added json handler for login

public/index.php

@@ -44,7 +44,20 @@ $authMiddleware = $container->get(AuthMiddleware::class);
 AppFactory::setContainer($container);
 
 $app->post('/login', function ($request, $response) use ($container) {
-    $data = $request->getParsedBody();
+    // Detect the content type of the request
+    $contentType = $request->getHeaderLine('Content-Type');
+
+    // Initialize $data to store parsed body
+    $data = [];
+
+    // If Content-Type is application/json, decode the JSON body
+    if (strstr($contentType, 'application/json')) {
+        $data = json_decode($request->getBody()->getContents(), true);
+    } else {
+        // Otherwise, parse the body as form data
+        $data = $request->getParsedBody();
+    }
+    if (isset($data['username'], $data['password'])) {
     $username = $data['username'];
     $password = $data['password'];
 
@@ -58,6 +71,12 @@ $app->post('/login', function ($request, $response) use ($container) {
         $response->getBody()->write(json_encode(['error' => 'Invalid credentials']));
         return $response->withStatus(401);
     }
+
+} else {
+        // Handle missing fields
+        $response->getBody()->write(json_encode(['error' => 'Username and password required']));
+        return $response->withHeader('Content-Type', 'application/json')->withStatus(400);
+    }
 });
 
 $app->post('/addUser', function ($request, $response) use ($container) {