package com.tarena.dang.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public final class ImageUtil {
	//private static final String[] chars = { "0", "1", "2", "3", "4", "5", "6",
	//		"7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I", "东",
	//		"南", "西", "北", "中", "发", "白" };
	
	private static final String[] chars = { "0", "1", "2", "3", "4", "5", "6","7", "8", "9"};
	private static final String[] cals = {"+", "-", "*", "/", "%"};
	private static final int SIZE = 4;//显示字符个数
	private static final int NUM = 2;//显示字符中的数字个数
	private static final int NUM1 = 1;//显示字符中的运算符个数
	private static final int LINES = 20;//干扰线数量
	private static final int WIDTH = 160;//图片宽度
	private static final int HEIGHT = 40;//图片高度
	private static final int FONT_SIZE = 40;//字体大小
	
	public static Map<Integer,BufferedImage> createImage() {
		BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
				BufferedImage.TYPE_INT_RGB);
		Graphics graphic = image.getGraphics();
		graphic.setColor(Color.LIGHT_GRAY);
		graphic.fillRect(0, 0, WIDTH, HEIGHT);
		Random ran = new Random();
		//记录字符中的数字
		int[] num = new int[NUM];
		int index = 0;
		//记录运算符号
		String[] cals1 = new String[NUM1];
		int index1 = 0;
		//画随机字符
		for(int i=1;i<SIZE;i++){
			//数字
			if(i%2==1) {
				int r = ran.nextInt(chars.length);
				graphic.setColor(getRandomColor());
				graphic.setFont(new Font(null,Font.BOLD+Font.ITALIC,FONT_SIZE));
				graphic.drawString(chars[r],(i-1)*WIDTH/SIZE , 7*HEIGHT/8);
				num[index++] = Integer.parseInt(chars[r]);
				
			} else {
				//画符号
				int r = ran.nextInt(cals.length);
				graphic.setColor(new Color(0,0,0));
				graphic.setFont(new Font(null,Font.BOLD+Font.ITALIC,FONT_SIZE));
				graphic.drawString(cals[r],(i-1)*WIDTH/SIZE , 7*HEIGHT/8);
				cals1[index1++] = cals[r];
			}
			if(i==SIZE-1) {
				graphic.setColor(new Color(0,0,0));
				graphic.setFont(new Font(null,Font.BOLD+Font.ITALIC,FONT_SIZE));
				graphic.drawString("=",i*WIDTH/SIZE , 7*HEIGHT/8);
			}
		}
		//计算字符运算结果
		int result = cal(num,cals1);
		
		//画干扰线
		for(int i=1;i<=LINES;i++){
			graphic.setColor(getRandomColor());
			graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT), ran.nextInt(WIDTH),ran.nextInt(HEIGHT));
		}
		
		Map<Integer,BufferedImage> map = new HashMap<Integer,BufferedImage>();
		//结果和图片成键值对
		map.put(result, image);
		return map;
	}
	
	private static int cal(int[] num, String[] cals1) {
		int result = 0;
		if("+".equals(cals1[0])) {
			result = num[0] + num[1];
		} else if("-".equals(cals1[0])) {
			result = num[0] - num[1];
		} else if("*".equals(cals1[0])) {
			result = num[0] * num[1];
		} else if("/".equals(cals1[0])) {
			result = num[0] / num[1];
		} else if("%".equals(cals1[0])) {
			result = num[0] % num[1];
		}
		return result;
	}

	public static InputStream change(BufferedImage image) throws Exception{
		//将image图片压缩成JPEG
		ByteArrayOutputStream bos = 
				new ByteArrayOutputStream();
		JPEGImageEncoder encode = 
			JPEGCodec.createJPEGEncoder(bos);
		encode.encode(image);
		//将bos中存储的JPEG格式图片字节取出
		byte[] bytes = bos.toByteArray();
		return new ByteArrayInputStream(bytes);
	}
	
	private static Color getRandomColor(){
		Random ran = new Random();
		Color color = new Color(ran.nextInt(256),ran.nextInt(256),ran.nextInt(256));
		return color;
	}
}