designPatternGuru/DesignPatternGuru/Iterator/Iterators/AlphabeticalOrderIterator.cs

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

namespace Iterator.Iterators
{
    internal class AlphabeticalOrderIterator : Iterator
    {
        private WordsCollection _collection;

        private int _position = -1;

        private bool _reverse = false;

        public AlphabeticalOrderIterator(WordsCollection collection, bool reverse = false)
        {
            _collection = collection;
            _reverse = reverse;

            if (_reverse)
            {
                _position = collection.GetItems().Count;
            }
        }

        public override object Current()
        {
            return _collection.GetItems()[_position];
        }

        public override int Key()
        {
            return _position;
        }

        public override bool MoveNext()
        {
            int updatedPosition = _position + (_reverse ? -1: 1);
            if (updatedPosition < 0 || updatedPosition >= _collection.GetItems().Count)
                return false;

            _position = updatedPosition;
            return true;
        }

        public override void Reset()
        {
            _position = _reverse ? _collection.GetItems().Count - 1 : 0;
        }
    }
}