Less abrupt link errors.

src/ClientsRoutes.php

@@ -40,7 +40,30 @@ class ClientsRoutes {
         }
     }
 
-    public function getClients() {
+    private const CLIENTS_ERRORS = [
+        'link' => [
+            'already' => 'You already have a linked Minecraft username, unlink the other one first.',
+            'format' => 'The Link Code you entered was is not in the correct format, check your input!',
+            'code' => 'The Link Code you entered is not valid, make sure you typed it correctly!',
+        ],
+    ];
+
+    public function getClients($response, $request) {
+        $errorCode = (string)$request->getParam('error');
+        if($errorCode !== '') {
+            $errorCode = explode(':', $errorCode, 2);
+            if(count($errorCode) === 2
+                && array_key_exists($errorCode[0], self::CLIENTS_ERRORS)
+                && array_key_exists($errorCode[1], self::CLIENTS_ERRORS[$errorCode[0]]))
+                $this->templating->addVars([
+                    'error' => [
+                        'section' => $errorCode[0],
+                        'code' => $errorCode[1],
+                        'message' => self::CLIENTS_ERRORS[$errorCode[0]][$errorCode[1]],
+                    ],
+                ]);
+        }
+
         try {
             $linkInfo = $this->accountLinks->getLink(userInfo: $this->authInfo->user_id);
             $clients = $this->authorisations->getAuthorisations($linkInfo);
@@ -55,20 +78,25 @@ class ClientsRoutes {
     }
 
     public function postLink($response, $request) {
-        if($this->accountLinks->checkHasLink($this->authInfo->user_id))
+        if($this->accountLinks->checkHasLink($this->authInfo->user_id)) {
-            return 403;
+            $response->redirect('/clients?error=link:already');
+            return;
+        }
 
         $body = $request->getContent();
         $code = (string)$body->getParam('code');
-        if(strlen($code) !== 10)
+        if(strlen($code) !== 10) {
-            return 400;
+            $response->redirect('/clients?error=link:format');
+            return;
+        }
 
         $code = strtr(strtoupper($code), '0189', 'OIBG');
 
         try {
             $verifyInfo = $this->verifications->getVerification(code: $code);
         } catch(RuntimeException $ex) {
-            return 404;
+            $response->redirect('/clients?error=link:code');
+            return;
         }
 
         $this->verifications->deleteVerification($verifyInfo);

templates/clients/index.twig

@@ -10,6 +10,11 @@
         <div class="section acclink">
             <h2>Link a Minecraft account</h2>
             <p>This will associate a Minecraft username with your Flashii ID. You may only have one linked at a time. In order to obtain a link code, connect to one of the Minecraft servers.</p>
+
+            {% if error is defined and error.section == 'link' %}
+                <p style="color: red;">{{ error.message }}</p>
+            {% endif %}
+
             <form method="post" action="/clients/link">
                 <input type="hidden" name="csrfp" value="{{ csrfp }}">
                 <label>