wpcom Features: add new Holiday Snow feature (#40478)

This commit brings a new feature to the mu-wpcom package:

- That feature can be toggled via Settings > General in wp-admin.
- It is active from December 1st to January 4th by default.

projects/packages/jetpack-mu-wpcom/.eslintignore

@@ -1 +1,2 @@
 src/features/newspack-blocks/synced-newspack-blocks
+src/features/holiday-snow/snowstorm.js

projects/packages/jetpack-mu-wpcom/changelog/add-holiday-snow

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+WordPress.com Features: add Holiday Snow functionality.

projects/packages/jetpack-mu-wpcom/src/class-jetpack-mu-wpcom.php

@@ -103,6 +103,7 @@ public static function load_features() {
 		require_once __DIR__ . '/features/first-posts-stream/first-posts-stream-helpers.php';
 		require_once __DIR__ . '/features/font-smoothing-antialiased/font-smoothing-antialiased.php';
 		require_once __DIR__ . '/features/google-analytics/google-analytics.php';
+		require_once __DIR__ . '/features/holiday-snow/class-holiday-snow.php';
 		require_once __DIR__ . '/features/import-customizations/import-customizations.php';
 		require_once __DIR__ . '/features/marketplace-products-updater/class-marketplace-products-updater.php';
 		require_once __DIR__ . '/features/media/heif-support.php';
@@ -118,6 +119,8 @@ public static function load_features() {
 		\Automattic\Jetpack\Classic_Theme_Helper\Main::init();
 		\Automattic\Jetpack\Classic_Theme_Helper\Featured_Content::setup();
 
+		\Automattic\Jetpack\Jetpack_Mu_Wpcom\Holiday_Snow::init();
+
 		// Gets autoloaded from the Scheduled_Updates package.
 		if ( class_exists( 'Automattic\Jetpack\Scheduled_Updates' ) ) {
 			Scheduled_Updates::init();

projects/packages/jetpack-mu-wpcom/src/features/holiday-snow/class-holiday-snow.php

@@ -0,0 +1,216 @@
+<?php
+/**
+ * Holiday Snow
+ * Adds falling snow to a blog starting December 1 and ending January 3.
+ *
+ * @since $$next-version$$
+ *
+ * @package automattic/jetpack-mu-wpcom
+ */
+
+namespace Automattic\Jetpack\Jetpack_Mu_Wpcom;
+
+/**
+ * Holiday Snow (admin and frontend).
+ */
+class Holiday_Snow {
+	/**
+	 * Option to decide if Holiday snow is enabled on the site.
+	 */
+	private const HOLIDAY_SNOW_OPTION_NAME = 'jetpack_holiday_snow_enabled';
+
+	/**
+	 * Check if it is the holiday snow season.
+	 * The season starts on December 1 and ends on January 4 by default.
+	 *
+	 * @return bool
+	 */
+	public static function is_snow_season() {
+		$is_snow_season = false;
+		$today          = time();
+		$first_snow_day = mktime( 0, 0, 0, 12, 1 );
+		$last_snow_day  = mktime( 0, 0, 0, 1, 4 );
+
+		if ( $today >= $first_snow_day || $today < $last_snow_day ) {
+			$is_snow_season = true;
+		}
+
+		/**
+		 * Filter to check if it is the snow season.
+		 * It allows to change the start and end dates of the season,
+		 * for regions where the holiday season may be different.
+		 *
+		 * @since $$next-version$$
+		 *
+		 * @param bool $is_holiday_snow_season Is it the  snow season?
+		 */
+		return apply_filters( 'jetpack_is_holiday_snow_season', $is_snow_season );
+	}
+
+	/**
+	 * Check if the snow is enabled.
+	 *
+	 * @return bool
+	 */
+	public static function is_snow_enabled() {
+		return (bool) get_option( self::HOLIDAY_SNOW_OPTION_NAME );
+	}
+
+	/**
+	 * Register the hooks.
+	 *
+	 * @return void
+	 */
+	public static function init() {
+		if ( ! self::is_snow_season() ) {
+			return;
+		}
+
+		add_filter( 'site_settings_endpoint_get', array( __CLASS__, 'add_option_api' ) );
+		add_filter( 'rest_api_update_site_settings', array( __CLASS__, 'update_option_api' ), 10, 2 );
+		add_action( 'admin_init', array( __CLASS__, 'register_settings' ) );
+		add_action( 'update_option_' . self::HOLIDAY_SNOW_OPTION_NAME, array( __CLASS__, 'holiday_snow_option_updated' ) );
+
+		if ( self::is_snow_enabled() ) {
+			add_action( 'wp_enqueue_scripts', array( __CLASS__, 'holiday_snow_script' ) );
+		}
+	}
+
+	/**
+	 * Enqueue the snowstorm script on the frontend.
+	 *
+	 * @return void
+	 */
+	public static function holiday_snow_script() {
+		if (
+			/**
+			 * Allow short-circuiting the snow, even when enabled on the site in settings.
+			 *
+			 * @since $$next-version$$
+			 *
+			 * @param bool true Whether to show the snow.
+			 */
+			! apply_filters( 'jetpack_holiday_chance_of_snow', true )
+		) {
+			return;
+		}
+
+		/**
+		 * Fires when the snow is falling.
+		 *
+		 * @since $$next-version$$
+		 */
+		do_action( 'jetpack_stats_extra', 'holiday_snow', 'snowing' );
+
+		/**
+		 * Filter the URL of the snowstorm script.
+		 *
+		 * @since $$next-version$$
+		 *
+		 * @param string $snowstorm_url URL of the snowstorm script.
+		 */
+		$snowstorm_url = apply_filters(
+			'jetpack_holiday_snow_js_url',
+			plugins_url( 'snowstorm.js', __FILE__ )
+		);
+
+		wp_enqueue_script(
+			'snowstorm',
+			$snowstorm_url,
+			array(),
+			\Automattic\Jetpack\Jetpack_Mu_Wpcom::PACKAGE_VERSION,
+			true
+		);
+	}
+
+	/**
+	 * Add the option to the v1 API site settings endpoint.
+	 *
+	 * @param array $settings A single site's settings.
+	 * @return array
+	 */
+	public static function add_option_api( $settings ) {
+		$settings[ self::HOLIDAY_SNOW_OPTION_NAME ] = self::is_snow_enabled();
+
+		return $settings;
+	}
+
+	/**
+	 * Update settings via public-api.wordpress.com.
+	 *
+	 * @param array $input             Associative array of site settings to be updated.
+	 *                                 Cast and filtered based on documentation.
+	 * @param array $unfiltered_input  Associative array of site settings to be updated.
+	 *                                 Neither cast nor filtered. Contains raw input.
+	 * @return array
+	 */
+	public static function update_option_api( $input, $unfiltered_input ) {
+		if ( isset( $unfiltered_input[ self::HOLIDAY_SNOW_OPTION_NAME ] ) ) {
+			$input[ self::HOLIDAY_SNOW_OPTION_NAME ] = (bool) $unfiltered_input[ self::HOLIDAY_SNOW_OPTION_NAME ];
+		}
+
+		return $input;
+	}
+
+	/**
+	 * Registers the settings section and fields.
+	 *
+	 * @return void
+	 */
+	public static function register_settings() {
+		register_setting(
+			'general',
+			self::HOLIDAY_SNOW_OPTION_NAME,
+			array(
+				'type'              => 'boolean',
+				'description'       => esc_attr__( 'Show falling snow on my site', 'jetpack-mu-wpcom' ),
+				'show_in_rest'      => true,
+				'default'           => false,
+				'sanitize_callback' => function ( $value ) {
+					return (bool) $value;
+				},
+			)
+		);
+
+		add_settings_field(
+			self::HOLIDAY_SNOW_OPTION_NAME,
+			esc_attr__( 'Snow', 'jetpack-mu-wpcom' ),
+			array( __CLASS__, 'option_field_display' ),
+			'general',
+			'default',
+			array(
+				'label_for' => self::HOLIDAY_SNOW_OPTION_NAME,
+			)
+		);
+	}
+
+	/**
+	 * Renders the Snow settings markup.
+	 *
+	 * @return void
+	 */
+	public static function option_field_display() {
+		printf(
+			'<input type="checkbox" name="%1$s" id="%1$s" %2$s/><label for="%1$s">%3$s</label>',
+			esc_attr( self::HOLIDAY_SNOW_OPTION_NAME ),
+			checked( self::is_snow_enabled(), true, false ),
+			wp_kses(
+				__( 'Show falling snow on my site until January 4<sup>th</sup>.', 'jetpack-mu-wpcom' ),
+				array(
+					'sup' => array(),
+				)
+			)
+		);
+	}
+
+	/**
+	 * Fires whenever the holiday snow option is updated.
+	 * Used to gather stats about modified options.
+	 *
+	 * @return void
+	 */
+	public static function holiday_snow_option_updated() {
+		/** This action is already documented in modules/widgets/gravatar-profile.php */
+		do_action( 'jetpack_stats_extra', 'holiday_snow', 'toggle' );
+	}
+}

projects/packages/sync/changelog/add-holiday-snow

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+WordPress.com Features: add Holiday Snow functionality.

projects/packages/sync/src/class-defaults.php

@@ -79,6 +79,7 @@ class Defaults {
 		'jetpack_comment_form_color_scheme',
 		'jetpack_comment_likes_enabled',
 		'jetpack_excluded_extensions',
+		'jetpack_holiday_snow_enabled',
 		'jetpack_mailchimp',
 		'jetpack_options',
 		'jetpack_portfolio',

projects/plugins/jetpack/changelog/add-holiday-snow

@@ -0,0 +1,4 @@
+Significance: patch
+Type: other
+
+Sync: synchronize Holiday snow option.

projects/plugins/jetpack/tests/php/sync/test_class.jetpack-sync-options.php

@@ -165,6 +165,7 @@ public function test_sync_default_options() {
 			'carousel_background_color'                    => 'pineapple',
 			'carousel_display_exif'                        => 'pineapple',
 			'carousel_display_comments'                    => 'pineapple',
+			'jetpack_holiday_snow_enabled'                 => false,
 			'jetpack_portfolio'                            => 'pineapple',
 			'jetpack_portfolio_posts_per_page'             => 'pineapple',
 			'jetpack_testimonial'                          => 'pineapple',