/*
 * Copyright (c) 2005-2006 Erik Tigerholm <eriktigerholm@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
using System;
using System.Collections.Generic;
using System.Text;

namespace OpenTraffic.Model.Graph.Partioning
{
    public class MultiGraph<TV, TE> : Graph<MultiVertex<TV>, GraphEdge<MultiVertex<TV>>>
        where TV : Vertex
        where TE : GraphEdge<TV>
    {
        private List<List<MultiVertex<TV>>> changeList;
        private List<MultiVertex<TV>> activeList;

        public MultiGraph()
            :
            base()
        {
            changeList = new List<List<MultiVertex<TV>>>();
        }

        public void NewPoint()
        {
            activeList = new List<MultiVertex<TV>>();
            changeList.Add(activeList);
        }

        public void Join(MultiVertex<TV> v1, MultiVertex<TV> v2)
        {
            if (v1 != null && v2 != null)
            {
                if (v2.Id == v1.Id) return;
                activeList.Insert(0, v1);
                // Change the edges to point to the new element
                foreach (GraphEdge<MultiVertex<TV>> pm in AdjLinks[v2])
                {
                    pm.Source = v1;
                    AdjLinks[v1].Add(pm);
                }

                foreach (GraphEdge<MultiVertex<TV>> pm in RevAdjLinks[v2])
                {
                    pm.Target = v1;
                    RevAdjLinks[v1].Add(pm);
                }
                v1.Join(v2);

                // Remove the joined element
                Nodes.Remove(v2);
                AdjLinks.Remove(v2);
                RevAdjLinks.Remove(v2);
            }
        }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")]
        public Dictionary<MultiVertex<TV>, MultiVertex<TV>> ReverseToNextPoint()
        {
            if (activeList == null) throw new InvalidOperationException("No more point stored");
            Dictionary<MultiVertex<TV>, MultiVertex<TV>> list = new Dictionary<MultiVertex<TV>, MultiVertex<TV>>();
            foreach (MultiVertex<TV> v in this.activeList)
            {
                MultiVertex<TV> v2 = v.Reverse();
                list.Add(v, v2);

                RevAdjLinks.Add(v2, new List<GraphEdge<MultiVertex<TV>>>());
                AdjLinks.Add(v2, new List<GraphEdge<MultiVertex<TV>>>());
                this.Expand(v, v2);
            }
            changeList.RemoveAt(changeList.Count - 1);
            if (changeList.Count == 0)
            {
                activeList = null;
            }
            else
            {
                activeList = changeList[changeList.Count - 1];
            }
            return list;
        }
        private void Expand(MultiVertex<TV> mv1, MultiVertex<TV> mv2)
        {
            if (mv1.Id == mv2.Id)
                return;
            foreach (GraphEdge<MultiVertex<TV>> pm in mv2.Edges)
            {
                if (pm.Source == mv1)
                {
                    pm.Source = mv2;
                    AdjLinks[mv1].Remove(pm);
                    AdjLinks[mv2].Add(pm);
                }
                else
                {
                    pm.Target = mv2;
                    RevAdjLinks[mv1].Remove(pm);
                    RevAdjLinks[mv2].Add(pm);

                }
            }

            Nodes.Add(mv2);
        }

        public override void Add(GraphEdge<MultiVertex<TV>> e)
        {
            if (e != null)
            {
                base.Add(e);
                e.Source.Edges.Add(e);
                e.Target.Edges.Add(e);
            }
        }
    }
}