<?php
/**
 * @file include/datetime.php
 * @brief Some functions for date and time related tasks.
 */


/**
 * @brief Two-level sort for timezones.
 *
 * @param string $a
 * @param string $b
 * @return int
 */
function timezone_cmp($a, $b) {
	if(strstr($a,'/') && strstr($b,'/')) {
		if ( t($a) == t($b)) return 0;
		return ( t($a) < t($b)) ? -1 : 1;
	}
	if(strstr($a,'/')) return -1;
	if(strstr($b,'/')) return  1;
	if ( t($a) == t($b)) return 0;

	return ( t($a) < t($b)) ? -1 : 1;
}

/**
 * @brief Emit a timezone selector grouped (primarily) by continent
 * 
 * @param string $current Timezone
 * @return string Parsed HTML output
 */
function select_timezone($current = 'America/Los_Angeles') {

	$timezone_identifiers = DateTimeZone::listIdentifiers();

	$o ='<select id="timezone_select" name="timezone">';

	usort($timezone_identifiers, 'timezone_cmp');
	$continent = '';
	foreach($timezone_identifiers as $value) {
		$ex = explode("/", $value);
		if(count($ex) > 1) {
			if($ex[0] != $continent) {
				if($continent != '')
					$o .= '</optgroup>';
				$continent = $ex[0];
				$o .= '<optgroup label="' . t($continent) . '">';
			}
			if(count($ex) > 2)
				$city = substr($value,strpos($value,'/')+1);
			else
				$city = $ex[1];
		}
		else {
			$city = $ex[0];
			if($continent != t('Miscellaneous')) {
				$o .= '</optgroup>';
				$continent = t('Miscellaneous');
				$o .= '<optgroup label="' . t($continent) . '">';
			}
		}
		$city = str_replace('_', ' ',  t($city));
		$selected = (($value == $current) ? " selected=\"selected\" " : "");
		$o .= "<option value=\"$value\" $selected >$city</option>";
	}
	$o .= '</optgroup></select>';
	return $o;
}



/**
 * @brief Generating a Timezone selector
 * 
 * Return a select using 'field_select_raw' template, with timezones
 * groupped (primarily) by continent
 * arguments follow convetion as other field_* template array:
 * 'name', 'label', $value, 'help'
 * 
 * @param string $name Name of the selector
 * @param string $label Label for the selector
 * @param string $current Timezone
 * @param string $help Help text
 * 
 * @return string Parsed HTML
 */
function field_timezone($name='timezone', $label='', $current = 'America/Los_Angeles', $help){
	$options = select_timezone($current);
	$options = str_replace('<select id="timezone_select" name="timezone">','', $options);
	$options = str_replace('</select>','', $options);

	$tpl = get_markup_template('field_select_raw.tpl');
	return replace_macros($tpl, array(
		'$field' => array($name, $label, $current, $help, $options),
	));

}

/**
 * @brief General purpose date parse/convert function.
 *
 * @param string $from Source timezone
 * @param string $to Dest timezone
 * @param string $s Some parseable date/time string
 * @param string $fmt Output format recognised from php's DateTime class
 *   http://www.php.net/manual/en/datetime.format.php
 * 
 * @return string Formatted date according to given format
 */
function datetime_convert($from = 'UTC', $to = 'UTC', $s = 'now', $fmt = "Y-m-d H:i:s") {

	// Defaults to UTC if nothing is set, but throws an exception if set to empty string.
	// Provide some sane defaults regardless.

	if($from === '')
		$from = 'UTC';
	if($to === '')
		$to = 'UTC';
	if( ($s === '') || (! is_string($s)) )
		$s = 'now';

	// Slight hackish adjustment so that 'zero' datetime actually returns what is intended
	// otherwise we end up with -0001-11-30 ...
	// add 32 days so that we at least get year 00, and then hack around the fact that
	// months and days always start with 1.

	if(substr($s,0,10) == '0000-00-00') {
		$d = new DateTime($s . ' + 32 days', new DateTimeZone('UTC'));
		return str_replace('1','0',$d->format($fmt));
	}

	try {
		$from_obj = new DateTimeZone($from);
	}
	catch(Exception $e) {
		$from_obj = new DateTimeZone('UTC');
	}

	try {
		$d = new DateTime($s, $from_obj);
	}
	catch(Exception $e) {
		logger('datetime_convert: exception: ' . $e->getMessage());
		$d = new DateTime('now', $from_obj);
	}

	try {
		$to_obj = new DateTimeZone($to);
	}
	catch(Exception $e) {
		$to_obj = new DateTimeZone('UTC');
	}

	$d->setTimeZone($to_obj);

	return($d->format($fmt));
}


/**
 * @brief Wrapper for date selector, tailored for use in birthday fields.
 *
 * @param string $dob Date of Birth
 * @return string Formatted html
 */
function dob($dob) {
	list($year,$month,$day) = sscanf($dob,'%4d-%2d-%2d');

	$f = get_config('system','birthday_input_format');
	if(! $f)
		$f = 'ymd';
	if($dob === '0000-00-00')
		$value = '';
	else
		$value = (($year) ? datetime_convert('UTC','UTC',$dob,'Y-m-d') : datetime_convert('UTC','UTC',$dob,'m-d'));

	$age = ((intval($value)) ? age($value, $a->user["timezone"], $a->user["timezone"]) : "");

	$o = replace_macros(get_markup_template("field_input.tpl"), array(
		'$field' => array(
			'dob',
			t('Birthday:'),
			$value,
			(((intval($age)) > 0 ) ? t('Age: ') . $age : ""),
			'',
			'placeholder="' . t('YYYY-MM-DD or MM-DD') . '"'
		)
	));

//	if ($dob && $dob != '0000-00-00')
//		$o = datesel($f,mktime(0,0,0,0,0,1900),mktime(),mktime(0,0,0,$month,$day,$year),'dob');
//	else
//		$o = datesel($f,mktime(0,0,0,0,0,1900),mktime(),false,'dob');

	return $o;
}

/**
 * @brief Returns a date selector
 * 
 * @param string $format
 *  Format string, e.g. 'ymd' or 'mdy'. Not currently supported
 * @param string $min
 *  Unix timestamp of minimum date
 * @param string $max
 *  Unix timestap of maximum date
 * @param string $default
 *  Unix timestamp of default date
 * @param string $id
 *  ID and name of datetimepicker (defaults to "datetimepicker")
 * 
 * @return string Parsed HTML output.
 */
function datesel($format, $min, $max, $default, $id = 'datepicker') {
	return datetimesel($format,$min,$max,$default,'',$id,true,false, '','');
}

/**
 * @brief Returns a time selector
 * 
 * @param string $format
 *  Format string, e.g. 'ymd' or 'mdy'. Not currently supported
 * @param $h
 *  Already selected hour
 * @param $m
 *  Already selected minute
 * @param string $id
 *  ID and name of datetimepicker (defaults to "timepicker")
 * 
 * @return string Parsed HTML output.
 */
function timesel($format, $h, $m, $id='timepicker') {
	return datetimesel($format,new DateTime(),new DateTime(),new DateTime("$h:$m"),'',$id,false,true);
}

/**
 * @brief Returns a datetime selector.
 *
 * @param string $format
 *  format string, e.g. 'ymd' or 'mdy'. Not currently supported
 * @param string $min
 *  unix timestamp of minimum date
 * @param string $max
 *  unix timestap of maximum date
 * @param string $default
 *  unix timestamp of default date
 * @param string $id
 *  id and name of datetimepicker (defaults to "datetimepicker")
 * @param bool $pickdate
 *  true to show date picker (default)
 * @param boolean $picktime
 *  true to show time picker (default)
 * @param $minfrom
 *  set minimum date from picker with id $minfrom (none by default)
 * @param $maxfrom
 *  set maximum date from picker with id $maxfrom (none by default)
 * @param bool $required default false
 * 
 * @return string Parsed HTML output.
 *
 * @todo Once browser support is better this could probably be replaced with
 * native HTML5 date picker.
 */
function datetimesel($format, $min, $max, $default, $label, $id = 'datetimepicker', $pickdate = true, $picktime = true, $minfrom = '', $maxfrom = '', $required = false) {

	// First day of the week (0 = Sunday)
	$firstDay = get_pconfig(local_user(),'system','first_day_of_week');
	if ($firstDay === false) $firstDay=0;

	$lang = substr(get_browser_language(), 0, 2);

	// Check if the detected language is supported by the picker
	if (!in_array($lang, array("ar", "ro", "id", "bg", "fa", "ru", "uk", "en", "el", "de", "nl", "tr", "fr", "es", "th", "pl", "pt", "ch", "se", "kr", "it", "da", "no", "ja", "vi", "sl", "cs", "hu")))
		$lang = ((isset($a->config['system']['language'])) ? $a->config['system']['language'] : 'en');

	$o = '';
	$dateformat = '';

	if($pickdate) $dateformat .= 'Y-m-d';
	if($pickdate && $picktime) $dateformat .= ' ';
	if($picktime) $dateformat .= 'H:i';

	$minjs = $min ? ",minDate: new Date({$min->getTimestamp()}*1000), yearStart: " . $min->format('Y') : '';
	$maxjs = $max ? ",maxDate: new Date({$max->getTimestamp()}*1000), yearEnd: " . $max->format('Y') : '';

	$input_text = $default ? date($dateformat, $default->getTimestamp()) : '';
	$defaultdatejs = $default ? ",defaultDate: new Date({$default->getTimestamp()}*1000)" : '';

	$pickers = '';
	if(!$pickdate) $pickers .= ',datepicker: false';
	if(!$picktime) $pickers .= ',timepicker: false';

	$extra_js = '';
	$pickers .= ",dayOfWeekStart: ".$firstDay.",lang:'".$lang."'";
	if($minfrom != '')
		$extra_js .= "\$('#id_$minfrom').data('xdsoft_datetimepicker').setOptions({onChangeDateTime: function (currentDateTime) { \$('#id_$id').data('xdsoft_datetimepicker').setOptions({minDate: currentDateTime})}})";
	if($maxfrom != '')
		$extra_js .= "\$('#id_$maxfrom').data('xdsoft_datetimepicker').setOptions({onChangeDateTime: function (currentDateTime) { \$('#id_$id').data('xdsoft_datetimepicker').setOptions({maxDate: currentDateTime})}})";

	$readable_format = $dateformat;
	$readable_format = str_replace('Y','yyyy',$readable_format);
	$readable_format = str_replace('m','mm',$readable_format);
	$readable_format = str_replace('d','dd',$readable_format);
	$readable_format = str_replace('H','HH',$readable_format);
	$readable_format = str_replace('i','MM',$readable_format);

	$tpl = get_markup_template('field_input.tpl');
	$o .= replace_macros($tpl,array(
			'$field' => array($id, $label, $input_text, '', (($required) ? '*' : ''), 'placeholder="' . $readable_format . '"'),
		));

	$o .= "<script type='text/javascript'>";
	$o .= "\$(function () {var picker = \$('#id_$id').datetimepicker({step:5,format:'$dateformat' $minjs $maxjs $pickers $defaultdatejs}); $extra_js})";
	$o .= "</script>";

	return $o;
}

/**
 * @brief Returns a relative date string.
 *
 * Implements "3 seconds ago" etc.
 * Based on $posted_date, (UTC).
 * Results relative to current timezone.
 * Limited to range of timestamps.
 *
 * @param string $posted_date MySQL-formatted date string (YYYY-MM-DD HH:MM:SS)
 * @param string $format (optional) Parsed with sprintf()
 *    <tt>%1$d %2$s ago</tt>, e.g. 22 hours ago, 1 minute ago
 *
 * @return string with relative date
 */
function relative_date($posted_date, $format = null) {

	$localtime = $posted_date . ' UTC';

	$abs = strtotime($localtime);

	if (is_null($posted_date) || $posted_date === '0000-00-00 00:00:00' || $abs === False) {
		 return t('never');
	}

	$etime = time() - $abs;

	if ($etime < 1) {
		return t('less than a second ago');
	}

	$a = array( 12 * 30 * 24 * 60 * 60  =>  array( t('year'),   t('years')),
				30 * 24 * 60 * 60       =>  array( t('month'),  t('months')),
				7  * 24 * 60 * 60       =>  array( t('week'),   t('weeks')),
				24 * 60 * 60            =>  array( t('day'),    t('days')),
				60 * 60                 =>  array( t('hour'),   t('hours')),
				60                      =>  array( t('minute'), t('minutes')),
				1                       =>  array( t('second'), t('seconds'))
	);

	foreach ($a as $secs => $str) {
		$d = $etime / $secs;
		if ($d >= 1) {
			$r = round($d);
			// translators - e.g. 22 hours ago, 1 minute ago
			if (!$format) {
				$format = t('%1$d %2$s ago');
			}

			return sprintf($format, $r, (($r == 1) ? $str[0] : $str[1]));
		}
	}
}

/**
 * @brief Returns timezone correct age in years.
 *
 * Returns the age in years, given a date of birth, the timezone of the person
 * whose date of birth is provided, and the timezone of the person viewing the
 * result.
 *
 * Why? Bear with me. Let's say I live in Mittagong, Australia, and my birthday
 * is on New Year's. You live in San Bruno, California.
 * When exactly are you going to see my age increase?
 *
 * A: 5:00 AM Dec 31 San Bruno time. That's precisely when I start celebrating
 * and become a year older. If you wish me happy birthday on January 1
 * (San Bruno time), you'll be a day late.
 *
 * @param string $dob Date of Birth
 * @param string $owner_tz (optional) Timezone of the person of interest
 * @param string $viewer_tz (optional) Timezone of the person viewing
 * 
 * @return int Age in years
 */
function age($dob,$owner_tz = '',$viewer_tz = '') {
	if(! intval($dob))
		return 0;
	if(! $owner_tz)
		$owner_tz = date_default_timezone_get();
	if(! $viewer_tz)
		$viewer_tz = date_default_timezone_get();

	$birthdate = datetime_convert('UTC',$owner_tz,$dob . ' 00:00:00+00:00','Y-m-d');
	list($year,$month,$day) = explode("-",$birthdate);
	$year_diff  = datetime_convert('UTC',$viewer_tz,'now','Y') - $year;
	$curr_month = datetime_convert('UTC',$viewer_tz,'now','m');
	$curr_day   = datetime_convert('UTC',$viewer_tz,'now','d');

	if(($curr_month < $month) || (($curr_month == $month) && ($curr_day < $day)))
		$year_diff--;

	return $year_diff;
}

/**
 * @brief Get days of a month in a given year.
 *
 * Returns number of days in the month of the given year.
 * $m = 1 is 'January' to match human usage.
 *
 * @param int $y Year
 * @param int $m Month (1=January, 12=December)
 * 
 * @return int Number of days in the given month
 */
function get_dim($y,$m) {

	$dim = array( 0,
		31, 28, 31, 30, 31, 30,
		31, 31, 30, 31, 30, 31);

	if($m != 2)
		return $dim[$m];

	if(((($y % 4) == 0) && (($y % 100) != 0)) || (($y % 400) == 0))
		return 29;

	return $dim[2];
}

/**
 * @brief Returns the first day in month for a given month, year.
 *
 * Months start at 1.
 *
 * @param int $y Year
 * @param int $m Month (1=January, 12=December)
 * 
 * @return string day 0 = Sunday through 6 = Saturday
 */
function get_first_dim($y,$m) {
	$d = sprintf('%04d-%02d-01 00:00', intval($y), intval($m));

	return datetime_convert('UTC','UTC',$d,'w');
}

/**
 * @brief Output a calendar for the given month, year.
 *
 * If $links are provided (array), e.g. $links[12] => 'http://mylink' ,
 * date 12 will be linked appropriately. Today's date is also noted by
 * altering td class.
 * Months count from 1.
 *
 * @param int $y Year
 * @param int $m Month
 * @param bool $links (default false)
 * @param string $class
 * 
 * @return string
 *
 * @todo Provide (prev,next) links, define class variations for different size calendars
 */
function cal($y = 0,$m = 0, $links = false, $class='') {


	// month table - start at 1 to match human usage.

	$mtab = array(' ',
		'January','February','March',
		'April','May','June',
		'July','August','September',
		'October','November','December'
	);

	$thisyear = datetime_convert('UTC',date_default_timezone_get(),'now','Y');
	$thismonth = datetime_convert('UTC',date_default_timezone_get(),'now','m');
	if(! $y)
		$y = $thisyear;
	if(! $m)
		$m = intval($thismonth);

	$dn = array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday');
	$f = get_first_dim($y,$m);
	$l = get_dim($y,$m);
	$d = 1;
	$dow = 0;
	$started = false;

	if(($y == $thisyear) && ($m == $thismonth))
		$tddate = intval(datetime_convert('UTC',date_default_timezone_get(),'now','j'));

	$str_month = day_translate($mtab[$m]);
	$o = '<table class="calendar' . $class . '">';
	$o .= "<caption>$str_month $y</caption><tr>";
	for($a = 0; $a < 7; $a ++)
		$o .= '<th>' . mb_substr(day_translate($dn[$a]),0,3,'UTF-8') . '</th>';

	$o .= '</tr><tr>';

	while($d <= $l) {
		if(($dow == $f) && (! $started))
			$started = true;

		$today = (((isset($tddate)) && ($tddate == $d)) ? "class=\"today\" " : '');
		$o .= "<td $today>";
		$day = str_replace(' ','&nbsp;',sprintf('%2.2d', $d));
		if($started) {
			if(is_array($links) && isset($links[$d]))
				$o .=  "<a href=\"{$links[$d]}\">$day</a>";
			else
				$o .= $day;

			$d ++;
		} else {
			$o .= '&nbsp;';
		}

		$o .= '</td>';
		$dow ++;
		if(($dow == 7) && ($d <= $l)) {
			$dow = 0;
			$o .= '</tr><tr>';
		}
	}
	if($dow)
		for($a = $dow; $a < 7; $a ++)
			$o .= '<td>&nbsp;</td>';

	$o .= '</tr></table>'."\r\n";

	return $o;
}

/**
 * @brief Create a birthday event.
 *
 * Update the year and the birthday.
 */
function update_contact_birthdays() {

	// This only handles foreign or alien networks where a birthday has been provided.
	// In-network birthdays are handled within local_delivery

	$r = q("SELECT * FROM contact WHERE `bd` != '' AND `bd` != '0000-00-00' AND SUBSTRING(`bd`,1,4) != `bdyear` ");
	if (dbm::is_result($r)) {
		foreach ($r as $rr) {

			logger('update_contact_birthday: ' . $rr['bd']);

			$nextbd = datetime_convert('UTC','UTC','now','Y') . substr($rr['bd'],4);

			/**
			 *
			 * Add new birthday event for this person
			 *
			 * $bdtext is just a readable placeholder in case the event is shared
			 * with others. We will replace it during presentation to our $importer
			 * to contain a sparkle link and perhaps a photo.
			 *
			 */

			$bdtext = sprintf( t('%s\'s birthday'), $rr['name']);
			$bdtext2 = sprintf( t('Happy Birthday %s'), ' [url=' . $rr['url'] . ']' . $rr['name'] . '[/url]') ;

			$r = q("INSERT INTO `event` (`uid`,`cid`,`created`,`edited`,`start`,`finish`,`summary`,`desc`,`type`,`adjust`)
				VALUES ( %d, %d, '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%d' ) ",
				intval($rr['uid']),
			 	intval($rr['id']),
				dbesc(datetime_convert()),
				dbesc(datetime_convert()),
				dbesc(datetime_convert('UTC','UTC', $nextbd)),
				dbesc(datetime_convert('UTC','UTC', $nextbd . ' + 1 day ')),
				dbesc($bdtext),
				dbesc($bdtext2),
				dbesc('birthday'),
				intval(0)
			);


			// update bdyear

			q("UPDATE `contact` SET `bdyear` = '%s', `bd` = '%s' WHERE `uid` = %d AND `id` = %d",
				dbesc(substr($nextbd,0,4)),
				dbesc($nextbd),
				intval($rr['uid']),
				intval($rr['id'])
			);

		}
	}
}