package com.goboosoft.common.pay.util;

import java.io.ByteArrayInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.Reader;

import java.io.StringWriter;

import java.io.Writer;

import java.security.KeyFactory;

import java.security.PrivateKey;

import java.security.PublicKey;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import org.apache.commons.codec.binary.Base64;

/**

 * Description:

 *

 * @author cy

 * @date 2019年02月28日 14:30

 * version 1.0

 */

public class RSA {

    private static final String SIGN_TYPE_RSA = "RSA";

    private static final String SIGN_TYPE_RSA2 = "RSA2";

    private static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    private static final String SIGN_SHA256RSA_ALGORITHMS = "SHA256WithRSA";

    private static final int DEFAULT_BUFFER_SIZE = ;

    /**

     * RSA/RSA2 生成签名

     *

     * @param map 包含 sign_type、privateKey、charset

     * @return

     * @throws Exception

     */

    public static String rsaSign(Map map) throws Exception {

        PrivateKey priKey = null;

        java.security.Signature signature = null;

        String signType = map.get("sign_type").toString();

        String privateKey = map.get("privateKey").toString();

        String charset = map.get("charset").toString();

        String content = getSignContent(map);

        map.put("content", content);

        System.out.println("请求参数生成的字符串为:" + content);

        if (SIGN_TYPE_RSA.equals(signType)) {

            priKey = getPrivateKeyFromPKCS8(SIGN_TYPE_RSA, new ByteArrayInputStream(privateKey.getBytes()));

            signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

        } else if (SIGN_TYPE_RSA2.equals(signType)) {

            priKey = getPrivateKeyFromPKCS8(SIGN_TYPE_RSA, new ByteArrayInputStream(privateKey.getBytes()));

            signature = java.security.Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);

        } else {

            throw new Exception("不是支持的签名类型 : : signType=" + signType);

        }

        signature.initSign(priKey);

        if (StringUtils.isEmpty(charset)) {

            signature.update(content.getBytes());

        } else {

            signature.update(content.getBytes(charset));

        }

        byte[] signed = signature.sign();

        return new String(Base64.encodeBase64(signed));

    }

    /**

     * RSA2 生成签名

     *

     * @param

     * @return

     * @throws Exception

     */

    public static String rsa2Sign(String content,String charset,String privateKey) throws Exception {

        PrivateKey priKey = null;

        java.security.Signature signature = null;

        priKey = getPrivateKeyFromPKCS8(SIGN_TYPE_RSA, new ByteArrayInputStream(privateKey.getBytes()));

        signature = java.security.Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);

        signature.initSign(priKey);

        signature.update(content.getBytes(charset));

        byte[] signed = signature.sign();

        return new String(Base64.encodeBase64(signed));

    }

    /**

     * 验签方法

     *

     * @param content   参数的合成字符串格式: key1=value1&key2=value2&key3=value3...

     * @param sign

     * @param publicKey

     * @param charset

     * @param signType

     * @return

     */

    public static boolean rsaCheck(Map map, String sign) throws Exception {

        java.security.Signature signature = null;

        String signType = map.get("sign_type").toString();

        String privateKey = map.get("privateKey").toString();

        String charset = map.get("charset").toString();

        String content = map.get("content").toString();

        String publicKey = map.get("publicKey").toString();

        System.out.println(">>验证的签名为:" + sign);

        System.out.println(">>生成签名的参数为:" + content);

        PublicKey pubKey = getPublicKeyFromX509("RSA", new ByteArrayInputStream(publicKey.getBytes()));

        if (SIGN_TYPE_RSA.equals(signType)) {

            signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

        } else if (SIGN_TYPE_RSA2.equals(signType)) {

            signature = java.security.Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);

        } else {

            throw new Exception("不是支持的签名类型 : signType=" + signType);

        }

        signature.initVerify(pubKey);

        if (StringUtils.isEmpty(charset)) {

            signature.update(content.getBytes());

        } else {

            signature.update(content.getBytes(charset));

        }

        return signature.verify(Base64.decodeBase64(sign.getBytes()));

    }

    public static PrivateKey getPrivateKeyFromPKCS8(String algorithm, InputStream ins) throws Exception {

        if (ins == null || StringUtils.isEmpty(algorithm)) {

            return null;

        }

        KeyFactory keyFactory = KeyFactory.getInstance(algorithm);

        byte[] encodedKey = readText(ins).getBytes();

        encodedKey = Base64.decodeBase64(encodedKey);

        return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(encodedKey));

    }

    public static PublicKey getPublicKeyFromX509(String algorithm, InputStream ins) throws Exception {

        KeyFactory keyFactory = KeyFactory.getInstance(algorithm);

        StringWriter writer = new StringWriter();

        io(new InputStreamReader(ins), writer, -);

        byte[] encodedKey = writer.toString().getBytes();

        encodedKey = Base64.decodeBase64(encodedKey);

        return keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

    }

    /**

     * 把参数合成成字符串

     *

     * @param sortedParams

     * @return

     */

    public static String getSignContent(Map<String, String> sortedParams) {

        StringBuffer content = new StringBuffer();

        // app_id,method,charset,sign_type,version,bill_type,timestamp,bill_date

        String[] sign_param = sortedParams.get("sign_param").split(",");// 生成签名所需的参数

        List<String> keys = new ArrayList<String>();

        for (int i = ; i < sign_param.length; i++) {

            keys.add(sign_param[i]);

        }

        Collections.sort(keys);

        int index = ;

        for (int i = ; i < keys.size(); i++) {

            String key = keys.get(i);

                   /*if ("biz_content".equals(key)) {

                 content.append(

                         (index == 0 ? "" : "&") + key + "={\"bill_date\":\"" + sortedParams.get("bill_date") + "\",")

                         .append("\"bill_type\":\"" + sortedParams.get("bill_type") + "\"}");

                 index++;

             } else {*/

            String value = sortedParams.get(key);

            if (StringUtils.isNotEmpty(key) && StringUtils.isNotEmpty(value)) {

                content.append((index ==  ? "" : "&") + key + "=" + value);

                index++;

            }

            //            }

        }

        return content.toString();

    }

    private static String readText(InputStream ins) throws IOException {

        Reader reader = new InputStreamReader(ins);

        StringWriter writer = new StringWriter();

        io(reader, writer, -);

        return writer.toString();

    }

    private static void io(Reader in, Writer out, int bufferSize) throws IOException {

        if (bufferSize == -) {

            bufferSize = DEFAULT_BUFFER_SIZE >> ;

        }

        char[] buffer = new char[bufferSize];

        int amount;

        while ((amount = in.read(buffer)) >= ) {

            out.write(buffer, , amount);

        }

    }

}