import com.ibm.icu.util.ChineseCalendar;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 *  ChineseCalendar 를 활용한 Date Utility Class 
 */

public class DateUtilityity
{
    public DateUtility()    {    }

    public static String getToday(String _format)
    {
        Date date = new Date();
        SimpleDateFormat sdate = new SimpleDateFormat(_format);
        return sdate.format(date);
    }

    public static String getTodayDateTime(String _format)
    {
        Date date = new Date();
        SimpleDateFormat sdate = new SimpleDateFormat(_format);
        String todayDateTime = sdate.format(date);
        String minute = todayDateTime.substring(10, 12);
        if(minute.compareTo("30") > 0)
            minute = "30";
        else
            minute = "00";
        todayDateTime = todayDateTime.substring(0, 10) + minute;
        return todayDateTime;
    }

    public static String getFmtDateString(Date _date, String _format)
    {
        SimpleDateFormat sdate = new SimpleDateFormat(_format);
        return sdate.format(_date);
    }

    public static String getFmtDateString(String _date, String _format)
    {
        Date date = toDate(_date);
        return getFmtDateString(date, _format);
    }

    public static String getDelimDateString(String _date, String _delim)
    {
        String unFmtDate = getUnFmtDateString(_date);
        StringBuffer buf = new StringBuffer();
        buf.append(unFmtDate.substring(0, 4));
        buf.append(_delim);
        buf.append(unFmtDate.substring(4, 6));
        buf.append(_delim);
        buf.append(unFmtDate.substring(6, 8));
        return buf.toString();
    }

    public static String getUnFmtDateString(String fmtDate)
    {
        boolean isCharater = false;
        boolean isCorrect = true;
        String strDate = "";
        String date = "";
        String result = "";
        if(fmtDate != null)
            strDate = fmtDate.trim();
        for(int inx = 0; inx < strDate.length(); inx++)
        {
            if(!Character.isLetter(strDate.charAt(inx)) && strDate.charAt(inx) != ' ')
                continue;
            isCorrect = false;
            break;
        }

        if(!isCorrect)
            return "";
        if(strDate.length() != 8)
        {
            if(strDate.length() != 6 && strDate.length() != 10)
                return "";
            if(strDate.length() == 6)
            {
                if(Integer.parseInt(strDate.substring(0, 2)) > 50)
                    date = "19";
                else
                    date = "20";
                result = date + strDate;
            }
            if(strDate.length() == 10)
                result = strDate.substring(0, 4) + strDate.substring(4, 8) + strDate.substring(8, 10);
        } else
        {
            try
            {
                Integer.parseInt(strDate);
            }
            catch(NumberFormatException ne)
            {
                isCharater = true;
            }
            if(isCharater)
            {
                date = strDate.substring(0, 2) + strDate.substring(3, 5) + strDate.substring(6, 8);
                if(Integer.parseInt(strDate.substring(0, 2)) > 50)
                    result = "19" + date;
                else
                    result = "20" + date;
            } else
            {
                return strDate;
            }
        }
        return result;
    }

    public static Date getRelativeDate(Date _date, int _year, int _month, int _day)
    {
        Calendar cal = Calendar.getInstance();
        cal.setTime(_date);
        cal.add(1, _year);
        cal.add(2, _month);
        cal.add(5, _day);
        return cal.getTime();
    }

    public static String getRelativeDateString(Date _date, int _year, int _month, int _day, String _format)
    {
        Date relativeDate = getRelativeDate(_date, _year, _month, _day);
        return getFmtDateString(relativeDate, _format);
    }

    public static Date getRelativeDate(Date _date, int _year, int _month, int _day, int _hour, int _minute)
    {
        Calendar cal = Calendar.getInstance();
        cal.setTime(_date);
        cal.add(1, _year);
        cal.add(2, _month);
        cal.add(5, _day);
        cal.add(11, _hour);
        cal.add(12, _minute);
        return cal.getTime();
    }

    public static String getRelativeDateString(Date _date, int _year, int _month, int _day, int _hour, int _minute, String _format)
    {
        Date relativeDate = getRelativeDate(_date, _year, _month, _day, _hour, _minute);
        return getFmtDateString(relativeDate, _format);
    }

    public static String getRelativeDateString(String _date, int _year, int _month, int _day, int _hour, int _minute, String _format)
    {
        Calendar cal = toCalendar(_date.substring(0, 8), Integer.parseInt(_date.substring(8, 10)), Integer.parseInt(_date.substring(10, 12)));
        cal.add(1, _year);
        cal.add(2, _month);
        cal.add(5, _day);
        cal.add(11, _hour);
        cal.add(12, _minute);
        SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
        return dateFormat.format(cal.getTime());
    }

    public static String getNextDate(String _date, int _days, String _format)
    {
        if(_days < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(5, _days);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static String getPrevDate(String _date, int _days, String _format)
    {
        if(_days < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(5, -_days);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static String getNextWeekDate(String _date, int _weeks, String _format)
    {
        if(_weeks < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(5, _weeks * 7);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static String getPrevWeekDate(String _date, int _weeks, String _format)
    {
        if(_weeks < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(5, _weeks * -7);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static String getNextMonthDate(String _date, int _months, String _format)
    {
        if(_months < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(2, _months);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static String getPrevMonthDate(String _date, int _months, String _format)
    {
        if(_months < 0)
        {
            return _date;
        } else
        {
            Calendar cal = toCalendar(_date);
            cal.add(2, -_months);
            SimpleDateFormat dateFormat = new SimpleDateFormat(_format);
            return dateFormat.format(cal.getTime());
        }
    }

    public static Calendar toCalendar(String fmtDate)
    {
        String date = getUnFmtDateString(fmtDate);
        GregorianCalendar calendar = new GregorianCalendar();
        calendar.set(Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(4, 6)) - 1, Integer.parseInt(date.substring(6, 8)));
        return calendar;
    }

    public static Calendar toCalendar(String fmtDate, int hour, int minute)
    {
        String date = getUnFmtDateString(fmtDate);
        GregorianCalendar calendar = new GregorianCalendar();
        calendar.set(Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(4, 6)) - 1, Integer.parseInt(date.substring(6, 8)), hour, minute);
        return calendar;
    }

    public static Date toDate(String fmtDate)
    {
        return toCalendar(fmtDate).getTime();
    }

    public static String getWeekDay(String _date, int _order)
    {
        String returnDay = null;
        Calendar curr = Calendar.getInstance();
        curr.set(Integer.parseInt(_date.substring(0, 4)), Integer.parseInt(_date.substring(4, 6)) - 1, Integer.parseInt(_date.substring(6, 8)));
        int weekday = curr.get(7);
        if(_order == weekday)
        {
            returnDay = _date;
        } else
        {
            curr.add(5, _order - weekday);
            SimpleDateFormat sdate = new SimpleDateFormat("yyyyMMdd");
            returnDay = sdate.format(curr.getTime());
        }
        return returnDay;
    }

    public static int getFirstDay(int _year, int _month)
    {
        int firstday = 0;
        Calendar curr = Calendar.getInstance();
        curr.set(_year, _month - 1, 1);
        firstday = curr.get(7);
        return firstday;
    }

	/**  해당 월의 마지막 날자를 가져온다. 윤달인 경우에만 2월의 마지막날자가 틀려진다. */
    public static int getLastDate(int _year, int _month)
    {
        int yy = _year;
        int mm = _month;
        switch(mm)
        {
        case 1: // '\001'
        case 3: // '\003'
        case 5: // '\005'
        case 7: // '\007'
        case 8: // '\b'
        case 10: // '\n'
        case 12: // '\f'
            return 31;

        case 4: // '\004'
        case 6: // '\006'
        case 9: // '\t'
        case 11: // '\013'
            return 30;
        }
        return (yy % 4 != 0 || yy % 100 == 0) && yy % 400 != 0 ? 28 : 29;
    }

    public static int getWeekDayCount(String _date)
    {
        Calendar curr = Calendar.getInstance();
        curr.set(Integer.parseInt(_date.substring(0, 4)), Integer.parseInt(_date.substring(4, 6)) - 1, Integer.parseInt(_date.substring(6, 8)));
        int weekday = curr.get(7);
        return weekday;
    }

    public static int getWeekCountMonth(int _day)
    {
        int remainCount = _day - (_day / 7) * 7;
        int weekCount;
        if(remainCount > 0)
            weekCount = _day / 7 + 1;
        else
            weekCount = _day / 7;
        return weekCount;
    }

    public static int getWeekCount(int _year, int _month)
    {
        Calendar curr = Calendar.getInstance();
        curr.set(_year, _month - 1, getLastDate(_year, _month));
        int weeks = curr.get(4);
        return weeks;
    }

    public static String calcDate(String _date, int _val, String _format)
    {
        Calendar curr = Calendar.getInstance();
        _date = unFmtDate(_date);
        curr.set(Integer.parseInt(_date.substring(0, 4)), Integer.parseInt(_date.substring(4, 6)) - 1, Integer.parseInt(_date.substring(6, 8)));
        curr.add(5, _val);
        SimpleDateFormat sdate = new SimpleDateFormat(_format);
        return sdate.format(curr.getTime());
    }

    public static String calcDateTime(String _dateTime, int _val, String _format)
    {
        Calendar curr = Calendar.getInstance();
        _dateTime = unFmtDate(_dateTime);
        curr.set(Integer.parseInt(_dateTime.substring(0, 4)), Integer.parseInt(_dateTime.substring(4, 6)) - 1, Integer.parseInt(_dateTime.substring(6, 8)), Integer.parseInt(_dateTime.substring(8, 10)), Integer.parseInt(_dateTime.substring(10, 12)));
        curr.add(12, _val);
        SimpleDateFormat sdate = new SimpleDateFormat(_format);
        return sdate.format(curr.getTime());
    }

    public static String unFmtDate(String _fmtdate)
    {
        StringBuffer buf = new StringBuffer();
        for(int i = 0; i < _fmtdate.length(); i++)
            if(_fmtdate.charAt(i) != '-')
                buf.append(_fmtdate.charAt(i));

        return buf.toString();
    }

    public static String[] getDatesInWeek(String _firstday, String _format)
    {
        String weekdays[] = new String[7];
        for(int i = 0; i < 7; i++)
            weekdays[i] = calcDate(_firstday, i, _format);

        return weekdays;
    }

    public static String[] getDatesInPeriod(String _startDate, String _endDate, String _format)
    {
        int dateDiffCount = getTwoDatesDifference(_startDate, _endDate);
        String days[] = new String[dateDiffCount + 1];
        for(int i = 0; i < dateDiffCount + 1; i++)
            days[i] = calcDate(_startDate, i, _format);

        return days;
    }

    public static String[] getDateTimesInPeriod(String _startDateTime, String _endDateTime, String _format)
    {
        int dateTimeDiffCount = getTwoDateTimesDifference(_startDateTime, _endDateTime);
        String dateTimes[] = new String[dateTimeDiffCount + 1];
        for(int i = 0; i < dateTimes.length; i++)
            dateTimes[i] = calcDateTime(_startDateTime, i * 30, _format);

        return dateTimes;
    }

    public static int getTwoDatesDifference(String strDate, String strComp)
    {
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        int year = Integer.parseInt(strDate.substring(0, 4));
        int month = Integer.parseInt(strDate.substring(4, 6));
        int day = Integer.parseInt(strDate.substring(6, 8));
        int compYear = Integer.parseInt(strComp.substring(0, 4));
        int compMonth = Integer.parseInt(strComp.substring(4, 6));
        int compDay = Integer.parseInt(strComp.substring(6, 8));
        cal1.set(year, month - 1, day);
        cal2.set(compYear, compMonth - 1, compDay);
        long cal1sec = cal1.getTime().getTime();
        long cal2sec = cal2.getTime().getTime();
        long gap = cal2sec - cal1sec;
        int gapday = Integer.parseInt(String.valueOf(gap / 0x15180L / 1000L));
        return gapday;
    }

    public static int getTwoDateTimesDifference(String strDateTime, String strCompTime)
    {
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        int year = Integer.parseInt(strDateTime.substring(0, 4));
        int month = Integer.parseInt(strDateTime.substring(4, 6));
        int day = Integer.parseInt(strDateTime.substring(6, 8));
        int hour = Integer.parseInt(strDateTime.substring(8, 10));
        int minute = Integer.parseInt(strDateTime.substring(10, 12));
        int compYear = Integer.parseInt(strCompTime.substring(0, 4));
        int compMonth = Integer.parseInt(strCompTime.substring(4, 6));
        int compDay = Integer.parseInt(strCompTime.substring(6, 8));
        int compHour = Integer.parseInt(strCompTime.substring(8, 10));
        int compMinute = Integer.parseInt(strCompTime.substring(10, 12));
        cal1.set(year, month - 1, day, hour, minute);
        cal2.set(compYear, compMonth - 1, compDay, compHour, compMinute);
        long cal1sec = cal1.getTime().getTime();
        long cal2sec = cal2.getTime().getTime();
        long gap = cal2sec - cal1sec;
        int gapDateTime = Integer.parseInt(String.valueOf(gap / 1800L / 1000L));
        return gapDateTime;
    }

    public static String getFromSolarDateToLunarDate(String yyyymmdd)
    {
        Calendar cal = Calendar.getInstance();
        ChineseCalendar cc = new ChineseCalendar();
        if(yyyymmdd == null)
            return "";
        String date = yyyymmdd.trim();
        if(date.length() != 8)
            if(date.length() == 4)
                date = date + "0101";
            else
            if(date.length() == 6)
                date = date + "01";
            else
            if(date.length() > 8)
                date = date.substring(0, 8);
            else
                return "";
        cal.set(1, Integer.parseInt(date.substring(0, 4)));
        cal.set(2, Integer.parseInt(date.substring(4, 6)) - 1);
        cal.set(5, Integer.parseInt(date.substring(6)));
        cc.setTimeInMillis(cal.getTimeInMillis());
        int y = cc.get(19) - 2637;
        int m = cc.get(2) + 1;
        int d = cc.get(5);
        StringBuffer ret = new StringBuffer();
        if(y < 1000)
            ret.append("0");
        else
        if(y < 100)
            ret.append("00");
        else
        if(y < 10)
            ret.append("000");
        ret.append(y);
        if(m < 10)
            ret.append("0");
        ret.append(m);
        if(d < 10)
            ret.append("0");
        ret.append(d);
        return ret.toString();
    }

    public static String getFromLunarDateToSolarDate(String yyyymmdd)
    {
        Calendar cal = Calendar.getInstance();
        ChineseCalendar cc = new ChineseCalendar();
        if(yyyymmdd == null)
            return "";
        String date = yyyymmdd.trim();
        if(date.length() != 8)
            if(date.length() == 4)
                date = date + "0101";
            else
            if(date.length() == 6)
                date = date + "01";
            else
            if(date.length() > 8)
                date = date.substring(0, 8);
            else
                return "";
        cc.set(19, Integer.parseInt(date.substring(0, 4)) + 2637);
        cc.set(2, Integer.parseInt(date.substring(4, 6)) - 1);
        cc.set(5, Integer.parseInt(date.substring(6)));
        cal.setTimeInMillis(cc.getTimeInMillis());
        int y = cal.get(1);
        int m = cal.get(2) + 1;
        int d = cal.get(5);
        StringBuffer ret = new StringBuffer();
        if(y < 1000)
            ret.append("0");
        else
        if(y < 100)
            ret.append("00");
        else
        if(y < 10)
            ret.append("000");
        ret.append(y);
        if(m < 10)
            ret.append("0");
        ret.append(m);
        if(d < 10)
            ret.append("0");
        ret.append(d);
        return ret.toString();
    }

    public static String getValidDate(String yyyymmdd)
    {
        String strYear = "";
        String strMonth = "";
        String strDay = "";
        int validMonthDay = 0;
        String validDate = "";
        if(yyyymmdd.length() == 8)
        {
            strYear = yyyymmdd.substring(0, 4);
            strMonth = yyyymmdd.substring(4, 6);
            strDay = yyyymmdd.substring(6, 8);
            validMonthDay = getLastDate(Integer.parseInt(strYear), Integer.parseInt(strMonth));
            if(Integer.parseInt(strDay) <= validMonthDay)
                validDate = yyyymmdd;
            else
                validDate = strYear + strMonth + String.valueOf(validMonthDay);
            return validDate;
        } else
        {
            return "";
        }
    }

    public static String getCurrentDatetime(Calendar cal)
    {
        StringBuffer buff = new StringBuffer();
        buff.append(cal.get(1)).append("/");
        buff.append(cal.get(2) + 1).append("/");
        buff.append(cal.get(5)).append(" ");
        buff.append(cal.get(11)).append(":");
        buff.append(cal.get(12));
        return buff.toString();
    }
}