// 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;
using System.Collections;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.Collections;
 
public sealed class Enumerator : IEnumerator, ICloneable
{
    internal static IEnumerator Create(Snapshot snapshot)
    {
        var newEnumerator = new Enumerator(snapshot);
        return (IEnumerator)ComAggregate.CreateAggregatedObject(newEnumerator);
    }
 
    private readonly Snapshot _snapshot;
    private int _currentItemIndex;
 
    private Enumerator(Snapshot snapshot)
    {
        _snapshot = snapshot;
        Reset();
    }
 
    public object Current
    {
        get { return _snapshot[_currentItemIndex]; }
    }
 
    public bool MoveNext()
    {
        if (_currentItemIndex >= _snapshot.Count - 1)
        {
            return false;
        }
 
        _currentItemIndex++;
        return true;
    }
 
    public void Reset()
        => _currentItemIndex = -1;
 
    public object Clone()
        => Create(_snapshot);
}