package com.bcxin.ins.weixin.util.weixin.util;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA1 {
	private final int[] abcde = { 0x67452301, 0xefcdab89, 0x98badcfe,
			0x10325476, 0xc3d2e1f0 };
	
	// 摘要数据存储数组
	private int[] digestInt = new int[5];
	
	// 计算过程中的临时数据存储数组
	private int[] tmpData = new int[80];

	/**
	 * 计算sha-1摘要
	 * 
	 * @param bytedata
	 * @return
	 */
	private int process_input_bytes(byte[] bytedata) {
		// 初试化常量
		System.arraycopy(abcde, 0, digestInt, 0, abcde.length);
		// 格式化输入字节数组，补10及长度数据
		byte[] newbyte = byteArrayFormatData(bytedata);
		// 获取数据摘要计算的数据单元个数
		int MCount = newbyte.length / 64;
		// 循环对每个数据单元进行摘要计算
		for (int pos = 0; pos < MCount; pos++) {
			// 将每个单元的数据转换成16个整型数据，并保存到tmpData的前16个数组元素中
			for (int j = 0; j < 16; j++) {
				tmpData[j] = byteArrayToInt(newbyte, (pos * 64) + (j * 4));
			}
			// 摘要计算函数
			encrypt();
		}
		return 20;
	}

	/**
	 * 格式化输入字节数组格式
	 * 
	 * @param bytedata
	 * @return
	 */
	private byte[] byteArrayFormatData(byte[] bytedata) {
		// 补0数量
		int zeros = 0;
		// 补位后总位数
		int size = 0;
		// 原始数据长度
		int n = bytedata.length;
		// 模64后的剩余位数
		int m = n % 64;
		// 计算添加0的个数以及添加10后的总长度
		if (m < 56) {
			zeros = 55 - m;
			size = n - m + 64;
		} else if (m == 56) {
			zeros = 63;
			size = n + 8 + 64;
		} else {
			zeros = 63 - m + 56;
			size = (n + 64) - m + 64;
		}
		// 补位后生成的新数组内容
		byte[] newbyte = new byte[size];
		// 复制数组的前面部分
		System.arraycopy(bytedata, 0, newbyte, 0, n);
		// 获得数组Append数据元素的位置
		int l = n;
		// 补1操作
		newbyte[l++] = (byte) 0x80;
		// 补0操作
		for (int i = 0; i < zeros; i++) {
			newbyte[l++] = (byte) 0x00;
		}
		// 计算数据长度，补数据长度位共8字节，长整型
		long N = (long) n * 8;
		byte h8 = (byte) (N & 0xFF);
		byte h7 = (byte) ((N >> 8) & 0xFF);
		byte h6 = (byte) ((N >> 16) & 0xFF);
		byte h5 = (byte) ((N >> 24) & 0xFF);
		byte h4 = (byte) ((N >> 32) & 0xFF);
		byte h3 = (byte) ((N >> 40) & 0xFF);
		byte h2 = (byte) ((N >> 48) & 0xFF);
		byte h1 = (byte) (N >> 56);
		newbyte[l++] = h1;
		newbyte[l++] = h2;
		newbyte[l++] = h3;
		newbyte[l++] = h4;
		newbyte[l++] = h5;
		newbyte[l++] = h6;
		newbyte[l++] = h7;
		newbyte[l++] = h8;
		return newbyte;
	}

	private int f1(int x, int y, int z) {
		return (x & y) | (~x & z);
	}

	private int f2(int x, int y, int z) {
		return x ^ y ^ z;
	}

	private int f3(int x, int y, int z) {
		return (x & y) | (x & z) | (y & z);
	}

	private int f4(int x, int y) {
		return (x << y) | x >>> (32 - y);
	}

	/**
	 * 单元摘要计算函数
	 */
	private void encrypt() {
		for (int i = 16; i <= 79; i++) {
			tmpData[i] = f4(tmpData[i - 3] ^ tmpData[i - 8] ^ tmpData[i - 14]
					^ tmpData[i - 16], 1);
		}
		int[] tmpabcde = new int[5];
		for (int i1 = 0; i1 < tmpabcde.length; i1++) {
			tmpabcde[i1] = digestInt[i1];
		}
		for (int j = 0; j <= 19; j++) {
			int tmp = f4(tmpabcde[0], 5)
					+ f1(tmpabcde[1], tmpabcde[2], tmpabcde[3]) + tmpabcde[4]
					+ tmpData[j] + 0x5a827999;
			tmpabcde[4] = tmpabcde[3];
			tmpabcde[3] = tmpabcde[2];
			tmpabcde[2] = f4(tmpabcde[1], 30);
			tmpabcde[1] = tmpabcde[0];
			tmpabcde[0] = tmp;
		}
		for (int k = 20; k <= 39; k++) {
			int tmp = f4(tmpabcde[0], 5)
					+ f2(tmpabcde[1], tmpabcde[2], tmpabcde[3]) + tmpabcde[4]
					+ tmpData[k] + 0x6ed9eba1;
			tmpabcde[4] = tmpabcde[3];
			tmpabcde[3] = tmpabcde[2];
			tmpabcde[2] = f4(tmpabcde[1], 30);
			tmpabcde[1] = tmpabcde[0];
			tmpabcde[0] = tmp;
		}
		for (int l = 40; l <= 59; l++) {
			int tmp = f4(tmpabcde[0], 5)
					+ f3(tmpabcde[1], tmpabcde[2], tmpabcde[3]) + tmpabcde[4]
					+ tmpData[l] + 0x8f1bbcdc;
			tmpabcde[4] = tmpabcde[3];
			tmpabcde[3] = tmpabcde[2];
			tmpabcde[2] = f4(tmpabcde[1], 30);
			tmpabcde[1] = tmpabcde[0];
			tmpabcde[0] = tmp;
		}
		for (int m = 60; m <= 79; m++) {
			int tmp = f4(tmpabcde[0], 5)
					+ f2(tmpabcde[1], tmpabcde[2], tmpabcde[3]) + tmpabcde[4]
					+ tmpData[m] + 0xca62c1d6;
			tmpabcde[4] = tmpabcde[3];
			tmpabcde[3] = tmpabcde[2];
			tmpabcde[2] = f4(tmpabcde[1], 30);
			tmpabcde[1] = tmpabcde[0];
			tmpabcde[0] = tmp;
		}
		for (int i2 = 0; i2 < tmpabcde.length; i2++) {
			digestInt[i2] = digestInt[i2] + tmpabcde[i2];
		}
		for (int n = 0; n < tmpData.length; n++) {
			tmpData[n] = 0;
		}
	}

	/**
	 * 4字节数组转换为整数
	 * 
	 * @param bytedata
	 * @param i
	 * @return
	 */
	private int byteArrayToInt(byte[] bytedata, int i) {
		return ((bytedata[i] & 0xff) << 24) | ((bytedata[i + 1] & 0xff) << 16)
				| ((bytedata[i + 2] & 0xff) << 8) | (bytedata[i + 3] & 0xff);
	}

	// 
	/**
	 * 整数转换为4字节数组
	 * 
	 * @param intValue
	 * @param byteData
	 * @param i
	 */
	private void intToByteArray(int intValue, byte[] byteData, int i) {
		byteData[i] = (byte) (intValue >>> 24);
		byteData[i + 1] = (byte) (intValue >>> 16);
		byteData[i + 2] = (byte) (intValue >>> 8);
		byteData[i + 3] = (byte) intValue;
	}

	/**
	 * 将字节转换为十六进制字符串
	 * 
	 * @param ib
	 * @return
	 */
	private static String byteToHexString(byte ib) {
		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A',
				'B', 'C', 'D', 'E', 'F' };
		char[] ob = new char[2];
		ob[0] = Digit[(ib >>> 4) & 0X0F];
		ob[1] = Digit[ib & 0X0F];
		String s = new String(ob);
		return s;
	}

	/**
	 * 将字节数组转换为十六进制字符串
	 * 
	 * @param bytearray
	 * @return
	 */
	private static String byteArrayToHexString(byte[] bytearray) {
		String strDigest = "";
		for (int i = 0; i < bytearray.length; i++) {
			strDigest += byteToHexString(bytearray[i]);
		}
		return strDigest;
	}

	/**
	 * 计算sha-1摘要，返回相应的字节数组
	 * 
	 * @param byteData
	 * @return
	 */
	public byte[] getDigestOfBytes(byte[] byteData) {
		process_input_bytes(byteData);
		byte[] digest = new byte[20];
		for (int i = 0; i < digestInt.length; i++) {
			intToByteArray(digestInt[i], digest, i * 4);
		}
		return digest;
	}

    /**
     * 计算sha-1摘要，返回相应的十六进制字符串 
     * 
     * @param byteData
     * @return
     */
    public String getDigestOfString(byte[] byteData) { 
        return byteArrayToHexString(getDigestOfBytes(byteData)); 
    } 
	
    /**
     * @param data
     * @return
     */
    public String Digest(String data){
    	return this.getDigestOfString(data.getBytes());
    }

    /**
     * @param data
     * @return
     */
    public String Digest(String data,String encode){
    	try {
			return this.getDigestOfString(data.getBytes(encode));
		} catch (UnsupportedEncodingException e) {
			return this.Digest(data);
		}
    }
    
    /**
     * @param text
     * @return
     */
    public static String SHA1Digest(String text) {
    	String pwd = "";
		try {
			MessageDigest md = MessageDigest.getInstance("SHA1");
			md.update(text.getBytes());
			pwd = new BigInteger(1, md.digest()).toString(16); 
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
    	return pwd;
    }
    
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		SHA1 sha1 = new SHA1();
		// 0805949359741CE14FE90402B25E2E023F449748
		System.out.println(sha1.Digest("我们","UTF-8"));
		// 24E384109C1FE06E363DB1FF6C8F8DDBF18C45EA
		System.out.println(sha1.Digest("我们"));
		
		// 24e384109c1fe06e363db1ff6c8f8ddbf18c45ea
		System.out.println(SHA1.SHA1Digest("我们"));
	}



	public static String encode(String str) {
		if (str == null) {
			return null;
		}
		try {
			MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
			messageDigest.update(str.getBytes());
			return getFormattedText(messageDigest.digest());
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	private static String getFormattedText(byte[] bytes) {
		int len = bytes.length;
		StringBuilder buf = new StringBuilder(len * 2);
		// 把密文转换成十六进制的字符串形式
		for (int j = 0; j < len; j++) {
			buf.append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);
			buf.append(HEX_DIGITS[bytes[j] & 0x0f]);
		}
		return buf.toString();
	}

	private static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5',
			'6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
}
