package com.smtaiserver.smtaiserver.util;

import com.smtaiserver.smtaiserver.control.SMTAIServerControl;
import com.smtaiserver.smtaiserver.core.SMTAIServerApp;
import com.smtservlet.core.SMTRequest;
import com.smtservlet.util.Json;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.springframework.boot.configurationprocessor.json.JSONObject;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static java.util.Arrays.sort;

public class SMTWXSStatic {
  private static Logger _logger = LogManager.getLogger(SMTAIServerControl.class);

  /** 微信验证 */
  public static ModelAndView getModelAndView(SMTRequest tranReq) throws Exception {
    String signature = tranReq.convParamToString("signature", true);
    String timestamp = tranReq.convParamToString("timestamp", true);
    String nonce = tranReq.convParamToString("nonce", true);
    String echostr = tranReq.convParamToString("echostr", true);
    // 获取微信请求参数
    _logger.info(
        "开始校验此次消息是否来自微信服务器，param->signature:{},\ntimestamp:{},\nnonce:{},\nechostr:{}",
        signature,
        timestamp,
        nonce,
        echostr);
    // 需要验证的时候就启用
    if (checkSignature(signature, timestamp, nonce)) {
      return tranReq.returnText(echostr);
    }
    return tranReq.returnText("");
  }

  /** 验证签名util */
  public static boolean checkSignature(String signature, String timestamp, String nonce)
      throws Exception {
    HashMap<String, String> weixinParam = getWeixinParam();
    String[] arr = new String[] {weixinParam.get("token"), timestamp, nonce};
    // 将token、timestamp、nonce三个参数进行字典序排序
    // Arrays.sort(arr);
    sort(arr);
    StringBuilder content = new StringBuilder();
    for (String s : arr) {
      content.append(s);
    }
    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 = byteToHex(digest);
    } catch (NoSuchAlgorithmException e) {
      _logger.error("签名异常", e);
    }
    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

    return tmpStr != null && tmpStr.equals(signature.toUpperCase());
  }

  public static HashMap<String, String> getWeixinParam() throws Exception {
    Object weixinParam = SMTAIServerApp.getApp().getGlobalConfig("weixin_core_param", "false");
    _logger.info("微信参数：{}", weixinParam);
    JSONObject weixinJson = new JSONObject(weixinParam.toString());
    String appId = (String) weixinJson.get("appId");
    String secret = (String) weixinJson.get("secret");
    String token = (String) weixinJson.get("token");
    HashMap<String, String> paramMap = new HashMap<>();
    paramMap.put("appId", appId);
    paramMap.put("secret", secret);
    paramMap.put("token", token);
    return paramMap;
  }

  public static Map<String, String> getWechatReqMap(HttpServletRequest request) {
    Map<String, String> requestMap = new HashMap<>();
    SAXReader reader = new SAXReader();
    try (ServletInputStream inputStream = request.getInputStream()) {
      Document document = reader.read(inputStream);
      Element root = document.getRootElement();
      List<Element> elementList = root.elements();
      for (Element e : elementList) {
        requestMap.put(e.getName(), e.getText());
      }
    } catch (IOException | DocumentException e) {
      throw new RuntimeException(e);
    }
    return requestMap;
  }

  public static String byteToHex(byte[] data)
  {
    String hex = "0123456789ABCDEF";
    StringBuilder sb = new StringBuilder();
    for(byte v : data)
    {
      sb.append(hex.charAt((v >> 4) & 0x0F));
      sb.append(hex.charAt(v & 0x0F));
      //sb.append(String.format("%02X", v));
    }
    return sb.toString();
  }

  public static String sendPost(String urlString, Json jsonParam) throws Exception {
    // 将参数转换为 JSON 格式字符串
    // JSONObject jsonParams = new JSONObject(params);
    String payload = jsonParam.toString();
    // 创建连接
    URL url = new URL(urlString);
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    connection.setRequestMethod("POST");
    // 设置请求头
    connection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
    connection.setDoOutput(true);
    // 写入请求体
    try (OutputStream os = connection.getOutputStream()) {
      byte[] input = payload.getBytes(StandardCharsets.UTF_8);
      os.write(input, 0, input.length);
    }
    // 读取响应
    try (java.io.InputStream in = connection.getInputStream()) {
      @SuppressWarnings("resource")
	java.util.Scanner scanner = new java.util.Scanner(in).useDelimiter("\\A");
      return scanner.hasNext() ? scanner.next() : "";
    }
  }
}