Merge pull request #622 from MyIgel/controllers

AuthController (login, logout), use templating, replaced gettext, input validation

25 files changed, 720 insertions, 132 deletions

diff --git a/src/Controllers/AuthController.php b/src/Controllers/AuthController.php
index cdaee167..55dd56b0 100644
--- a/src/Controllers/AuthController.php
+++ b/src/Controllers/AuthController.php
@@ -2,8 +2,14 @@
 
 namespace Engelsystem\Controllers;
 
+use Carbon\Carbon;
+use Engelsystem\Helpers\Authenticator;
+use Engelsystem\Http\Request;
 use Engelsystem\Http\Response;
 use Engelsystem\Http\UrlGeneratorInterface;
+use Engelsystem\Models\User\User;
+use Illuminate\Support\Arr;
+use Illuminate\Support\Collection;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
 class AuthController extends BaseController
@@ -17,17 +23,91 @@ class AuthController extends BaseController
     /** @var UrlGeneratorInterface */
     protected $url;
 
-    public function __construct(Response $response, SessionInterface $session, UrlGeneratorInterface $url)
-    {
+    /** @var Authenticator */
+    protected $auth;
+
+    /** @var array */
+    protected $permissions = [
+        'login'     => 'login',
+        'postLogin' => 'login',
+    ];
+
+    /**
+     * @param Response              $response
+     * @param SessionInterface      $session
+     * @param UrlGeneratorInterface $url
+     * @param Authenticator         $auth
+     */
+    public function __construct(
+        Response $response,
+        SessionInterface $session,
+        UrlGeneratorInterface $url,
+        Authenticator $auth
+    ) {
         $this->response = $response;
         $this->session = $session;
         $this->url = $url;
+        $this->auth = $auth;
+    }
+
+    /**
+     * @return Response
+     */
+    public function login(): Response
+    {
+        return $this->showLogin();
+    }
+
+    /**
+     * @param bool $showRecovery
+     * @return Response
+     */
+    protected function showLogin($showRecovery = false): Response
+    {
+        $errors = Collection::make(Arr::flatten($this->session->get('errors', [])));
+        $this->session->remove('errors');
+
+        return $this->response->withView(
+            'pages/login',
+            ['errors' => $errors, 'show_password_recovery' => $showRecovery]
+        );
+    }
+
+    /**
+     * Posted login form
+     *
+     * @param Request $request
+     * @return Response
+     */
+    public function postLogin(Request $request): Response
+    {
+        $data = $this->validate($request, [
+            'login'    => 'required',
+            'password' => 'required',
+        ]);
+
+        $user = $this->auth->authenticate($data['login'], $data['password']);
+
+        if (!$user instanceof User) {
+            $this->session->set('errors', $this->session->get('errors', []) + ['auth.not-found']);
+
+            return $this->showLogin(true);
+        }
+
+        $this->session->invalidate();
+        $this->session->set('user_id', $user->id);
+        $this->session->set('locale', $user->settings->language);
+
+        $user->last_login_at = new Carbon();
+        $user->save(['touch' => false]);
+
+        return $this->response->redirectTo('news');
     }
 
     /**
      * @return Response
      */
-    public function logout()
+    public function logout(): Response
     {
         $this->session->invalidate();
 
diff --git a/src/Controllers/BaseController.php b/src/Controllers/BaseController.php
index cbc00931..655ed759 100644
--- a/src/Controllers/BaseController.php
+++ b/src/Controllers/BaseController.php
@@ -2,8 +2,12 @@
 
 namespace Engelsystem\Controllers;
 
+use Engelsystem\Http\Validation\ValidatesRequest;
+
 abstract class BaseController
 {
+    use ValidatesRequest;
+
     /** @var string[]|string[][] A list of Permissions required to access the controller or certain pages */
     protected $permissions = [];
 
diff --git a/src/Controllers/Metrics/MetricsEngine.php b/src/Controllers/Metrics/MetricsEngine.php
index 1e0f6957..21ae8fd0 100644
--- a/src/Controllers/Metrics/MetricsEngine.php
+++ b/src/Controllers/Metrics/MetricsEngine.php
@@ -9,13 +9,13 @@ class MetricsEngine implements EngineInterface
     /**
      * Render metrics
      *
-     * @example $data = ['foo' => [['labels' => ['foo'=>'bar'], 'value'=>42]], 'bar'=>123]
-     *
      * @param string  $path
      * @param mixed[] $data
      * @return string
+     *
+     * @example $data = ['foo' => [['labels' => ['foo'=>'bar'], 'value'=>42]], 'bar'=>123]
      */
-    public function get($path, $data = []): string
+    public function get(string $path, array $data = []): string
     {
         $return = [];
         foreach ($data as $name => $list) {
@@ -52,7 +52,7 @@ class MetricsEngine implements EngineInterface
      * @param string $path
      * @return bool
      */
-    public function canRender($path): bool
+    public function canRender(string $path): bool
     {
         return $path == '/metrics';
     }
@@ -60,8 +60,8 @@ class MetricsEngine implements EngineInterface
     /**
      * @param string      $name
      * @param array|mixed $row
-     * @see https://prometheus.io/docs/instrumenting/exposition_formats/
      * @return string
+     * @see https://prometheus.io/docs/instrumenting/exposition_formats/
      */
     protected function formatData($name, $row): string
     {
@@ -135,4 +135,12 @@ class MetricsEngine implements EngineInterface
             $value
         );
     }
+
+    /**
+     * Does nothing as shared data will onyly result in unexpected behaviour
+     *
+     * @param string|mixed[] $key
+     * @param mixed          $value
+     */
+    public function share($key, $value = null) { }
 }
diff --git a/src/Helpers/Authenticator.php b/src/Helpers/Authenticator.php
index 61d07980..db33339b 100644
--- a/src/Helpers/Authenticator.php
+++ b/src/Helpers/Authenticator.php
@@ -25,6 +25,9 @@ class Authenticator
     /** @var string[] */
     protected $permissions;
 
+    /** @var int */
+    protected $passwordAlgorithm = PASSWORD_DEFAULT;
+
     /**
      * @param ServerRequestInterface $request
      * @param Session                $session
@@ -48,7 +51,7 @@ class Authenticator
             return $this->user;
         }
 
-        $userId = $this->session->get('uid');
+        $userId = $this->session->get('user_id');
         if (!$userId) {
             return null;
         }
@@ -104,17 +107,15 @@ class Authenticator
         $abilities = (array)$abilities;
 
         if (empty($this->permissions)) {
-            $userId = $this->user ? $this->user->id : $this->session->get('uid');
+            $user = $this->user();
 
-            if ($userId) {
-                if ($user = $this->user()) {
-                    $this->permissions = $this->getPermissionsByUser($user);
+            if ($user) {
+                $this->permissions = $this->getPermissionsByUser($user);
 
-                    $user->last_login_at = new Carbon();
-                    $user->save();
-                } else {
-                    $this->session->remove('uid');
-                }
+                $user->last_login_at = new Carbon();
+                $user->save();
+            } elseif ($this->session->get('user_id')) {
+                $this->session->remove('user_id');
             }
 
             if (empty($this->permissions)) {
@@ -132,6 +133,78 @@ class Authenticator
     }
 
     /**
+     * @param string $login
+     * @param string $password
+     * @return User|null
+     */
+    public function authenticate(string $login, string $password)
+    {
+        /** @var User $user */
+        $user = $this->userRepository->whereName($login)->first();
+        if (!$user) {
+            $user = $this->userRepository->whereEmail($login)->first();
+        }
+
+        if (!$user) {
+            return null;
+        }
+
+        if (!$this->verifyPassword($user, $password)) {
+            return null;
+        }
+
+        return $user;
+    }
+
+    /**
+     * @param User   $user
+     * @param string $password
+     * @return bool
+     */
+    public function verifyPassword(User $user, string $password)
+    {
+        $algorithm = $this->passwordAlgorithm;
+
+        if (!password_verify($password, $user->password)) {
+            return false;
+        }
+
+        if (password_needs_rehash($user->password, $algorithm)) {
+            $this->setPassword($user, $password);
+        }
+
+        return true;
+    }
+
+    /**
+     * @param UserRepository $user
+     * @param string         $password
+     */
+    public function setPassword(User $user, string $password)
+    {
+        $algorithm = $this->passwordAlgorithm;
+
+        $user->password = password_hash($password, $algorithm);
+        $user->save();
+    }
+
+    /**
+     * @return int
+     */
+    public function getPasswordAlgorithm()
+    {
+        return $this->passwordAlgorithm;
+    }
+
+    /**
+     * @param int $passwordAlgorithm
+     */
+    public function setPasswordAlgorithm(int $passwordAlgorithm)
+    {
+        $this->passwordAlgorithm = $passwordAlgorithm;
+    }
+
+    /**
      * @param User $user
      * @return array
      * @codeCoverageIgnore
diff --git a/src/Helpers/AuthenticatorServiceProvider.php b/src/Helpers/AuthenticatorServiceProvider.php
index 715a592f..f06e635d 100644
--- a/src/Helpers/AuthenticatorServiceProvider.php
+++ b/src/Helpers/AuthenticatorServiceProvider.php
@@ -2,14 +2,18 @@
 
 namespace Engelsystem\Helpers;
 
+use Engelsystem\Config\Config;
 use Engelsystem\Container\ServiceProvider;
 
 class AuthenticatorServiceProvider extends ServiceProvider
 {
     public function register()
     {
+        /** @var Config $config */
+        $config = $this->app->get('config');
         /** @var Authenticator $authenticator */
         $authenticator = $this->app->make(Authenticator::class);
+        $authenticator->setPasswordAlgorithm($config->get('password_algorithm'));
 
         $this->app->instance(Authenticator::class, $authenticator);
         $this->app->instance('authenticator', $authenticator);
diff --git a/src/Helpers/Translation/GettextTranslator.php b/src/Helpers/Translation/GettextTranslator.php
new file mode 100644
index 00000000..7f2299e2
--- /dev/null
+++ b/src/Helpers/Translation/GettextTranslator.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Engelsystem\Helpers\Translation;
+
+use Gettext\Translator;
+
+class GettextTranslator extends Translator
+{
+    /**
+     * @param string $domain
+     * @param string $context
+     * @param string $original
+     * @return string
+     * @throws TranslationNotFound
+     */
+    public function dpgettext($domain, $context, $original)
+    {
+        $this->assertHasTranslation($domain, $context, $original);
+
+        return parent::dpgettext($domain, $context, $original);
+    }
+
+    /**
+     * @param string $domain
+     * @param string $context
+     * @param string $original
+     * @param string $plural
+     * @param string $value
+     * @return string
+     * @throws TranslationNotFound
+     */
+    public function dnpgettext($domain, $context, $original, $plural, $value)
+    {
+        $this->assertHasTranslation($domain, $context, $original);
+
+        return parent::dnpgettext($domain, $context, $original, $plural, $value);
+    }
+
+    /**
+     * @param string $domain
+     * @param string $context
+     * @param string $original
+     * @throws TranslationNotFound
+     */
+    protected function assertHasTranslation($domain, $context, $original)
+    {
+        if ($this->getTranslation($domain, $context, $original)) {
+            return;
+        }
+
+        throw new TranslationNotFound(implode('/', [$domain, $context, $original]));
+    }
+}
diff --git a/src/Helpers/Translation/TranslationNotFound.php b/src/Helpers/Translation/TranslationNotFound.php
new file mode 100644
index 00000000..1552838b
--- /dev/null
+++ b/src/Helpers/Translation/TranslationNotFound.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Engelsystem\Helpers\Translation;
+
+use Exception;
+
+class TranslationNotFound extends Exception
+{
+}
diff --git a/src/Helpers/Translation/TranslationServiceProvider.php b/src/Helpers/Translation/TranslationServiceProvider.php
new file mode 100644
index 00000000..09337dad
--- /dev/null
+++ b/src/Helpers/Translation/TranslationServiceProvider.php
@@ -0,0 +1,86 @@
+<?php
+
+namespace Engelsystem\Helpers\Translation;
+
+use Engelsystem\Config\Config;
+use Engelsystem\Container\ServiceProvider;
+use Gettext\Translations;
+use Symfony\Component\HttpFoundation\Session\Session;
+
+class TranslationServiceProvider extends ServiceProvider
+{
+    /** @var GettextTranslator */
+    protected $translators = [];
+
+    public function register(): void
+    {
+        /** @var Config $config */
+        $config = $this->app->get('config');
+        /** @var Session $session */
+        $session = $this->app->get('session');
+
+        $locales = $config->get('locales');
+        $locale = $config->get('default_locale');
+        $fallbackLocale = $config->get('fallback_locale', 'en_US');
+
+        $sessionLocale = $session->get('locale', $locale);
+        if (isset($locales[$sessionLocale])) {
+            $locale = $sessionLocale;
+        }
+
+        $session->set('locale', $locale);
+
+        $translator = $this->app->make(
+            Translator::class,
+            [
+                'locale'                => $locale,
+                'locales'               => $locales,
+                'fallbackLocale'        => $fallbackLocale,
+                'getTranslatorCallback' => [$this, 'getTranslator'],
+                'localeChangeCallback'  => [$this, 'setLocale'],
+            ]
+        );
+        $this->app->instance(Translator::class, $translator);
+        $this->app->instance('translator', $translator);
+    }
+
+    /**
+     * @param string $locale
+     * @codeCoverageIgnore
+     */
+    public function setLocale(string $locale): void
+    {
+        $locale .= '.UTF-8';
+        // Set the users locale
+        putenv('LC_ALL=' . $locale);
+        setlocale(LC_ALL, $locale);
+
+        // Reset numeric formatting to allow output of floats
+        putenv('LC_NUMERIC=C');
+        setlocale(LC_NUMERIC, 'C');
+    }
+
+    /**
+     * @param string $locale
+     * @return GettextTranslator
+     */
+    public function getTranslator(string $locale): GettextTranslator
+    {
+        if (!isset($this->translators[$locale])) {
+            $file = $this->app->get('path.lang') . '/' . $locale . '/default.mo';
+
+            /** @var GettextTranslator $translator */
+            $translator = $this->app->make(GettextTranslator::class);
+
+            /** @var Translations $translations */
+            $translations = $this->app->make(Translations::class);
+            $translations->addFromMoFile($file);
+
+            $translator->loadTranslations($translations);
+
+            $this->translators[$locale] = $translator;
+        }
+
+        return $this->translators[$locale];
+    }
+}
diff --git a/src/Helpers/Translator.php b/src/Helpers/Translation/Translator.php
index 94fbd795..8b11ecb4 100644
--- a/src/Helpers/Translator.php
+++ b/src/Helpers/Translation/Translator.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Engelsystem\Helpers;
+namespace Engelsystem\Helpers\Translation;
 
 class Translator
 {
@@ -10,6 +10,12 @@ class Translator
     /** @var string */
     protected $locale;
 
+    /** @var string */
+    protected $fallbackLocale;
+
+    /** @var callable */
+    protected $getTranslatorCallback;
+
     /** @var callable */
     protected $localeChangeCallback;
 
@@ -17,15 +23,24 @@ class Translator
      * Translator constructor.
      *
      * @param string   $locale
+     * @param string   $fallbackLocale
+     * @param callable $getTranslatorCallback
      * @param string[] $locales
      * @param callable $localeChangeCallback
      */
-    public function __construct(string $locale, array $locales = [], callable $localeChangeCallback = null)
-    {
+    public function __construct(
+        string $locale,
+        string $fallbackLocale,
+        callable $getTranslatorCallback,
+        array $locales = [],
+        callable $localeChangeCallback = null
+    ) {
         $this->localeChangeCallback = $localeChangeCallback;
+        $this->getTranslatorCallback = $getTranslatorCallback;
 
         $this->setLocale($locale);
-        $this->setLocales($locales);
+        $this->fallbackLocale = $fallbackLocale;
+        $this->locales = $locales;
     }
 
     /**
@@ -37,9 +52,7 @@ class Translator
      */
     public function translate(string $key, array $replace = []): string
     {
-        $translated = $this->translateGettext($key);
-
-        return $this->replaceText($translated, $replace);
+        return $this->translateText('gettext', [$key], $replace);
     }
 
     /**
@@ -53,7 +66,29 @@ class Translator
      */
     public function translatePlural(string $key, string $pluralKey, int $number, array $replace = []): string
     {
-        $translated = $this->translateGettextPlural($key, $pluralKey, $number);
+        return $this->translateText('ngettext', [$key, $pluralKey, $number], $replace);
+    }
+
+    /**
+     * @param string $type
+     * @param array  $parameters
+     * @param array  $replace
+     * @return mixed|string
+     */
+    protected function translateText(string $type, array $parameters, array $replace = [])
+    {
+        $translated = $parameters[0];
+
+        foreach ([$this->locale, $this->fallbackLocale] as $lang) {
+            /** @var GettextTranslator $translator */
+            $translator = call_user_func($this->getTranslatorCallback, $lang);
+
+            try {
+                $translated = call_user_func_array([$translator, $type], $parameters);
+                break;
+            } catch (TranslationNotFound $e) {
+            }
+        }
 
         return $this->replaceText($translated, $replace);
     }
@@ -75,32 +110,6 @@ class Translator
     }
 
     /**
-     * Translate the key via gettext
-     *
-     * @param string $key
-     * @return string
-     * @codeCoverageIgnore
-     */
-    protected function translateGettext(string $key): string
-    {
-        return gettext($key);
-    }
-
-    /**
-     * Translate the key via gettext
-     *
-     * @param string $key
-     * @param string $keyPlural
-     * @param int    $number
-     * @return string
-     * @codeCoverageIgnore
-     */
-    protected function translateGettextPlural(string $key, string $keyPlural, int $number): string
-    {
-        return ngettext($key, $keyPlural, $number);
-    }
-
-    /**
      * @return string
      */
     public function getLocale(): string
diff --git a/src/Helpers/TranslationServiceProvider.php b/src/Helpers/TranslationServiceProvider.php
deleted file mode 100644
index 4565dfcd..00000000
--- a/src/Helpers/TranslationServiceProvider.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php
-
-namespace Engelsystem\Helpers;
-
-use Engelsystem\Config\Config;
-use Engelsystem\Container\ServiceProvider;
-use Symfony\Component\HttpFoundation\Session\Session;
-
-class TranslationServiceProvider extends ServiceProvider
-{
-    public function register()
-    {
-        /** @var Config $config */
-        $config = $this->app->get('config');
-        /** @var Session $session */
-        $session = $this->app->get('session');
-
-        $locales = $config->get('locales');
-        $locale = $config->get('default_locale');
-
-        $sessionLocale = $session->get('locale', $locale);
-        if (isset($locales[$sessionLocale])) {
-            $locale = $sessionLocale;
-        }
-
-        $this->initGettext();
-        $session->set('locale', $locale);
-
-        $translator = $this->app->make(
-            Translator::class,
-            ['locale' => $locale, 'locales' => $locales, 'localeChangeCallback' => [$this, 'setLocale']]
-        );
-        $this->app->instance(Translator::class, $translator);
-        $this->app->instance('translator', $translator);
-    }
-
-    /**
-     * @param string $textDomain
-     * @param string $encoding
-     * @codeCoverageIgnore
-     */
-    protected function initGettext($textDomain = 'default', $encoding = 'UTF-8')
-    {
-        bindtextdomain($textDomain, $this->app->get('path.lang'));
-        bind_textdomain_codeset($textDomain, $encoding);
-        textdomain($textDomain);
-    }
-
-    /**
-     * @param string $locale
-     * @codeCoverageIgnore
-     */
-    public function setLocale($locale)
-    {
-        // Set the users locale
-        putenv('LC_ALL=' . $locale);
-        setlocale(LC_ALL, $locale);
-
-        // Reset numeric formatting to allow output of floats
-        putenv('LC_NUMERIC=C');
-        setlocale(LC_NUMERIC, 'C');
-    }
-}
diff --git a/src/Http/Exceptions/ValidationException.php b/src/Http/Exceptions/ValidationException.php
new file mode 100644
index 00000000..e48fb0c3
--- /dev/null
+++ b/src/Http/Exceptions/ValidationException.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Engelsystem\Http\Exceptions;
+
+use Engelsystem\Http\Validation\Validator;
+use RuntimeException;
+use Throwable;
+
+class ValidationException extends RuntimeException
+{
+    /** @var Validator */
+    protected $validator;
+
+    /**
+     * @param Validator      $validator
+     * @param string         $message
+     * @param int            $code
+     * @param Throwable|null $previous
+     */
+    public function __construct(
+        Validator $validator,
+        string $message = '',
+        int $code = 0,
+        Throwable $previous = null
+    ) {
+        $this->validator = $validator;
+        parent::__construct($message, $code, $previous);
+    }
+
+    /**
+     * @return Validator
+     */
+    public function getValidator(): Validator
+    {
+        return $this->validator;
+    }
+}
diff --git a/src/Http/Validation/Rules/In.php b/src/Http/Validation/Rules/In.php
new file mode 100644
index 00000000..d585cc3d
--- /dev/null
+++ b/src/Http/Validation/Rules/In.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Engelsystem\Http\Validation\Rules;
+
+use Respect\Validation\Rules\In as RespectIn;
+
+class In extends RespectIn
+{
+    /**
+     * @param mixed $haystack
+     * @param bool  $compareIdentical
+     */
+    public function __construct($haystack, $compareIdentical = false)
+    {
+        if (!is_array($haystack)) {
+            $haystack = explode(',', $haystack);
+        }
+
+        parent::__construct($haystack, $compareIdentical);
+    }
+}
diff --git a/src/Http/Validation/Rules/NotIn.php b/src/Http/Validation/Rules/NotIn.php
new file mode 100644
index 00000000..7f223c42
--- /dev/null
+++ b/src/Http/Validation/Rules/NotIn.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Engelsystem\Http\Validation\Rules;
+
+class NotIn extends In
+{
+    /**
+     * @param mixed $input
+     * @return bool
+     */
+    public function validate($input)
+    {
+        return !parent::validate($input);
+    }
+}
diff --git a/src/Http/Validation/ValidatesRequest.php b/src/Http/Validation/ValidatesRequest.php
new file mode 100644
index 00000000..33ff76af
--- /dev/null
+++ b/src/Http/Validation/ValidatesRequest.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Engelsystem\Http\Validation;
+
+use Engelsystem\Http\Exceptions\ValidationException;
+use Engelsystem\Http\Request;
+
+trait ValidatesRequest
+{
+    /** @var Validator */
+    protected $validator;
+
+    /**
+     * @param Request $request
+     * @param array   $rules
+     * @return array
+     */
+    protected function validate(Request $request, array $rules)
+    {
+        if (!$this->validator->validate(
+            (array)$request->getParsedBody(),
+            $rules
+        )) {
+            throw new ValidationException($this->validator);
+        }
+
+        return $this->validator->getData();
+    }
+
+    /**
+     * @param Validator $validator
+     */
+    public function setValidator(Validator $validator)
+    {
+        $this->validator = $validator;
+    }
+}
diff --git a/src/Http/Validation/ValidationServiceProvider.php b/src/Http/Validation/ValidationServiceProvider.php
new file mode 100644
index 00000000..14530ae6
--- /dev/null
+++ b/src/Http/Validation/ValidationServiceProvider.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Engelsystem\Http\Validation;
+
+use Engelsystem\Application;
+use Engelsystem\Container\ServiceProvider;
+use Engelsystem\Controllers\BaseController;
+
+class ValidationServiceProvider extends ServiceProvider
+{
+    public function register()
+    {
+        $validator = $this->app->make(Validator::class);
+        $this->app->instance(Validator::class, $validator);
+        $this->app->instance('validator', $validator);
+
+        $this->app->afterResolving(function ($object, Application $app) {
+            if (!$object instanceof BaseController) {
+                return;
+            }
+
+            $object->setValidator($app->get(Validator::class));
+        });
+    }
+}
diff --git a/src/Http/Validation/Validator.php b/src/Http/Validation/Validator.php
new file mode 100644
index 00000000..976f5682
--- /dev/null
+++ b/src/Http/Validation/Validator.php
@@ -0,0 +1,122 @@
+<?php
+
+namespace Engelsystem\Http\Validation;
+
+use Illuminate\Support\Str;
+use InvalidArgumentException;
+use Respect\Validation\Exceptions\ComponentException;
+use Respect\Validation\Validator as RespectValidator;
+
+class Validator
+{
+    /** @var string[] */
+    protected $errors = [];
+
+    /** @var array */
+    protected $data = [];
+
+    /** @var array */
+    protected $mapping = [
+        'accepted' => 'TrueVal',
+        'int'      => 'IntVal',
+        'required' => 'NotEmpty',
+    ];
+
+    /** @var array */
+    protected $nestedRules = ['optional', 'not'];
+
+    /**
+     * @param array $data
+     * @param array $rules
+     * @return bool
+     */
+    public function validate($data, $rules)
+    {
+        $this->errors = [];
+        $this->data = [];
+
+        foreach ($rules as $key => $values) {
+            $v = new RespectValidator();
+            $v->with('\\Engelsystem\\Http\\Validation\\Rules', true);
+
+            $value = isset($data[$key]) ? $data[$key] : null;
+            $values = explode('|', $values);
+
+            $packing = [];
+            foreach ($this->nestedRules as $rule) {
+                if (in_array($rule, $values)) {
+                    $packing[] = $rule;
+                }
+            }
+
+            $values = array_diff($values, $this->nestedRules);
+            foreach ($values as $parameters) {
+                $parameters = explode(':', $parameters);
+                $rule = array_shift($parameters);
+                $rule = Str::camel($rule);
+                $rule = $this->map($rule);
+
+                // To allow rules nesting
+                $w = $v;
+                try {
+                    foreach (array_reverse(array_merge($packing, [$rule])) as $rule) {
+                        if (!in_array($rule, $this->nestedRules)) {
+                            call_user_func_array([$w, $rule], $parameters);
+                            continue;
+                        }
+
+                        $w = call_user_func_array([new RespectValidator(), $rule], [$w]);
+                    }
+                } catch (ComponentException $e) {
+                    throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+                }
+
+                if ($w->validate($value)) {
+                    $this->data[$key] = $value;
+                } else {
+                    $this->errors[$key][] = implode('.', ['validation', $key, $this->mapBack($rule)]);
+                }
+
+                $v->removeRules();
+            }
+        }
+
+        return empty($this->errors);
+    }
+
+    /**
+     * @param string $rule
+     * @return string
+     */
+    protected function map($rule)
+    {
+        return $this->mapping[$rule] ?? $rule;
+    }
+
+    /**
+     * @param string $rule
+     * @return string
+     */
+    protected function mapBack($rule)
+    {
+        $mapping = array_flip($this->mapping);
+
+        return $mapping[$rule] ?? $rule;
+    }
+
+    /**
+     * @return array
+     */
+    public function getData(): array
+    {
+        return $this->data;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getErrors(): array
+    {
+        return $this->errors;
+    }
+}
diff --git a/src/Middleware/ErrorHandler.php b/src/Middleware/ErrorHandler.php
index 29b1fac1..544f35d5 100644
--- a/src/Middleware/ErrorHandler.php
+++ b/src/Middleware/ErrorHandler.php
@@ -3,7 +3,10 @@
 namespace Engelsystem\Middleware;
 
 use Engelsystem\Http\Exceptions\HttpException;
+use Engelsystem\Http\Exceptions\ValidationException;
+use Engelsystem\Http\Request;
 use Engelsystem\Http\Response;
+use Illuminate\Support\Arr;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
@@ -19,6 +22,16 @@ class ErrorHandler implements MiddlewareInterface
     protected $viewPrefix = 'errors/';
 
     /**
+     * A list of inputs that are not saved from form input
+     *
+     * @var array
+     */
+    protected $formIgnore = [
+        'password',
+        'password_confirmation',
+    ];
+
+    /**
      * @param TwigLoader $loader
      */
     public function __construct(TwigLoader $loader)
@@ -43,6 +56,21 @@ class ErrorHandler implements MiddlewareInterface
             $response = $handler->handle($request);
         } catch (HttpException $e) {
             $response = $this->createResponse($e->getMessage(), $e->getStatusCode(), $e->getHeaders());
+        } catch (ValidationException $e) {
+            $response = $this->createResponse('', 302, ['Location' => $this->getPreviousUrl($request)]);
+
+            if ($request instanceof Request) {
+                $session = $request->getSession();
+                $session->set(
+                    'errors',
+                    array_merge_recursive(
+                        $session->get('errors', []),
+                        ['validation' => $e->getValidator()->getErrors()]
+                    )
+                );
+
+                $session->set('form-data', Arr::except($request->request->all(), $this->formIgnore));
+            }
         }
 
         $statusCode = $response->getStatusCode();
@@ -106,4 +134,17 @@ class ErrorHandler implements MiddlewareInterface
     {
         return response($content, $status, $headers);
     }
+
+    /**
+     * @param ServerRequestInterface $request
+     * @return string
+     */
+    protected function getPreviousUrl(ServerRequestInterface $request)
+    {
+        if ($header = $request->getHeader('referer')) {
+            return array_pop($header);
+        }
+
+        return '/';
+    }
 }
diff --git a/src/Middleware/LegacyMiddleware.php b/src/Middleware/LegacyMiddleware.php
index af2c6a70..27a15faa 100644
--- a/src/Middleware/LegacyMiddleware.php
+++ b/src/Middleware/LegacyMiddleware.php
@@ -3,7 +3,7 @@
 namespace Engelsystem\Middleware;
 
 use Engelsystem\Helpers\Authenticator;
-use Engelsystem\Helpers\Translator;
+use Engelsystem\Helpers\Translation\Translator;
 use Engelsystem\Http\Request;
 use Engelsystem\Http\Response;
 use Psr\Container\ContainerInterface;
@@ -19,7 +19,6 @@ class LegacyMiddleware implements MiddlewareInterface
         'angeltypes',
         'atom',
         'ical',
-        'login',
         'public_dashboard',
         'rooms',
         'shift_entries',
@@ -175,10 +174,6 @@ class LegacyMiddleware implements MiddlewareInterface
                 $title = settings_title();
                 $content = user_settings();
                 return [$title, $content];
-            case 'login':
-                $title = login_title();
-                $content = guest_login();
-                return [$title, $content];
             case 'register':
                 $title = register_title();
                 $content = guest_register();
diff --git a/src/Middleware/SetLocale.php b/src/Middleware/SetLocale.php
index 86fa0b7f..568adbe6 100644
--- a/src/Middleware/SetLocale.php
+++ b/src/Middleware/SetLocale.php
@@ -2,7 +2,7 @@
 
 namespace Engelsystem\Middleware;
 
-use Engelsystem\Helpers\Translator;
+use Engelsystem\Helpers\Translation\Translator;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
diff --git a/src/Renderer/Engine.php b/src/Renderer/Engine.php
new file mode 100644
index 00000000..60f1d686
--- /dev/null
+++ b/src/Renderer/Engine.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Engelsystem\Renderer;
+
+abstract class Engine implements EngineInterface
+{
+    /** @var array */
+    protected $sharedData = [];
+
+    /**
+     * @param mixed[]|string $key
+     * @param null           $value
+     */
+    public function share($key, $value = null)
+    {
+        if (!is_array($key)) {
+            $key = [$key => $value];
+        }
+
+        $this->sharedData = array_replace_recursive($this->sharedData, $key);
+    }
+}
diff --git a/src/Renderer/EngineInterface.php b/src/Renderer/EngineInterface.php
index ca468db5..3bce9c02 100644
--- a/src/Renderer/EngineInterface.php
+++ b/src/Renderer/EngineInterface.php
@@ -11,11 +11,17 @@ interface EngineInterface
      * @param mixed[] $data
      * @return string
      */
-    public function get($path, $data = []);
+    public function get(string $path, array $data = []): string;
 
     /**
      * @param string $path
      * @return bool
      */
-    public function canRender($path);
+    public function canRender(string $path): bool;
+
+    /**
+     * @param string|mixed[] $key
+     * @param mixed          $value
+     */
+    public function share($key, $value = null);
 }
diff --git a/src/Renderer/HtmlEngine.php b/src/Renderer/HtmlEngine.php
index 1feafcda..0ccffa65 100644
--- a/src/Renderer/HtmlEngine.php
+++ b/src/Renderer/HtmlEngine.php
@@ -2,7 +2,7 @@
 
 namespace Engelsystem\Renderer;
 
-class HtmlEngine implements EngineInterface
+class HtmlEngine extends Engine
 {
     /**
      * Render a template
@@ -11,9 +11,11 @@ class HtmlEngine implements EngineInterface
      * @param mixed[] $data
      * @return string
      */
-    public function get($path, $data = [])
+    public function get(string $path, array $data = []): string
     {
+        $data = array_replace_recursive($this->sharedData, $data);
         $template = file_get_contents($path);
+
         if (is_array($data)) {
             foreach ($data as $name => $content) {
                 $template = str_replace('%' . $name . '%', $content, $template);
@@ -27,7 +29,7 @@ class HtmlEngine implements EngineInterface
      * @param string $path
      * @return bool
      */
-    public function canRender($path)
+    public function canRender(string $path): bool
     {
         return mb_strpos($path, '.htm') !== false && file_exists($path);
     }
diff --git a/src/Renderer/Twig/Extensions/Translation.php b/src/Renderer/Twig/Extensions/Translation.php
index 41619c19..3e6f30b4 100644
--- a/src/Renderer/Twig/Extensions/Translation.php
+++ b/src/Renderer/Twig/Extensions/Translation.php
@@ -2,7 +2,7 @@
 
 namespace Engelsystem\Renderer\Twig\Extensions;
 
-use Engelsystem\Helpers\Translator;
+use Engelsystem\Helpers\Translation\Translator;
 use Twig_Extension as TwigExtension;
 use Twig_Extensions_TokenParser_Trans as TranslationTokenParser;
 use Twig_Filter as TwigFilter;
diff --git a/src/Renderer/TwigEngine.php b/src/Renderer/TwigEngine.php
index 55a2e299..aa51a177 100644
--- a/src/Renderer/TwigEngine.php
+++ b/src/Renderer/TwigEngine.php
@@ -7,7 +7,7 @@ use Twig_Error_Loader as LoaderError;
 use Twig_Error_Runtime as RuntimeError;
 use Twig_Error_Syntax as SyntaxError;
 
-class TwigEngine implements EngineInterface
+class TwigEngine extends Engine
 {
     /** @var Twig */
     protected $twig;
@@ -25,8 +25,10 @@ class TwigEngine implements EngineInterface
      * @return string
      * @throws LoaderError|RuntimeError|SyntaxError
      */
-    public function get($path, $data = [])
+    public function get(string $path, array $data = []): string
     {
+        $data = array_replace_recursive($this->sharedData, $data);
+
         return $this->twig->render($path, $data);
     }
 
@@ -34,7 +36,7 @@ class TwigEngine implements EngineInterface
      * @param string $path
      * @return bool
      */
-    public function canRender($path)
+    public function canRender(string $path): bool
     {
         return $this->twig->getLoader()->exists($path);
     }
diff --git a/src/helpers.php b/src/helpers.php
index 111141e4..051b78a3 100644
--- a/src/helpers.php
+++ b/src/helpers.php
@@ -4,7 +4,7 @@
 use Engelsystem\Application;
 use Engelsystem\Config\Config;
 use Engelsystem\Helpers\Authenticator;
-use Engelsystem\Helpers\Translator;
+use Engelsystem\Helpers\Translation\Translator;
 use Engelsystem\Http\Request;
 use Engelsystem\Http\Response;
 use Engelsystem\Http\UrlGeneratorInterface;