File ICal/Timezone/CompositeTimezoneResolver.php

1:	<?php
2:	declare(strict_types=1);
3:
4:	namespace om\ICal\Timezone;
5:
6:	use DateTimeZone;
7:	use om\ICal\Component;
8:
9:	/**
10:	* Asks the resolvers in order and returns the first result.
11:	*/
12:	final readonly class CompositeTimezoneResolver implements TimezoneResolver {
13:	/** @var list<TimezoneResolver> */
14:	private array $resolvers;
15:
16:	public function __construct(TimezoneResolver ...$resolvers) {
17:	$this->resolvers = array_values($resolvers);
18:	}
19:
20:	/**
21:	* VTIMEZONE of the calendar, IANA names, aliases, then the optional fallback.
22:	*/
23:	public static function default(?DateTimeZone $fallback = null): self {
24:	$names = new self(new IanaTimezoneResolver(), new AliasTimezoneResolver());
25:	return new self(new VTimezoneResolver($names), $names, ...($fallback === null ? [] : [new FallbackTimezoneResolver($fallback)]));
26:	}
27:
28:	public function resolve(string $tzid, Component $calendar): ?ResolvedTimezone {
29:	foreach ($this->resolvers as $resolver) {
30:	if (($resolved = $resolver->resolve($tzid, $calendar)) !== null) {
31:	return $resolved;
32:	}
33:	}
34:	return null;
35:	}
36:	}
37: