package cn.emay.sdk.util;

import java.util.Calendar;
import java.util.Date;

/**
 * 唯一序列生成器
 *
 * @author Frank
 *
 */
public class OnlyIdGenerator {

	/**
	 * 补全字段
	 */
	private static String ZERO10 = "0000000000";

	/**
	 * ID 序列
	 */
	private static int ID_INDEX = 0;

	/**
	 * ID 序列计算时间
	 */
	private static long ID_END_MILLIS = 0l;

	/**
	 * 生成18位的唯一数字ID<br/>
	 * 当前毫秒数(13) + 序列(2) + 服务标识(3)<br/>
	 * 等待机制：如果当前毫秒数的序列超过100，则等待累加到下一毫秒。即每毫秒最多生成100个smsid
	 *
	 * @return
	 */
	public synchronized static String genOnlyId(String serverCode) {
		long millis = System.currentTimeMillis();
		if (millis == ID_END_MILLIS) {
			ID_INDEX++;
		} else {
			ID_INDEX = 0;
			ID_END_MILLIS = millis;
		}
		if (ID_INDEX > 99) {
			boolean wait = true;
			while (wait) {
				millis = System.currentTimeMillis();
				if (millis != ID_END_MILLIS) {
					wait = false;
					ID_END_MILLIS = millis;
					ID_INDEX = 0;
				}
			}
		}
		String indexStr = ZERO10 + ID_INDEX;
		indexStr = indexStr.substring(indexStr.length() - 2, indexStr.length());
		String smsId = millis + indexStr + serverCode;
		return smsId;
	}

	/**
	 * BID 序列
	 */
	private static int BID_INDEX = 0;

	/**
	 * BID 序列计算时间
	 */
	private static String BID_END_MILLIS = "";

	/**
	 * 生成唯一BID编码<br/>
	 * yyyyMMddHHmmss(14) + 序列(7) + 服务标识(3)<br/>
	 *
	 */
	public synchronized static String genOblyBId(String serverCode) {
		String time = DateUtil.toString(new Date(), "yyyyMMddHHmmss");
		if (BID_END_MILLIS.equals(time)) {
			BID_INDEX++;
		} else {
			BID_INDEX = 0;
			BID_END_MILLIS = time;
		}
		String indexStr = ZERO10 + BID_INDEX;
		indexStr = indexStr.substring(indexStr.length() - 7, indexStr.length());
		String no = time + indexStr + serverCode;
		return no;
	}

	public static String paramSmsId(String smsId) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTimeInMillis(Long.parseLong(smsId.substring(0, 13)));
		String name = DateUtil.toString(calendar.getTime(), "yyyyMMdd");
		return name;
	}

	public static void main(String[] args) {
		String genid = genOnlyId("111");
		System.out.println(genid + "\t" + genid.length());
	}
}