using System.Collections;
using System.Collections.Generic;

namespace JungleDB
{
	public class NetworkNodePath : NodePath
	{
		LinkedList<int> Path;

		public NetworkNodePath()
		{
			Path = new LinkedList<int>();
			Path.AddFirst(-1);
		}

		public NetworkNodePath(NodePath path)
		{
			Path = new LinkedList<int>();
			foreach (int p in path)
			{
				Path.AddLast(p);
			}
		}

		// msg pack ni pointer wo watasenai point youso wo narabikaeru.
		private NetworkNodePath(LinkedList<int> path)
		{
			this.Path = path;
		}

		IEnumerator IEnumerable.GetEnumerator()
		{
			return this.GetEnumerator();
		}

		public IEnumerator<int> GetEnumerator()
		{
			foreach (var l in Path)
			{
				yield return l;
			}
		}

		public NodePath add(int pos)
		{
			LinkedList<int> newPath = copyPath();
			newPath.AddLast(pos);
			return new NetworkNodePath(newPath);
		}

		public NodePath addHead(int pos)
		{ // still java code.
			LinkedList<int> newPath = copyPath();
			newPath.AddFirst(pos);
			return new NetworkNodePath(newPath);
		}

		public Pair<int, NodePath> pop()
		{
			LinkedList<int> cPath = copyPath();
			int e = cPath.First.Value;
			cPath.RemoveFirst();
			return new Pair<int, NodePath>(e, new NetworkNodePath(cPath));
		}

		public int size()
		{
			return this.Path.Count;
		}


		public LinkedList<int> copyPath()
		{
			LinkedList<int> newPath = new LinkedList<int>();
			foreach (int i in this.Path)
			{
				newPath.AddLast(i);
			}
			return newPath;
		}

		public override string ToString()
		{
			return Path.ToString();
		}

		public NodePath tail()
		{
			this.Path.RemoveLast();
			return new NetworkNodePath(this.Path);
		}

		public Pair<int, NodePath> last()
		{
			int lastValue = this.Path.Last.Value;
			this.Path.RemoveLast();
			return new Pair<int, NodePath>(lastValue, new NetworkNodePath(this.Path));
		}



	}
}