package com.hx.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Base64;

import javax.imageio.ImageIO;

/**
 * 验证码生成器
 * @author ChenJiaHe
 * @Date 2020-06-17
 */
public class CheckCodeImageUtil {
	
	private final static int WIDTH = 60;
    private final static int HEIGHT = 20;
    
	private static char[] generateCheckCode() {
        // ������֤����ַ��
        String chars = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        char[] rands = new char[4];
        for (int i = 0; i < 4; i++) {
            int rand = (int) (Math.random() * 35);
            rands[i] = chars.charAt(rand);
        }
        return rands;
    }

	private static void drawRands(Graphics g, char[] rands) {
        g.setColor(Color.BLACK);
        g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 18));
        // �ڲ�ͬ�ĸ߶��������֤���ÿ���ַ�
        g.drawString("" + rands[0], 1, 17);
        g.drawString("" + rands[1], 16, 15);
        g.drawString("" + rands[2], 31, 18);
        g.drawString("" + rands[3], 46, 16);
    }

	private static void drawBackground(Graphics g) {
        // ������
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, WIDTH, HEIGHT);
        // ������120�����ŵ�
        for (int i = 0; i < 120; i++) {
            int x = (int) (Math.random() * WIDTH);
            int y = (int) (Math.random() * HEIGHT);
            int red = (int) (Math.random() * 255);
            int green = (int) (Math.random() * 255);
            int blue = (int) (Math.random() * 255);
            g.setColor(new Color(red, green, blue));
            g.drawOval(x, y, 1, 0);
        }
    }
    
    public static String[] createImage(String id)
    {
    	ByteArrayOutputStream bos = null;
    	String reStr = "";
    	char[] rands = null;
    	try {
	    	BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
	        Graphics g = image.getGraphics();
	
	        rands = generateCheckCode();
	
	        drawBackground(g);
	        drawRands(g, rands);
	
	        g.dispose();
	
	        bos = new ByteArrayOutputStream();
	        ImageIO.write(image, "JPEG", bos);
	        byte[] buf = bos.toByteArray();
	        reStr = Base64.getEncoder().encodeToString(buf);
	        
    	}catch (Exception e) {
			e.printStackTrace();
		}finally {
			if(bos != null)
			{
				try {
					bos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
				bos = null;
			}
		}
    	return new String[] {new String(rands),reStr};
    }
}