/*
 * Proxy.java
 *
 * Created on 11. November 2005, 14:00
 *
 * To change this template, choose Tools | Options and locate the template under
 * the Source Creation and Management node. Right-click the template and choose
 * Open. You can then make changes to the template in the Source Editor.
 */

package org.semports.handshakes;

import java.util.HashSet;
import java.util.Iterator;

/**
 * This class represents the PSI sets of one Proxy.
 *  
 * @author Lutz Maicher
 **/

public class Proxy {
    
    String id;
    HashSet repository; 
    HashSet repository_new;
    HashSet proxyRepository;
    HashSet proxyRepository_new;
    
    public HashSet getRepository()
    {
        return repository;
    }
    
    /** This function tests whether this Proxy is equal to an other Proxy.
     * Equality is decided according the TMDM: if both have a pair of
     * equal PSIs in their repository equality holds.
     */
    public boolean equal(Proxy req)
    {
        /*
        HashSet test = new HashSet(repository);
        test.retainAll(req.getRepository());
        return !test.isEmpty();
         */
        /** Für große Mengen ist es billiger durch die 
         *  kleinere von beiden Mengen zu iterieren und
         *  zu schauen, ob ein Element in der größeren
         *  Menge vorkommt.
         **/
        Iterator it;
        HashSet check;
        boolean equal = false;
        if (req.repository.size()<this.repository.size())
        {
            it = req.repository.iterator();
            check = this.repository;
        }
        else 
        { 
             it = this.repository.iterator();
             check= req.repository;
        }
        
        while (it.hasNext() & !equal)
            equal = check.contains(it.next());
       return equal;
    }
    
    /** This function adds the unification of the repository of the given 
     * Proxy and of the req Proxy into the repository_new.
     * In fact, thats the same functionality as merging.
     **/
    public void merge(Proxy req)
    {
        // Merge this with req ...
        repository_new.addAll(req.getRepository());
        proxyRepository_new.addAll(req.proxyRepository);
        
        // ... and merge req with this
        req.repository_new.addAll(this.getRepository());
        req.proxyRepository_new.addAll(this.proxyRepository);
        
    }
        
    /** This function cleans up the current Proxy after a merge roundtrip.
     *  The content of the repository will become the content of repository_new.
     **/
    public void prepareNextMergeRoundtrip()
    {
        repository = (HashSet) repository_new.clone();
        proxyRepository = new HashSet(proxyRepository_new);
        repository_new = repository;     
        proxyRepository_new = proxyRepository;
    }
    
    /** This function outputs the PSI set of the current Proxy in a line
     */
    public String getRepositoryContent()
    {
        Iterator it_repository = this.repository.iterator();
        String result = this.id + " cardI("+this.id+")="+repository.size()+ " | cardI("+this.id+")="+this.proxyRepository.size()+ " : ";
        while (it_repository.hasNext())
        {
            result = result + (String)it_repository.next() + " ";
        }
        result = result + " | ";        
        Iterator it_repository_top = this.proxyRepository.iterator();
        while (it_repository_top.hasNext())
        {
            result = result + (String)it_repository_top.next() + " ";
        }
        return result;
    }
    
    /** Adds a PSI to the repository. 
     **/
    public void addPSI(String PSI)
    {
        repository.add(PSI);
        repository_new.add(PSI);
    }
    
    /** Creates a new instance of Proxy */
    public Proxy(String id) {
        this.id = id;
        repository = new HashSet();
        repository_new = new HashSet();
        proxyRepository = new HashSet();
        proxyRepository_new = new HashSet();
        proxyRepository.add(this.id);
        proxyRepository_new.add(this.id);
    }
    
}