add platform

app/Http/Middleware/Platform.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+
+class Platform
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure  $next
+     * @return mixed
+     */
+    public function handle(Request $request, Closure $next)
+    {
+        if (empty(CURRENT_PLATFORM)) {
+            throw new \InvalidArgumentException("Require platform header.");
+        }
+        if (!in_array(CURRENT_PLATFORM, PLATFORMS)) {
+            throw new \InvalidArgumentException("Invalid platform: " . CURRENT_PLATFORM);
+        }
+        return $next($request);
+    }
+}