/**
* 版本号: Version 1.0
* 文件名: lunarDate.js
* 描  述: 用查表法实现公历到农历日期的转换。可接受的公历日期范围是2001-1-1至2050-12-31。
* 作  者: Psylyx
* 时  间: 2006.08
*/

var LunarDaysOfMonth = new Array

(

    0xd4a8, 0xd4a0, 0xda50, 0x5aa8, 0x56a0, 0xaad8, 0x25d0, 0x92d0, 0xc958, 0xa950, 

    0xb4a0, 0xb550, 0xb550, 0x55a8, 0x4ba0, 0xa5b0, 0x52b8, 0x52b0, 0xa930, 0x74a8,  

    0x6aa0, 0xad50, 0x4da8, 0x4b60, 0x9570, 0xa4e0, 0xd260, 0xe930, 0xd530, 0x5aa0, 

    0x6b50, 0x96d0, 0x4ae8, 0x4ad0, 0xa4d0, 0xd258, 0xd250, 0xd520, 0xdaa0, 0xb5a0, 

    0x56d0, 0x4ad8, 0x49b0, 0xa4b8, 0xa4b0, 0xaa50, 0xb528, 0x6d20, 0xada0, 0x55b0  

);


var LunarLeapYear = new Array

(

    0x40, 0x02, 0x07, 0x00, 0x50,  

    0x04, 0x09, 0x00, 0x60, 0x04, 

    0x00, 0x20, 0x60, 0x05, 0x00, 

    0x30, 0xb0, 0x06, 0x00, 0x50,  

    0x02, 0x07, 0x00, 0x50, 0x03  

);



function GetLeapMonth(iLunarYear)

{ 

    var Leap = LunarLeapYear[(iLunarYear - 2001) >> 1];

    return (((iLunarYear - 2001) & 1) == 0) ? (Leap >> 4) : (Leap & 0x0f);

} 


function LunarMonthDays(iLunarYear, iLunarMonth)

{ 

    var High;

    var Low;

    var Bit;

 

    High = 0;

    Low = 29;

    Bit = 16 - iLunarMonth;

    if ((iLunarMonth > GetLeapMonth(iLunarYear)) && (GetLeapMonth(iLunarYear) > 0))  Bit--;

    if ((LunarDaysOfMonth[iLunarYear - 2001] & (1 << Bit)) > 0)  Low++;

    if (iLunarMonth == GetLeapMonth(iLunarYear))

    {

        High = ((LunarDaysOfMonth[iLunarYear - 2001] & (1 << (Bit-1))) > 0) ?  30 : 29;

    }

 

    return Low + (High << 16);

} 


function LunarYearDays(iLunarYear)

{ 

    var Days;

    var tmp;

 

    Days = 0;

    for (var i=1; i <= 12; i++)

    {

        tmp = LunarMonthDays(iLunarYear, i);

        Days = Days + ((tmp >> 16) & 0xffff);  

        Days = Days + (tmp & 0xffff);  

    }

 

    return Days;

} 
 

function FormatLunarYear(iLunarYear)

{ 

    var szText1 = new String("甲乙丙丁戊己庚辛壬癸");

    var szText2 = new String("子丑寅卯辰巳午未申酉戌亥");

    var strYear;

  

    strYear = szText1.substr((iLunarYear - 4) % 10, 1);

    strYear = strYear + szText2.substr((iLunarYear - 4) % 12, 1);

 

    return strYear + "年 ";

}


function FormatLunarMonth(iLunarMonth)

{ 

    var szText = new String("正二三四五六七八九十");

    var strMonth;

 

    if (iLunarMonth <= 10)

    {

        strMonth = szText.substr(iLunarMonth - 1, 1);

    }

    else if (iLunarMonth == 11) strMonth = "十一";

    else strMonth = "十二";

 

    return strMonth + "月";

} 


function FormatLunarDay(iLunarDay)

{ 

    var szText1 = new String("初十廿三");

    var szText2 = new String("一二三四五六七八九十");

    var strDay;

    if ((iLunarDay != 20) && (iLunarDay != 30))

    {

        strDay = szText1.substr((iLunarDay - 1) / 10, 1) + szText2.substr((iLunarDay - 1) % 10, 1);

    }

    else if (iLunarDay != 20)

    {

        strDay = szText1.substr(iLunarDay / 10, 1) + "十";

    }

    else

    {

        strDay = "二十";

    }

  

    return strDay;

} 


function GetLunarDateString(SolarDate)

{

    var tmp;

    var iLunarYear;

    var iLunarMonth;

    var iLunarDay;

    var Leap = false;

    var MinMilli = 1000 * 60;

    var HrMilli = MinMilli * 60;

    var DyMilli = HrMilli * 24;

  

    var iSpanDays = Math.round(SolarDate.getTime() / DyMilli) - 11323;


    if (iSpanDays < 23)

    {

        iYear = 2000;

        iLunarMonth = 12;

        iLunarDay = iSpanDays + 7;

    }

    else

    {


        iSpanDays = iSpanDays - 23;

        iLunarYear = 2001;

        iLunarMonth = 1;

        iLunarDay = 1;

  


        tmp = LunarYearDays(iLunarYear);

        while (iSpanDays >= tmp)

        {

            iSpanDays -= tmp;

            iLunarYear++;

            tmp = LunarYearDays(iLunarYear);

        }

 


        tmp = LunarMonthDays(iLunarYear, iLunarMonth) & 0xffff; 

        while (iSpanDays >= tmp)

        {

            iSpanDays -= tmp;

            if (iLunarMonth == GetLeapMonth(iLunarYear))  

            {

                tmp = LunarMonthDays(iLunarYear, iLunarMonth) >> 16; 

                if (iSpanDays < tmp)

                {

                    Leap = (tmp > 0) ? true : false;  

                    break;

                }

                iSpanDays = iSpanDays - tmp;

            }

  

            iLunarMonth++;

            tmp = LunarMonthDays(iLunarYear,iLunarMonth) & 0xffff; 

        }


        iLunarDay += iSpanDays;

    }

  

    return FormatLunarYear(iLunarYear) + (Leap ? "闰" : "") + FormatLunarMonth(iLunarMonth) + FormatLunarDay(iLunarDay);

}