//**************************************
//     
// Name: moon info
// Description:get info on moon phase fo
//     r a given date
// By: marcojetson
//
//This code is copyrighted and has// limited warranties.Please see http://
//     www.Planet-Source-Code.com/vb/scripts/Sh
//     owCode.asp?txtCodeId=6576&lngWId=2//for details.//**************************************
//     

/*
* calc info about moon phase for a given date
* @author marco
*/


    function moon() {
    this.date = false;
    /*
    * date to milliseconds
    * @param str YYYY-MM-DD
    * @return int
    */


        this.strtotime = function(str) {
        var r = false, x = str.split('-');
        if (x.length === 3) r = Date.UTC(x[0], x[1], x[2]);
        return r;
    };

    /*
    * milliseconds to date
    * @param str milliseconds
    * @return string
    */


        this.parsedate = function(n) {
        var d = new Date();
        d.setTime(n);
        return d.getFullYear()+'-'+d.getMonth()+'-'+d.getDate();
    }

    /*
    * set a property, only date at this time
    * @param prop date
    * @param val YYYY-MM-DD
    * @return bool
    */


        this.set = function(prop, val) {


            switch (prop) {
            case 'date':
            var x = this.strtotime(val);
            if (x) this.date = x;
        }

        return Boolean(this.date);
    }

    /*
    * get percentage of moon phase
    * @return int
    */


        this.get_phase_percent = function() {
        var r = false, x;


            if (this.date) {
            x = (this.date - 603240000) / 2551392000;
            x -= parseInt(x);
            r = Math.round(x * 100);
        }

        return r;
    };

    /*
    * get visibility of the moon
    * @return int
    */


        this.get_visibility = function() {
        var r = false;
        if (this.date) r = (50 - Math.abs(50 - this.get_phase_percent())) * 2;
        return r;
    };

    /*
    * get phase name
    * @return string
    */


        this.get_phase_name = function() {
        var r = false, x;


            if (this.date) {
            x = Math.round(this.get_phase_percent() * 0.1) * 10;
            if (x == 0 ||x == 100) r = 'New';
            else if (x > 0 && x < 25) r = 'Waxing crescent';
            else if (x == 25) r = 'First quarter';
            else if (x > 25 && x < 50) r = 'Waxing gibbous';
            else if (x == 50) r = 'Full';
            else if (x > 50 && x < 75) r = 'Waning gibbous';
            else if (x == 75) r = 'Last quarter';
            else if (x > 75) r = 'Waning crescent';
        }

        return r;
    };

    /*
    * get date for next new moon
    * @param ts if true return as timestamp
    * @return mixed
    */


        this.get_next_newmoon = function(ts) {
        if (typeof ts == 'undefined') ts = false;
        var r = false, x;


            if (this.date) {
            x = this.date + 2551392000 - (this.date - 603240000) % 2551392000;
            r = ts ? x : this.parsedate(x);
        }

        return r;
    };

    /*
    * get date for next full moon
    * @param ts if true return as timestamp
    * @return mixed
    */


        this.get_next_fullmoon = function(ts) {
        if (typeof ts == 'undefined') ts = false;
        var r = false, x;


            if (this.date) {
            x = this.get_next_newmoon(true) + 1275696000;
            r = ts ? x : this.parsedate(x);
        }

        return r;
    };

}

var moon_info = new moon();
moon_info.set('date', '2005-05-25');
document.write('<UL>');
document.write('<LI>phase percent: '+moon_info.get_phase_percent()+'%</LI>');
document.write('<LI>visibility: '+moon_info.get_visibility()+'%</LI>');
document.write('<LI>phase name: '+moon_info.get_phase_name()+'</LI>');
document.write('<LI>next new moon: '+moon_info.get_next_newmoon()+'</LI>');
document.write('<LI>next full moon: '+moon_info.get_next_fullmoon()+'</LI>');
document.write('<UL>');