Show hint about upload permissions on LotW page

application/controllers/Lotw.php

@@ -55,6 +55,10 @@ class Lotw extends CI_Controller {
 		// Set Page Title
 		$data['page_title'] = "Logbook of the World";
 
+		// Check folder permissions
+		$uploads_folder = $this->is_really_writable('uploads');
+		$data['uploads_folder'] = $uploads_folder;
+
 		// Load Views
 		$this->load->view('interface_assets/header', $data);
 		$this->load->view('lotw_views/index');
@@ -1123,4 +1127,31 @@ class Lotw extends CI_Controller {
 		endswitch;
 	}
 
+	private function is_really_writable($folder) {
+		// Get the absolute path to the folder
+		$path = FCPATH . $folder;
+
+		// Check if the folder exists
+		if (!file_exists($path)) {
+			return false;
+		}
+
+		// Check if the folder is writable
+		if (is_writable($path)) {
+			// Check if the subdirectories are writable (recursive check)
+			$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));
+			foreach ($iterator as $item) {
+				if ($item->isDir() && basename($item->getPathName()) != '..') {
+					if (!is_writable($item->getRealPath())) {
+						return false;
+					}
+				}
+			}
+
+			return true;
+		}
+
+		return false;
+	}
+
 } // end class

application/language/english/lotw_lang.php

@@ -61,3 +61,6 @@ $lang['lotw_cert_expired'] = 'At least one of your LoTW certificates is expired!
 // Lotw User
 $lang['lotw_user'] = 'This station uses LoTW.';
 $lang['lotw_last_upload'] = 'Last upload';
+
+// Upload folder permissions
+$lang['lotw_upload_folder_permissions'] = 'Upload folder is not writable. Please contact your admin.';

application/views/lotw_views/index.php

@@ -1,4 +1,9 @@
 <div class="container lotw">
+<?php if($uploads_folder != true) { ?>
+	<div class="alert alert-warning" role="alert" style="margin-top: 1rem;">
+		<span class="badge text-bg-info"><?php echo lang('general_word_important'); ?></span> <i class="fas fa-ban"></i> <?php echo lang('lotw_upload_folder_permissions'); ?>
+	</div>
+<?php } ?>
 <br>
 	<a class="btn btn-outline-primary btn-sm float-end" href="<?php echo site_url('/lotw/import'); ?>" role="button"><i class="fas fa-cloud-download-alt"></i> <?php echo lang('lotw_btn_lotw_import'); ?></a>
 	<h2><?php echo lang('lotw_title'); ?></h2>