PluginManager: Extract checkPluginLoadability() to a PluginLoadabilityChecker unit

this can be more easily unit-tested.

src/plugin/PluginLoadabilityChecker.php

@@ -0,0 +1,108 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\plugin;
+
+use pocketmine\lang\KnownTranslationFactory;
+use pocketmine\lang\Translatable;
+use pocketmine\network\mcpe\protocol\ProtocolInfo;
+use pocketmine\utils\Utils;
+use pocketmine\utils\VersionString;
+use function array_intersect;
+use function count;
+use function implode;
+use function in_array;
+use function phpversion;
+use function stripos;
+use function strlen;
+use function substr;
+use function version_compare;
+
+final class PluginLoadabilityChecker{
+
+	public function __construct(
+		private string $apiVersion
+	){}
+
+	public function check(PluginDescription $description) : Translatable|null{
+		$name = $description->getName();
+		if(stripos($name, "pocketmine") !== false or stripos($name, "minecraft") !== false or stripos($name, "mojang") !== false){
+			return KnownTranslationFactory::pocketmine_plugin_restrictedName();
+		}
+
+		foreach($description->getCompatibleApis() as $api){
+			if(!VersionString::isValidBaseVersion($api)){
+				return KnownTranslationFactory::pocketmine_plugin_invalidAPI($api);
+			}
+		}
+
+		if(!ApiVersion::isCompatible($this->apiVersion, $description->getCompatibleApis())){
+			return KnownTranslationFactory::pocketmine_plugin_incompatibleAPI(implode(", ", $description->getCompatibleApis()));
+		}
+
+		$ambiguousVersions = ApiVersion::checkAmbiguousVersions($description->getCompatibleApis());
+		if(count($ambiguousVersions) > 0){
+			return KnownTranslationFactory::pocketmine_plugin_ambiguousMinAPI(implode(", ", $ambiguousVersions));
+		}
+
+		if(count($description->getCompatibleOperatingSystems()) > 0 and !in_array(Utils::getOS(), $description->getCompatibleOperatingSystems(), true)) {
+			return KnownTranslationFactory::pocketmine_plugin_incompatibleOS(implode(", ", $description->getCompatibleOperatingSystems()));
+		}
+
+		if(count($pluginMcpeProtocols = $description->getCompatibleMcpeProtocols()) > 0){
+			$serverMcpeProtocols = [ProtocolInfo::CURRENT_PROTOCOL];
+			if(count(array_intersect($pluginMcpeProtocols, $serverMcpeProtocols)) === 0){
+				return KnownTranslationFactory::pocketmine_plugin_incompatibleProtocol(implode(", ", $pluginMcpeProtocols));
+			}
+		}
+
+		foreach($description->getRequiredExtensions() as $extensionName => $versionConstrs){
+			$gotVersion = phpversion($extensionName);
+			if($gotVersion === false){
+				return KnownTranslationFactory::pocketmine_plugin_extensionNotLoaded($extensionName);
+			}
+
+			foreach($versionConstrs as $k => $constr){ // versionConstrs_loop
+				if($constr === "*"){
+					continue;
+				}
+				if($constr === ""){
+					return KnownTranslationFactory::pocketmine_plugin_emptyExtensionVersionConstraint(extensionName: $extensionName, constraintIndex: "$k");
+				}
+				foreach(["<=", "le", "<>", "!=", "ne", "<", "lt", "==", "=", "eq", ">=", "ge", ">", "gt"] as $comparator){
+					// warning: the > character should be quoted in YAML
+					if(substr($constr, 0, strlen($comparator)) === $comparator){
+						$version = substr($constr, strlen($comparator));
+						if(!version_compare($gotVersion, $version, $comparator)){
+							return KnownTranslationFactory::pocketmine_plugin_incompatibleExtensionVersion(extensionName: $extensionName, extensionVersion: $gotVersion, pluginRequirement: $constr);
+						}
+						continue 2; // versionConstrs_loop
+					}
+				}
+				return KnownTranslationFactory::pocketmine_plugin_invalidExtensionVersionConstraint(extensionName: $extensionName, versionConstraint: $constr);
+			}
+		}
+
+		return null;
+	}
+}