package org.springblade.common.utils;

import com.google.common.hash.Hashing;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Map;

public class Md5SignUtil {
	private final static Logger logger = LoggerFactory.getLogger(Md5SignUtil.class);

	public static String signRequest(Map<String, Object> params, String secret) throws IOException {
		// 第一步：检查参数是否已经排序
		String[] keys = params.keySet().toArray(new String[0]);
		Arrays.sort(keys);

		// 第二步：把所有参数名和参数值串在一起
		StringBuilder query = new StringBuilder();
		query.append(secret);
		for (String key : keys) {
			Object o = params.get(key);
			if (o!= null && o!="") {
				query.append(key).append(o);
			}
		}
		query.append(secret);
//		logger.info("query={}",query);

		// 第三步：使用MD5加密
		byte[] bytes = encryptMD5(query.toString());

		// 第四步：把二进制转化为大写的十六进制(正确签名应该为32大写字符串，此方法需要时使用)
		return byte2hex(bytes);
	}

	public static byte[] encryptMD5(String data) throws IOException {
		return Hashing.md5().hashBytes(data.getBytes("utf-8")).asBytes();
	}

	public static String byte2hex(byte[] bytes) {
		StringBuilder sign = new StringBuilder();
		for (int i = 0; i < bytes.length; i++) {
			String hex = Integer.toHexString(bytes[i] & 0xFF);
			if (hex.length() == 1) {
				sign.append("0");
			}
			sign.append(hex.toUpperCase());
		}
		return sign.toString();
	}

	/***
	 * MD5加码 生成32位md5码
	 */
	public static String string2MD5(String inStr) {
		MessageDigest md5 = null;
		try {
			md5 = MessageDigest.getInstance("MD5");
		} catch (Exception e) {
			e.printStackTrace();
			return "";
		}
		char[] charArray = inStr.toCharArray();
		byte[] byteArray = new byte[charArray.length];

		for (int i = 0; i < charArray.length; i++) {
			byteArray[i] = (byte) charArray[i];
		}
		byte[] md5Bytes = md5.digest(byteArray);
		StringBuffer hexValue = new StringBuffer();
		for (int i = 0; i < md5Bytes.length; i++) {
			int val = ((int) md5Bytes[i]) & 0xff;
			if (val < 16) {
				hexValue.append("0");
			}
			hexValue.append(Integer.toHexString(val));
		}
		return hexValue.toString();
	}

	/**
	 * 加密解密算法 执行一次加密，两次解密
	 */
	public static String convertMD5(String inStr) {

		char[] a = inStr.toCharArray();
		for (int i = 0; i < a.length; i++) {
			a[i] = (char) (a[i] ^ 't');
		}
		String s = new String(a);
		return s;

	}

}