package com.lnwazg.kit.qrcode;

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.lnwazg.kit.file.PathKit;

/**
 * 二维码工具类<br>
 * 使用方法请参考main()以及generateQrCode()这两个方法<br>
 * 自闭流,是最强大可靠的存在(无须依赖外界,即可自我生产、自我进攻,例如迫击炮流!)
 */
public class QRCodeUtil
{
    private static final String CHARSET = "utf-8";
    
    private static final String FORMAT_NAME = "JPG";
    
    // 二维码尺寸
    private static final int QRCODE_SIZE = 300;
    
    // LOGO宽度
    private static final int WIDTH = 60;
    
    // LOGO高度
    private static final int HEIGHT = 60;
    
    public static void main(String[] args)
        throws Exception
    {
        String text = "http://baoxian.haiziwang.com";
        QRCodeUtil.encode(text, "c:/code.png", "c:/", true);
    }
    
    /**
     * 生成二维码,并将响应的字节流输出到页面中
     * 
     * @author nan.li
     * @param url
     * @param rsp
     */
    public static void generateQrCode(String url, HttpServletRequest req, HttpServletResponse rsp)
    {
        try
        {
            // 二维码中间的图片
            String imgPath = String.format("%s/images/qrcode/logo.png", PathKit.getRealPath(req));
            // System.out.println("the img path is: " + imgPath);
            BufferedImage image = QRCodeUtil.createImage(url, imgPath, true);
            ImageIO.write(image, FORMAT_NAME, rsp.getOutputStream());
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
    
    private static BufferedImage createImage(String content, String imgPath, boolean needCompress)
        throws Exception
    {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);
        int width = bitMatrix.getWidth();
        int height = bitMatrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++)
        {
            for (int y = 0; y < height; y++)
            {
                image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        if (imgPath == null || "".equals(imgPath))
        {
            return image;
        }
        // 插入图片
        QRCodeUtil.insertImage(image, imgPath, needCompress);
        return image;
    }
    
    /**
     * 插入LOGO
     * 
     * @param source
     *            二维码图片
     * @param imgPath
     *            LOGO图片地址
     * @param needCompress
     *            是否压缩
     * @throws Exception
     */
    private static void insertImage(BufferedImage source, String imgPath, boolean needCompress)
        throws Exception
    {
        File file = new File(imgPath);
        if (!file.exists())
        {
            System.err.println("" + imgPath + "   该文件不存在!");
            return;
        }
        Image src = ImageIO.read(new File(imgPath));
        int width = src.getWidth(null);
        int height = src.getHeight(null);
        if (needCompress)
        { // 压缩LOGO
            if (width > WIDTH)
            {
                width = WIDTH;
            }
            if (height > HEIGHT)
            {
                height = HEIGHT;
            }
            Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics g = tag.getGraphics();
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图
            g.dispose();
            src = image;
        }
        // 插入LOGO
        Graphics2D graph = source.createGraphics();
        int x = (QRCODE_SIZE - width) / 2;
        int y = (QRCODE_SIZE - height) / 2;
        graph.drawImage(src, x, y, width, height, null);
        Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    }
    
    /**
     * 生成二维码(内嵌LOGO)
     * 
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存放目录
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath, boolean needCompress)
        throws Exception
    {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
        mkdirs(destPath);
        String file = new Random().nextInt(99999999) + ".jpg";
        ImageIO.write(image, FORMAT_NAME, new File(destPath + "/" + file));
    }
    
    /**
     * 当文件夹不存在时,mkdirs会自动创建多层目录,区别于mkdir.(mkdir如果父目录不存在则会抛出异常)
     * 
     * @author lanyuan Email: [email protected]
     * @date 2013-12-11 上午10:16:36
     * @param destPath
     *            存放目录
     */
    public static void mkdirs(String destPath)
    {
        File file = new File(destPath);
        // 当文件夹不存在时,mkdirs会自动创建多层目录,区别于mkdir.(mkdir如果父目录不存在则会抛出异常)
        if (!file.exists() && !file.isDirectory())
        {
            file.mkdirs();
        }
    }
    
    /**
     * 生成二维码(内嵌LOGO)
     * 
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath)
        throws Exception
    {
        QRCodeUtil.encode(content, imgPath, destPath, false);
    }
    
    /**
     * 生成二维码
     * 
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String destPath, boolean needCompress)
        throws Exception
    {
        QRCodeUtil.encode(content, null, destPath, needCompress);
    }
    
    /**
     * 生成二维码
     * 
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String destPath)
        throws Exception
    {
        QRCodeUtil.encode(content, null, destPath, false);
    }
    
    /**
     * 生成二维码(内嵌LOGO)
     * 
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param output
     *            输出流
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
        throws Exception
    {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
        ImageIO.write(image, FORMAT_NAME, output);
    }
    
    /**
     * 生成二维码
     * 
     * @param content
     *            内容
     * @param output
     *            输出流
     * @throws Exception
     */
    public static void encode(String content, OutputStream output)
        throws Exception
    {
        QRCodeUtil.encode(content, null, output, false);
    }
    
    /**
     * 解析二维码
     * 
     * @param file
     *            二维码图片
     * @return
     * @throws Exception
     */
    public static String decode(File file)
        throws Exception
    {
        BufferedImage image;
        image = ImageIO.read(file);
        if (image == null)
        {
            return null;
        }
        BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        Result result;
        Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
        hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }
    
    /**
     * 解析二维码
     * 
     * @param path
     *            二维码图片地址
     * @return
     * @throws Exception
     */
    public static String decode(String path)
        throws Exception
    {
        return QRCodeUtil.decode(new File(path));
    }
    
}