package com.espeed.reading.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * 
 * @项目名称: 鹰眼搜搜索系统
 * @版权所有: 深圳市科飞时速网络技术有限公司(0755-88843776)
 * @技术支持: info@21gmail.com
 * @单元名称: 加密工具
 * @开始时间: 2017-10-12
 * @开发人员: 杨志钊
 */
public class EncryptionUtil {

	private static char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D',
			'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
			'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
			'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',
			'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',
			'4', '5', '6', '7', '8', '9', '+', '/' };

	private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,
			-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
			-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
			-1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
			60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
			10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,
			-1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
			38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,
			-1, -1 };

	/**
	 * SHA1加密
	 * 
	 * @param str
	 * @return
	 */
	public static String encodeBySha1(String str) {
		if (null == str || 0 == str.length()) {
			return null;
		}
		char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
				'a', 'b', 'c', 'd', 'e', 'f' };
		try {
			MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
			mdTemp.update(str.getBytes("UTF-8"));

			byte[] md = mdTemp.digest();
			int j = md.length;
			char[] buf = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++) {
				byte byte0 = md[i];
				buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
				buf[k++] = hexDigits[byte0 & 0xf];
			}

			return new String(buf);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}

		return null;
	}

	/**
	 * 对字符进行排序
	 * 
	 * @param str
	 * @return
	 */
	public static String sortingStr(String str) {
		if (null == str || 0 == str.length()) {
			return null;
		}
		char[] arr = str.toCharArray();
		Arrays.sort(arr);
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < arr.length; i++) {
			buf.append(arr[i]);
		}
		return buf.toString();
	}

	/**
	 * Base64加密
	 * 
	 * @param str
	 * @return
	 */
	public static String encodeByBase64(String str) {
		if (null == str || 0 == str.length()) {
			return null;
		}

		byte[] data = null;
		try {
			data = str.getBytes("UTF-8");
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
			return null;
		}

		StringBuffer sb = new StringBuffer();
		int len = data.length;
		int i = 0;
		int b1, b2, b3;
		while (i < len) {
			b1 = data[i++] & 0xff;
			if (i == len) {
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
				sb.append("==");
				break;
			}
			b2 = data[i++] & 0xff;
			if (i == len) {
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[((b1 & 0x03) << 4)
						| ((b2 & 0xf0) >>> 4)]);
				sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
				sb.append("=");
				break;
			}
			b3 = data[i++] & 0xff;
			sb.append(base64EncodeChars[b1 >>> 2]);
			sb.append(base64EncodeChars[((b1 & 0x03) << 4)
					| ((b2 & 0xf0) >>> 4)]);
			sb.append(base64EncodeChars[((b2 & 0x0f) << 2)
					| ((b3 & 0xc0) >>> 6)]);
			sb.append(base64EncodeChars[b3 & 0x3f]);
		}

		return sb.toString();
	}
	/**
	 * Base64加密
	 * 
	 * @param str
	 * @return
	 */
	public static String encodeByBase64(byte[] data) {
		if (null == data || 0 == data.length) {
			return null;
		}
		
		StringBuffer sb = new StringBuffer();
		int len = data.length;
		int i = 0;
		int b1, b2, b3;
		while (i < len) {
			b1 = data[i++] & 0xff;
			if (i == len) {
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
				sb.append("==");
				break;
			}
			b2 = data[i++] & 0xff;
			if (i == len) {
				sb.append(base64EncodeChars[b1 >>> 2]);
				sb.append(base64EncodeChars[((b1 & 0x03) << 4)
				                            | ((b2 & 0xf0) >>> 4)]);
				sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
				sb.append("=");
				break;
			}
			b3 = data[i++] & 0xff;
			sb.append(base64EncodeChars[b1 >>> 2]);
			sb.append(base64EncodeChars[((b1 & 0x03) << 4)
			                            | ((b2 & 0xf0) >>> 4)]);
			sb.append(base64EncodeChars[((b2 & 0x0f) << 2)
			                            | ((b3 & 0xc0) >>> 6)]);
			sb.append(base64EncodeChars[b3 & 0x3f]);
		}
		
		return sb.toString();
	}

	/**
	 * Base64解密
	 * 
	 * @param str
	 * @return
	 */
	public static String decodeByBase64(String str) {
		try {
			if (null == str || 0 == str.length()) {
				return null;
			}

			StringBuffer sb = new StringBuffer();
			byte[] data = null;
			try {
				data = str.getBytes("UTF-8");
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
				return null;
			}
			int len = data.length;
			int i = 0;
			int b1, b2, b3, b4;
			while (i < len) {

				do {
					b1 = base64DecodeChars[data[i++]];
				} while (i < len && b1 == -1);
				if (b1 == -1)
					break;

				do {
					b2 = base64DecodeChars[data[i++]];
				} while (i < len && b2 == -1);
				if (b2 == -1)
					break;
				sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

				do {
					b3 = data[i++];
					if (b3 == 61)
						return sb.toString();
					b3 = base64DecodeChars[b3];
				} while (i < len && b3 == -1);
				if (b3 == -1)
					break;
				sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

				do {
					b4 = data[i++];
					if (b4 == 61)
						return sb.toString();
					b4 = base64DecodeChars[b4];
				} while (i < len && b4 == -1);
				if (b4 == -1)
					break;
				sb.append((char) (((b3 & 0x03) << 6) | b4));
			}
			return sb.toString();
		} catch (Exception e) {

			return null;
		}

	}

	/**
	 * MD5加密
	 * 
	 * @param str
	 * @return
	 */
	public static String encodeByMD5(String str) {
		if (null == str || 0 == str.length()) {
			return null;
		}
		String resutl = null;
		try {
			MessageDigest instance = MessageDigest.getInstance("MD5");// 获取MD5算法对象
			byte[] digest = instance.digest(str.getBytes());// 对字符串加密,返回字节数组
			StringBuffer strBuffer = new StringBuffer();
			for (byte b : digest) {
				int i = b & 0xff;
				String hexString = Integer.toHexString(i);// 将整数转为16进制
				if (hexString.length() < 2) {
					hexString = "0" + hexString;// 如果是1位的话,补0
				}
				strBuffer.append(hexString);
			}
			resutl = strBuffer.toString();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		return resutl;
	}

	public static String encodePassword(String password) {

		if (null == password || 0 == password.length()) {
			return null;
		}

		return encodeByBase64(encodeByBase64(password));
	}
	
	public static String decodePassword(String password) {
		
		if (null == password || 0 == password.length()) {
			return null;
		}
		
		return decodeByBase64(decodeByBase64(password));
	}
	
}