Add the Chronological

vendor/sabre/vobject/lib/TimezoneGuesser/FindFromTimezoneMap.php

@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabre\VObject\TimezoneGuesser;
+
+use DateTimeZone;
+
+/**
+ * Some clients add 'X-LIC-LOCATION' with the olson name.
+ */
+class FindFromTimezoneMap implements TimezoneFinder
+{
+    private $map = [];
+
+    private $patterns = [
+        '/^\((UTC|GMT)(\+|\-)[\d]{2}\:[\d]{2}\) (.*)/',
+        '/^\((UTC|GMT)(\+|\-)[\d]{2}\.[\d]{2}\) (.*)/',
+    ];
+
+    public function find(string $tzid, bool $failIfUncertain = false): ?DateTimeZone
+    {
+        // Next, we check if the tzid is somewhere in our tzid map.
+        if ($this->hasTzInMap($tzid)) {
+            return new DateTimeZone($this->getTzFromMap($tzid));
+        }
+
+        // Some Microsoft products prefix the offset first, so let's strip that off
+        // and see if it is our tzid map.  We don't want to check for this first just
+        // in case there are overrides in our tzid map.
+        foreach ($this->patterns as $pattern) {
+            if (!preg_match($pattern, $tzid, $matches)) {
+                continue;
+            }
+            $tzidAlternate = $matches[3];
+            if ($this->hasTzInMap($tzidAlternate)) {
+                return new DateTimeZone($this->getTzFromMap($tzidAlternate));
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * This method returns an array of timezone identifiers, that are supported
+     * by DateTimeZone(), but not returned by DateTimeZone::listIdentifiers().
+     *
+     * We're not using DateTimeZone::listIdentifiers(DateTimeZone::ALL_WITH_BC) because:
+     * - It's not supported by some PHP versions as well as HHVM.
+     * - It also returns identifiers, that are invalid values for new DateTimeZone() on some PHP versions.
+     * (See timezonedata/php-bc.php and timezonedata php-workaround.php)
+     *
+     * @return array
+     */
+    private function getTzMaps()
+    {
+        if ([] === $this->map) {
+            $this->map = array_merge(
+                include __DIR__.'/../timezonedata/windowszones.php',
+                include __DIR__.'/../timezonedata/lotuszones.php',
+                include __DIR__.'/../timezonedata/exchangezones.php',
+                include __DIR__.'/../timezonedata/php-workaround.php'
+            );
+        }
+
+        return $this->map;
+    }
+
+    private function getTzFromMap(string $tzid): string
+    {
+        return $this->getTzMaps()[$tzid];
+    }
+
+    private function hasTzInMap(string $tzid): bool
+    {
+        return isset($this->getTzMaps()[$tzid]);
+    }
+}