Prevent indexing of non-production environments by default

docs/README.md

@@ -12,12 +12,18 @@ The following JSON is the default configuration for the module and can be overri
         "altis": {
             "modules": {
                 "seo": {
-                    "enabled": true
-                    },
-                    "redirects": true
+                    "enabled": true,
+                    "redirects": true,
+                    "allow_indexing": true
                 }
             }
         }
     }
 }
 ```
+
+### Configuration Options
+
+- **enabled** (bool): Enable or disable the SEO module. Default: `true`
+- **redirects** (bool): Enable or disable the redirects functionality. Default: `true`
+- **allow_indexing** (bool): Allow search engines to index the site. Default: `true` for production environments, `false` for all other environments (development, staging, etc.). When set to `false`, the robots.txt file will include directives to disallow indexing.

inc/namespace.php

@@ -22,6 +22,11 @@ function bootstrap( Module $module ) {
 	if ( $settings['redirects'] ) {
 		add_action( 'muplugins_loaded', __NAMESPACE__ . '\\load_redirects', 0 );
 	}
+
+	// Disallow indexing if the allow_indexing setting is false.
+	if ( ! ( $settings['allow_indexing'] ?? true ) ) {
+		add_filter( 'robots_txt', __NAMESPACE__ . '\\disallow_indexing', 10, 2 );
+	}
 }
 
 /**
@@ -32,3 +37,15 @@ function bootstrap( Module $module ) {
 function load_redirects() {
 	require_once Altis\ROOT_DIR . '/vendor/humanmade/hm-redirects/hm-redirects.php';
 }
+
+/**
+ * Disallow indexing in robots.txt.
+ *
+ * @param string $output The robots.txt output.
+ * @param string $public Whether the site is public.
+ * @return string Modified robots.txt output.
+ */
+function disallow_indexing( string $output, string $public ) : string {
+	$output .= "\nUser-agent: *\nDisallow: /\n";
+	return $output;
+}

load.php

@@ -13,6 +13,7 @@
 	$default_settings = [
 		'enabled' => true,
 		'redirects' => true,
+		'allow_indexing' => Altis\get_environment_type() === 'production',
 	];
 	$options = [
 		'defaults' => $default_settings,