using System.Collections.Generic;
using UnityEngine;

namespace NWH.DWP2.MeshDecimation
{
    public class Vert
    {
        public Vector3    position;
        public List<Tri>  face     = new List<Tri>();
        public List<Vert> neighbor = new List<Vert>();

        public int   id;
        public float cost;
        public Vert  collapse;
        public bool  selected;
        public bool  deleted;


        public Vert(Vector3 position, int id, bool selected)
        {
            this.position = position;
            this.id       = id;
            this.selected = selected;

            cost     = 0f;
            collapse = null;
        }


        public void RemoveVert()
        {
            Vert nb;
            while (neighbor.Count > 0)
            {
                nb = neighbor[0];
                nb.neighbor.Remove(this);
                neighbor.Remove(nb);
            }

            deleted = true;
        }


        public bool IsBorder()
        {
            int  j;
            int  n = neighbor.Count;
            Vert nb;
            int  face_len;
            Tri  f;
            int  count = 0;

            for (int i = 0; i < n; ++i)
            {
                count    = 0;
                nb       = neighbor[i];
                face_len = face.Count;
                for (j = 0; j < face_len; ++j)
                {
                    f = face[j];
                    if (f.HasVertex(nb))
                    {
                        ++count;
                    }
                }

                if (count == 1)
                {
                    return true;
                }
            }

            return false;
        }


        public void AddFace(Tri f)
        {
            face.Add(f);
        }


        public void RemoveFace(Tri f)
        {
            face.Remove(f);
        }


        public void AddNeighbor(Vert v)
        {
            int i;
            int foundAt = -1;
            int n       = neighbor.Count;

            for (i = 0; i < n; ++i)
            {
                if (neighbor[i] == v)
                {
                    foundAt = i;
                    break;
                }
            }

            if (foundAt == -1)
            {
                neighbor.Add(v);
            }
        }


        public void RemoveIfNonNeighbor(Vert v)
        {
            int i;
            int foundAt = -1;
            int n       = neighbor.Count;
            Tri f;

            for (i = 0; i < n; ++i)
            {
                if (neighbor[i] == v)
                {
                    foundAt = i;
                    break;
                }
            }

            if (foundAt == -1)
            {
                return;
            }

            n = face.Count;
            for (i = 0; i < n; ++i)
            {
                f = face[i];
                if (f.HasVertex(v))
                {
                    return;
                }
            }

            neighbor.Remove(v);
        }
    }
}