package com.epmet.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Enumeration;


/**
 * desc:微信配置测试
 *
 * @author generator generator@elink-cn.com
 * @since v1.0.0 2020-03-08
 */
@RestController
@RequestMapping("wechat")
public class WxController {
    private static Logger log = LoggerFactory.getLogger(WxController.class);


    @RequestMapping("check")
    public void get(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("========WechatController========= ");
        Enumeration pNames = request.getParameterNames();
        while (pNames.hasMoreElements()) {
            String name = (String) pNames.nextElement();
            String value = request.getParameter(name);
            // out.print(name + "=" + value);

            String log = "name =" + name + "     value =" + value;
        }

        String signature = request.getParameter("signature");/// 微信加密签名
        String timestamp = request.getParameter("timestamp");/// 时间戳
        String nonce = request.getParameter("nonce"); /// 随机数
        String echostr = request.getParameter("echostr"); // 随机字符串
        response.reset();
        PrintWriter out = response.getWriter();

//        if (this.checkSignature(signature, timestamp, nonce)) {
//            out.print(echostr);
//        }
        out.close();
        out = null;
    }


    /**
     * 校验签名
     */
    public static boolean checkSignature(String signature, String timestamp, String nonce) {
        System.out.println("signature:" + signature + "timestamp:" + timestamp + "nonc:" + nonce);
        String WECHAT_TOKEN = "1jkoyyih83nj8";
        String[] arr = new String[]{WECHAT_TOKEN, timestamp, nonce};
        // 将token、timestamp、nonce三个参数进行字典序排序
        Arrays.sort(arr);
        StringBuilder content = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            content.append(arr[i]);
        }
        MessageDigest md = null;
        String tmpStr = null;

        try {
            md = MessageDigest.getInstance("SHA-1");
            // 将三个参数字符串拼接成一个字符串进行sha1加密
            byte[] digest = md.digest(content.toString().getBytes());
            tmpStr = byteToStr(digest);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }

        content = null;
        // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
        System.out.println(tmpStr.equals(signature.toUpperCase()));
        return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
    }

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

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

        String s = new String(tempArr);
        return s;
    }


    /**
     * 打开开发者模式签名认证
     * @param signature
     * @param timestamp
     * @param nonce
     * @param echostr
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/service", method = RequestMethod.GET)
    public Object defaultView(String signature, String timestamp, String nonce, String echostr) {
        if (echostr == null || echostr.isEmpty()) {
            return nonce;
        }
        if (this.checkSignature(signature, timestamp, nonce)) {
            return echostr;
        }
        return nonce;
    }


}