using System;
using System.Collections;

namespace MagicArray
{
	/// <summary>
	/// ACHTUNG:
	/// NACH COPYTO ARBEITET FASTCONTAINS NICHT DA HASHTABLE LEER!
	/// </summary>
	public class FastArrayList : ArrayList 
	{

		// für viele Elemente optimieren
		Hashtable _innerHash = new Hashtable(20000);

		/*
		 * Wird von Add Range gebraucht, scheint allerdings keine Seiteneffekte zu haben
		 * 
		public override void CopyTo(int index, Array array, int arrayIndex, int count)
		{
			throw new NotImplementedException("CopyTo steht in FastArrayList nicht zur Verfügung");
		}
		public override void CopyTo(Array array)
		{
			throw new NotImplementedException("CopyTo steht in FastArrayList nicht zur Verfügung");
		}
		public override void CopyTo(Array array, int arrayIndex)
		{
			throw new NotImplementedException("CopyTo steht in FastArrayList nicht zur Verfügung");
		}
	*/

		private void addToHash(object obj) 
		{
			if (_innerHash.ContainsKey(obj)) 
			{
				// erhöhe Zähler für dieses Object
				_innerHash[obj] = (int)_innerHash[obj] + 1;
			}
			else 
			{
				_innerHash[obj] = 1;
			}
		}

		private void removeFromHash(object obj) 
		{
			if (_innerHash.Contains(obj)) 
			{
				int c = (int)_innerHash[obj];
				if (c > 1) 
				{
					_innerHash[obj] = c - 1;
				}
				else 
				{
					_innerHash.Remove(obj);
				}
			}
		}

		public FastArrayList() : base()
		{
		}

		public FastArrayList(ICollection c) : base(c)
		{
			foreach (object obj in c) addToHash(obj);
		}

	
		public override int Add(object o) 
		{
			addToHash(o);
			return base.Add(o);
		}

		public override void AddRange(ICollection c) 
		{
			base.AddRange(c);
			foreach (object o in c) addToHash(o);
		}

		public override void Clear() 
		{
			base.Clear();
			_innerHash.Clear();
		}

		public override object Clone() 
		{
			FastArrayList o = (FastArrayList) base.Clone();
			o._innerHash = (Hashtable) _innerHash.Clone();
			return o;
		}

		public bool FastContains(object o)
		{
			return _innerHash.ContainsKey(o);
		}

		public override bool Contains(object o) 
		{
			return base.Contains(o);
		}

		public override void Insert(int index, object value) 
		{
			if(index < base.Count && index >= 0 && base[index]!=null)
			{
				removeFromHash(base[index]);
			}
			base.Insert(index, value);
			addToHash(value);
		}

		public override void InsertRange(int index, ICollection c) 
		{
		
			for(int i = index; i < Math.Min(this.Count, index + c.Count); i++)
			{
				removeFromHash(base[i]);
			}
			base.InsertRange(index, c);
			foreach (object o in c) addToHash(o);
		}

		public override void Remove(object o) 
		{
			base.Remove(o);
			removeFromHash(o);
		}

		public override void RemoveAt(int index) 
		{
			removeFromHash(base[index]);
			base.RemoveAt(index);
		}

		public override void RemoveRange(int index, int count)
		{
			for(int i = index; i < count; i++)
			{
				removeFromHash(base[i]);
			}
			base.RemoveRange (index, count);
		}

		public override void SetRange(int index, ICollection c) 
		{
			int j = 0;
			int i = 0;
			IEnumerator ienum = c.GetEnumerator();
			while(ienum.MoveNext())
			{
				if(i >= index)
				{
					this.Insert(j, ienum.Current);
					j++;
				}
				i++;
			}	
		}

		public override object this[int index]
		{
			get
			{
				return base[index];
			}
			set
			{
				removeFromHash(base[index]);
				base[index] = value;				
				addToHash(value);
			}
		}


	}

}