Add Malaysia holiday (#17)

* add Malaysia holiday date

* run test on Malaysia

* fix typo and add pesta kaamatan second day

* add region support

* update malaysia test snapshot

* update code to meet PHPStan analysis

* add Malaysia region validation

* update fix holiday to string and easter function

* update Malaysia test with region and invalid region

* refactor new year holiday into function

* update invalid region exception

* refactor chinese calendar to use trait

* update invalid region exception

* refactor CNY and Aidilfitri holiday function

* refactor new year holiday to string

* refactor islamic calendar to trait

* refactor chinese function to use trait

* refactor function placeholder

---------

Co-authored-by: Niels Vanpachtenbeke <10651054+Nielsvanpach@users.noreply.github.com>

src/Calendars/IslamicCalendar.php

@@ -2,15 +2,21 @@
 
 namespace Spatie\Holidays\Calendars;
 
-use Carbon\CarbonImmutable;
+use DateTime;
+use DateTimeZone;
+use IntlCalendar;
+use IntlDateFormatter;
 use Carbon\CarbonPeriod;
+use Carbon\CarbonImmutable;
 use Carbon\Exceptions\InvalidFormatException;
 use Spatie\Holidays\Countries\Country;
 use Spatie\Holidays\Exceptions\InvalidYear;
 
 /** @mixin Country */
 trait IslamicCalendar
 {
+      protected string $islamicCalendarTimezone = 'UTC';
+
     /** @return array<CarbonPeriod> */
     public function eidAlFitr(int $year, int $totalDays = 3): array
     {
@@ -138,4 +144,47 @@ protected function getOverlapping(array $collection, int $year, int $totalDays):
 
         return null;
     }
+
+    public function setIslamicCalendarTimezone(string $islamicCalendarTimezone): static
+    {
+        $this->islamicCalendarTimezone = $islamicCalendarTimezone;
+
+        return $this;
+    }
+
+    protected function getIslamicCalendarFormatter(): IntlDateFormatter
+    {
+        return new IntlDateFormatter(
+            'en_US@calendar=islamic-civil',
+            IntlDateFormatter::FULL,
+            IntlDateFormatter::FULL,
+            'UTC',
+            IntlDateFormatter::TRADITIONAL,
+            'yyyy-MM-dd'
+        );
+    }
+
+    protected function getHijriYear(int $year, bool $nextYear = false): int
+    {
+        $formatter = $this->getIslamicCalendarFormatter();
+        $formatter->setPattern('yyyy');
+        $dateTime = DateTime::createFromFormat('d/m/Y', '01/01/' . ($nextYear ? $year + 1 : $year));
+
+        if (!$dateTime) {
+            throw InvalidYear::invalidHijriYear();
+        }
+
+        return (int) $formatter->format($dateTime->getTimestamp());
+    }
+
+    protected function islamicToGregorianDate(string $input, int $year, bool $nextYear = false): CarbonImmutable
+    {
+        $hijriYear = $this->getHijriYear(year: $year, nextYear: $nextYear);
+        $formatter = $this->getIslamicCalendarFormatter();
+        $timestamp = (int) $formatter->parse(sprintf('%s-%s', $hijriYear, $input));
+
+        return (new CarbonImmutable())
+            ->setTimeStamp($timestamp)
+            ->setTimezone(new DateTimeZone($this->islamicCalendarTimezone));
+    }
 }