// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Collections;

namespace System.Windows.Forms;

internal class ArraySubsetEnumerator : IEnumerator
{
    private readonly object[] _array;
    private readonly int _total;
    private int _current;

    public ArraySubsetEnumerator(object[] array, int count)
    {
        Debug.Assert(count == 0 || array is not null, "if array is null, count should be 0");
        Debug.Assert(array is null || count <= array.Length, "Trying to enumerate more than the array contains");
        _array = array!;
        _total = count;
        _current = -1;
    }

    public bool MoveNext()
    {
        if (_current < _total - 1)
        {
            _current++;
            return true;
        }

        return false;
    }

    public void Reset() => _current = -1;

    public object? Current => _current == -1 ? null : _array[_current];
}
