package cn.songm.common.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;

public class RandomCode {
    private Random random = new Random();
    /** 随机产生的字符串 */
    private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    // 图片宽
    private int width = 80;
    // 图片高
    private int height = 26;
    // 干扰线数量
    private int lineSize = 50;
    // 随机产生字符数量
    private int stringNum = 4;

    private String code;

    public RandomCode() {
        StringBuffer str = new StringBuffer();
        for (int i = 1; i <= stringNum; i++) {
            int num = random.nextInt(randString.length());
            str.append(String.valueOf(randString.charAt(num)));
        }
        this.code = str.toString();
    }

    /**
     * 获得字体
     */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /**
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * 生成随机图片
     * 
     * @throws IOException
     */
    public void getRandcode(OutputStream output) throws IOException {
        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        // 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
        Graphics g = image.getGraphics();
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
        g.setColor(getRandColor(110, 133));
        // 绘制干扰线
        for (int i = 1; i <= lineSize; i++) {
            drowLine(g);
        }
        // 绘制随机字符
        for (int i = 0; i < code.length(); i++) {
            drowString(g, String.valueOf(code.charAt(i)), i);
        }
        g.dispose();
        // 将内存中的图片通过流动形式输出到客户端
        ImageIO.write(image, "JPEG", output);
    }

    /**
     * 绘制字符串
     */
    private void drowString(Graphics g, String rand, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(rand, 13 * i + 13, 16);
    }

    /**
     * 绘制干扰线
     */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    public String getCode() {
        return this.code;
    }
}