MAPG-69 add simple JWT parser

src/Util/JwtParser.php

@@ -0,0 +1,33 @@
+<?php namespace MapGuesser\Util;
+
+class JwtParser
+{
+    private array $token;
+
+    public function __construct(?string $token = null)
+    {
+        if ($token !== null) {
+            $this->setToken($token);
+        }
+    }
+
+    public function setToken(string $token)
+    {
+        $this->token = explode('.', str_replace(['_', '-'], ['/', '+'], $token));
+    }
+
+    public function getHeader(): array
+    {
+        return json_decode(base64_decode($this->token[0]), true);
+    }
+
+    public function getPayload(): array
+    {
+        return json_decode(base64_decode($this->token[1]), true);
+    }
+
+    public function getSignature(): string
+    {
+        return base64_decode($this->token[2]);
+    }
+}