import javax.swing.*;

    public class RouterNode {
      private int myID;
      private GuiTextArea myGUI;
      private RouterSimulator sim;
      private int [] Neighbours = new int[RouterSimulator.NUM_NODES];
      private int[][] UpdatedConnectcosts = new int[RouterSimulator.NUM_NODES][RouterSimulator.NUM_NODES];

      private int[] costs = new int[RouterSimulator.NUM_NODES];
      private int[] ByNode = new int[RouterSimulator.NUM_NODES];
      private boolean PoisonedReverse = false;

      //--------------------------------------------------
      public RouterNode(int ID, RouterSimulator sim, int[] costs) {
        myID = ID;
        this.sim = sim;
        myGUI =new GuiTextArea("  Output window for Router #"+ ID + "  ");

        //Added
        System.arraycopy(costs, 0, this.costs, 0, RouterSimulator.NUM_NODES);
        System.arraycopy(costs, 0, this.Neighbours, 0, RouterSimulator.NUM_NODES);

        for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
        {
            if (i == this.myID)
            {
                //costs[this.myID] = 0;
                System.arraycopy(costs, 0, this.UpdatedConnectcosts[i], 0, RouterSimulator.NUM_NODES);

            }
            else
            {
                for (int j = 0; j < RouterSimulator.NUM_NODES; j++)
                    {
                        this.UpdatedConnectcosts[i][j] = RouterSimulator.INFINITY;
                    }
            }
        }

        sendCosts();

        for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
            {
                if (costs[i] != RouterSimulator.INFINITY){
                    ByNode[i] = i;
                }
                else{
                    ByNode[i] = -1;
                }

            }

      }


      //--------------------------------------------------
        private void sendCosts()
        {
            for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
            {
                if ( i != this.myID && !PoisonedReverse && Neighbours[i] != RouterSimulator.INFINITY)
                    {
                        //Make a Router_Packet and send it.
                        RouterPacket pkt = new RouterPacket(this.myID, i, this.costs);
                        sendUpdate(pkt);
                    }
                else
                    {
                        //PoisonedReverse
                    }
            }
        }



      //--------------------------------------------------
      public void recvUpdate(RouterPacket pkt) {


          System.arraycopy(pkt.mincost,0,this.UpdatedConnectcosts[pkt.sourceid],0,RouterSimulator.NUM_NODES);
          myGUI.println ("Update received from pkt: " + pkt.destid)    ;

          // If the Bellman function modify something
          if( Bellman() )
              {

                  // Send the modification to neighbors
                  sendCosts();

              }


      }


      //--------------------------------------------------
      private void sendUpdate(RouterPacket pkt) {
        sim.toLayer2(pkt);

      }


      //--------------------------------------------------
      public void printDistanceTable() {
              myGUI.println("Current table for " + myID +
                            "  at time " + sim.getClocktime());
              myGUI.println("Distancetable:");
              myGUI.print("    dst  |");
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                              myGUI.print("     " + i);
              }
              myGUI.println();
              myGUI.print("---------");
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                  myGUI.print("-------");
              }
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                      // If it's a direct neighbor
                     // if(Neighbours[i] != RouterSimulator.INFINITY && i != myID)
                      //{
                          myGUI.println();
                          myGUI.print(F.format(" nbr", 6));
                          myGUI.print(i + " |");
                          for(int j = 0; j < RouterSimulator.NUM_NODES; j++)
                              {
                                      myGUI.print("  " + F.format(UpdatedConnectcosts[i][j], 3));
                              }
                     // }
              }
              myGUI.println();
              myGUI.println();
              myGUI.println("Our distance vector and routes:");
              myGUI.print("    dst  |");
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                  myGUI.print(F.format(i,4));
              }
              myGUI.println();
              myGUI.print("---------");
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                      myGUI.print("-------");
              }
              myGUI.println();
              myGUI.print(" cost   |");
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                      myGUI.print("  " + F.format(costs[i], 3));
              }
              myGUI.println();
              myGUI.print(F.format(" route |",8));
              for (int i = 0; i < RouterSimulator.NUM_NODES; i++)
              {
                  if (ByNode[i] != -1)
                  {
                      myGUI.print("  " + F.format(ByNode[i], 3));
                  }
                  else
                  {
                      myGUI.print("  " + F.format('-', 3));
                  }
              }
              myGUI.println();
              myGUI.println();
      }


      //--------------------------------------------------
      private  boolean Bellman()
        {

            boolean changed = false;


            for(int dest = 0; dest < RouterSimulator.NUM_NODES; dest++)
            {
                int firstHop = RouterSimulator.INFINITY;
                int min_cost = RouterSimulator.INFINITY;
                if(dest==this.myID)
                {
                    costs[dest] = 0;
                }
                else
                {
                    for (int neig = 0; neig < RouterSimulator.NUM_NODES; neig++)
                    {
                        if ((Neighbours[neig] != RouterSimulator.INFINITY) && (Neighbours[neig] != 0))
                        {

                            if (Neighbours[neig] + UpdatedConnectcosts[neig][dest] < min_cost)
                            {
                                min_cost = Neighbours[neig] + UpdatedConnectcosts[neig][dest];
                                firstHop = neig;

                            }
                        }
                    }

                    if ((min_cost != this.costs[dest]) && (min_cost != RouterSimulator.INFINITY))
                    {
                        ByNode[dest] = firstHop;
                        this.costs[dest] = min_cost;
                        changed = true;
                    }
                }
            }
            if (changed){
                UpdatedConnectcosts[this.myID] = this.costs;
            }
            return changed;
        }


      //--------------------------------------------------
      public void updateLinkCost(int dest, int newcost) {

      }

    }