Add features that allow restriction of the number of wpcom plugins per plan to wpsh

projects/plugins/wpcomsh/changelog/update-add-plugins-one-and-three-features

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+wpcomsh: add plugin limit features to be used for lower tier plans

projects/plugins/wpcomsh/constants.php

@@ -33,3 +33,18 @@
 
 // Date for lowering storage from 200 GB to 50 GB for business and higher plans. Ref: D108151-code.
 define( 'LEGACY_200GB_CUTOFF_DATE', '2023-07-20' );
+
+define(
+	'WOA_SOFTWARE_SET_DEFAULT',
+	array(
+		'plugins/akismet',
+		'plugins/jetpack',
+		'plugins/classic-editor',
+		'plugins/gutenberg',
+		'plugins/layout-grid',
+		'plugins/page-optimize',
+		'plugins/crowdsignal-forms',
+		'plugins/polldaddy',
+		'themes/pub/twentytwentytwo',
+	)
+);

projects/plugins/wpcomsh/feature-plugins/hooks.php

@@ -347,3 +347,73 @@ function wpcomsh_remove_jetpack_manage_menu_item() {
 }
 
 add_action( 'admin_menu', 'wpcomsh_remove_jetpack_manage_menu_item', 1001 ); // Automattic\Jetpack\Admin_UI\Admin_Menu uses 1000.
+
+/**
+ * Prevent plugin activation if it would exceed the plan's plugin limit.
+ *
+ * @param array $new_value The new value of the option.
+ * @param array $old_value The old value of the option.
+ * @return array|WP_Error The filtered value.
+ */
+function wpcomsh_prevent_exceeding_plugin_limit( $new_value, $old_value ) {
+	// Skip check for network-wide operations
+	if ( is_multisite() && is_network_admin() ) {
+		return $new_value;
+	}
+
+	$newly_activated = array_diff( $new_value, $old_value );
+	if ( empty( $newly_activated ) ) {
+		return $new_value;
+	}
+
+	// Check if all newly activated plugins are default plugins
+	$has_non_default = false;
+	foreach ( $newly_activated as $plugin ) {
+		if ( ! wpcomsh_is_default_plugin( $plugin ) ) {
+			$has_non_default = true;
+			break;
+		}
+	}
+
+	// If all newly activated plugins are default plugins, allow the activation
+	if ( ! $has_non_default ) {
+		return $new_value;
+	}
+
+	// Otherwise check if we would exceed the limit
+	if ( wpcomsh_would_exceed_plugin_limit( $new_value ) ) {
+		// Return the old value to prevent the update
+		return $old_value;
+	}
+
+	return $new_value;
+}
+add_filter( 'pre_update_option_active_plugins', 'wpcomsh_prevent_exceeding_plugin_limit', 10, 2 );
+
+/**
+ * Remove activation links for non-default plugins when the plugin limit is reached.
+ *
+ * @param array  $actions     Array of plugin action links.
+ * @param string $plugin_file Path to the plugin file relative to the plugins directory.
+ * @return array Modified array of plugin action links.
+ */
+function wpcomsh_maybe_remove_activation_link( $actions, $plugin_file ) {
+	// Skip if no activate action or if it's a default plugin
+	if ( ! isset( $actions['activate'] ) || wpcomsh_is_default_plugin( $plugin_file ) ) {
+		return $actions;
+	}
+
+	// Get currently active plugins
+	$active_plugins = get_option( 'active_plugins', array() );
+
+	// Add this plugin to the list to simulate its activation
+	$active_plugins[] = $plugin_file;
+
+	// Check if activating this plugin would exceed the limit
+	if ( wpcomsh_would_exceed_plugin_limit( $active_plugins ) ) {
+		$actions['activate'] = __( 'Plugin limit reached', 'wpcomsh' );
+	}
+
+	return $actions;
+}
+add_filter( 'plugin_action_links', 'wpcomsh_maybe_remove_activation_link', 10, 2 );

projects/plugins/wpcomsh/functions.php

@@ -434,3 +434,63 @@ function wpcomsh_newsletter_categories_location() {
  * @see https://github.com/Automattic/wp-calypso/issues/100279
  */
 add_filter( 'send_email_change_email', '__return_false' );
+
+/**
+ * Check if a plugin is part of the default WOA software set.
+ *
+ * @param string $plugin Plugin path relative to the plugins directory (e.g. 'akismet/akismet.php').
+ * @return bool True if the plugin is part of the default set, false otherwise.
+ */
+function wpcomsh_is_default_plugin( $plugin ) {
+	if ( ! defined( 'WOA_SOFTWARE_SET_DEFAULT' ) ) {
+		return false;
+	}
+
+	// Extract the plugin folder name from the full plugin path
+	$plugin_folder = explode( '/', $plugin )[0];
+
+	// Check if the plugin folder exists in the default set
+	foreach ( WOA_SOFTWARE_SET_DEFAULT as $default_item ) {
+		if ( strpos( $default_item, 'plugins/' ) === 0 && $plugin_folder === substr( $default_item, 8 ) ) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/**
+ * Check if the given list of plugins would exceed the plan's plugin limit.
+ *
+ * @param array $plugins Array of plugin paths to check.
+ * @return bool True if the plugin count would exceed the limit, false otherwise.
+ */
+function wpcomsh_would_exceed_plugin_limit( $plugins ) {
+	if ( ! is_array( $plugins ) ) {
+		return false;
+	}
+
+	// If site doesn't have either limit feature, no limit applies
+	if ( ! wpcom_site_has_feature( WPCOM_Features::PLUGINS_ALLOW_ONE ) && ! wpcom_site_has_feature( WPCOM_Features::PLUGINS_ALLOW_THREE ) ) {
+		return false;
+	}
+
+	// Count non-default active plugins
+	$active_count = 0;
+	foreach ( $plugins as $plugin ) {
+		if ( ! wpcomsh_is_default_plugin( $plugin ) ) {
+			++$active_count;
+		}
+	}
+
+	// Check against plan limits
+	if ( wpcom_site_has_feature( WPCOM_Features::PLUGINS_ALLOW_ONE ) && $active_count > 1 ) {
+		return true;
+	}
+
+	if ( wpcom_site_has_feature( WPCOM_Features::PLUGINS_ALLOW_THREE ) && $active_count > 3 ) {
+		return true;
+	}
+
+	return false;
+}

projects/plugins/wpcomsh/wpcom-features/class-wpcom-features.php

@@ -397,6 +397,8 @@ class WPCOM_Features {
 	public const OPTIONS_PERMALINK                 = 'options-permalink';
 	public const PAYMENTS                          = 'payments';
 	public const PERFORMANCE_HISTORY               = 'performance-history';
+	public const PLUGINS_ALLOW_ONE                 = 'plugins-allow-one';
+	public const PLUGINS_ALLOW_THREE               = 'plugins-allow-three';
 	public const POLLDADDY                         = 'polldaddy';
 	public const PREMIUM_CONTENT_CONTAINER         = 'premium-content/container';
 	public const PERSONAL_THEMES                   = 'personal-themes';
@@ -884,6 +886,12 @@ class WPCOM_Features {
 			self::JETPACK_BOOST_PLANS,
 			self::JETPACK_COMPLETE_PLANS,
 		),
+		self::PLUGINS_ALLOW_ONE                 => array(
+			self::WPCOM_PERSONAL_PLANS,
+		),
+		self::PLUGINS_ALLOW_THREE               => array(
+			self::WPCOM_PREMIUM_PLANS,
+		),
 		self::POLLDADDY                         => array(
 			self::JETPACK_BUSINESS_PLANS,
 		),