package com.noisycloud;

import java.io.IOException;
import java.util.Random;

import javax.servlet.*;
import javax.servlet.http.*;

import com.google.appengine.api.datastore.*;


@SuppressWarnings("serial")
public class Shakespearemonkey extends HttpServlet {

    static final String lstAlphabet     = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    static final int    intNumLoops     = 1000;
    static String       Shakespeare     = "All your base are belong to me";
    static Key          theResultsKey   = KeyFactory.createKey("Results","tblMonkeyResults");
    DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();

    private static char generateRandomLetter(){
        //I generate a random character and return it.
        Random rnd = new Random();
        char strChar = lstAlphabet.charAt(rnd.nextInt(lstAlphabet.length()));
        return strChar;
    }

    private void writeResultsToFile(int intKeyStrokes, String strBestGuess){
        //I write the number of keystrokes and the best guess so far to the datastore
        Entity objDaoOut = new Entity("Results", "tblMonkeyResults");

        objDaoOut.setProperty("intKeyStrokes",intKeyStrokes);
        objDaoOut.setProperty("strBestGuess", strBestGuess);

        datastore.put(objDaoOut);
    }

    private MonkeyResults readResultsFromFile() {
        //I read results from the datastore and return an instance of class MonkeyResults
        MonkeyResults monkeyResults = new MonkeyResults();
        long intStrokes = 0;
        String strGuess = "";

        try{
            Entity objDaoIn = datastore.get(theResultsKey);

            intStrokes  = (long) objDaoIn.getProperty("intKeyStrokes");
            strGuess    = (String) objDaoIn.getProperty("strBestGuess");
        }catch(EntityNotFoundException e){
            //e.printStackTrace();
        }finally{
            monkeyResults.setKeyStrokes((int)intStrokes);
            monkeyResults.setBestGuess(strGuess);
        }

        return monkeyResults;
    }

    private void trackProgress(int intKeyStrokes, String strBestGuess) {
        String              strBestGuessFromFile    = "";
        int                 intKeyStrokesFromFile   = 0;
        String              strNewBestGuess         = "";
        int                 intNewStrokes           = 0;
        MonkeyResults       monkeyResults           = readResultsFromFile();

        if(monkeyResults.getKeyStrokes() != 0 && monkeyResults.getBestGuess() != ""){
            strBestGuessFromFile    = (String) monkeyResults.getBestGuess();
            intKeyStrokesFromFile   = (int) monkeyResults.getKeyStrokes();
        }

        //whichever string is longer, this is the new best guess
        if(strBestGuess.length() > strBestGuessFromFile.length()){
            strNewBestGuess     = strBestGuess;
        }else{
            strNewBestGuess     = strBestGuessFromFile;
        }

        //number of key strokes is cumulative
        intNewStrokes           = intKeyStrokes + intKeyStrokesFromFile;

        writeResultsToFile(intNewStrokes,strNewBestGuess);
    }


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
        int         intCount                = 0;
        String      strSubString            = "";
        String      strShakespeare          = Shakespeare.replaceAll("[^a-zA-Z]", ""); //Shakespeare without spaces etc
        String      strMonkeyString         = "";
        String      strBestSoFar            = "";
        response.setContentType("text/html");

        while (intCount < intNumLoops) {
            intCount++;

            //generate the random guess, one keystroke at a time
            strMonkeyString = strMonkeyString + Character.toString(generateRandomLetter());

            strSubString    =   strShakespeare.substring(0,strMonkeyString.length());

            //check if we've guessed correctly so far
            if(strMonkeyString.equalsIgnoreCase(strSubString)){
                //Is this our best guess so far
                if(strSubString.length() > strBestSoFar.length()){
                    strBestSoFar    =   strSubString;
                }
            }else{
                //incorrect guess, start again
                strMonkeyString = "";
            }
        }

        trackProgress(intCount,strBestSoFar);

        //purely for output, re-read the latest and update user on progress
        try {
            response.getWriter().println("Good Morning, I am your monkey! I will be trying to guess the string: " + strShakespeare + "<br />");
            MonkeyResults monkeyresults = readResultsFromFile();
            response.getWriter().println("My best guess so far is: ");
            response.getWriter().println((String) monkeyresults.getBestGuess());
            response.getWriter().println("<br />I have made ");
            response.getWriter().println((int) monkeyresults.getKeyStrokes());
            response.getWriter().println("keystrokes");
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}