namespace Qrakhen.Qamp.Core.Collections;

/// <summary>
///     Stack-like implementation with a few added features like seeking and setting values.
/// </summary>
/// <typeparam name="T"></typeparam>
public class StackLike<T> : Expander<T>,
    IPush<long, T>,
    IPop<T>,
    ISeekable<long, T>,
    IPeekable<T>,
    IToArray<T>
{
    public long Position => Count;

    public T this[int position] {
        get => Data[position];
        set => Data[position] = value;
    }

    public StackLike(int capacity = 0x10)
    {
        Data = new T[capacity];
        Count = 0;
    }

    public StackLike(IEnumerable<T> data)
    {
        Data = data.ToArray();
        Count = 0;
    }

    public long Push(T value) => Add(value);

    public T Pop() => Data[--Count];

    public T Seek(long position)
    {
        Count = position;
        return this[Count];
    }

    public T Peek(int delta = -1) => Data[Count + delta];

    public bool CanPeek(int delta = 0) 
        => Count + delta > -1 && Count + delta < Count;

    /// <summary>
    ///     Decimates this stack down to the given position, overwriting everything beyond that when pushing in the future.
    /// </summary>
    public void Decimate(long position)
    {
        Count = position;
    }

    public T[] ToArray() => Data.ToArray();
}