mlocati/timezone-constants-creator.php

## timezone-constants-creator.php
<?php

/*
 * License: MIT
 * Author: Michele Locati <michele@locati.it>
 */

declare(strict_types=1);

set_error_handler(
    static function ($errno, $errstr) {
        throw new RuntimeException($errstr);
    },
    -1
);

function getXMLDocument(): DOMDocument
{
    $xml = file_get_contents('https://raw.githubusercontent.com/unicode-org/cldr/release-44-1/common/supplemental/windowsZones.xml');
    $doc  = new DOMDocument();
    if (!$doc->loadXML($xml)) {
        throw new RuntimeException('Failed to load xml');
    }

    return $doc;
}

function sortTimeZoneIdentifiers(string $timeZoneA, string $timeZoneB): int
{
    $matchesA = [];
    $matchesB = [];
    preg_match('/^(?<pre>.*?)(?<num>[+\-]?\d+)(?<post>.*?)$/', $timeZoneA, $matchesA);
    if ($matchesA === []) {
        preg_match('/^(?<pre>.*?)(?<num>[+\-]?\d+)(?<post>.*?)$/', $timeZoneA . '+0', $matchesA);
    }
    preg_match('/^(?<pre>.*?)(?<num>[+\-]?\d+)(?<post>.*?)$/', $timeZoneB, $matchesB);
    if ($matchesB === []) {
        preg_match('/^(?<pre>.*?)(?<num>[+\-]?\d+)(?<post>.*?)$/', $timeZoneB . '+0', $matchesB);
    }
    if ($matchesA['pre'] === $matchesB['pre'] && $matchesA['post'] === $matchesB['post']) {
        return (int) $matchesA['num'] - (int) $matchesB['num'];
    }

    return strcasecmp($timeZoneA, $timeZoneB);
}

function normalizePhpTimeZoneID(string $timeZoneIdentifier): string
{
    set_error_handler(static function() {}, -1);
    try {
        $timeZone = timezone_open($timeZoneIdentifier);
    } finally {
        restore_error_handler();
    }

    return $timeZone instanceof DateTimeZone ? $timeZone->getName() : '';
}

function buildWindowsToPhp(DOMDocument $doc): array
{
    $xpath = new DOMXPath($doc);
    $mapZones = $xpath->query('/supplementalData/windowsZones/mapTimezones/mapZone');
    $map = [];
    foreach ($mapZones as $mapZone) {
        $windowsName = (string) $mapZone->getAttribute('other');
        if ($windowsName === '') {
            throw new RuntimeException('Failed to retrieve Windows time zone from XML ' . $doc->saveXML($mapZone));
        }
        if (!isset($map[$windowsName])) {
            $map[$windowsName] = [];
        }
        $phpNames = (string) $mapZone->getAttribute('type');
        if ($phpNames === '') {
            throw new RuntimeException('Failed to retrieve PHP time zones from ' . $doc->saveXML($phpNames));
        }
        foreach (array_unique(preg_split('/\s+/', $phpNames, -1, PREG_SPLIT_NO_EMPTY)) as $phpName) {
            $actualPhpName = normalizePhpTimeZoneID($phpName);
            if ($actualPhpName === '') {
                fwrite(STDERR, "Invalid PHP time zone name: '{$phpName}'\n");
            } elseif (!in_array($actualPhpName, $map[$windowsName], true)) {
                $map[$windowsName][] = $actualPhpName;
            }
        }
    }
    foreach ($map as $windowsName => $phpNames) {
        if ($phpNames === []) {
            throw new RuntimeException("No PHP time zone is applicable to the Windows time zone '{$windowsName}'");
        }
    }
    uksort($map, 'sortTimeZoneIdentifiers');

    return array_map(
        static function (array $phpNames): array {
            usort($phpNames, 'sortTimeZoneIdentifiers');

            return $phpNames;
        },
        $map
    );
}

function buildPhpToWindows(array $windowsToPhp): array
{
    $map = [];
    foreach ($windowsToPhp as $windows => $phpNames) {
        foreach ($phpNames as $phpName) {
            if (isset($map[$phpName])) {
                throw new RuntimeException("The PHP time zone '{$phpName}' is applicable to more than one Windows time zone");
            }
            $map[$phpName] = $windows;
        }
    }
    uksort($map, 'sortTimeZoneIdentifiers');

    return $map;
}

function quote(string $s): string
{
    return "'" . addcslashes($s, "'\\") . "'";
}

$doc = getXMLDocument();
$windowsToPhp = buildWindowsToPhp($doc);
$phpToWindows = buildPhpToWindows($windowsToPhp);

echo "const WINDOWS_TO_PHP = [\n";
foreach ($windowsToPhp as $windows => $phps) {
    echo '    ', quote($windows), ' => [' . implode(', ', array_map('quote', $phps)), '],', "\n";
}
echo "\n";
echo "const PHP_TO_WINDOWS = [\n";
foreach ($phpToWindows as $php => $windows) {
    echo '    ', quote($php), ' => ', quote($windows), ",\n";
}
echo "];\n";

echo "\n";

echo "const PHP_TO_WINDOWS = [\n";
foreach ($phpToWindows as $php => $windows) {
    echo '    ', quote($php), ' => ', quote($windows), ",\n";
}
echo "];\n";
	<?php

	/*
	* License: MIT
	* Author: Michele Locati <michele@locati.it>
	*/

	declare(strict_types=1);

	set_error_handler(
	static function ($errno, $errstr) {
	throw new RuntimeException($errstr);
	},
	-1
	);

	function getXMLDocument(): DOMDocument
	{
	$xml = file_get_contents('https://raw.githubusercontent.com/unicode-org/cldr/release-44-1/common/supplemental/windowsZones.xml');
	$doc = new DOMDocument();
	if (!$doc->loadXML($xml)) {
	throw new RuntimeException('Failed to load xml');
	}

	return $doc;
	}

	function sortTimeZoneIdentifiers(string $timeZoneA, string $timeZoneB): int
	{
	$matchesA = [];
	$matchesB = [];
	preg_match('/^(?<pre>.?)(?<num>[+\-]?\d+)(?<post>.?)$/', $timeZoneA, $matchesA);
	if ($matchesA === []) {
	preg_match('/^(?<pre>.?)(?<num>[+\-]?\d+)(?<post>.?)$/', $timeZoneA . '+0', $matchesA);
	}
	preg_match('/^(?<pre>.?)(?<num>[+\-]?\d+)(?<post>.?)$/', $timeZoneB, $matchesB);
	if ($matchesB === []) {
	preg_match('/^(?<pre>.?)(?<num>[+\-]?\d+)(?<post>.?)$/', $timeZoneB . '+0', $matchesB);
	}
	if ($matchesA['pre'] === $matchesB['pre'] && $matchesA['post'] === $matchesB['post']) {
	return (int) $matchesA['num'] - (int) $matchesB['num'];
	}

	return strcasecmp($timeZoneA, $timeZoneB);
	}

	function normalizePhpTimeZoneID(string $timeZoneIdentifier): string
	{
	set_error_handler(static function() {}, -1);
	try {
	$timeZone = timezone_open($timeZoneIdentifier);
	} finally {
	restore_error_handler();
	}

	return $timeZone instanceof DateTimeZone ? $timeZone->getName() : '';
	}

	function buildWindowsToPhp(DOMDocument $doc): array
	{
	$xpath = new DOMXPath($doc);
	$mapZones = $xpath->query('/supplementalData/windowsZones/mapTimezones/mapZone');
	$map = [];
	foreach ($mapZones as $mapZone) {
	$windowsName = (string) $mapZone->getAttribute('other');
	if ($windowsName === '') {
	throw new RuntimeException('Failed to retrieve Windows time zone from XML ' . $doc->saveXML($mapZone));
	}
	if (!isset($map[$windowsName])) {
	$map[$windowsName] = [];
	}
	$phpNames = (string) $mapZone->getAttribute('type');
	if ($phpNames === '') {
	throw new RuntimeException('Failed to retrieve PHP time zones from ' . $doc->saveXML($phpNames));
	}
	foreach (array_unique(preg_split('/\s+/', $phpNames, -1, PREG_SPLIT_NO_EMPTY)) as $phpName) {
	$actualPhpName = normalizePhpTimeZoneID($phpName);
	if ($actualPhpName === '') {
	fwrite(STDERR, "Invalid PHP time zone name: '{$phpName}'\n");
	} elseif (!in_array($actualPhpName, $map[$windowsName], true)) {
	$map[$windowsName][] = $actualPhpName;
	}
	}
	}
	foreach ($map as $windowsName => $phpNames) {
	if ($phpNames === []) {
	throw new RuntimeException("No PHP time zone is applicable to the Windows time zone '{$windowsName}'");
	}
	}
	uksort($map, 'sortTimeZoneIdentifiers');

	return array_map(
	static function (array $phpNames): array {
	usort($phpNames, 'sortTimeZoneIdentifiers');

	return $phpNames;
	},
	$map
	);
	}

	function buildPhpToWindows(array $windowsToPhp): array
	{
	$map = [];
	foreach ($windowsToPhp as $windows => $phpNames) {
	foreach ($phpNames as $phpName) {
	if (isset($map[$phpName])) {
	throw new RuntimeException("The PHP time zone '{$phpName}' is applicable to more than one Windows time zone");
	}
	$map[$phpName] = $windows;
	}
	}
	uksort($map, 'sortTimeZoneIdentifiers');

	return $map;
	}

	function quote(string $s): string
	{
	return "'" . addcslashes($s, "'\\") . "'";
	}

	$doc = getXMLDocument();
	$windowsToPhp = buildWindowsToPhp($doc);
	$phpToWindows = buildPhpToWindows($windowsToPhp);

	echo "const WINDOWS_TO_PHP = [\n";
	foreach ($windowsToPhp as $windows => $phps) {
	echo ' ', quote($windows), ' => [' . implode(', ', array_map('quote', $phps)), '],', "\n";
	}
	echo "\n";
	echo "const PHP_TO_WINDOWS = [\n";
	foreach ($phpToWindows as $php => $windows) {
	echo ' ', quote($php), ' => ', quote($windows), ",\n";
	}
	echo "];\n";

	echo "\n";

	echo "const PHP_TO_WINDOWS = [\n";
	foreach ($phpToWindows as $php => $windows) {
	echo ' ', quote($php), ' => ', quote($windows), ",\n";
	}
	echo "];\n";