package com.nova.sankuai.domain.api.yixin;


import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.nova.sankuai.security.HexUtil;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;

public class YXSignUtil {

    public static final String reqSysCode = "WHKJ";

    public static final String KEY_ALGORITHM = "RSA";

    //本地公钥
    public static final String LOCAL_PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDPlqGyVfCliU1SmhdGKem9+p63rIb78bu3Yj9DWQv1c+fbFLV0OkfeMvyTAJi95PozH+JlDqt3gWWLyCXEb7M6pPNEJmUjGHX4+tCykUbooY55zr8En3DM4MMRvOz5hhkle7tosT4Iejhtuwsah9heWd4AuM84gw8C7LVA7XbOkQIDAQAB";

    //本地私钥
    public static final String LOCAL_PRIVATE_KEY = "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";


    /**
     * 构造合作方请求绿地报文
     *
     * @param bizMap     业务报文集
     * @param privateKey 合作方私钥
     * @param publicKey  绿地公钥
     * @return
     */
    public static String buildRequest(Map<String, Object> bizMap, PrivateKey privateKey, PublicKey publicKey, String funding) throws Exception {
        // 业务报文
        String params = JSON.toJSONString(bizMap);
        // 时间戳
        String timestamp = DateTimeFormatter.ofPattern("yyyyMMddHHmmss").format(LocalDateTime.now());
        // 构建签名
        SortedMap<String, String> map = new TreeMap<>();
        map.put("params", params);
        map.put("timestamp", timestamp);

        // 待签名明文
        String plain = toSortedString(map);
        // 做md5摘要处理
        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);
        // 签名
        String sign = sign(md5, privateKey);
        map.put("sign", sign);

        // 生成16位AES密钥
        String aesKey = generateAesKey();
        // 对params进行AES加密, 并替换进map
        params = encrypt(params, aesKey);
        map.replace("params", params);

        // 对AES密钥进行RSA加密, 并将加密后的AES密钥加入map
        aesKey = encryptRSA(aesKey, publicKey);
        map.put("key", aesKey);
        map.put("reqSysCode", reqSysCode);
        map.put("funding", funding);

        return JSON.toJSONString(map);
    }

    /**
     * 绿地处理合作方发起的请求
     *
     * @param strReq     合作方请求到达绿地的json字符串请求报文
     * @param privateKey 绿地私钥
     * @param publicKey  合作方公钥
     * @return
     */
    public static Map<String, Object> parseRequest(String strReq, PrivateKey privateKey, PublicKey publicKey) throws Exception {
        JSONObject json = JSON.parseObject(strReq);
        String params = json.getString("params");
        String aesKey = json.getString("key");
        String sign = json.getString("sign");
        String timestamp = json.getString("timestamp");

        // 对AESkey进行RSA解密
        aesKey = decryptRSA(aesKey, privateKey);
        // 对params进行AES解密
        params = decrypt(params, aesKey);

        // 构建验签明文
        TreeMap<String, String> map = new TreeMap<>();
        map.put("params", params);
        map.put("timestamp", timestamp);
        String plain = toSortedString(map);

        // 做md5摘要
        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);

        // 验签
        boolean passed = verify(sign, md5, publicKey);
        if (!passed) {
            throw new RuntimeException("验签失败");
        }
        return JSON.parseObject(params);
    }

    /**
     * 绿地处理合作方发起的请求
     *
     * @param strReq     合作方请求到达绿地的json字符串请求报文
     * @param privateKey 本地私钥
     * @param publicKey  绿地公钥
     * @return
     */
    public static Map<String, Object> parseLVDiRequest(Map<String, String> strReq, PrivateKey privateKey, PublicKey publicKey) throws Exception {
        String params = strReq.get("params");
        String aesKey = strReq.get("key");
        String signkeyIndex = strReq.get("signkeyIndex");
        String appId = strReq.get("appId");
        String version = strReq.get("version");
        String sign = strReq.get("sign");
        String timestamp = strReq.get("timestamp");

        // 对AESkey进行RSA解密
        aesKey = decryptRSA(aesKey, privateKey);
        // 对params进行AES解密
        params = decrypt(params, aesKey);

        // 构建验签明文
        Map<String, Object> map = new HashMap<>();
        map.put("params", params);
        map.put("timestamp", timestamp);
        map.put("signkeyIndex", signkeyIndex);
        map.put("appId", appId);
        map.put("version", version);
//        String plain = toSortedString(map);

        // 做md5摘要
//        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);

        // 验签
//        boolean passed = verify(sign, md5, publicKey);
//        if (!passed) {
//            throw new RuntimeException("验签失败");
//        }
        return map;
    }

    /**
     * 绿地给合作方的同步响应报文构建
     *
     * @param bizMap     业务报文
     * @param privateKey 绿地私钥
     * @param publicKey  合作方公钥
     * @return
     */
    public static String buildResponse(Map<String, Object> bizMap, PrivateKey privateKey, PublicKey publicKey) throws Exception {
        JSONObject json = new JSONObject();
        TreeMap<String, String> map = new TreeMap<>();
        String params = JSON.toJSONString(bizMap);
        map.put("params", params);

        // 处理签名
        String plain = toSortedString(map);
        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);
        String sign = sign(md5, privateKey);
        map.put("sign", sign);
        // 处理加密
        String aesKey = generateAesKey();
        params = encrypt(params, aesKey);
        map.replace("params", params);
        map.put("key", encryptRSA(aesKey, publicKey));
        map.put("encrypt", "true");
        return JSON.toJSONString(map);
    }


    /**
     * 绿地回调请求合作方报文构建
     *
     * @param bizMap     业务报文
     * @param privateKey 绿地私钥
     * @param publicKey  合作方公钥
     * @return
     */
    public static String buildCallbackRequest(Map<String, Object> bizMap, PrivateKey privateKey, PublicKey publicKey) throws Exception {

        // 参数
        String params = JSON.toJSONString(bizMap);
        // 签名
        TreeMap<String, String> map = new TreeMap<>();
        map.put("params", params);
        map.put("timestamp", DateTimeFormatter.ofPattern("yyyyMMddHHmmss").format(LocalDateTime.now()));
        map.put("appId", "");// 固定,待合作方分配
        map.put("version", "1.0");// 固定,由具体接口文档定

        String plain = toSortedString(map);
        // MD5
        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);
        // 签名
        String sign = sign(md5, privateKey);
        map.put("sign", sign);

        // AES密钥
        String aesKey = generateAesKey();
        // 加密
        map.replace("params", encrypt(params, aesKey));
        map.put("key", encryptRSA(aesKey, publicKey));

        map.put("signType", "");// 具体由接口文档定
        map.put("signkeyIndex", "");// 固定，由合作方分配

        return JSON.toJSONString(map);
    }

    /**
     * 绿地处理合作方的回调响应
     *
     * @param strResp
     * @param privateKey
     * @param publicKey
     * @return
     */
    public static String parseCallbackResponse(String strResp, PrivateKey privateKey, PublicKey publicKey) throws Exception {
        JSONObject json = JSON.parseObject(strResp);
        String sign = (String) json.remove("gsSign");
        TreeMap<String, String> map = new TreeMap<>();
        json.forEach((k, v) -> map.put(k, v.toString()));
        String plain = toSortedString(map);
        String md5 = MD5.digest(plain, StandardCharsets.UTF_8);
        boolean verify = verify(sign, md5, publicKey);
        if (!verify) {
            throw new RuntimeException("验签失败");
        }
        String params = json.getString("params");
        Boolean encrypted = json.getBoolean("encrypt");
        if (encrypted != null && encrypted) {
            String aesKey = json.getString("key");
            aesKey = decryptRSA(aesKey, privateKey);
            params = decrypt(params, aesKey);
        }

        return params;
    }


    /**
     * RSA签名
     *
     * @param data
     * @param privateKey
     * @return
     */
    public static String sign(String data, PrivateKey privateKey) throws Exception {
        Signature signature = Signature.getInstance("SHA1WithRSA");
        signature.initSign(privateKey);
        signature.update(data.getBytes(StandardCharsets.UTF_8));
        return Base64.getEncoder().encodeToString(signature.sign());
    }

    /**
     * 验签
     *
     * @param sign
     * @param md5
     * @param publicKey
     * @return
     */
    public static boolean verify(String sign, String md5, PublicKey publicKey) throws Exception {
        byte[] signBytes = Base64.getDecoder().decode(sign);
        Signature signature = Signature.getInstance("SHA1WithRSA");
        signature.initVerify(publicKey);
        signature.update(md5.getBytes(StandardCharsets.UTF_8));
        return signature.verify(signBytes);
    }


    /**
     * 将需要加签的数据拼接为'='和'&'拼接的格式
     *
     * @param map
     * @return
     */
    private static String toSortedString(SortedMap<String, String> map) {
        StringBuilder sb = new StringBuilder();
        Iterator<Map.Entry<String, String>> it = map.entrySet().iterator();
        while (true) {
            Map.Entry<String, String> entry = it.next();
            sb.append(entry.getKey()).append('=').append(entry.getValue());
            if (it.hasNext()) {
                sb.append('&');
            } else {
                break;
            }
        }
        return sb.toString();
    }

    /**
     * 生成16位不重复的随机数，含数字+大小写
     * 作为AES密钥使用
     */
    private static String generateAesKey() {
        StringBuilder uid = new StringBuilder();
        //产生16位的强随机数
        Random rd = new SecureRandom();
        for (int i = 0; i < 16; i++) {
            int type = rd.nextInt(3);
            switch (type) {
                case 0:
                    uid.append(rd.nextInt(10));
                    break;
                case 1:
                    uid.append((char) (rd.nextInt(25) + 65));
                    break;
                case 2:
                    uid.append((char) (rd.nextInt(25) + 97));
                    break;
                default:
                    break;
            }
        }
        return uid.toString();
    }

    /**
     * AES加密
     *
     * @param content 需要加密的内容
     * @param strKey  加密秘钥
     * @return 加密后的比特流
     */
    private static String encrypt(String content, String strKey) throws Exception {
        SecretKeySpec key = new SecretKeySpec(strKey.getBytes(), "AES"); //NOSONAR
        Cipher cipher = Cipher.getInstance("AES");
        byte[] byteContent = content.getBytes(StandardCharsets.UTF_8);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        return byte2hex(cipher.doFinal(byteContent));
    }

    /**
     * AES解密
     *
     * @param content 待解密内容
     * @param strKey  解密密钥
     * @return 解密后的
     */
    private static String decrypt(String content, String strKey) throws Exception {
        SecretKeySpec key = new SecretKeySpec(strKey.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, key);
        return new String(cipher.doFinal(hex2byte(content)));
    }

    /**
     * RSA加密
     *
     * @param data
     * @param publicKey
     * @return
     */
    public static String encryptRSA(String data, PublicKey publicKey) throws Exception {
        // 对数据加密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        return byte2hex(cipher.doFinal(data.getBytes()));
    }

    /**
     * RSA解密
     *
     * @param message
     * @param privateKey
     * @return
     */
    public static String decryptRSA(String message, PrivateKey privateKey) throws Exception {
        byte[] bytes = hex2byte(message);
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(2, privateKey);
        byte[] result = cipher.doFinal(bytes);
        return new String(result);
    }

    /**
     * 16进制string转byte[]
     *
     * @param str
     * @return
     */
    private static byte[] hex2byte(final String str) {
        if (str == null) {
            return new byte[]{};
        }
        String newStr = str.trim();
        int len = newStr.length();
        if (len <= 0 || len % 2 != 0) {
            return new byte[]{};
        }
        byte[] b = new byte[len / 2];
        try {
            for (int i = 0; i < newStr.length(); i += 2) {
                b[i / 2] = (byte) Integer.decode("0x" + newStr.substring(i, i + 2)).intValue();
            }
            return b;
        } catch (Exception e) { //NOSONAR
            return new byte[]{};
        }
    }

    /**
     * byte[]转16进制string
     *
     * @param b
     * @return
     */
    private static String byte2hex(byte[] b) {
        StringBuilder hs = new StringBuilder();
        for (byte bi : b) {
            String temp = Integer.toHexString(bi & 0XFF);
            if (temp.length() == 1) {
                hs.append("0");
            }
            hs.append(temp);
        }
        return hs.toString().toUpperCase();
    }


    /**
     * MD5工具类
     */
    private static class MD5 {
        private static ThreadLocal threadLocal = new ThreadLocal() {
            @Override
            protected synchronized Object initialValue() {
                MessageDigest messagedigest = null;

                try {
                    messagedigest = MessageDigest.getInstance("MD5");
                } catch (NoSuchAlgorithmException var3) {

                }

                return messagedigest;
            }
        };

        public MD5() {
        }

        public static MessageDigest getMessageDigest() {
            return (MessageDigest) threadLocal.get();
        }

        public static String digest(String s, Charset charset) {
            getMessageDigest().update(s.getBytes(charset));
            return HexUtil.bytes2Hexstr(getMessageDigest().digest());
        }
    }


}