Themes: share one WordPress.com themes data layer between the Marketplace tab and wpcomsh

projects/packages/jetpack-mu-wpcom/changelog/dotcom-18877-dont-cache-failures

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Themes: retry after a failed read of the WordPress.com theme list, rather than caching the failure for a day.

projects/packages/jetpack-mu-wpcom/changelog/dotcom-18877-shared-themes-data-layer

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Themes: share the WordPress.com themes API, cache, mapper and tier reader with wpcomsh rather than each keeping a copy.

projects/plugins/wpcomsh/wpcom-themes/includes/class-wpcom-themes-api.php → projects/packages/jetpack-mu-wpcom/src/features/wpcom-themes/class-wpcom-themes-api.php

@@ -3,7 +3,7 @@
  * Class WPCom_Themes_Api.
  * Retrieves themes from the WordPress.com themes API.
  *
- * @package wpcom-themes
+ * @package automattic/jetpack-mu-wpcom
  */
 
 /**
@@ -51,8 +51,13 @@ protected function fetch_themes( string $cache_key, array $params = array() ): a
 
 		return $this->cache->run_cached(
 			$cache_key,
-			fn() => $this->handle_request( $url )->themes ?? array()
-		);
+			function () use ( $url ) {
+				$body = $this->handle_request( $url );
+
+				// Null, not an empty array: run_cached() stores anything else.
+				return isset( $body->themes ) && is_array( $body->themes ) ? $body->themes : null;
+			}
+		) ?? array();
 	}
 
 	/**

projects/plugins/wpcomsh/wpcom-themes/includes/class-wpcom-themes-cache.php → projects/packages/jetpack-mu-wpcom/src/features/wpcom-themes/class-wpcom-themes-cache.php

@@ -3,7 +3,7 @@
  * Class WPCom_Themes_Cache.
  * Caches WPCom themes.
  *
- * @package wpcom-themes
+ * @package automattic/jetpack-mu-wpcom
  */
 
 /**
@@ -29,8 +29,15 @@ class WPCom_Themes_Cache {
 	public function run_cached( string $cache_key, callable $lambda, int $ttl = DAY_IN_SECONDS ) {
 		$data = wp_cache_get( $cache_key, self::CACHE_GROUP );
 
-		if ( false === $data || defined( 'IGNORE_CACHED_WPCOM_THEMES' ) ) {
-			$data = $lambda();
+		if ( false !== $data && ! defined( 'IGNORE_CACHED_WPCOM_THEMES' ) ) {
+			return $data;
+		}
+
+		$data = $lambda();
+
+		// Null means the read failed rather than came back empty, and a failure is not cached: a
+		// moment's trouble reaching WordPress.com would otherwise empty the theme lists for a day.
+		if ( null !== $data ) {
 			wp_cache_set( $cache_key, $data, self::CACHE_GROUP, $ttl );
 		}
 

projects/plugins/wpcomsh/wpcom-themes/includes/class-wpcom-themes-mapper.php → projects/packages/jetpack-mu-wpcom/src/features/wpcom-themes/class-wpcom-themes-mapper.php

@@ -3,7 +3,7 @@
  * Class WPCom_Themes_Mapper.
  * Responsible for mapping theme objects between WPCom and WPOrg formats.
  *
- * @package wpcom-themes
+ * @package automattic/jetpack-mu-wpcom
  */
 
 /**
@@ -46,7 +46,14 @@ public function map_wpcom_to_wporg( stdClass $wpcom_theme ): stdClass {
 		$theme                 = new stdClass();
 		$theme->name           = $wpcom_theme->name;
 		$theme->slug           = $wpcom_theme->id;
-		$theme->preview_url    = $wpcom_theme->demo_uri . '?demo=true&iframe=true&theme_preview=true';
+		$theme->preview_url    = add_query_arg(
+			array(
+				'demo'          => 'true',
+				'iframe'        => 'true',
+				'theme_preview' => 'true',
+			),
+			$wpcom_theme->demo_uri
+		);
 		$theme->author         = array( 'display_name' => $wpcom_theme->author );
 		$theme->screenshot_url = $wpcom_theme->screenshot;
 		$theme->homepage       = "https://wordpress.com/theme/$wpcom_theme->id";

projects/packages/jetpack-mu-wpcom/src/features/wpcom-themes/class-wpcom-themes-tiers.php

@@ -0,0 +1,62 @@
+<?php
+/**
+ * Class WPCom_Themes_Tiers.
+ * What a site's plan includes, by theme tier.
+ *
+ * @package automattic/jetpack-mu-wpcom
+ */
+
+/**
+ * Answers which theme tiers a site's plan includes.
+ *
+ * Entitlement only. Whether a surface shows a tier it cannot install is that surface's own
+ * decision: core's Add Themes tabs hide partner themes because they need their own subscription,
+ * while the Marketplace tab lists them to sell them.
+ */
+class WPCom_Themes_Tiers {
+
+	/**
+	 * The tier every site can use.
+	 */
+	const FREE = 'free';
+
+	/**
+	 * The tier of a theme as WordPress.com returns it.
+	 *
+	 * @param stdClass $theme A theme from the WordPress.com themes API.
+	 * @return string Tier slug, premium for a theme that reports none.
+	 */
+	public static function tier_of( $theme ): string {
+		return $theme->theme_tier->slug ?? 'premium';
+	}
+
+	/**
+	 * The capability name gating a tier.
+	 *
+	 * @param string $tier Tier slug.
+	 * @return string
+	 */
+	public static function feature_for( string $tier ): string {
+		return $tier . '-themes';
+	}
+
+	/**
+	 * Whether this site's plan includes a tier.
+	 *
+	 * Necessary but not sufficient for the partner tier, which every paid plan includes while each
+	 * partner theme still needs its own subscription that no plan feature reports.
+	 *
+	 * @param string $tier Tier slug.
+	 * @return bool True for the free tier, which needs no plan. For the rest, false when the
+	 *              platform cannot answer, so an unknown host offers nothing.
+	 */
+	public static function site_can_use( string $tier ): bool {
+		// There is no free-themes capability, so asking the platform would deny every free theme.
+		if ( self::FREE === $tier ) {
+			return true;
+		}
+
+		return function_exists( 'wpcom_site_has_feature' )
+			&& (bool) wpcom_site_has_feature( self::feature_for( $tier ) );
+	}
+}