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

import org.graphstream.graph.Edge;
import org.graphstream.graph.Node;
import org.graphstream.graph.implementations.MultiGraph;

public class SFG {


    private ArrayList<Boolean> visited;
    private ArrayList<Pair <ArrayList<Node>,Integer>> fwPaths;
    private HashSet<Pair <ArrayList<Node>,Integer>> loops;
    //private DFS pathCalculator;

    public SFG (){
        visited = new ArrayList<Boolean>();
        fwPaths = new ArrayList<Pair<ArrayList<Node>,Integer>>();
        loops = new HashSet<Pair<ArrayList<Node>,Integer>>();
        //pathCalculator = new DFS();
    }

    public void calculatePathsandLoops (MultiGraph graph){
        fwPaths.clear();
        loops.clear();
        visited.clear();
        Node dis= null;
        for(Node n:graph.getEachNode()) {
            visited.add(false);
            dis = n;
        }
        ArrayList<Node> currentPath = new ArrayList<Node>();
        Integer gain = new Integer(1);
        Pair<ArrayList<Node>,Integer> path = new Pair <ArrayList<Node>,Integer> (currentPath,gain);
        traverseGraph (graph,visited, graph.getNode(0),dis,path);
    }

    private void traverseGraph (MultiGraph graph, ArrayList<Boolean> visited,Node current, Node des,Pair<ArrayList<Node>,Integer> path){

        if (current == des){
            path.getLeft().add(des);
            /*printPath(path.getLeft());
            System.out.println(path.getRight());*/
            fwPaths.add(path.clone());
            path.getLeft().remove(current);
            return;
        }
        else {
           visited.set(current.getIndex(),true);
           path.getLeft().add(current);
           for (Edge e : current.getEachLeavingEdge()){
               Node two = e.getNode1();
               if (visited.get(two.getIndex())){
                   //System.out.println(current.getId()+" "+two.getId());
                  int index = path.getLeft().indexOf(two);
                  ArrayList <Node> currentLoop =new ArrayList<Node>(path.getLeft().subList(index,path.getLeft().size()));
                  currentLoop.add(two);
                  /* gain2 to be edited */
                  Integer gain2 = new Integer(1);

                  loops.add(new Pair<ArrayList<Node>,Integer>(currentLoop,gain2));
               }
               else{
                  Integer gain = path.getRight() * (Integer) e.getAttribute("gain");
                  path.setRight(gain);
                  traverseGraph (graph,visited,two,des,path);
                  gain = path.getRight() / (Integer) e.getAttribute("gain");
                  path.setRight(gain);
               }
           }
           visited.set(current.getIndex(),false);
           path.getLeft().remove(current);
        }
    }

    public void printPath (ArrayList<Node> path){
        for (Node n : path){
            System.out.print(n.getId());
        }
        System.out.print("\n");
    }

    public void printLoops (){
        Iterator<Pair<ArrayList<Node>,Integer>> it = loops.iterator();
        while (it.hasNext()){
            Pair<ArrayList<Node>,Integer> temp = it.next();
            printPath(temp.getLeft());
            System.out.println(temp.getRight());
        }
        System.out.println(loops.size());
    }

}