/**
 * selma
 */

package SSF.OS.BGP4;


import java.io.*;
import java.util.*;
import SSF.OS.BGP4.Comm.*;
import SSF.OS.BGP4.Path.*;
import SSF.OS.BGP4.Util.*;


// ===== class SSF.OS.BGP4.PathChangeEvent =========================================== //

public class PathChangeEvent {

    String sign;  //"plus" or "minus"
    ArrayList aspath; //aspath = null;

    /////////////////
    public PathChangeEvent(){
	sign="";
	aspath=new ArrayList();
    }

    public PathChangeEvent computePCE(Route old, String sign,String as_nh ){
	//to make a pce =(sign , ASpath of old)
	PathChangeEvent pce=null;
	if (old==null) return null;
	else {
	    pce=new PathChangeEvent();   pce.sign = sign;
	    ASpath copied = (((ASpath)old.pas[ASpath.TYPECODE]));
	    ArrayList segs=copied.segs;	
	    for (int i=0; i<segs.size(); i++){ 	//System.out.println(" in here??  4");
		Segment ns=new Segment ((Segment)segs.get(i));
		ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
		pce.aspath.add(ns);
	    }
	    return pce;
	}
    }

    public PathChangeEvent computePCE(Route r_old, Route r_new,String as_nh ){

	PathChangeEvent pce=null;

	if (r_old==null && r_new!=null){
	    History h=((History)(r_new.pas[History.TYPECODE]));
	    if (h!=null)
		    pce=new PathChangeEvent();   
		    pce.sign = "plus";
		    ASpath copied = (((ASpath)r_new.pas[ASpath.TYPECODE]));
		    ArrayList segs=copied.segs;	
		    for (int i=0; i<segs.size(); i++){ 
			Segment ns=new Segment ((Segment)segs.get(i));
			ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
			pce.aspath.add(ns);
		    }
	}
	else if (!r_old.equal_attribs(r_new)) { 
		
	     if ( r_old.pas[ASpath.TYPECODE]==null && r_new.pas[ASpath.TYPECODE]!=null ){  
	    	ASpath copied = (((ASpath)r_new.pas[ASpath.TYPECODE]));
		ArrayList segs=copied.segs;
	
		pce=new PathChangeEvent();   
		for (int i=0; i<segs.size(); i++){ 
		  
		    pce.sign = "plus";
		    Segment ns=new Segment ((Segment)segs.get(i));
		    ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
		    pce.aspath.add(ns);
		}
	
	    }	
	    else if (r_old.pas[ASpath.TYPECODE]!=null && r_new.pas[ASpath.TYPECODE]==null)  { 
	
		ASpath copied = (((ASpath)r_old.pas[ASpath.TYPECODE]));
		ArrayList segs=copied.segs;
	
		pce=new PathChangeEvent();  
		for (int i=0; i<segs.size(); i++){ 
		  
		    pce.sign = "minus"; 
		    Segment ns=new Segment ((Segment)segs.get(i));
		    ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
		    pce.aspath.add(ns);
		}
	    }	
	     else if (r_old.localpref() < r_new.localpref()) { 
		ASpath copied = (((ASpath)r_new.pas[ASpath.TYPECODE]));
		ArrayList segs=copied.segs;
		pce=new PathChangeEvent();    
		for (int i=0; i<segs.size(); i++){    
                    pce.sign = "plus";
		    Segment ns=new Segment ((Segment)segs.get(i));
		    ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
		    pce.aspath.add(ns); 
		   
		}
	    }
	     else if (r_old.localpref() > r_new.localpref()){ 

		ASpath copied = (((ASpath)r_old.pas[ASpath.TYPECODE]));
		ArrayList segs=copied.segs;
		pce=new PathChangeEvent(); 
		for (int i=0; i<segs.size(); i++){  
		  
		    pce.sign = "minus";  
		    Segment ns=new Segment ((Segment)segs.get(i));
		    ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
		    pce.aspath.add(ns); 
		    
		}
	    }
	     else if((r_old.localpref() == r_new.localpref()) && !(r_old.equals(r_new)) ) { 
		History hst=((History)(r_new.pas[History.TYPECODE]));
		//hst may be empty
                if (hst.history.size()==0) {
		    ASpath copied = (((ASpath)r_new.pas[ASpath.TYPECODE]));
		    ArrayList segs=copied.segs;
		   
		    pce=new PathChangeEvent();    
		    for (int i=0; i<segs.size(); i++){    
			pce.sign = "plus";
			Segment ns=new Segment ((Segment)segs.get(i));
			ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
			pce.aspath.add(ns); 
			
			}
		}
		else {
		    String tmp=((PathChangeEvent)(hst.history.elementAt(hst.history.size()-1))).sign;
		    if (tmp.equals("plus")){
			if (r_new.pas[ASpath.TYPECODE] != null) {

			    ASpath copied = (((ASpath)r_new.pas[ASpath.TYPECODE]));
			    ArrayList segs=copied.segs;

			    pce=new PathChangeEvent(); 
			    for (int i=0; i<segs.size(); i++){
				
				pce.sign = "plus";
				Segment ns=new Segment ((Segment)segs.get(i));
				ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
				pce.aspath.add(ns); 
			    }
			}
		    }
		    else if (tmp.equals("minus")){
			if (r_old.pas[ASpath.TYPECODE] != null) {

			    ASpath copied = (((ASpath)r_old.pas[ASpath.TYPECODE]));
			    ArrayList segs=copied.segs; 
			    pce=new PathChangeEvent(); 
			    for (int i=0; i<segs.size(); i++){	
				
				pce.sign = "minus";
				Segment ns=new Segment ((Segment)segs.get(i));
				ns.asnhs.add(0,as_nh);   //add this BGPspeaker's asnhs to the beginning of the segment
				pce.aspath.add(ns);
			    }
			}
		    }

		}
	    }
	    else if (r_old.equals(r_new)) {
		return null;
	    }
	    //return pce;

	}//else
	return pce;
    }




    //copy 
    public  PathChangeEvent copyPCE() {
	PathChangeEvent pce=new PathChangeEvent();
        pce.sign=sign;
	pce.aspath = new ArrayList(); 
	for (int i=0; i<aspath.size(); i++) {
	    pce.aspath.add(new Segment((Segment)aspath.get(i)));
	}
	return pce;
    }

    //print
    public String printPCE(){
	String s=""; String tmp=null;
	//System.out.println("(sign="+sign+", path=");
	if (sign.equals("plus")) tmp="+";
	else if  (sign.equals("minus")) tmp="-";
	
	s="("+tmp+", ";	
	for (int i=0; i<aspath.size(); i++){
	    s+=((Segment)aspath.get(i)).printSegment();
	}	
	//System.out.print(")");
	s+=")";
	return s;
    }

    //equals
    public boolean equals(PathChangeEvent pce){
	if (sign!=pce.sign) return false;
	else {
	    for (int i=0; i<aspath.size(); i++){
		if (!((Segment)aspath.get(i)).equals((Segment)pce.aspath.get(i))) return false;
	    }
	}
	return true;
    }

    //for checking the cycles in history look for opposite signs!!
    public boolean equalforCycle(PathChangeEvent pce){
	//	if (sign==pce.sign) return false; //4 mart 2005 kapali idi actim // 7/15/2004
	//else 
           {
	    for (int i=0; i<aspath.size(); i++){
		if (!((Segment)aspath.get(i)).equals((Segment)pce.aspath.get(i))) return false;
	    }
	}
	return true;
    }


    //bytecount
    public int bytecount(){
	int octets = 1;	      //1 octet for sign

	if (aspath.size()>255)
	    octets+=2;  //2 octets for lenght of aspath
	else octets++;
	for (int i=0; i<aspath.size(); i++) {
	    // 1 octet for the seg type, 1 for seg length, 2 per AS# in segment
	    octets += 1 + 1 + 2*(((Segment)aspath.get(i)).size());
	}
	
	if (octets > 255) { // 1 or 2 octets for the attribute length field
	    octets += 2;
	} else {
	    octets++;
	}
	return octets;
    } 
} // end class