package com.zy.system.entity.license;

import de.schlichtherle.license.*;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.poi.util.IOUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.text.DateFormat;
import java.text.MessageFormat;
import java.text.SimpleDateFormat;
import java.util.prefs.Preferences;

/**
 * License校验类
 */
public class LicenseVerify {
    private static Logger logger = LogManager.getLogger(LicenseVerify.class);

    /**
     * 安装License证书
     */
    public synchronized LicenseContent install(LicenseVerifyParam param){
        LicenseContent result = null;
        DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        //1. 安装证书
        try{
            LicenseManager licenseManager = LicenseManagerHolder.getInstance(initLicenseParam(param));
            licenseManager.uninstall();

            InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(param.getLicensePath());
            File file = new File(param.getLicensePath());
            try (FileOutputStream out = new FileOutputStream(file)) {
                IOUtils.copy(inputStream, out);
            }

            result = licenseManager.install(new File(param.getLicensePath()));
            logger.info(MessageFormat.format("许可证加载成功，许可证有效期：{0} - {1}",format.format(result.getNotBefore()),format.format(result.getNotAfter())));
        }catch (Exception e){
            logger.error("许可证加载失败！",e);
        }

        return result;
    }

    /**
     * 校验License证书
     */
    public boolean verify(){
        try {
            LicenseManager licenseManager = LicenseManagerHolder.getInstance(null);
            DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

            if (!updateSystemTime()) {
                //时间更新失败，系统时间被更改
                return false;
            }

            LicenseContent licenseContent = licenseManager.verify();
            logger.info(MessageFormat.format("许可证校验通过，许可证有效期：{0} - {1}",format.format(licenseContent.getNotBefore()),format.format(licenseContent.getNotAfter())));
            return true;
        }catch (Exception e){
            logger.error("许可证校验失败！",e);
            return false;
        }
    }

    /**
     * 校验License证书并获取证书信息
     */
    public LicenseContent getVerifyInfo(){
        LicenseManager licenseManager = LicenseManagerHolder.getInstance(null);

        if (!updateSystemTime()) {
            //时间更新失败，系统时间被更改
            return null;
        }

        //校验证书
        try {
            LicenseContent licenseContent = licenseManager.verify();
            return licenseContent;
        }catch (Exception e){
            logger.error("许可证校验失败！",e);
            return null;
        }
    }

    /**
     * 初始化证书生成参数
     * @param param License校验类需要的参数
     * @return de.schlichtherle.license.LicenseParam
     */
    private LicenseParam initLicenseParam(LicenseVerifyParam param){
        Preferences preferences = Preferences.userNodeForPackage(LicenseVerify.class);

        CipherParam cipherParam = new DefaultCipherParam(param.getStorePass());

        KeyStoreParam publicStoreParam = new CustomKeyStoreParam(LicenseVerify.class
                ,param.getPublicKeysStorePath()
                ,param.getPublicAlias()
                ,param.getStorePass()
                ,null);

        return new DefaultLicenseParam(param.getSubject()
                ,preferences
                ,publicStoreParam
                ,cipherParam);
    }

    /**
     * 更新时间到注册表中
     */
    private boolean updateSystemTime() {
        // 获取用户根节点
        Preferences userRoot = Preferences.userRoot();
        // 获取指定路径下的节点
        Preferences node = userRoot.node("/zhongyang");
        String key = "time";
        // 读取注册表
        String value = node.get(key, null);
        if (value != null) {
            long originTime = Long.parseLong(value);
            long now = System.currentTimeMillis();
            long diff = now - originTime;//现在时间 - 源时间 = 时间差
            if (diff > 0) {
                //时间差大于0才允许更新注册表时间
                node.put(key, String.valueOf(System.currentTimeMillis()));
                return true;
            }
        }else {
            // 写入注册表
            node.put(key, String.valueOf(System.currentTimeMillis()));
            return true;
        }
        return false;
    }

}