Limoncello\Core\Application\Application

Complexity

Total Complexity

30

Size/Duplication

Total Lines	386
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	10

Test Coverage

Coverage

100%

Importance

Changes

0

20 Methods

Rating	Name	Duplication	Size	Complexity
	setUpExceptionHandler()	0	1	?
A	setSapi()	0	6	1
	createSettingsProvider()	0	1	?
	createContainerInstance()	0	1	?
A	createTerminalHandler()	0	9	1
B	run()	0	54	9
A	getDefaultRequestFactory()	0	4	1
A	defaultRequestFactory()	0	15	1
A	handleRequest()	0	8	1
A	createEmptyResponse()	0	6	1
A	getRouter()	0	4	1
B	configureContainer()	0	18	5
A	addMiddlewareChain()	0	11	1
A	callHandler()	0	21	1
A	initRouter()	0	12	1
A	createRequest()	0	20	1
A	createMethodNotAllowedTerminalHandler()	0	7	1
A	createNotFoundTerminalHandler()	0	7	1
A	createMiddlewareChainImpl()	0	12	2
A	createMiddlewareChainLink()	0	20	1

<?php namespace Limoncello\Core\Application;

/**
 * Copyright 2015-2017 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 Closure;
use Limoncello\Contracts\Container\ContainerInterface as LimoncelloContainerInterface;
use Limoncello\Contracts\Core\ApplicationInterface;
use Limoncello\Contracts\Core\SapiInterface;
use Limoncello\Contracts\Routing\RouterInterface;
use Limoncello\Contracts\Settings\SettingsProviderInterface;
use Limoncello\Core\Contracts\CoreSettingsInterface;
use Limoncello\Core\Reflection\CheckCallableTrait;
use Limoncello\Core\Routing\Router;
use LogicException;
use Psr\Container\ContainerInterface as PsrContainerInterface;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Zend\Diactoros\Response\EmptyResponse;
use Zend\Diactoros\ServerRequest;

/**
 * @package Limoncello\Core
 *
 * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
 */
abstract class Application implements ApplicationInterface
{
    use CheckCallableTrait;

    /** Method name for default request factory. */
    const FACTORY_METHOD = 'defaultRequestFactory';

    /**
     * @var SapiInterface|null
     */
    private $sapi;

    /**
     * @var RouterInterface|null
     */
    private $router = null;

    /**
     * @return SettingsProviderInterface
     */
    abstract protected function createSettingsProvider(): SettingsProviderInterface;

    /**
     * @return LimoncelloContainerInterface
     */
    abstract protected function createContainerInstance(): LimoncelloContainerInterface;

    /**
     * Exception handler should not use container before actual error occurs.
     *
     * @param SapiInterface         $sapi
     * @param PsrContainerInterface $container
     *
     * @return void
     */
    abstract protected function setUpExceptionHandler(SapiInterface $sapi, PsrContainerInterface $container): void;

    /**
     * @inheritdoc
     */
    public function setSapi(SapiInterface $sapi): ApplicationInterface
    {
        $this->sapi = $sapi;

        return $this;
    }

    /**
     * @inheritdoc
     *
     * @SuppressWarnings(PHPMD.StaticAccess)
     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
     */
    public function run(): void
    {
        if ($this->sapi === null) {
            throw new LogicException('SAPI not set.');
        }

        $container = $this->createContainerInstance();

        $this->setUpExceptionHandler($this->sapi, $container);

        $settingsProvider = $this->createSettingsProvider();
        $container->offsetSet(SettingsProviderInterface::class, $settingsProvider);

        $coreSettings = $settingsProvider->get(CoreSettingsInterface::class);

        // match route from `Request` to handler, route container configurators/middleware, etc
        list($matchCode, $allowedMethods, $handlerParams, $handler,
            $routeMiddleware, $routeConfigurators, $requestFactory) = $this->initRouter($coreSettings)
                ->match($this->sapi->getMethod(), $this->sapi->getUri()->getPath());

        // configure container
        $globalConfigurators = BaseCoreSettings::getGlobalConfiguratorsFromData($coreSettings);
        $this->configureContainer($container, $globalConfigurators, $routeConfigurators);

        // build pipeline for handling `Request`: global middleware -> route middleware -> handler (e.g. controller)

        // select terminal handler
        switch ($matchCode) {
            case RouterInterface::MATCH_FOUND:
                $handler = $this->createTerminalHandler($handler, $handlerParams, $container);
                break;
            case RouterInterface::MATCH_METHOD_NOT_ALLOWED:
                $handler = $this->createMethodNotAllowedTerminalHandler($allowedMethods);
                break;
            default:
                assert($matchCode === RouterInterface::MATCH_NOT_FOUND);
                $handler = $this->createNotFoundTerminalHandler();
                break;
        }

        $globalMiddleware = BaseCoreSettings::getGlobalMiddlewareFromData($coreSettings);
        $hasMiddleware    = empty($globalMiddleware) === false || empty($routeMiddleware) === false;

        $handler = $hasMiddleware === true ?
            $this->addMiddlewareChain($handler, $container, $globalMiddleware, $routeMiddleware) : $handler;

        $request = $requestFactory === null && $hasMiddleware === false && $matchCode === RouterInterface::MATCH_FOUND ?
            null :
            $this->createRequest($this->sapi, $container, $requestFactory ?? static::getDefaultRequestFactory());

        // Execute the pipeline by sending `Request` down all middleware (global then route's then
        // terminal handler in `Controller` and back) and then send `Response` to SAPI
        $this->sapi->handleResponse($this->handleRequest($handler, $request));
    }

    /**
     * @return callable

Consider making the return type a bit more specific; maybe use string[].

     */
    public static function getDefaultRequestFactory(): callable
    {
        return [static::class, static::FACTORY_METHOD];
    }

    /**
     * @param SapiInterface $sapi
     *
     * @return ServerRequestInterface
     */
    public static function defaultRequestFactory(SapiInterface $sapi): ServerRequestInterface
    {
        return new ServerRequest(
            $sapi->getServer(),
            $sapi->getFiles(),
            $sapi->getUri(),
            $sapi->getMethod(),
            $sapi->getRequestBody(),
            $sapi->getHeaders(),
            $sapi->getCookies(),
            $sapi->getQueryParams(),
            $sapi->getParsedBody(),
            $sapi->getProtocolVersion()
        );
    }

    /**
     * @param Closure               $handler
     * @param RequestInterface|null $request
     *
     * @return ResponseInterface
     */
    protected function handleRequest(Closure $handler, RequestInterface $request = null): ResponseInterface
    {
        $response = call_user_func($handler, $request);

        assert($response instanceof ResponseInterface);

        return $response;
    }

    /**
     * @param int   $status
     * @param array $headers
     *
     * @return ResponseInterface
     */
    protected function createEmptyResponse($status = 204, array $headers = []): ResponseInterface
    {
        $response = new EmptyResponse($status, $headers);

        return $response;
    }

    /**
     * @return RouterInterface|null
     */
    protected function getRouter(): ?RouterInterface
    {
        return $this->router;
    }

    /**
     * @param LimoncelloContainerInterface $container
     * @param callable[]|null              $globalConfigurators
     * @param callable[]|null              $routeConfigurators
     *
     * @return void
     */
    protected function configureContainer(
        LimoncelloContainerInterface $container,
        array $globalConfigurators = null,
        array $routeConfigurators = null
    ): void {
        if (empty($globalConfigurators) === false) {
            foreach ($globalConfigurators as $configurator) {
                assert($this->checkPublicStaticCallable($configurator, [LimoncelloContainerInterface::class]));
                $configurator($container);
            }
        }
        if (empty($routeConfigurators) === false) {
            foreach ($routeConfigurators as $configurator) {
                assert($this->checkPublicStaticCallable($configurator, [LimoncelloContainerInterface::class]));
                $configurator($container);
            }
        }
    }

    /**
     * @param Closure               $handler
     * @param PsrContainerInterface $container
     * @param array|null            $globalMiddleware
     * @param array|null            $routeMiddleware
     *
     * @return Closure
     */
    protected function addMiddlewareChain(
        Closure $handler,
        PsrContainerInterface $container,
        array $globalMiddleware,
        array $routeMiddleware = null
    ): Closure {
        $handler = $this->createMiddlewareChainImpl($handler, $container, $routeMiddleware);
        $handler = $this->createMiddlewareChainImpl($handler, $container, $globalMiddleware);

        return $handler;
    }

    /**
     * @param callable                    $handler
     * @param array                       $handlerParams
     * @param PsrContainerInterface       $container
     * @param ServerRequestInterface|null $request
     *
     * @return ResponseInterface
     */
    protected function callHandler(
        callable $handler,
        array $handlerParams,
        PsrContainerInterface $container,
        ServerRequestInterface $request = null
    ): ResponseInterface {
        // check the handler method signature
        assert(
            $this->checkPublicStaticCallable(
                $handler,
                ['array', PsrContainerInterface::class, ServerRequestInterface::class],
                ResponseInterface::class
            ),
            'Handler method should have signature ' .
            '`public static methodName(array, PsrContainerInterface, ServerRequestInterface): ResponseInterface`'
        );

        $response = call_user_func($handler, $handlerParams, $container, $request);

        return $response;
    }

    /**
     * @param array $coreSettings
     *
     * @return RouterInterface
     *
     * @SuppressWarnings(PHPMD.StaticAccess)
     */
    protected function initRouter(array $coreSettings): RouterInterface
    {
        $routerParams    = BaseCoreSettings::getRouterParametersFromData($coreSettings);
        $routesData      = BaseCoreSettings::getRoutesDataFromData($coreSettings);
        $generatorClass  = BaseCoreSettings::getGeneratorFromParametersData($routerParams);
        $dispatcherClass = BaseCoreSettings::getDispatcherFromParametersData($routerParams);

        $this->router = new Router($generatorClass, $dispatcherClass);
        $this->router->loadCachedRoutes($routesData);

        return $this->router;
    }

    /**
     * @param SapiInterface         $sapi
     * @param PsrContainerInterface $container
     * @param callable              $requestFactory
     *
     * @return ServerRequestInterface
     */
    private function createRequest(
        SapiInterface $sapi,
        PsrContainerInterface $container,
        callable $requestFactory
    ): ServerRequestInterface {
        // check the factory method signature
        assert(
            $this->checkPublicStaticCallable(
                $requestFactory,
                [SapiInterface::class, PsrContainerInterface::class],
                ServerRequestInterface::class
            ),
            'Factory method should have signature ' .
            '`public static methodName(SapiInterface, PsrContainerInterface): ServerRequestInterface`'
        );

        $request = call_user_func($requestFactory, $sapi, $container);

        return $request;
    }

    /**
     * @param callable              $handler
     * @param array                 $handlerParams
     * @param PsrContainerInterface $container
     *
     * @return Closure
     */
    private function createTerminalHandler(
        callable $handler,
        array $handlerParams,
        PsrContainerInterface $container
    ): Closure {
        return function (ServerRequestInterface $request = null) use ($handler, $handlerParams, $container) {
            return $this->callHandler($handler, $handlerParams, $container, $request);
        };
    }

    /**
     * @param array $allowedMethods
     *
     * @return Closure
     */
    private function createMethodNotAllowedTerminalHandler(array $allowedMethods): Closure
    {
        // 405 Method Not Allowed
        return function () use ($allowedMethods) {
            return $this->createEmptyResponse(405, ['Accept' => implode(',', $allowedMethods)]);
        };
    }

    /**
     * @return Closure
     */
    private function createNotFoundTerminalHandler(): Closure
    {
        // 404 Not Found
        return function () {
            return $this->createEmptyResponse(404);
        };
    }

    /**
     * @param Closure               $handler
     * @param PsrContainerInterface $container
     * @param array|null            $middleware
     *
     * @return Closure
     */
    private function createMiddlewareChainImpl(
        Closure $handler,
        PsrContainerInterface $container,
        array $middleware = null
    ): Closure {
        $start = count($middleware) - 1;
        for ($index = $start; $index >= 0; $index--) {
            $handler = $this->createMiddlewareChainLink($handler, $middleware[$index], $container);
        }

        return $handler;
    }

    /**
     * @param Closure               $next
     * @param callable              $middleware
     * @param PsrContainerInterface $container
     *
     * @return Closure
     */
    private function createMiddlewareChainLink(
        Closure $next,
        callable $middleware,
        PsrContainerInterface $container
    ): Closure {
        // check the middleware method signature
        assert(
            $this->checkPublicStaticCallable(
                $middleware,
                [ServerRequestInterface::class, Closure::class, PsrContainerInterface::class],
                ResponseInterface::class
            ),
            'Middleware method should have signature ' .
            '`public static methodName(ServerRequestInterface, Closure, PsrContainerInterface): ResponseInterface`'
        );

        return function (ServerRequestInterface $request) use ($next, $middleware, $container): ResponseInterface {
            return call_user_func($middleware, $request, $next, $container);
        };
    }
}