using System.Collections;

namespace Numbers.NumberFactory;

/// <summary>
///     An enumerator for a list of numbers
/// </summary>
/// <inheritdoc cref="IEnumerator{T}" />
public sealed class NumbersEnumerator : IEnumerator<long>
{
    /// <summary>
    ///     Creates a new instance of <see cref="NumbersEnumerator" /> which will enumerate over the given list
    /// </summary>
    /// <param name="list">List to iterate over</param>
    public NumbersEnumerator(List<long> list)
    {
        List = list;
        Index = -1;
    }

    private int Index { get; set; }
    private List<long> List { get; }

    public long Current
    {
        get
        {
            if (Index < 0 || Index >= List.Count)
            {
                return -1;
            }
            
            return List[Index];
        }
    }

    public void Dispose() { }

    object IEnumerator.Current => Current;

    public bool MoveNext()
    {
        if (Index >= List.Count - 1)
        {
            return false;
        }

        Index++;
        return true;

    }

    public void Reset()
    {
        Index = -1;
    }
}