New code for API 2

app/Http/Middleware/AcceptHeaders.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace FireflyIII\Http\Middleware;
+
+use FireflyIII\Exceptions\BadHttpHeaderException;
+use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Log;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+
+/**
+ *
+ */
+class AcceptHeaders
+{
+    /**
+     * Handle the incoming requests.
+     *
+     * @param Request $request
+     * @param callable $next
+     * @return Response
+     * @throws BadHttpHeaderException
+     */
+    public function handle($request, $next): mixed
+    {
+        $method = $request->getMethod();
+
+        if ('GET' === $method && !$request->accepts(['application/json', 'application/vdn.api+json'])) {
+            throw new BadHttpHeaderException('Your request must accept either application/json or application/vdn.api+json.');
+        }
+        if (('POST' === $method || 'PUT' === $method) && 'application/json' !== (string)$request->header('Content-Type')) {
+            $error             = new BadHttpHeaderException('B');
+            $error->statusCode = 415;
+            throw $error;
+        }
+
+        // throw bad request if trace id is not a UUID
+        $uuid = $request->header('X-Trace-Id', null);
+        if (is_string($uuid) && '' !== trim($uuid) && (preg_match('/^[a-f\d]{8}(-[a-f\d]{4}){4}[a-f\d]{8}$/i', trim($uuid)) !== 1)) {
+            throw new BadRequestHttpException('Bad X-Trace-Id header.');
+        }
+
+        return $next($request);
+    }
+}