<?php


use Code\Lib\Features;
use Code\Lib\Time;
use Code\Render\Theme;


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


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

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

function is_null_date($s)
{
    return $s === '0000-00-00 00:00:00' || $s === '0001-01-01 00:00:00';
}

/**
 * @brief Return timezones grouped (primarily) by continent.
 *
 * @see timezone_cmp()
 * @return array
 */
function get_timezones()
{
    $timezone_identifiers = DateTimeZone::listIdentifiers();

    usort($timezone_identifiers, 'timezone_cmp');
    $continent = '';
    $continents = [];
    foreach ($timezone_identifiers as $value) {
        $ex = explode("/", $value);
        if (count($ex) > 1) {
            $continent = t($ex[0]);
            if (count($ex) > 2) {
                $city = substr($value, strpos($value, '/') + 1);
            } else {
                $city = $ex[1];
            }
        } else {
            $city = $ex[0];
            $continent = t('Miscellaneous');
        }
        $city = str_replace('_', ' ', t($city));

        if (!x($continents, $ex[0])) {
            $continents[$ex[0]] = [];
        }
        $continents[$continent][$value] = $city;
    }

    return $continents;
}

/**
 * @brief General purpose date parse/convert function.
 *
 * @param string $from source timezone
 * @param string $to dest timezone
 * @param string $datetime some parseable date/time string
 * @param string $format output format recognised from php's DateTime class
 *   http://www.php.net/manual/en/datetime.format.php
 * @return string
 */
function datetime_convert($from = 'UTC', $to = 'UTC', $datetime = 'now', $format = "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 === '') {
        $to = 'UTC';
    }
    if (($datetime === '') || (! is_string($datetime))) {
        $datetime = 'now';
    }

    if (is_null_date($datetime)) {
        $d = new DateTime('0001-01-01 00:00:00', new DateTimeZone('UTC'));
        return $d->format($format);
    }

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

    try {
        $d = new DateTime($datetime, $from_obj);
    } catch (Exception $e) {
        logger('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($d->format($format));
}

/**
 * @brief Wrapper for date selector, tailored for use in birthday fields.
 *
 * @param string $dob Date of Birth
 * @return string Parsed HTML with selector
 */
function dob($dob)
{

    $y = substr($dob, 0, 4);
    if ((! ctype_digit($y)) || ($y < 1900)) {
        $ignore_year = true;
    } else {
        $ignore_year = false;
    }

    if ($dob === '0000-00-00' || $dob === '') {
        $value = '';
    } else {
        $value = (($ignore_year) ? Time::convert('UTC', 'UTC', $dob, 'm-d') : Time::convert('UTC', 'UTC', $dob, 'Y-m-d'));
    }

    $age = age($value, App::$user['timezone'], App::$user['timezone']);

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


    return $o;
}

/**
 * @brief Returns a datetime selector.
 *
 * @param string $format
 *   format string, e.g. 'ymd' or 'mdy'. Not currently supported
 * @param DateTime $min
 *   unix timestamp of minimum date
 * @param DateTime $max
 *   unix timestap of maximum date
 * @param DateTime $default
 *   unix timestamp of default date
 * @param string $label
 * @param string $id
 *   id and name of datetimepicker (defaults to "datetimepicker")
 * @param bool $pickdate
 *   true to show date picker (default)
 * @param bool $picktime
 *   true to show time picker (default)
 * @param DateTime $minfrom
 *   set minimum date from picker with id $minfrom (none by default)
 * @param DateTime $maxfrom
 *   set maximum date from picker with id $maxfrom (none by default)
 * @param bool $required default false
 * @param int $first_day (optional) default 0
 * @return string Parsed HTML output.
 *
 * @todo Once browser support is better this could probably be replaced with
 * native HTML5 date picker.
 */
function datetimesel($format, $min, $max, $default, $label, $id = 'datetimepicker', $pickdate = true, $picktime = true, $minfrom = '', $maxfrom = '', $required = false, $first_day = 0)
{

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

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

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

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

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

    $extra_js = '';
    if ($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 = Theme::get_template('field_input.tpl');
    $o .= replace_macros($tpl, [
            '$field' => [$id, $label, $input_text, (($required) ? t('Required') : ''), (($required) ? '*' : ''), 'placeholder="' . $readable_format . '"'],
    ]);
    $o .= "<script>\$(function () {let picker = \$('#id_$id').datetimepicker({step:15,format:'$dateformat' $minjs $maxjs $pickers $defaultdatejs,dayOfWeekStart:$first_day}); $extra_js})</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
 * @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 = Time::convert('UTC', date_default_timezone_get(), $posted_date);

    $abs = strtotime($localtime);

    if (is_null($posted_date) || is_null_date($posted_date) || $abs === false) {
        return t('never');
    }

    if ($abs > time()) {
        $direction = t('from now');
        $etime = $abs - time();
    } else {
        $direction = t('ago');
        $etime = time() - $abs;
    }

    if ($etime < 1) {
        return sprintf(t('less than a second %s'), $direction);
    }

    $a = [12 * 30 * 24 * 60 * 60  =>  'y',
                30 * 24 * 60 * 60       =>  'm',
                7  * 24 * 60 * 60       =>  'w',
                24 * 60 * 60            =>  'd',
                60 * 60                 =>  'h',
                60                      =>  'i',
                1                       =>  's'
    ];


    foreach ($a as $secs => $str) {
        $d = $etime / $secs;
        if ($d >= 1) {
            $r = round($d);
            if (! $format) {
                $format = t('%1$d %2$s %3$s', 'e.g. 22 hours ago, 1 minute ago');
            }
            return sprintf($format, $r, plural_dates($str, $r), $direction);
        }
    }
}

function plural_dates($k, $n)
{

    return match ($k) {
        'y' => tt('year', 'years', $n, 'relative_date'),
        'm' => tt('month', 'months', $n, 'relative_date'),
        'w' => tt('week', 'weeks', $n, 'relative_date'),
        'd' => tt('day', 'days', $n, 'relative_date'),
        'h' => tt('hour', 'hours', $n, 'relative_date'),
        'i' => tt('minute', 'minutes', $n, 'relative_date'),
        's' => tt('second', 'seconds', $n, 'relative_date'),
        default => '',
    };
}

/**
 * @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 $viewer_tz (optional) timezone of the person viewing
 * @return number
 */
function age($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 = Time::convert('UTC', $owner_tz, $dob . ' 00:00:00+00:00', 'Y-m-d');
    list($year,$month,$day) = explode("-", $birthdate);
    $year_diff  = Time::convert('UTC', $viewer_tz, 'now', 'Y') - $year;
    $curr_month = Time::convert('UTC', $viewer_tz, 'now', 'm');
    $curr_day   = Time::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 = [ 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 Time::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 number $y Year
 * @param number $m Month
 * @param string $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 = [ ' ', 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December' ];

    $thisyear = Time::convert('UTC', date_default_timezone_get(), 'now', 'Y');
    $thismonth = Time::convert('UTC', date_default_timezone_get(), 'now', 'm');
    if (! $y) {
        $y = $thisyear;
    }
    if (! $m) {
        $m = intval($thismonth);
    }

    $dn = [ '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(Time::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 Return the next birthday, converted from the owner's timezone to UTC.
 *
 * This makes it globally portable.
 * If the provided birthday lacks a month and or day, return an empty string.
 * A missing year is acceptable.
 *
 * @param string $dob Date of Birth
 * @param string $tz Timezone
 * @param string $format
 * @return string
 */
function z_birthday($dob, $tz, $format = "Y-m-d H:i:s")
{

    if (! strlen($tz)) {
        $tz = 'UTC';
    }

    $birthday = '';
    $tmp_dob = substr($dob, 5);
    $tmp_d = substr($dob, 8);
    if (intval($tmp_dob) && intval($tmp_d)) {
        $y = Time::convert($tz, $tz, 'now', 'Y');
        $bd = $y . '-' . $tmp_dob . ' 00:00';
        $t_dob = strtotime($bd);
        $now = strtotime(Time::convert($tz, $tz, 'now'));
        if ($t_dob < $now) {
            $bd = sprintf("%d-%s 00:00", intval($y) + 1, $tmp_dob);
        }

        $birthday = Time::convert($tz, 'UTC', $bd, $format);
    }

    return $birthday;
}

/**
 * @brief Create a birthday event for any connections with a birthday in the next 1-2 weeks.
 *
 * Update the year so that we don't create another event until next year.
 */
function update_birthdays()
{

    require_once('include/event.php');
    require_once('include/permissions.php');

    $r = q(
        "SELECT * FROM abook left join xchan on abook_xchan = xchan_hash
		WHERE abook_dob > %s + %s and abook_dob < %s + %s",
        db_utcnow(),
        db_quoteinterval('7 day', true),
        db_utcnow(),
        db_quoteinterval('14 day', true)
    );
    if ($r) {
        foreach ($r as $rr) {
            if (! perm_is_allowed($rr['abook_channel'], $rr['xchan_hash'], 'send_stream')) {
                continue;
            }

            $ev = [
                'uid'         => $rr['abook_channel'],
                'account'     => $rr['abook_account'],
                'event_xchan' => $rr['xchan_hash'],
                'dtstart'     => Time::convert('UTC', 'UTC', $rr['abook_dob']),
                'dtend'       => Time::convert('UTC', 'UTC', $rr['abook_dob'] . ' + 1 day '),
                'adjust'      => intval(Features::enabled($rr['abook_channel'], 'smart_birthdays')),
                'summary'     => sprintf(t('%1$s\'s birthday'), $rr['xchan_name']),
                'description' => sprintf(t('Happy Birthday %1$s'), '[zrl=' . $rr['xchan_url'] . ']' . $rr['xchan_name'] . '[/zrl]'),
                'etype'       => 'birthday',
            ];

            $z = event_store_event($ev);
            if ($z) {
                event_store_item($ev, $z, deliver: false, addAndSync: false);
                q(
                    "update abook set abook_dob = '%s' where abook_id = %d",
                    dbesc(intval($rr['abook_dob']) + 1 . substr($rr['abook_dob'], 4)),
                    intval($rr['abook_id'])
                );
            }
        }
    }
}