chippyash/Validation

<?php

declare(strict_types=1);

/**
 * Chippyash/validation
 *
 * Functional validation
 *
 * Common validations
 *
 * @author    Ashley Kitson
 * @copyright Ashley Kitson, 2015, UK
 *
 * @link http://en.wikipedia.org/wiki/ISO_8601
 * @link http://php.net/manual/en/class.datetime.php
 */

namespace Chippyash\Validation\Common\ISO8601;

use Chippyash\Validation\Common\ISO8601\Constants as C;
use Monad\Match;

/**
 * Utility helper for ISODateString validator
 * Splits a datestring into component parts
 */
class SplitDate
{
    /**
     * Have we found a time part?
     * @var boolean
     */
    protected $timepartFound = false;
    /**
     * Have we found a zone part?
     * @var boolean
     */
    protected $zonepartFound = false;
    /**
     * Are we allowing a lax time sparator?
     * @var boolean
     */
    protected $laxTime = false;
    /**
     * Are we allowing a lax zone separator?
     * @var boolean
     */
    protected $laxZone = false;

    /**
     * The format we are using
     * @var int
     */
    protected $format = C::FORMAT_EXTENDED;

    public function __construct($laxTime, $laxZone, $format)
    {
        $this->laxTime = (bool)$laxTime;
        $this->laxZone = (bool)$laxZone;
        $this->format = $format;
    }

    /**
     * Split date by its parts
     *
     * @param  string $value ISO datetime string
     * @return array[date, time, zone, timePartFound]
     */
    public function splitDate($value)
    {
        $parts = Match::on($this->laxTime)
            ->test(true, function () use ($value) {
                $parts = explode(' ', $value);
                //join back zone part if found
                if (count($parts) == 3) {
                    $parts[1] .= ' ' . $parts[2];
                    unset($parts[2]);
                }
                return $parts;
            })
            ->test(false, function () use ($value) {
                return explode('t', $value);
            })
            ->value();
        //guard
        if (count($parts) == 0 || count($parts) > 2 || (count($parts) == 1 && empty($parts[0]))) {
            return [null, null, null, $this->timepartFound, $this->zonepartFound];
        }
        if (count($parts) == 1) {
            //we have a date only
            return [$parts[0], null, null, $this->timepartFound, $this->zonepartFound];
        }
        if (count($parts) == 2) {
            $this->timepartFound = true;
            //we have a date and something else
            [$time, $zone] = $this->splitTime($parts[1]);
            if (!is_null($zone)) {
                return [$parts[0], $time, $zone, $this->timepartFound, $this->zonepartFound];
            } elseif (!is_null($time)) {
                return [$parts[0], $time, null, $this->timepartFound, $this->zonepartFound];
            }

            return [$parts[0], null, null, $this->timepartFound, $this->zonepartFound];
        }

        return [$parts[0], null, null, $this->timepartFound, $this->zonepartFound];
    }

    /**
     * Split timezone by its parts
     *
     * @param  string $value
     * @return array[time, zone]
     */
    protected function splitTime($value)
    {
        //guard
        if (empty($value)) {
            return [null, null];
        }

        //try to find zone, z == UTC
        $partsZ = explode('z', $value);
        $partsM = explode('-', $value);
        $partsP = explode('+', $value);
        if ($this->laxZone) {
            //trim the time part cus there may be a space
            $partsZ[0] = rtrim($partsZ[0]);
            $partsM[0] = rtrim($partsM[0]);
            $partsP[0] = rtrim($partsP[0]);
        }
        //guard
        if (count($partsZ) == 0 && count($partsM) == 0 && count($partsP) == 0) {
            return [null, null];
        }
        //UTC timezone stated
        if (count($partsZ) == 2 && empty($partsZ[1])) {
            $this->zonepartFound = true;
            return [$partsZ[0], $this->getUTCTimezone()];
        }

        //minus timezone stated
        if (count($partsM) == 2) {
            $this->zonepartFound = true;
            return [$partsM[0], "-{$partsM[1]}"];
        }

        //plus timezone stated
        if (count($partsP) == 2) {
            $this->zonepartFound = true;
            return [$partsP[0], "+{$partsP[1]}"];
        }

        //no zone found
        return [(empty($value) ? null : $value), null];
    }

    /**
     * Get current UTC timezone offset
     *
     * @return string|null
     */
    protected function getUTCTimezone()
    {
        if (\date_default_timezone_get() == 'UTC') {
            return 'UTC'; //already in UTC. workaround as zone must be non empty
        }
         
        $timezone = new \DateTimeZone(\date_default_timezone_get()); // Get default system timezone to create a new DateTimeZone object
        $offset = $timezone->getOffset(new \DateTime()); // Offset in seconds to UTC
        $offsetHours = round(abs($offset) / 3600);
        $offsetMinutes = round((abs($offset) - $offsetHours * 3600) / 60);
        return ($offset < 0 ? '-' : '+')
            . ($offsetHours < 10 ? '0' : '') . $offsetHours
            . ($this->format == C::FORMAT_EXTENDED || $this->format == C::FORMAT_EXTENDED_SIGNED ? ':' : '')
            . ($offsetMinutes < 10 ? '0' : '') . $offsetMinutes;
    }
}