package com.ydtech.modules.order.utils;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.ydtech.constants.InsuranceEnum;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.Base64Utils;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.*;

/**
 * 签名工具
 */
@Slf4j
public class SignatureUtils {

    private SignatureUtils(){
        throw new IllegalStateException("Utility class");
    }
    /**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

    /**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

    /**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;

    /**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;

    /**
     * 验签并解密
     * <p>
     * 对于<b>银保信</b>，publicKey是指合作方的公钥，privateKey是指银保信的私钥<br>
     * 对于<b>合作方</b>，publicKey是指银保信的公钥，privateKey是指合作方的私钥<br>
     *
     * @param request     原始报文(JSON字符串)
     * @param publicKey   公钥
     * @param privateKey  私钥
     * @param isCheckSign 是否验签
     * @param isDecrypt   是否解密
     * @return 解密后的明文，验签失败则异常抛出
     */
    public static String checkSignAndDecrypt(String request, String sign, String publicKey, String privateKey, boolean isCheckSign,
                                             boolean isDecrypt) {
        boolean verifyResult = false;
        JSONObject requestJSONObject = JSONObject.parseObject(request);
        String bizContent = requestJSONObject.getString("bizContent");// 获取的业务数据密文
        String signContent = getSignContent(requestJSONObject);// 所有key排序后放入LingkedMap后map.toString()
        if (isCheckSign) {
            verifyResult = verify(signContent, sign, publicKey);
        }
        if (!isCheckSign) {
            verifyResult = true;
        }
        if (isDecrypt && verifyResult) {
            return decryptByPrivateKey(bizContent, privateKey);
        }
        return null;
    }

    public static String checkSignAndDecryptNew(String request, String sign, String publicKey, String privateKey, boolean isCheckSign,
                                                boolean isDecrypt) throws Exception {
        boolean verifyResult = false;
        JSONObject requestJSONObject = JSONObject.parseObject(request);
        String bizContent = requestJSONObject.getString("bizContent");// 获取的业务数据密文
        String insurerCode = requestJSONObject.getString("insurerCode");
        String sysSourceCode = requestJSONObject.getString("sysSourceCode");
        String signContent = getSignContent(requestJSONObject);// 所有key排序后放入LingkedMap后map.toString()
        if (isCheckSign) {
            verifyResult = verify(signContent, sign, publicKey);
        }
        if (!isCheckSign) {
            verifyResult = true;
        }
        if (isDecrypt && verifyResult) {
            String json = decryptByPrivateKey(bizContent, privateKey);
            String oldChar = "\\{";
            String newChar = "{\"sysSourceCode\": \"" + sysSourceCode + "\",\"insurerCode\": \"" + insurerCode + "\",";
            return json.replaceFirst(oldChar, newChar);
        }
        return null;
    }

    /**
     * 加密并签名
     * <p>
     * 对于<b>银保信</b>，publicKey是指合作方的公钥，privateKey是指银保信的私钥<br>
     * 对于<b>合作方</b>，publicKey是指银保信的公钥，privateKey是指合作方的私钥<br>
     *
     * @param publicKey      公钥
     * @param requestContent 报文原文
     * @param isCheckSign    是否签名
     * @param isEncrypt      是否加密
     * @return 加密加签后的返回报文
     * @throws Exception
     */
    public static Map<String, String> encryptAndSign(String privateKey, String publicKey, String requestContent, boolean isCheckSign,
                                                     boolean isEncrypt) throws Exception {
        JSONObject requestJSONObject = JSONObject.parseObject(requestContent);
        String bizContent = requestJSONObject.getString("bizContent");
        Map<String, String> map = new HashMap<String, String>();
        if (isEncrypt) {
            //加密
            String encryptBizContent = encryptByPublicKey(bizContent, publicKey);//对业务数据进行加密
            requestJSONObject.put("bizContent", encryptBizContent);//将加密后的数据替换原有的明文
            map.put("content", requestJSONObject.toJSONString());
            if (isCheckSign) {
                //加签
                String signContent = getSignContent(requestJSONObject);// 所有key排序后放入LingkedMap后map.toString()
                String sign = sign(signContent, privateKey);
                map.put("signature", sign);
            }
        } else if (isCheckSign) {// 只加签、不加密
            String signContent = getSignContent(requestJSONObject);// 所有key排序后放入LingkedMap后map.toString()
            String sign = sign(signContent, privateKey);
            map.put("signature", sign);
        }
        return map;
    }

    /**
     * 封装待验签的内容
     *
     * @param sortedParam
     * @return
     */
    public static String getSignContent(Map<String, Object> sortedParam) {
        LinkedHashMap map = new LinkedHashMap();
        List<String> keys = new ArrayList<String>(sortedParam.keySet());
        Collections.sort(keys);
        for (int i = 0; i < keys.size(); i++) {
            String key = keys.get(i);
            String value = sortedParam.get(key).toString();
            map.put(key, value);
        }
        return map.toString();
    }

    /**
     * 验签
     *
     * @param request
     * @param sign
     * @param
     * @return
     */
    public static boolean verify(String request, String sign, String publicKey) {
        try {
            return SignatureUtils.verify(request.getBytes(), publicKey, sign);
        } catch (Exception e) {
            log.error("验签异常，inputParams: {} and publicKey: {} and sign: {} and errorMessage: {}", request, publicKey, sign,
                    e.getMessage(), e);
            throw new RuntimeException(e);
        }
    }

    /**
     * <p>
     * 校验数字签名
     * </p>
     *
     * @param data      已加密数据
     * @param publicKey 公钥(BASE64编码)
     * @param sign      数字签名
     * @return
     * @throws Exception
     */
    public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey.getBytes());
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicK = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(publicK);
        signature.update(data);
        return signature.verify(Base64Utils.decode(sign.getBytes()));
    }

    /**
     * 私钥对数据进行解密
     *
     * @param bizContent
     * @param privateKey
     * @return
     */
    public static String decryptByPrivateKey(String bizContent, String privateKey) {
        try {
            return new String(SignatureUtils.decryptByPrivateKey(Base64Utils.decode(bizContent.getBytes()), privateKey));
        } catch (Exception e) {
            log.error("私钥解密异常，inputParams: {} and privateKey: {}  and errorMessage: {}", bizContent, privateKey, e.getMessage(), e);
            throw new RuntimeException(e);
        }
    }

    /**
     * <P>
     * 私钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param privateKey    私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey.getBytes());
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /**
     * 公钥加密
     *
     * @param request
     * @param publicKey
     * @return
     */
    public static String encryptByPublicKey(String request, String publicKey) throws Exception {
        return new String(Base64Utils.encode(SignatureUtils.encryptByPublicKey(request.getBytes(), publicKey)));
    }

    /**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data      源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey.getBytes());
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /**
     * 加签
     *
     * @param
     * @param privateKey
     * @return
     */
    public static String sign(String request, String privateKey) {
        try {
            return SignatureUtils.sign(request.getBytes(), privateKey);
        } catch (Exception e) {
            log.error("加签异常，inputParams: {} and privateKey: {}  and errorMessage: {}", request, privateKey, e.getMessage(), e);
            throw new RuntimeException(e);
        }
    }

    /**
     * <p>
     * 用私钥对信息生成数字签名
     * </p>
     *
     * @param data       已加密数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static String sign(byte[] data, String privateKey) throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey.getBytes());
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(privateK);
        signature.update(data);
        return new String(Base64Utils.encode(signature.sign()));
    }


    public static <T> T decryptMessage(String s, Class<T> c, String message, String sessionKey) {
        InsuranceLog.infoLog(InsuranceEnum.ZMBX.getPinyin(), "\n\t---------> 解密前的参数:{}", s);
        // 解密
        String text = decryptByPrivateKey(s.replace("\n", ""), sessionKey);
        InsuranceLog.infoLog(InsuranceEnum.ZMBX.getPinyin(), "\n\t---------> {}:{}", message, text);
        return JSON.parseObject(text, c);
    }

}