package com.dollearn.student.network;
import android.util.Base64;
import android.util.Log;


import com.dollearn.student.utils.Const;
import com.dollearn.student.utils.HMACSHA1;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

import cn.sinata.util.Base64DES;

public class SignUtil {
	
	/*
	 * 不要写成：Cipher cipher = Cipher.getInstance("DES");
	 * 或：Cipher cipher = Cipher.getInstance("DES/CBC/NoPadding");
	 * 原因是Cipher cipher = Cipher.getInstance("DES");
	 * 与Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
	 * 等同，填充方式错误，加密的时候会得到16长度的字节数组。
	 * 应该写成
	 * Cipher cipher = Cipher.getInstance("DES/ECB/NoPadding");
	 */

	/**
	 * 生成签名
	 * @param map
	 * @return
	 */
	public static String getSign(Map<String, Object> map) {

		String result = "";
		try {
			List<Map.Entry<String, Object>> infoIds = new ArrayList<>(map.entrySet());
			if (infoIds.size()>0){
				// 对所有传入参数按照字段名的 ASCII 码从小到大排序（字典序）
				Collections.sort(infoIds, new Comparator<Map.Entry<String, Object>>() {
					@Override
					public int compare(Map.Entry<String, Object> o1, Map.Entry<String, Object> o2) {
						return (o1.getKey()).compareTo(o2.getKey());
					}
				});
				// 构造签名键值对的格式
				StringBuilder sb = new StringBuilder();
				for (Map.Entry<String, Object> item : infoIds) {
					if (item.getKey() == null) {
						item.getKey();
					}
					String key = item.getKey();
					Object val = item.getValue();
					if (!(val == "" || val == null)) {
						sb.append(key).append("=").append(val).append("&");
					}
				}
				result = sb.toString();
				result = result.substring(0,result.length() - 1);
				Log.e(Const.Tag, "getSign: ====》"+result);
			}
			result = Base64DES.INSTANCE.encode(HMACSHA1.HmacSHA1Encrypt(result, Const.APP_KEY));
		} catch (Exception e) {
			return null;
		}
		return result;
	}
	private static final String MAC_NAME = "HmacSHA1";
	private static final String ENCODING = "UTF-8";
	public static String genHMAC(String data, String key) {
		byte[] result = null;
		try {
			//根据给定的字节数组构造一个密钥,第二参数指定一个密钥算法的名称
			SecretKeySpec signinKey = new SecretKeySpec(key.getBytes(), MAC_NAME);
			//生成一个指定 Mac 算法 的 Mac 对象
			Mac mac = Mac.getInstance(MAC_NAME);
			//用给定密钥初始化 Mac 对象
			mac.init(signinKey);
			//完成 Mac 操作
			byte[] rawHmac = mac.doFinal(data.getBytes());
			result = Base64.encode(rawHmac, Base64.DEFAULT);
		} catch (NoSuchAlgorithmException e) {
			System.err.println(e.getMessage());
		} catch (InvalidKeyException e) {
			System.err.println(e.getMessage());
		}
		if (null != result) {
			return new String(result);
		} else {
			return null;
		}
	}

}