<?php

namespace Symfony\Component\HttpKernel;

use Symfony\Component\HttpKernel\Controller\ControllerResolverInterface;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\HttpKernel\Event\FilterControllerEvent;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\Event\PostResponseEvent;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;

class HttpKernel implements HttpKernelInterface, TerminableInterface
{
    protected $dispatcher;
    protected $resolver;

    public function __construct(EventDispatcherInterface $dispatcher, ControllerResolverInterface $resolver)
    {
        $this->dispatcher = $dispatcher;
        $this->resolver = $resolver;
    }

    public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
    {
        try {
            return $this->handleRaw($request, $type);
        } catch (\Exception $e) {
            if (false === $catch) {
                throw $e;
            }

            return $this->handleException($e, $request, $type);
        }
    }

    public function terminate(Request $request, Response $response)
    {
        $this->dispatcher->dispatch(KernelEvents::TERMINATE, new PostResponseEvent($this, $request, $response));
    }

    private function handleRaw(Request $request, $type = self::MASTER_REQUEST)
    {
        // request
        $event = new GetResponseEvent($this, $request, $type);
        $this->dispatcher->dispatch(KernelEvents::REQUEST, $event);

        if ($event->hasResponse()) {
            return $this->filterResponse($event->getResponse(), $request, $type);
        }

        // load controller
        if (false === $controller = $this->resolver->getController($request)) {
            throw new NotFoundHttpException(sprintf('Unable to find the controller for path "%s". Maybe you forgot to add the matching route in your routing configuration?', $request->getPathInfo()));
        }

        $event = new FilterControllerEvent($this, $controller, $request, $type);
        $this->dispatcher->dispatch(KernelEvents::CONTROLLER, $event);
        $controller = $event->getController();

        // controller arguments
        $arguments = $this->resolver->getArguments($request, $controller);

        // call controller
        $response = call_user_func_array($controller, $arguments);

        // view
        if (!$response instanceof Response) {
            $event = new GetResponseForControllerResultEvent($this, $request, $type, $response);
            $this->dispatcher->dispatch(KernelEvents::VIEW, $event);

            if ($event->hasResponse()) {
                $response = $event->getResponse();
            }

            if (!$response instanceof Response) {
                $msg = sprintf('The controller must return a response (%s given).', $this->varToString($response));

                // the user may have forgotten to return something
                if (null === $response) {
                    $msg .= ' Did you forget to add a return statement somewhere in your controller?';
                }
                throw new \LogicException($msg);
            }
        }

        return $this->filterResponse($response, $request, $type);
    }

    private function filterResponse(Response $response, Request $request, $type)
    {
        $event = new FilterResponseEvent($this, $request, $type, $response);

        $this->dispatcher->dispatch(KernelEvents::RESPONSE, $event);

        return $event->getResponse();
    }

    private function handleException(\Exception $e, $request, $type)
    {
        $event = new GetResponseForExceptionEvent($this, $request, $type, $e);
        $this->dispatcher->dispatch(KernelEvents::EXCEPTION, $event);

        // a listener might have replaced the exception
        $e = $event->getException();

        if (!$event->hasResponse()) {
            throw $e;
        }

        $response = $event->getResponse();

        // ensure that we actually have an error response
        if (!$response->isClientError() && !$response->isServerError() && !$response->isRedirect()) {
            if ($e instanceof HttpExceptionInterface) {
                // keep the HTTP status code and headers
                $response->setStatusCode($e->getStatusCode());
                $response->headers->add($e->getHeaders());
            } else {
                $response->setStatusCode(500);
            }
        }

        try {
            return $this->filterResponse($response, $request, $type);
        } catch (\Exception $e) {
            return $response;
        }
    }

    private function varToString($var)
    {
        if (is_object($var)) {
            return sprintf('Object(%s)', get_class($var));
        }

        if (is_array($var)) {
            $a = array();
            foreach ($var as $k => $v) {
                $a[] = sprintf('%s => %s', $k, $this->varToString($v));
            }

            return sprintf("Array(%s)", implode(', ', $a));
        }

        if (is_resource($var)) {
            return sprintf('Resource(%s)', get_resource_type($var));
        }

        if (null === $var) {
            return 'null';
        }

        if (false === $var) {
            return 'false';
        }

        if (true === $var) {
            return 'true';
        }

        return (string) $var;
    }
}