package com.psddev.cms.tool.page;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Hashtable;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.psddev.cms.tool.PageServlet;
import com.psddev.cms.tool.ToolPageContext;
import com.psddev.dari.util.RoutingFilter;

@RoutingFilter.Path(application = "cms", value = "qrCode")
@SuppressWarnings("serial")
public class QrCode extends PageServlet {

    @Override
    protected String getPermissionId() {
        return null;
    }

    @Override
    protected void doService(ToolPageContext page) throws IOException, ServletException {
        try {
            String data = page.param(String.class, "data");
            int size = page.paramOrDefault(int.class, "size", 200);
            Hashtable<EncodeHintType, ErrorCorrectionLevel> hintMap = new Hashtable<EncodeHintType, ErrorCorrectionLevel>();

            hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);

            QRCodeWriter writer = new QRCodeWriter();
            BitMatrix matrix = writer.encode(data, BarcodeFormat.QR_CODE, size, size, hintMap);
            BufferedImage image = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);

            image.createGraphics();

            Graphics2D graphics = (Graphics2D) image.getGraphics();

            graphics.setColor(Color.WHITE);
            graphics.fillRect(0, 0, size, size);
            graphics.setColor(Color.BLACK);

            for (int i = 0; i < size; ++ i) {
                for (int j = 0; j < size; ++ j) {
                    if (matrix.get(i, j)) {
                        graphics.fillRect(i, j, 1, 1);
                    }
                }
            }

            HttpServletResponse response = page.getResponse();
            ServletOutputStream output = response.getOutputStream();

            response.setContentType("image/png");
            ImageIO.write(image, "png", output);
            output.flush();

        } catch (WriterException error) {
            throw new IOException(error);
        }
    }
}