namespace Qrakhen.Qamp.Core.Collections;

/// <summary>
///     Push-only Stack that is based on <see cref="Expander{T}"/>.
/// </summary>
/// <typeparam name="T"></typeparam>
public class PushStack<T> : 
    Expander<T>, 
    IPush<long, T>,
    IToArray<T>
{
    public PushStack(int initialCapacity = 0x10)
    {
        Data = new T[initialCapacity];
    }

    public T? Find(Func<T, bool> callback)
    {
        for (int i = 0; i < Count; i++)
            if (callback(Data[i]))
                return Data[i];
        return default;
    }

    public void Push(T[] array)
    {
        foreach (T value in array) {
            Add(value);
        }
    }

    public void Push(IEnumerable<T> array)
    {
        foreach (T value in array) {
            Add(value);
        }
    }

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

    public bool TryGet(long index, out T value)
    {
        value = default;
        if (index < 0 || index >= Count)
            return false;
        value = Data[index];
        return true;
    }

    public T[] ToArray() => Data.Subset(0, Count);

    public T[] Subset(long from, int length)
    {
        T[] result = new T[length];
        Array.Copy(Data, from, result, 0, length);
        return result;
    }
}