import java.awt.Color;

import java.io.IOException;

import java.util.Random;

import javax.servlet.http.HttpServletResponse;

import org.patchca.color.ColorFactory;

import org.patchca.filter.predefined.CurvesRippleFilterFactory;

import org.patchca.filter.predefined.DiffuseRippleFilterFactory;

import org.patchca.filter.predefined.DoubleRippleFilterFactory;

import org.patchca.filter.predefined.MarbleRippleFilterFactory;

import org.patchca.filter.predefined.WobbleRippleFilterFactory;

import org.patchca.service.ConfigurableCaptchaService;

import org.patchca.utils.encoder.EncoderHelper;

import org.patchca.word.RandomWordFactory;

public class CaptchaUtil {

    private static ConfigurableCaptchaService cs = new ConfigurableCaptchaService();

    private static Random random = new Random();

    static {

        cs.setColorFactory(new ColorFactory() {

            @Override

            public Color getColor(int x) {

                int[] c = new int[3];

                int i = random.nextInt(c.length);

                for (int fi = 0; fi < c.length; fi++) {

                    if (fi == i) {

                        c[fi] = random.nextInt(71);

                    } else {

                        c[fi] = random.nextInt(256);

                    }

                }

                return new Color(c[0], c[1], c[2]);

            }

        });

        RandomWordFactory wf = new RandomWordFactory();

        wf.setCharacters("23456789abcdefghigkmnpqrstuvwxyzABCDEFGHIGKLMNPQRSTUVWXYZ");

        wf.setMaxLength(4);

        wf.setMinLength(4);

        cs.setWordFactory(wf);

    }

    public static String generate(HttpServletResponse response) throws IOException{

        switch (random.nextInt(5)) {

            case 0:

                cs.setFilterFactory(new CurvesRippleFilterFactory(cs.getColorFactory()));

                break;

            case 1:

                cs.setFilterFactory(new MarbleRippleFilterFactory());

                break;

            case 2:

                cs.setFilterFactory(new DoubleRippleFilterFactory());

                break;

            case 3:

                cs.setFilterFactory(new WobbleRippleFilterFactory());

                break;

            case 4:

                cs.setFilterFactory(new DiffuseRippleFilterFactory());

                break;

        }

        setResponseHeaders(response);

        return EncoderHelper.getChallangeAndWriteImage(cs, "png", response.getOutputStream());

    }

    private static void setResponseHeaders(HttpServletResponse response) {

        response.setContentType("image/png");

        response.setHeader("Cache-Control", "no-cache, no-store");

        response.setHeader("Pragma", "no-cache");

        long time = System.currentTimeMillis();

        response.setDateHeader("Last-Modified", time);

        response.setDateHeader("Date", time);

        response.setDateHeader("Expires", time);

    }

}