<?php
/**
 * Time.php
 *
 * -Description-
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * @link       https://www.librenms.org
 *
 * @copyright  2018 Tony Murray
 * @author     Tony Murray <murraytony@gmail.com>
 */

namespace LibreNMS\Util;

class Time
{
    public static function legacyTimeSpecToSecs($description)
    {
        $conversion = [
            'now' => 0,
            'onehour' => 3600,
            'fourhour' => 14400,
            'sixhour' => 21600,
            'twelvehour' => 43200,
            'day' => 86400,
            'twoday' => 172800,
            'week' => 604800,
            'twoweek' => 1209600,
            'month' => 2678400,
            'twomonth' => 5356800,
            'threemonth' => 8035200,
            'year' => 31536000,
            'twoyear' => 63072000,
        ];

        return isset($conversion[$description]) ? $conversion[$description] : 0;
    }

    public static function formatInterval($interval, $format = 'long')
    {
        $result = '';
        $data = [
            'years' => 31536000,
            'days' => 86400,
            'hours' => 3600,
            'minutes' => 60,
            'seconds' => 1,
        ];

        foreach ($data as $k => $v) {
            if ($interval >= $v) {
                $diff = floor($interval / $v);

                $result .= " $diff";
                if ($format == 'short') {
                    $result .= substr($k, 0, 1);
                }

                if ($format != 'short' && $diff > 1) {
                    $result .= ' ' . $k;
                }

                if ($format != 'short' && $diff < 2) {
                    $result .= ' ' . substr($k, 0, -1);
                }

                $interval -= $v * $diff;
            }
        }

        return $result;
    }

    /*
     * @param integer seconds of a time period
     * @return string human readably time period
     */
    public static function humanTime($s)
    {
        $ret = [];

        if ($s >= 86400) {
            $d = floor($s / 86400);
            $s -= $d * 86400;
            if ($d == 1) {
                $ret[] = $d . ' day';
            } else {
                $ret[] = $d . ' days';
            }
        }

        if ($s >= 3600) {
            $h = floor($s / 3600);
            $s -= $h * 3600;
            if ($h == 1) {
                $ret[] = $h . ' hour';
            } else {
                $ret[] = $h . ' hours';
            }
        }

        if ($s >= 60) {
            $m = floor($s / 60);
            $s -= $m * 60;
            if ($m == 1) {
                $ret[] = $m . ' minute';
            } else {
                $ret[] = $m . ' minutes';
            }
        }

        if ($s > 0) {
            if ($s == 1) {
                $ret[] = $s . ' second';
            } else {
                $ret[] = $s . ' seconds';
            }
        }

        return implode(' ,', $ret);
    }

    /**
     * Parse a time string into a timestamp including signed relative times using:
     * m - month
     * d - day
     * h - hour
     * y - year
     */
    public static function parseAt(string|int $time): int
    {
        if (is_numeric($time)) {
            return $time < 0 ? time() + $time : intval($time);
        }

        if (preg_match('/^[+-]\d+[hdmy]$/', $time)) {
            $units = [
                'm' => 60,
                'h' => 3600,
                'd' => 86400,
                'y' => 31557600,
            ];
            $value = Number::cast(substr($time, 1, -1));
            $unit = substr($time, -1);

            $offset = ($time[0] == '-' ? -1 : 1) * $units[$unit] * $value;

            return time() + $offset;
        }

        return (int) strtotime($time);
    }
}