var divCal;
var LastCal;

var ds_i_date 	= new Date();
var ds_sh_date 	= new Date();
ds_c_month 		= ds_i_date.getMonth() + 1;
ds_c_year 		= ds_i_date.getFullYear();
ds_c_day		= ds_i_date.getDate(); //today
ds_c_m			= ds_i_date.getMonth() + 1;

// Get Element By Id
function ds_getel(id) {
	var element = null;
	
	try {
		element = document.getElementById(id);		
	} catch(e) {
		try {
			element = document.all[id];
		} catch(e) {
			try {
				element = document.layers[id];
			} catch(e) {};		
		};	
	};
	
	return element;	
}

// Get the left and the top of the element.
function ds_getleft(el) {
	var tmp = el.offsetLeft;
	el 		= el.offsetParent
	while(el) {
		tmp += el.offsetLeft;
		el = el.offsetParent;
	}
	return tmp;
}

//
function ds_gettop(el) {
	var tmp = el.offsetTop;
	el 		= el.offsetParent
	while(el) {
		tmp += el.offsetTop;
		el = el.offsetParent;
	}
	return tmp;
}


// Output Buffering
var ds_ob = '';
function ds_ob_clean() {
	ds_ob = '';
}
function ds_ob_flush() {
	divCal.innerHTML = ds_ob;
	ds_ob_clean();
}
function ds_echo(t) {
	ds_ob += t;
}

var ds_element; // Text Element...

var ds_monthnames = [
'STY', 'LUT', 'MAR', 'KWI', 'MAJ', 'CZE',
'LIP', 'SIE', 'WRZ', 'PAZ', 'LIS',  'GRU'
]; // You can translate it for your language.

var ds_daynames = [
'Pon', 'Wt', 'Sr', 'Czw', 'Pt', 'Sob', 'Ndz'
]; // You can translate it for your language.

// Calendar template
function ds_template_main_above(t) {
	return '<div id="month_prev"><a href="javascript:ds_pm();" title="Poprzedni miesiąc"><img src="_p/img/lewo.gif" alt="Poprzedni miesiąc" /></a></div>'
				+'<div id="month" >' + t + '</div>'
				+'<div id="month_next"><a href="javascript:ds_nm();" title="Następny miesią…c"><img src="_p/img/prawo.gif" alt="Następny miesiąc" class="v_middle" /></a></div>'
				+'<br class="clear" />'
				+'<div id="week">'
				+'<div>Ndz</div><div>Pon</div><div>Wt</div><div>Sro</div><div>Czw</div><div>Pt</div><div>Sob</div>'
				+'</div>';


}

function ds_template_new_week() {
	return '<br class="clear" />';
}

function ds_template_blank_cell(colspan) {
	rt = '';
	for(i = 1; i <= colspan; i++) {
	   rt += '<div class="calendar_day"></div>';
	};
	return rt;
}

function ds_template_day(d, m, y) {
	if(ds_c_day==d && ds_c_m==m){
		s1='class="today"';
	} else {
		s1='';
	}
	return '<div class="calendar_day"><a href="javascript:ds_onclick(' + d + ',' + m + ',' + y + ')" '+ s1 +'>' + d + '</a></div>';
	// Define width the day row.
}

function ds_template_main_below() {
	return '<br class="clear" /><img src="_p/img/zamknij.gif" onclick="ds_hi();" style="cursor:pointer;" title="Zamknij kalendarz" />'
	     + '</div>';
		
}

// This one draws calendar...
function ds_draw_calendar(m, y) {
	// First clean the output buffer.
	ds_ob_clean();
	// Here we go, do the header
	ds_echo (ds_template_main_above(ds_monthnames[m - 1] + ' ' + y));
//	var ds_dc_date = null;

	
	ds_dc_date = null;
	ds_dc_date = new Date();
	ds_dc_date.setYear(y);
	ds_dc_date.setMonth(m-1, 1);
	
	if (m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12) {
		days = 31;
	} else if (m == 4 || m == 6 || m == 9 || m == 11) {
		days = 30;
	} else {
		days = (y % 4 == 0) ? 29 : 28;
	}
	var first_day = ds_dc_date.getDay();
	var first_loop = 1;
	// Start the first week
	//ds_echo (ds_template_new_week());
	// If sunday is not the first day of the month, make a blank cell...
	if (first_day != 0) {
		ds_echo (ds_template_blank_cell(first_day));
	}
	var j = first_day;
	for (i = 0; i < days; i ++) {
		// Today is sunday, make a new week.
		// If this sunday is the first day of the month,
		// we've made a new row for you already.
		if (j == 0 && !first_loop) {
			// New week!!
			ds_echo (ds_template_new_week());
		}
		// Make a row of that day!
		ds_echo (ds_template_day(i + 1, m, y));
		// This is not first loop anymore...
		first_loop = 0;
		// What is the next day?
		j ++;
		j %= 7;
	}
	ds_echo (ds_template_main_below());
	ds_ob_flush();
}


function ds_sh(v,img) {
	// TODO: how retrieve this information from html?
	var divCalLeft  = 80;
	var imgObj 		= null;
	
	if(!divCal){
		LastCal	  	= img;
		divCal = document.createElement('div');
		divCal.setAttribute('id', 'calendar');
		divCal.className = "calendar";
		t = ds_getel(v);
		ds_element 	= t;
		ds_c_month 	= ds_sh_date.getMonth() + 1;
		ds_c_year 	= ds_sh_date.getFullYear();
		
		w_B 		= document.all ? document.body.clientWidth : document.documentElement.offsetWidth;		
		w_B			= (w_B > 1000) ? Math.round(((w_B - 1000)/2)+ divCalLeft) :  divCalLeft;
		
		imgObj 		= ds_getel(img);		
		the_left 	= ds_getleft(imgObj);
		the_left 	= the_left + 20;
		the_top 	= ds_gettop(t) + t.offsetHeight;
		the_top		= the_top - 20;
					
		divCal.style.left = the_left + 'px';
		divCal.style.top  = the_top + 'px';
		
		
	    ds_getel('Content').appendChild(divCal);
		ds_draw_calendar(ds_c_month, ds_c_year);
		divCal.style.display='';
	} else {
		if(LastCal != img) {
			ds_hi();
			setTimeout(function() {
						 ds_sh(v,img);
						},102);
		} else {
			ds_hi();
		}
	}
}

function ds_hi() {
		ds_getel('Content').removeChild(divCal);
		divCal=null;
		

}

// Moves to the next month...
function ds_nm() {
	// Increase the current month.
	ds_c_month ++;
	// We have passed December, let's go to the next year.
	// Increase the current year, and set the current month to January.
	if (ds_c_month > 12) {
		ds_c_month = 1;
		ds_c_year++;
	}
	// Redraw the calendar.
	ds_draw_calendar(ds_c_month, ds_c_year);
}

// Moves to the previous month...
function ds_pm() {
	ds_c_month = ds_c_month - 1; // Can't use dash-dash here, it will make the page invalid.
	// We have passed January, let's go back to the previous year.
	// Decrease the current year, and set the current month to December.
	if (ds_c_month < 1) {
		ds_c_month = 12;
		ds_c_year = ds_c_year - 1; // Can't use dash-dash here, it will make the page invalid.
	}
	// Redraw the calendar.
	ds_draw_calendar(ds_c_month, ds_c_year);
}

// Moves to the next year...
function ds_ny() {
	// Increase the current year.
	ds_c_year++;
	// Redraw the calendar.
	ds_draw_calendar(ds_c_month, ds_c_year);
}

// Moves to the previous year...
function ds_py() {
	// Decrease the current year.
	ds_c_year = ds_c_year - 1; // Can't use dash-dash here, it will make the page invalid.
	// Redraw the calendar.
	ds_draw_calendar(ds_c_month, ds_c_year);
}

// Format the date to output.
function ds_format_date(d, m, y) {
	// 2 digits month.
	m2 = '00' + m;
	m2 = m2.substr(m2.length - 2);
	// 2 digits day.
	d2 = '00' + d;
	d2 = d2.substr(d2.length - 2);
	// YYYY-MM-DD
	return d2 + '/' + m2 + '/' + y;
}

// When the user clicks the day.
function ds_onclick(d, m, y) {
	// Hide the calendar.
	ds_hi();
	// Set the value of it, if we can.
	if (typeof(ds_element.value) != 'undefined') {
		ds_element.value = ds_format_date(d, m, y);
	// Maybe we want to set the HTML in it.
	} else if (typeof(ds_element.innerHTML) != 'undefined') {
		ds_element.innerHTML = ds_format_date(d, m, y);
	// I don't know how should we display it, just alert it to user.
	} else {
		alert (ds_format_date(d, m, y));
	}
}