Added request data identification middleware (#207)

* Added request data identification middleware

* Fixed styling

* Changed to Illuminate request instead of helper

* Enabled header and querystring customisation

Co-authored-by: Jesper Jacobsen <joj@webshipper.com>

src/Middleware/InitializeTenancyByRequestData.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Stancl\Tenancy\Exceptions\TenantCouldNotBeIdentifiedException;
+
+class InitializeTenancyByRequestData
+{
+    /** @var callable */
+    protected $onFail;
+
+    public function __construct(callable $onFail = null)
+    {
+        $this->onFail = $onFail ?? function ($e) {
+            throw $e;
+        };
+    }
+
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure  $next
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        if ($request->method() !== 'OPTIONS') {
+            try {
+                $this->parseTenant($request);
+            } catch (TenantCouldNotBeIdentifiedException $e) {
+                ($this->onFail)($e);
+            }
+        }
+
+        return $next($request);
+    }
+
+    protected function parseTenant(Request $request)
+    {
+        if (tenancy()->initialized) {
+            return;
+        }
+
+        $header = config('tenancy.identification.header');
+        $query = config('tenancy.identification.query_parameter');
+
+        $tenant = null;
+        if ($request->hasHeader($header)) {
+            $tenant = $request->header($header);
+        } elseif ($request->has($query)) {
+            $tenant = $request->get($query);
+        } elseif (! in_array($request->getHost(), config('tenancy.exempt_domains', []), true)) {
+            $tenant = explode('.', $request->getHost())[0];
+        }
+
+        if (! $tenant) {
+            throw new TenantCouldNotBeIdentifiedException($request->getHost());
+        }
+
+        tenancy()->initialize(tenancy()->find($tenant));
+    }
+}