lax/lib/Date.php
2020-04-26 09:41:33 -04:00

208 lines
8 KiB
PHP

<?php
/** @license MIT
* Copyright 2018 J. King et al.
* See LICENSE and AUTHORS files for details */
declare(strict_types=1);
namespace MensBeam\Lax;
class Date extends \DateTimeImmutable implements \JsonSerializable {
protected const PATTERN_RFC3339 = '/^(\d{4}-\d\d-\d\d)[Tt ](\d\d:\d\d(?::\d\d(?:\.\d+)?)?)\s*([Zz]|[+\-]\d\d:?\d\d)?$/';
protected const PATTERN_RFC8XX = '/^(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun|(?:Mon|Tues|Wednes|Thurs|Fri|Satur|Sun)day)(?:, ?| )(\d\d)(?<dd> |-)(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)(?P=dd)(\d\d(?:\d\d)?) (\d\d:\d\d(?::\d\d(?:\.\d+)?)?)\s*(?-i:([A-Z]|GMT|UTC?|[ECMP][SD]T|[+\-]\d\d:?\d\d)?)$/i';
protected const PATTERN_ASCTIME = '/^(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun) (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) (\d\d?) (\d\d:\d\d:\d\d) (\d{4})$/';
protected const INPUT_FORMAT = '!Y-m-d\TH:i:s.uO';
protected const MICROTIME_PRECSISION = 6;
protected const MONTH_MAP = ['Jan' => "01", 'Feb' => "02", 'Mar' => "03", 'Apr' => "04", 'May' => "05", 'Jun' => "06", 'Jul' => "07", 'Aug' => "08", 'Sep' => "09", 'Oct' => "10", 'Nov' => "11", 'Dec' => "12"];
protected const TZ_MAP = [
'A' => "+0100",
'B' => "+0200",
'C' => "+0300",
'D' => "+0400",
'E' => "+0500",
'F' => "+0600",
'G' => "+0700",
'H' => "+0800",
'I' => "+0900",
'J' => "-0000",
'K' => "+1000",
'L' => "+1100",
'M' => "+1200",
'N' => "-0100",
'O' => "-0200",
'P' => "-0300",
'Q' => "-0400",
'R' => "-0500",
'S' => "-0600",
'T' => "-0700",
'U' => "-0800",
'V' => "-0900",
'W' => "-1000",
'X' => "-1100",
'Y' => "-1200",
'Z' => "+0000",
'UT' => "+0000",
'UTC' => "+0000",
'GMT' => "+0000",
'EST' => "-0500",
'EDT' => "-0400",
'CST' => "-0600",
'CDT' => "-0500",
'MST' => "-0700",
'MDT' => "-0600",
'PST' => "-0800",
'PDT' => "-0700",
];
/*
Important formats:
// RFC 3339 formats
'Y-m-d\TH:i:s.uO',
// HTTP format (and similar)
'D, d M Y H:i:s \G\M\T',
// HTTP obsolete format (assumed UTC)
'D M j H:i:s Y',
*/
protected static function create(\DateTimeInterface $temp): self {
return (new self)->setTimestamp($temp->getTimestamp())->setTimezone($temp->getTimezone())->setTime((int) $temp->format("H"), (int) $temp->format("i"), (int) $temp->format("s"), (int) $temp->format("u"));
}
public function __construct($time = "now", $timezone = null) {
parent::__construct($time, $timezone);
}
/** Returns a date parsed from a string in any of the following formats:
*
* - RFC 3339
* - RFC 822
* - RFC 850
* - ANSI C asctime()
*
* Subsets of RFC 822 and RFC 850 formats and asctime() format are used
* by RFC 7231 (HTTP), and the latter definition was consulted for
* guidance. RFC 3339 and RFC 822 formats are both supported in full, and
* the ambiguous century of RFC 822 and RFC 850 formats is interpreted per
* RFC 7231. Timezones used for RFC 822 are also accepted for RFC 850.
*
* All formats except asctime() are also accepted with subsecond precision,
* or with minute precision. Whitespace before the timezone may be omitted
* or used in all formats as well (RFC 3339 does not normally allow
* whitespace, while other formats require it).
*
* If no timezone is specified, -00:00 is used.
*
* @see https://tools.ietf.org/html/rfc3339
* @see https://tools.ietf.org/html/rfc822#section-5
* @see https://tools.ietf.org/html/rfc850#section-2.1.4
* @see https://tools.ietf.org/html/rfc7231#section-7.1.1.1
*/
public static function createFromString(string $timeSpec): ?self {
$ambiguousCentury = false;
$now = new self;
$timeSpec = trim(preg_replace('/\s{2,}/', " ", $timeSpec));
if (preg_match(self::PATTERN_RFC3339, $timeSpec, $match)) {
$date = $match[1];
$time = self::parseTime($match[2]);
$zone = self::parseZone($match[3] ?? "");
} elseif (preg_match(self::PATTERN_RFC8XX, $timeSpec, $match)) {
$day = $match[1];
$month = self::MONTH_MAP[ucfirst(strtolower($match[3]))] ?? null;
assert(!is_null($month));
$year = $match[4];
$time = self::parseTime($match[5]);
$zone = self::parseZone($match[6] ?? "");
if (strlen($year) === 2) {
$ambiguousCentury = true;
// get the current century
$century = intdiv((int) $now->format("Y"), 100) * 100;
$year = (string) ($century + (int) $year);
}
$date = "$year-$month-$day";
} elseif (preg_match(self::PATTERN_ASCTIME, $timeSpec, $match)) {
$month = self::MONTH_MAP[$match[1]] ?? null;
assert(!is_null($month));
$day = str_pad($match[2], 2, "0", \STR_PAD_LEFT);
assert(strlen($day) === 2);
$time = self::parseTime($match[3]);
$year = $match[4];
$zone = "-0000";
$date = "$year-$month-$day";
} else {
return null;
}
$tz = new \DateTimeZone("UTC");
$out = self::createFromFormat(self::INPUT_FORMAT, "{$date}T$time$zone", $tz);
// ensure there has been no roll-over
$cDate = $out->format("Y-m-d");
$cTime = $out->format("H:i:s.u");
if ($cDate !== $date || $cTime !== $time) {
return null;
}
if ($ambiguousCentury && $out->normalize() > $now->add(new \DateInterval("P50Y"))->normalize()) {
$year = (int) substr($date, 0, 4);
$year = (string) ($year - 100);
$date = $year.substr($date, 4);
return self::createFromFormat(self::INPUT_FORMAT, "{$date}T$time$zone", $tz);
}
return $out;
}
protected static function parseZone(string $zone): string {
$out = self::TZ_MAP[strtoupper($zone)] ?? null;
if ($out) {
return $out;
}
$zone = str_replace(":", "", $zone);
if (preg_match('/^[+\-]\d{4}$/', $zone)) {
return $zone;
}
return "-0000";
}
protected static function parseTime(string $time): string {
$micro = str_pad("", self::MICROTIME_PRECSISION, "0");
if (strlen($time) === 5) {
$time .= ":00.$micro";
} elseif (strlen($time) === 8) {
$time .= ".$micro";
} else {
$time = str_pad($time, 9 + self::MICROTIME_PRECSISION, "0");
}
$time = substr($time, 0, 9 + self::MICROTIME_PRECSISION);
assert((bool) preg_match('/^\d\d:\d\d:\d\d\.\d{'.self::MICROTIME_PRECSISION.'}$/', $time));
return $time;
}
public static function createFromFormat($format, $time, $timezone = null): ?self {
$temp = parent::createFromFormat("!".$format, $time, $timezone);
return $temp ? static::create($temp) : null;
}
public static function createFromMutable($datetime): ?self {
$temp = parent::createFromMutable($datetime);
return $temp ? static::create($temp) : null;
}
public static function createFromImmutable($datetime): ?self {
$temp = \DateTime::createFromImmutable($datetime);
return $temp ? static::create($temp) : null;
}
/** Returns a normalized string representation of the instance's moment in time, useful for comparisons */
public function normalize(): string {
return $this->setTimezone(new \DateTimeZone("UTC"))->format("Y-m-d\TH:i:s.u\Z");
}
public function __toString() {
if ((int) $this->format("u")) {
return $this->format("Y-m-d\TH:i:s.uP");
} else {
return $this->format("Y-m-d\TH:i:sP");
}
}
public function jsonSerialize() {
return $this->__toString();
}
}