Add database management back to front-end and begin some refactoring

Here we go again boys...

app/Http/Middleware/Server/DatabaseBelongsToServer.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Pterodactyl\Http\Middleware\Server;
+
+use Closure;
+use Illuminate\Http\Request;
+use Pterodactyl\Contracts\Repository\DatabaseRepositoryInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+class DatabaseBelongsToServer
+{
+    /**
+     * @var \Pterodactyl\Contracts\Repository\DatabaseRepositoryInterface
+     */
+    protected $repository;
+
+    /**
+     * DatabaseAccess constructor.
+     *
+     * @param \Pterodactyl\Contracts\Repository\DatabaseRepositoryInterface $repository
+     */
+    public function __construct(DatabaseRepositoryInterface $repository)
+    {
+        $this->repository = $repository;
+    }
+
+    /**
+     * Check if a database being requested belongs to the currently loaded server.
+     * If it does not, throw a 404 error, otherwise continue on with the request
+     * and set an attribute with the database.
+     *
+     * @param \Illuminate\Http\Request $request
+     * @param \Closure                 $next
+     * @return mixed
+     *
+     * @throws \Pterodactyl\Exceptions\Repository\RecordNotFoundException
+     */
+    public function handle(Request $request, Closure $next)
+    {
+        $server = $request->attributes->get('server');
+
+        $database = $this->repository->find($request->input('database'));
+        if ($database->server_id !== $server->id) {
+            throw new NotFoundHttpException;
+        }
+
+        $request->attributes->set('database', $database);
+
+        return $next($request);
+    }
+}