/**
 * Copyright &copy; 2012-2014 <a href="https://github.com/thinkgem/jeesite">JeeSite</a> All rights reserved.
 */
package com.ejweb.core.utils;

import java.io.Serializable;
import java.security.SecureRandom;
//import java.util.UUID;

import org.activiti.engine.impl.cfg.IdGenerator;
import org.apache.shiro.session.Session;
import org.apache.shiro.session.mgt.eis.SessionIdGenerator;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * @author ThinkGem
 * @version 2013-01-15
 */
@Service
@Lazy(false)
public class IdGen implements IdGenerator, SessionIdGenerator {

    private static SecureRandom random = new SecureRandom();
    
    /**
     * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
     */
    public static String uuid() {
        return IdWorker.getNextId();
//        return UUID.randomUUID().toString().replaceAll("-", "");
    }
    
    /**
     * 使用SecureRandom随机生成Long. 
     */
    public static long randomLong() {
        return Math.abs(random.nextLong());
    }

    /**
     * 基于Base62编码的SecureRandom随机生成bytes.
     */
    public static String randomBase62(int length) {
        byte[] randomBytes = new byte[length];
        random.nextBytes(randomBytes);
        return Encodes.encodeBase62(randomBytes);
    }
    
    /**
     * Activiti ID 生成
     */
    @Override
    public String getNextId() {
        return IdWorker.getNextId();
//        return IdGen.uuid();
    }

    @Override
    public Serializable generateId(Session session) {
        return IdWorker.getNextId();
//        return IdGen.uuid();
    }
    
//    public static void main(String[] args) {
//        System.out.println(IdGen.uuid());
//        System.out.println(IdGen.uuid().length());
//        System.out.println(new IdGen().getNextId());
//        for (int i=0; i<1000; i++){
//            System.out.println(IdGen.randomLong() + "  " + IdGen.randomBase62(5));
//        }
//    }

}
