/**
 * Created by rebeccamancy on 23/01/2014.
 */

import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;

public class QSD {
    Map<BitSet,StateCounter> M;
    private int totalClicks;

    /**
     * Construct an empty HashMap in order to store the sites
     */
    public QSD() {
        M = new HashMap<BitSet,StateCounter>();
        totalClicks = 0;
    }

    /**
     * Draws a value from the QSD representation proportional to relative time in each state (a hashtable with BitSet keys and counts)
     * @return an integer array (because this is how the rest of the code is built, rather than on BitSets)
     */
    public int[] drawFromQSD(){
        int[] draw;
        BitSet bitRepState = new BitSet();
        double p = Math.random() * this.totalClicks;
        double clickCount = 0;

        Iterator it = M.entrySet().iterator();
        // Loop over each entry in the hashtable until total count exceeds our random number
        while (it.hasNext()){
            Map.Entry pairs = (Map.Entry)it.next();
            StateCounter s = (StateCounter)pairs.getValue();   // cast it into a StateCounter to access counter
            clickCount = clickCount + (s.getCounter());
            if (clickCount > p) {
                bitRepState = s.getState();
                break;
            }
        }
        draw = Util.BitSet2bin(bitRepState);
        return draw;
    }

    public void add(BitSet key, int clicks){  // key is the system state represented as a bitset
        // Look in the hashmap to see if the represented state is already there
        StateCounter state = M.get(key);
        if (state != null) state.add(clicks); // if it is, then increment the counter by number of clicks
        else M.put(key,new StateCounter(key)); // else create a new state for it
        this.totalClicks = this.totalClicks + clicks;
    }

    public int getTotalClicks() {
        return totalClicks;
    }



    /*public void add(BitSet key, double time){  // key is the system state represented as a bitset
        // Look in the hashmap to see if the represented state is already there
        StateCounter state = M.get(key);
        if (state != null) state.add(time); // if it is, then increment the counter by number of clicks
        else M.put(key,new StateCounter(key)); // else create a new state for it
    }*/

    /**
     * Writes out the QSD hashmap to a file (item-by-item to save memory)
     * @param f            filename and path
     */
    public void write(String f) {
        PrintWriter outputWriter = null;
        try {
            outputWriter = new PrintWriter(f);
        }  // Catch file opening errors and close files
        catch (IOException e) {
            System.out.println("Error opening file: " + e);
            System.exit(1);
        }
        try {
            Iterator it = M.entrySet().iterator();
            while (it.hasNext()){
                Map.Entry pairs = (Map.Entry)it.next();
                outputWriter.println(pairs.getValue());
            }
        } catch (Exception e) {
            System.out.println("Error processing file: " + f + " Error: " + e); System.exit(1);
        }
        finally {
            if (outputWriter != null) outputWriter.close();
        }
        System.out.println("Total states in QSD: " + M.size());
    }


}