package Simulator;

import java.io.*;

/**
  * Models links in the simulator.
*/
public class Link extends NetComponents {

    // Fields
    private int number;   // link number
    double Distance;
    double LocalTime;   // need to be reset to zero in Cprobing Statistic
    private double propagationTime;
    private NetworkConfigure simulator;

    // the following variables are used only for bandwidth measurement
    // These variables are meaningful only for the bottleneck link
    double Tstarting_time = 0.0;  // traffic measurement starting time
    //double end_time;              // traffic measurement end time
    long   Transfered_bit = 0;  // the transfered bits in a traffic measure cycle
    //int DelayTransfered_bit = 0;  // the bits delay to transfer at the next time cycle
    boolean BottleneckLink;     // whether the link is the bottleneck link
    double LinkBandwidth;

    PrintWriter OFILE;     // only for the bottleneck link log purpose.

    // Constructor
    public Link(NetworkConfigure simulator, double distance, int number, double LinkBandwidth) {
        String k = simulator.getClass().getName();
        this.simulator = simulator;
        this.BottleneckLink = false;
        this.propagationTime = distance / simulator.signalPropagationSpeed;
        this.number = number;
        this.LocalTime = 0.0;
        this.LinkBandwidth = LinkBandwidth;
        this.Distance = distance;
        //this.end_time = Tstarting_time + simulator.TBIntervalTime;

        try {
          this.OFILE = new PrintWriter(new FileWriter("LFile"+number+".txt"));
        }
        catch (IOException e) {
        }
    }

    // Commands
    public boolean EventHandler (Message Mess) {
      int index=0;
      double ATime = Mess.getArrivalTime();

      if (Mess.MessageType.compareTo("ICMP-request") == 0)
        index = Mess.NextObjectIndex;
      else
        index = 2*(simulator.RoadTable[Mess.RouterTableNum].numOfNode-1)-Mess.NextObjectIndex; //"ICMP-response"


      if (BottleneckLink  && (Mess.getArrivalTime()>7.752) && (Mess.getArrivalTime()<7.758))
          ATime = Mess.getArrivalTime();

      if (LocalTime > Mess.getArrivalTime()) {
        if ((Mess.MessageType.compareTo("ICMP-request") == 0)
           || (Mess.MessageType.compareTo("ICMP-response") == 0))
          Mess.QueuingTime[index] = LocalTime - Mess.getArrivalTime();
      }
      else {
        LocalTime = Mess.getArrivalTime();
        if ((Mess.MessageType.compareTo("ICMP-request") == 0)
           || (Mess.MessageType.compareTo("ICMP-response") == 0))
          Mess.QueuingTime[index] = 0.0;
      }
      //double begin_handleTime = LocalTime;    // what is the real time to handle the message

      double transmissionTime = Mess.getSize()/LinkBandwidth;
      LocalTime += transmissionTime;
      Mess.setTime(LocalTime+propagationTime);
      Mess.setNextNode(simulator.RoadTable[Mess.RouterTableNum].numOfNode);

      if (BottleneckLink  && simulator.NeedTraffic) {
          //if (LocalTime <= end_time)
              Transfered_bit += Mess.getSize();
          //else {  // one message is handled across the traffic measurement time boundary
          //    Transfered_bit += (long)(((end_time - begin_handleTime)/(LocalTime - begin_handleTime))*Mess.getSize())+DelayTransfered_bit;
          //    DelayTransfered_bit = (int)(((LocalTime - end_time)/(LocalTime - begin_handleTime))*Mess.getSize());
          //}
      }

      // Link always return false because a link is unlikely to be the
      // last object in a road table. A road always starts and ends by a router
      OFILE.println(Mess.MessNum + "  : "+ATime+"  |  "+LocalTime+"  |  "+Mess.MessageType+"  |  "+Mess.getSize());
      return false;
    }

    public void reset_bottlelink (double init_time) {
      this.Tstarting_time = init_time;
      //this.end_time = init_time + simulator.TBIntervalTime;
      //this.Transfered_bit = DelayTransfered_bit;     // a new measure cycle
      //this.DelayTransfered_bit = 0;
      this.Transfered_bit = 0;
    }


    public double getLocalTime() {
        return LocalTime;
    }
}