using System.Collections.Generic;

using Rokojori.Extensions;
namespace Rokojori;


public class RingBuffer<T>
{
    protected readonly T[] _buffer;
    protected int _head;
    protected int _count;

    public RingBuffer( int capacity )
    {
      _buffer = new T[capacity];
    }

    public int count => _count;
    public int capacity => _buffer.Length;

    public void ForEach( System.Action<T> callback )
    {      
      for ( int i = 0; i < _count; i++ )
      {
        callback( this[ i ] );
      }
    }

    public int CountItems( System.Predicate<T> predicate  )
    {      
      var num = 0;

      for ( int i = 0; i < _count; i++ )
      {
        if ( predicate( this[ i ] ) )
        {
          num ++;
        }
      }

      return num;
    }

    public void Add( T item )
    {
      int index = (_head + _count) % capacity;

      _buffer[index] = item;

      if (_count == capacity)
      {
        _head = (_head + 1) % capacity;
      }
      else
      {
        _count ++;
      }
    }

    public T this[int index]
    {
      get
      {
        if ( (uint)index >= (uint)_count )
        {
          throw new System.ArgumentOutOfRangeException( nameof( index ) );
        }

        return _buffer[ ( _head + index ) % capacity ];
      }
    }
}