/************************************************************************************
 * Copyright (C) 2008 by Politehnica University of Bucharest and Rutgers University
 * All rights reserved.
 * Refer to LICENSE for terms and conditions of use.
 ***********************************************************************************/
package vnsim.applications.vitp.utils;

import java.util.*;

public class URIParser {
	//this class contains static methods, that help parsing a URI;

	//URI Format: "/type/tag?[cnt=*&tout=*]&param1=*&param2=*..."

	//all the methods return null if the format of the URI is wrong

	public static String getType(String uri) {
		if(uri==null) return null;
		if(!uri.startsWith("/")) return null;
		int i1=uri.indexOf('/',1);
		if(i1==-1) return null;
		return uri.substring(1,i1);
	}

	public static String getTag(String uri) {
		if(uri==null) return null;
		if(!uri.startsWith("/")) return null;
		int i1=uri.indexOf('/',1);
		if(i1==-1) return null;
		int i2=uri.indexOf('?',i1);
		if(i2==-1) return uri.substring(i1+1);
		return uri.substring(i1+1,i2);
	}

	public static Vector<String> getRCExpressions(String uri){
		//returns a vector of all expressions within the brackets;
		//the corresponding service should do more parsing inside
		//each expression, since it could have particular formats
		//(e.g with < > *)

		if(uri==null) return null;
		if(!uri.startsWith("/")) return null;
		int i1=uri.indexOf('/',1);
		if(i1==-1) return null;
		int i2=uri.indexOf('?',i1);
		if(i2==-1) return null;
		if(uri.charAt(i2+1)!='[') return null;
		int index=i2+2;
		int finIndex=uri.indexOf(']',index);
		if(finIndex==-1) return null;
		String rcs=uri.substring(index,finIndex);
		Vector<String> ret=new Vector<String>();
		StringTokenizer st=new StringTokenizer(rcs,"&");
		while(st.hasMoreTokens()) {
			ret.addElement(st.nextToken());
		}
		return ret;
	}

	public static Vector<String> getParams(String uri){
		//returns the parameters after the [] as a vector of Strings
		//the corresponding service should do more parsing inside
		//each expression, since it could have particular formats
		//(e.g with < > *)
		if(uri==null) return null;
		if(!uri.startsWith("/")) return null;
		int i1=uri.indexOf('/',1);
		if(i1==-1) return null;
		i1=uri.indexOf('?',i1);
		if(i1==-1) return null;
		i1=uri.indexOf('[',i1);
		if(i1==-1) return null;
		i1=uri.indexOf(']',i1);
		if(i1==-1) return null;
		Vector<String> ret=new Vector<String>();
		i1++;
		if(i1>=uri.length()) return ret;
		if(uri.charAt(i1)!='&') return null;
		StringTokenizer st=new StringTokenizer(uri.substring(i1),"&");
		while(st.hasMoreTokens()) {
			ret.addElement(st.nextToken());
		}
		return ret;
	}

	public static String getURIFromParts(String type, String tag, Vector h1, Vector h2){
		if(type==null || tag==null || h1==null || h2==null)
			return null;
		String ret="/"+type+"/"+tag+"?[";
		for(int i=0;i<h1.size();i++) {
			ret=ret+((String)h1.elementAt(i));
			if(i<h1.size()-1)
				ret=ret+"&";
		}
		ret=ret+"]";
		for(int i=0;i<h2.size();i++) {
			ret=ret+"&"+((String)h2.elementAt(i));
		}
		return ret;
	}
}