# Interface protocol

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;


import com.alibaba.fastjson.JSON;

public class TestSign {
	private static String encodingCharset = "UTF-8";
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("mchId", "10000XXX");
		map.put("mchOrderNo", "6199200000006");
		map.put("channelId", "WX_MICROPAY");
		map.put("currency", "CAD");
		map.put("codeType", "barcode");
		map.put("amount", "1");
		map.put("clientIp", "127.0.0.1");
		map.put("identityCode", "135021906891251756");
		map.put("device", "superscanner");
		map.put("deviceId", "superscanner_NS010");
		map.put("notifyUrl", "http://www.xxxx.ca/getnotify");
		map.put("subject", "test");
		map.put("body", "test body");
		String merchantKey = "xxxxxxxxxxxxxxxxxxxx";
		String sign = getSign(map, merchantKey);
		System.out.println("sign is [" + sign + "]");
		//sign is [E7F9184356482199D44C9FC20704B798]
		map.put("sign", sign);
		try {
			String strSubjectEncode = URLEncoder.encode(map.get("subject")+"", StandardCharsets.UTF_8.toString());
			map.put("subject", strSubjectEncode);
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		try {
			String strBodyEncode = URLEncoder.encode(map.get("body")+"", StandardCharsets.UTF_8.toString());
			map.put("body", strBodyEncode);
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		String strParam = JSON.toJSONString(map);
		
		String strOutputParams = "params=" + strParam; // for credit card, there is no 'params=', just send json string
		String url = "https://api.iotpaycloud.com/v1/create_order";
		String result = Http(url, strOutputParams);

	}
	public static String Http(String url, String param) {
		String result = "";
		//please add your http request here.
		return result;
	}
	public static String toHex(byte input[]) {
		if (input == null)
			return null;
		StringBuffer output = new StringBuffer(input.length * 2);
		for (int i = 0; i < input.length; i++) {
			int current = input[i] & 0xff;
			if (current < 16)
				output.append("0");
			output.append(Integer.toString(current, 16));
		}

		return output.toString();
	}
	public static String md5(String value, String charset) {
		MessageDigest md = null;
		try {
			byte[] data = value.getBytes(charset);
			md = MessageDigest.getInstance("MD5");
			byte[] digestData = md.digest(data);
			return toHex(digestData);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
			return null;
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
			return null;
		}
	}
	public static String getSign(Map<String,Object> map, String key){
		ArrayList<String> list = new ArrayList<String>();
		for(Map.Entry<String,Object> entry:map.entrySet()){
			if(!"".equals(entry.getValue())){
				list.add(entry.getKey() + "=" + entry.getValue() + "&");
			}
		}
		int size = list.size();
		String [] arrayToSort = list.toArray(new String[size]);
		Arrays.sort(arrayToSort, String.CASE_INSENSITIVE_ORDER);
		StringBuilder sb = new StringBuilder();
		for(int i = 0; i < size; i ++) {
			sb.append(arrayToSort[i]);
		}
		String result = sb.toString();
		result += "key=" + key;
		result = md5(result, encodingCharset).toUpperCase();
		return result;
	}
}