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
    //long queuing_size = 0;    // holding the message size which is need to be queued.
    //boolean updated = false;  // if set queuing_size=0
    double end_time;          // what is the time of a general probing end
    long   Transfered_bit = 0;  // the transfered bits in a traffic measure cycle
    boolean BottleneckLink;     // whether the link is the bottleneck link

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

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

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

    /*
    public Link(Measurement simulator, double distance, int number) {
        this.number = number;
        this.LocalTime = 0.0;
        this.Distance = distance;
        //this.Distance = 1000;
        this.simulator = simulator;
        this.BottleneckLink = false;
        this.propagationTime = distance / simulator.signalPropagationSpeed;
        try {
          this.OFILE = new PrintWriter(new FileWriter("LFile"+number+".txt"));
        }
        catch (IOException e) {
        }
    }


    public Link(CprobStatistic simulator, double distance, int number) {
        this.number = number;
        this.LocalTime = 0.0;
        this.Distance = distance;
        //this.Distance = 1000;
        this.simulator = simulator;
        this.BottleneckLink = false;
        this.propagationTime = distance / simulator.signalPropagationSpeed;
        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 (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 old_LocalTime = LocalTime;

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

      if (BottleneckLink  && simulator.NeedTraffic) {
        // this is the bottleneck, count the precise bits sent in a statistic cycle
        if (LocalTime <= end_time)
           Transfered_bit = Transfered_bit + Mess.getSize();
        else {  // Local time is greater than end time
          if (old_LocalTime < end_time) { // arrival time is less than end_time
            Transfered_bit = Transfered_bit + (long)(Math.floor(Mess.getSize()*
                      ((end_time-old_LocalTime)/(LocalTime-old_LocalTime))));
            // update the log file and chart
            simulator.UpdateLog(end_time);
            double old_endtime = end_time;
            reset_bottlelink(end_time);
            Transfered_bit = (long)(Math.ceil(Mess.getSize()*((LocalTime-old_endtime)/(LocalTime-old_LocalTime))));
          }
          else  { // arrival time is greater than end_time
            simulator.UpdateLog(end_time);
            reset_bottlelink(end_time);
            Transfered_bit = Mess.getSize();
          }
        }
      }
      // Link always return False because a link is unlikely to be the
      // last object in a road. A road always starts and ends at 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.Transfered_bit = 0;     // a new measure cycle
      this.end_time = Tstarting_time + simulator.TBIntervalTime;
    }


    public double getLocalTime() {
        return LocalTime;
    }
}