using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WinFormsApp1
{
    internal class SetTraktorGeneric<T>
              where T : class
    {
        private readonly List<T> _places;
        public int Count => _places.Count;
        private readonly int _maxCount;
        private int TractorPlaces = 0;

        public SetTraktorGeneric(int count)
        {
            _maxCount = count;
            _places = new List<T>(); ;
        }

        public int Insert(T tractor)
        {
            return Insert(tractor, 0);
        }

        public int Insert(T tractor, int position)
        {
            if (position < 0 && position > _maxCount)
            {
                return -1;
            }
            else
            {
                _places.Insert(position, tractor);
                return position;
            }
        }

        public T Remove(int position)
        {
            if (position < 0 || position >= _maxCount)
            {
                return null;
            }
            var result = _places[position];
            _places.RemoveAt(position);
            return result;
        }

       
        public T this[int position]
        {
            get
            {
                if (position >= 0 && position < _maxCount && position < Count)
                {
                    return _places[position];
                }
                else
                {
                    return null;
                }
            }
            set
            {
                Insert(value, position);
            }
        }

        public IEnumerable<T> GetBuses()
        {
            foreach (var traktor in _places)
            {
                if (traktor != null)
                {
                    yield return traktor;
                }
                else
                {
                    yield break;
                }
            }
        }
    }
}