Refactor Google callback handling in SocialAuthController to improve error messaging and user experience

This commit updates the handleGoogleCallback method to store the Google user's email in a variable for better readability. It also adds an error message redirect for users whose email is not found in the database, prompting them to register first. This enhances the overall user experience during the authentication process.

Author: Level237

app/Http/Controllers/Auth/SocialAuthController.php

@@ -37,15 +37,18 @@ public function handleGoogleCallback(): RedirectResponse
             Log::error("Erreur de callback Google: " . $e->getMessage());
             return redirect("{$frontendUrl}/login?error=google_auth_failed");
         }
-
-        $user = User::where('email', $googleUser->getEmail())->first();
+        $email = $googleUser->getEmail();
+        $user = User::where('email', $email)->first();
 
         if($user){
             if (is_null($user->google_id)) {
                 $user->google_id = $googleUser->getId();
             }
             // Mettre à jour d'autres informations si nécessaire
             $user->save();
+        }else{
+            $errorMsg = urlencode("Cette adresse email ({$email}) n'existe pas dans nos bases de données. Veuillez vous enregistrer d'abord.");
+            return redirect("{$frontendUrl}/login?code=401");
         }
 
         $scope = $this->getUserScope($user->role_id);