celt;
        return VSConstants.S_OK;
    }
}