/*
Threads the find best k shapelets method
 */

package weka.filters.timeseries.shapelet_transforms;

import java.util.*;
import weka.core.Instances;
import weka.core.shapelet.Shapelet;

/**
 *
 * @author ajb
 */
public class ThreadedShapeletTransform extends ShapeletTransform implements Runnable{
    public static int numThreads=16;
    public int startInst,endInst;
    public static Instances sharedInstances;
    public static int numS;
    public static int minL;
    public static int maxL;
    ArrayList<Shapelet> candidates;
    
    ThreadedShapeletTransform(int s, int e){
        startInst=s;
        endInst=e;
    }
    @Override
    public void run() {
        
//Performs find k best shapelets         
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
    
    /**
     * protected method for extracting k shapelets.
     *
     * @param numShapelets the target number of shapelets to generate
     * @param data the data that the shapelets will be taken from
     * @param minShapeletLength the minimum length of possible shapelets
     * @param maxShapeletLength the maximum length of possible shapelets
     * Creates a new shapelet transform 
     * 
     */
    
    @Override
    public ArrayList<Shapelet> findBestKShapeletsCache(int numShapelets, Instances data, int minShapeletLength, int maxShapeletLength)throws Exception{
//       
        sharedInstances =data;
        numS=numShapelets;
        minL=minShapeletLength;
        maxL=maxShapeletLength;
        ThreadedShapeletTransform[] splits = new ThreadedShapeletTransform[numThreads];
//Set the start and end instances for each thread.
        int interval=sharedInstances.numInstances()/numThreads;
        int s=0;
        for(int i=0;i<numThreads-1;i++){
            splits[i]=new ThreadedShapeletTransform(s,s+interval);
            s+=interval;
        }
        splits[numThreads-1]=new ThreadedShapeletTransform(s,sharedInstances.numInstances());
        Thread[] threads= new Thread[numThreads];
//Generate the candidate shapelets for each thread
        try{
            for(int i=0;i<numThreads;i++){
                threads[i]=new Thread(threads[i]);
                threads[i].start();
            }
            for(int i=0;i<numThreads;i++)
                threads[i].join();
        }catch(InterruptedException e){
            System.out.println(" Fatal Error, thread interrupted, exit "+e);
        }
//Wait for finish, then merge them back together.
        ArrayList<Shapelet> all = mergeShapelets(splits);
        return null;
    }
    public static ArrayList<Shapelet> mergeShapelets(ThreadedShapeletTransform[] s){
//Get all shapelets
        TreeSet<Shapelet> all = new TreeSet<>();
        for(ThreadedShapeletTransform sh:s)
            all.addAll(sh.candidates);
//Extract out the top k
        
        
        return null;
    }
    
}