package com.ruoyi.common.utils;

import com.ruoyi.common.utils.ip.IpUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.atomic.AtomicLong;

public class OrderNos {

    public static final char PADCHAR = '0';



    /**
     * 长度24位全球唯一标识
     */

    /**
     * 统一不重复内部订单号
     *
     * @param systemCode
     *            4字节系统编码
     * @return 24字节不重复编码
     */
    public static String oid(String systemCode) {
        StringBuilder sb = new StringBuilder();
        sb.append(padding(systemCode, 4));
        sb.append(Did.getInstance().getId(20));
        return sb.toString();
    }

    public static String oid() {
        return oid("O001");
    }

    /**
     * 获取分布式Id
     *
     * @return 默认20字符长度的数字不重复编码
     */
    public static String getDid() {
        return Did.getInstance().getId();
    }

    public static String getDid(int size) {
        return Did.getInstance().getId(size);
    }

    public static String getDid(String prefix) {
        return prefix + Did.getInstance().getId();
    }

    private static String padding(String text, int size) {
        String txt = StringUtils.trimToEmpty(text);
        if (StringUtils.length(txt) > size) {
            txt = StringUtils.substring(txt, StringUtils.length(txt) - size);
        }
        return StringUtils.leftPad(txt, size, PADCHAR);
    }

    /**
     * ID生成器
     *
     * 20字符长度 yyMMddHHmmss+3位本机IP末三位+5位随机数字
     *
     * @author zhangpu
     *
     */
    public static class Did {
        private static final Logger logger = LoggerFactory.getLogger(OrderNos.class);
        private static final int MIN_LENGTH = 19;
        private static final int SEQU_MAX = 99999;
        private static final int SEQU_19_MAX = 9999;
        private volatile static long BASE = 0;
        private AtomicLong sequence = new AtomicLong(0);
        private String nodeFlag;
        private Object nodeFlagLock = new Object();
        private static Did did = new Did();


        public static Did getInstance() {
            return did;
        }

        /**
         * 生产新Id
         *
         * @return
         */
        public  String getId() {
            return getId(20);
        }

        public  String getId(int size) {
            if (size < MIN_LENGTH) {
                throw new RuntimeException("did最小长度为" + MIN_LENGTH);
            }
            StringBuilder sb = new StringBuilder();
            sb.append(DateUtils.dateTimeNow("yyMMddHHmmss"));
            sb.append(getNodeFlag());
            sb.append(getSequ(size-15));
            return sb.toString();
        }

        public synchronized String getSequ(int size) {
            long timeCount = System.currentTimeMillis() / 1000;

            while (true) {
                long now = sequence.get();
                if (timeCount > now) {
                    // 已经过了本秒，则设置新的值
                    if (sequence.compareAndSet(now, timeCount)) {
                        break;
                    }
                } else {
                    if (sequence.compareAndSet(now, now + 1)) {
                        timeCount = now + 1;
                        break;
                    }
                }
            }
            int sn = (int) (timeCount % (size>=5?SEQU_MAX:SEQU_19_MAX));
            return StringUtils.leftPad(String.valueOf(sn), size, '0');
        }

        private  String  getNodeFlag(){
            if (this.nodeFlag == null) {
                synchronized (Did.class){
                    if (this.nodeFlag==null){
                        this.nodeFlag = generateNodeFlag();
                    }
                }
            }
            return this.nodeFlag;
        }

        /**
         * 简单节点编码
         *
         * 逻辑：Ip地址后三位，便于快速知道是哪个节点
         *
         * @return
         */
        private String generateNodeFlag() {
            String ipPostfix = null;
            try {
                String ip = IpUtils.getFirstNoLoopbackIPV4Address();
                ipPostfix = StringUtils.substringAfterLast(ip, ".");
            } catch (Exception e) {
                logger.warn("生产DID要素本机IP获取失败:" + e.getMessage());
            }
            return StringUtils.leftPad(ipPostfix, 3, "0");
        }

        private Did() {
            super();
        }
    }



}