limoncello-php-dist / events

src/Package/EventSettings.php

<?php declare(strict_types=1);

namespace Limoncello\Events\Package;

/**
 * Copyright 2015-2019 info@neomerx.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

use Limoncello\Contracts\Settings\Packages\EventSettingsInterface;
use Limoncello\Common\Reflection\ClassIsTrait;
use Limoncello\Events\Contracts\EventHandlerInterface;
use Limoncello\Events\Contracts\EventInterface;
use Limoncello\Events\SimpleEventEmitter;
use ReflectionClass;
use ReflectionException;
use ReflectionMethod;
use function assert;
use function class_exists;
use function class_implements;
use function count;
use function glob;
use function in_array;
use function interface_exists;
use function iterator_to_array;

/**
 * @package Limoncello\Events
 */
abstract class EventSettings implements EventSettingsInterface
{
    use ClassIsTrait;

    /**
     * @param array $appConfig
     *
     * @return array
     *
     * @throws ReflectionException
     */
    final public function get(array $appConfig): array
    {
        assert($appConfig !== null);

        $defaults = $this->getSettings();

        $eventsFolder = $defaults[static::KEY_EVENTS_FOLDER] ?? null;
        assert(
            $eventsFolder !== null && empty(glob($eventsFolder)) === false,
            "Invalid Events folder `$eventsFolder`."
        );

        $eventsFileMask = $defaults[static::KEY_EVENTS_FILE_MASK] ?? null;
        assert(empty($eventsFileMask) === false, "Invalid Events file mask `$eventsFileMask`.");

        $subscribersFolder = $defaults[static::KEY_SUBSCRIBERS_FOLDER] ?? null;
        assert(
            $subscribersFolder !== null && empty(glob($subscribersFolder)) === false,
            "Invalid Subscribers folder `$subscribersFolder`."
        );

        $subscribersFileMask = $defaults[static::KEY_SUBSCRIBERS_FILE_MASK] ?? null;
        assert(empty($subscribersFileMask) === false, "Invalid Subscribers file mask `$subscribersFileMask`.");

        $eventsPath      = $eventsFolder . DIRECTORY_SEPARATOR . $eventsFileMask;
        $subscribersPath = $subscribersFolder . DIRECTORY_SEPARATOR . $subscribersFileMask;

        $emitter      = new SimpleEventEmitter();
        /** @noinspection PhpParamsInspection */
        $eventClasses = iterator_to_array(
            $this->selectClasses($eventsPath, EventInterface::class)
        );
        /** @noinspection PhpParamsInspection */
        $handlerClasses = iterator_to_array(
            $this->selectClasses($subscribersPath, EventHandlerInterface::class)
        );

        $allowedEvents = $this->getParentEvents($eventClasses);

$eventClasses is of type array, but the function expects a object<Limoncello\Events\Package\iterable>.

        $emitter->addAllowedEvents($allowedEvents);

        foreach ($this->getEventSubscribers($eventClasses, $handlerClasses) as $eventClass => $subscriber) {

$eventClasses is of type array, but the function expects a object<Limoncello\Events\Package\iterable>.

$handlerClasses is of type array, but the function expects a object<Limoncello\Events\Package\iterable>.

            $emitter->subscribe($eventClass, $subscriber);

$subscriber is of type *, but the function expects a callable.

        }

        $cacheData = $emitter->getData();

        return $defaults + [static::KEY_CACHED_DATA => $cacheData];
    }

    /**
     * @return array
     */
    protected function getSettings(): array
    {
        return [
            static::KEY_EVENTS_FILE_MASK      => '*.php',
            static::KEY_SUBSCRIBERS_FILE_MASK => '*.php',
        ];
    }

    /**
     * @param iterable $eventClasses
     * @param iterable $handlerClasses
     *
     * @return iterable

Should the return type not be \Generator?

     *
     * @throws ReflectionException
     */
    private function getEventSubscribers(iterable $eventClasses, iterable $handlerClasses): iterable
    {
        foreach ($handlerClasses as $handlerClass) {
            foreach ($this->selectEvenHandlers($handlerClass) as $eventClass => $subscriber) {
                foreach ($this->getChildEvents($eventClass, $eventClasses) as $childEventClass) {
                    yield $childEventClass => $subscriber;
                }
            }
        }
    }

    /**
     * @param string $handlerClass
     *
     * @return iterable

Should the return type not be \Generator?

     *
     * @throws ReflectionException
     */
    private function selectEvenHandlers(string $handlerClass): iterable
    {
        $reflection = new ReflectionClass($handlerClass);
        foreach ($reflection->getMethods(ReflectionMethod::IS_STATIC | ReflectionMethod::IS_PUBLIC) as $method) {
            if ($this->isEventHandlerMethod($method) === true) {
                $eventClass = $method->getParameters()[0]->getClass()->getName();
                $subscriber = [$handlerClass, $method->getName()];
                yield $eventClass => $subscriber;
            }
        }
    }

    /**
     * @param string   $eventClass
     * @param iterable $eventClasses
     *
     * @return iterable

Should the return type not be \Generator?

     *
     * @throws ReflectionException
     */
    private function getChildEvents(string $eventClass, iterable $eventClasses): iterable
    {
        $reflection = new ReflectionClass($eventClass);
        foreach ($eventClasses as $curEventClass) {
            $curReflection = new ReflectionClass($curEventClass);
            if ($curReflection->isAbstract() === false) {
                if ($eventClass === $curEventClass ||
                    $curReflection->isSubclassOf($eventClass) === true ||
                    ($reflection->isInterface() === true && $curReflection->implementsInterface($eventClass))
                ) {
                    yield $curEventClass;
                }
            }
        }
    }

    /**
     * @param iterable $eventClasses
     *
     * @return array
     */
    private function getParentEvents(iterable $eventClasses): array
    {
        $matches = [];

        foreach ($eventClasses as $eventClass) {
            // class itself
            if ($this->doesImplementEventInterface($eventClass) === true) {
                $matches[$eventClass] = true;
            }
            // parent classes or interfaces
            foreach (class_implements($eventClass, true) as $classOrInterface) {
                if ($this->doesImplementEventInterface($classOrInterface) === true) {
                    $matches[$classOrInterface] = true;
                }
            }
        }

        return array_keys($matches);
    }

    /**
     * @param ReflectionMethod $method
     *
     * @return bool
     */
    private function isEventHandlerMethod(ReflectionMethod $method): bool
    {
        $result =
            $method->isPublic() === true &&
            $method->isStatic() === true &&
            count($params = $method->getParameters()) === 1 &&
            $params[0]->getClass()->implementsInterface(EventInterface::class) === true;

        return $result;
    }

    /**
     * @param string $classOrInterface
     *
     * @return bool
     */
    private function doesImplementEventInterface(string $classOrInterface): bool
    {
        $isClass     = class_exists($classOrInterface, true);
        $isInterface = interface_exists($classOrInterface, true);
        assert($isClass xor $isInterface);

        $isEvent = in_array(EventInterface::class, class_implements($classOrInterface));

        return $isEvent;
    }
}