Pathsite

using UnityEngine;
using System.Collections.Generic;
using System;
using System.Linq;


public class PathSite : MonoBehaviour, Node{

    private List<PathSite> previousNeighbouringSites=new List<PathSite>();
    public List<PathSite> NeighbouringSites=new List<PathSite>();

    void OnValidate(){
        List<PathSite> wereRemoved = previousNeighbouringSites.Except<PathSite>(NeighbouringSites).ToList();
        List<PathSite> wereAdded = NeighbouringSites.Except<PathSite>(previousNeighbouringSites).ToList();

        foreach (PathSite p in wereRemoved){
            if(p != null && p.NeighbouringSites.Contains(this)){
                Debug.Log("removed site");
                p.NeighbouringSites.Remove(this);
                p.previousNeighbouringSites=new List<PathSite>(p.NeighbouringSites);
            }
        }

        foreach (PathSite p in wereAdded){
            if(p!= null && !p.NeighbouringSites.Contains(this)){
                Debug.Log("added site");
                //check if there any empty slots
                int i=p.NeighbouringSites.IndexOf(null);
                if(i!=-1){
                    p.NeighbouringSites[i]=this;
                }else{
                    p.NeighbouringSites.Add(this);
                }
                p.previousNeighbouringSites=new List<PathSite>(p.NeighbouringSites);
            }
        }

        previousNeighbouringSites=new List<PathSite>(NeighbouringSites);
    }


    void Start(){}

    void Update(){}

    public List<Node> neighbours(){
        List<Node> recastedNodes=new List<Node>();
        foreach (PathSite n in NeighbouringSites){
            recastedNodes.Add(n);
        }
        return recastedNodes;
    }

    public Double weight(Node n){
        return 1;
    }

    public void OnDrawGizmos() {
        Transform me=this.GetComponent<Transform>();
        foreach (PathSite n in NeighbouringSites) {
            if(n!= null && n.NeighbouringSites.Contains(this)){
                Gizmos.color = Color.blue;
                Transform neighbour=n.GetComponent<Transform>();
               Gizmos.DrawLine(neighbour.position, me.position);
            }else{
                Gizmos.color = Color.red;
                Gizmos.DrawSphere(me.position, .4f);
            }
        }
        Gizmos.color = Color.blue;
        Gizmos.DrawSphere(me.position, .25f);
        Gizmos.color = Color.black;
        Gizmos.DrawSphere(me.position-2*Vector3.up, .4f);
    }


}