Flagship Landing: Add initial functionality

It's disabled because the design hasn't been implemented yet.

.gitignore

@@ -113,4 +113,6 @@ public_html/wp-content/themes/twentytwentyfour
 public_html/wp-content/themes/wporg-parent-2021
 public_html/wp-content/themes/wporg-events-2023/style.css
 public_html/wp-content/themes/wporg-events-2023/editor.css
+public_html/wp-content/themes/wporg-flagship-landing/style.css
+public_html/wp-content/themes/wporg-flagship-landing/editor.css
 public_html/wp-content/fonts

package.json

@@ -19,7 +19,8 @@
 		"public_html/wp-content/plugins/wcpt",
 		"public_html/wp-content/plugins/wordcamp-forms-to-drafts",
 		"public_html/wp-content/plugins/wordcamp-speaker-feedback",
-		"public_html/wp-content/themes/wporg-events-2023"
+		"public_html/wp-content/themes/wporg-events-2023",
+		"public_html/wp-content/themes/wporg-flagship-landing"
 	],
 	"browserslist": [
 		"extends @wordpress/browserslist-config"

public_html/wp-content/mu-plugins/load-other-mu-plugins.php

@@ -16,6 +16,10 @@ function wcorg_include_common_plugins() {
 		require_once dirname( __DIR__ ) . '/mu-plugins-private/wporg-mu-plugins.php';
 	}
 
+	// Include the public `wporg-mu-plugins` that are synced from Git to SVN. These are different than the
+	// ones included in `wcorg_include_common_plugins()`.
+	require_once dirname( __DIR__ ) . '/mu-plugins-private/wporg-mu-plugins/pub-sync/loader.php';
+
 	wcorg_include_individual_mu_plugins();
 	wcorg_include_mu_plugin_folders();
 }
@@ -27,9 +31,6 @@ function wcorg_include_network_only_plugins() {
 	if ( EVENTS_NETWORK_ID === SITE_ID_CURRENT_SITE ) {
 		$network_folder = 'events';
 
-		// Include the public `wporg-mu-plugins` that are synced from Git to SVN. These are different than the
-		// ones included in `wcorg_include_common_plugins()`.
-		require_once dirname( __DIR__ ) . '/mu-plugins-private/wporg-mu-plugins/pub-sync/loader.php';
 	} else {
 		$network_folder = 'wordcamp';
 	}

public_html/wp-content/sunrise-wordcamp.php

@@ -1,6 +1,9 @@
 <?php
 
 namespace WordCamp\Sunrise;
+use WP_Network, WP_Site;
+use WordCamp_Loader;
+
 defined( 'WPINC' ) || die();
 
 // phpcs:disable WordPress.WP.AlternativeFunctions.parse_url_parse_url -- It's not available this early.
@@ -44,6 +47,82 @@ function main() {
 		'path'   => $path
 	) = guess_requested_domain_path();
 
+	/*
+	 * @todo enable this when design is implemented.
+	if ( is_flagship_landing_url( $domain, $path ) ) {
+		if ( setup_flagship_landing_site( $domain ) ) {
+			return;
+		}
+	}
+	*/
+
+	redirect_to_site( $domain, $path );
+}
+
+/**
+ * Show the flagship landing page.
+ */
+function setup_flagship_landing_site( string $domain ): bool {
+	$latest_site = get_latest_site( $domain );
+
+	if ( ! $latest_site ) {
+		return false;
+	}
+
+	set_network_and_site( $latest_site );
+
+	remove_action( 'template_redirect', 'redirect_canonical' );
+
+	add_filter(
+		'template',
+		function (): string {
+			return 'wporg-parent-2021';
+		}
+	);
+
+	add_filter(
+		'stylesheet',
+		function (): string {
+			return 'wporg-flagship-landing';
+		}
+	);
+
+	add_filter(
+		'option_wccsp_settings',
+		function ( array $settings ): array {
+			$settings['enabled'] = 'off';
+
+			return $settings;
+		}
+	);
+
+	return true;
+}
+
+/**
+ * Set the current network and site when given a site.
+ *
+ * phpcs:disable WordPress.WP.GlobalVariablesOverride.Prohibited -- WP is designed in a way that requires this.
+ * Setting these vars is what `sunrise.php` is designed to do.
+ */
+function set_network_and_site( object $site ) {
+	global $current_site, $current_blog, $blog_id, $site_id, $domain, $path, $public;
+
+	// Originally WP referred to networks as "sites" and sites as "blogs".
+	$current_site = WP_Network::get_instance( WORDCAMP_NETWORK_ID );
+	$site_id      = $current_site->id;
+	$path         = stripslashes( $_SERVER['REQUEST_URI'] );
+	$current_blog = WP_Site::get_instance( $site->blog_id );
+
+	$blog_id = $current_blog->id;
+	$domain  = $current_blog->domain;
+	$public  = $current_blog->public;
+}
+
+/**
+ * Redirect requests to the correct site.
+ */
+function redirect_to_site( string $domain, string $path ): void {
 	add_action( 'template_redirect', __NAMESPACE__ . '\redirect_duplicate_year_permalinks_to_post_slug' );
 
 	$status_code = 301;
@@ -131,6 +210,20 @@ function guess_requested_domain_path() {
 	);
 }
 
+/**
+ * Check if the given domain/path is a flagship landing page.
+ */
+function is_flagship_landing_url( string $domain, string $path ): bool {
+	$flagship_events    = array( 'asia', 'centroamerica', 'europe', 'us' );
+	$third_level_domain = explode( '.', $domain )[0];
+
+	if ( in_array( $third_level_domain, $flagship_events ) && '/' === $path ) {
+		return true;
+	}
+
+	return false;
+}
+
 /**
  * Redirect root site front-end requests to Central.
  *
@@ -528,8 +621,19 @@ function get_canonical_year_url( $domain, $path ) {
 			break;
 	}
 
+	$latest = get_latest_site( $domain );
+
+	return $latest ? 'https://' . $latest->domain . $latest->path : false;
+}
+
+/**
+ * Get the latest site for a given city.
+ */
+function get_latest_site( string $domain ) {
+	global $wpdb;
+
 	$latest = $wpdb->get_row( $wpdb->prepare( "
-		SELECT `domain`, `path`
+		SELECT `blog_id`, `domain`, `path`
 		FROM $wpdb->blogs
 		WHERE
 			( domain =    %s AND path != '/' ) OR -- Match city/year format.
@@ -540,7 +644,7 @@ function get_canonical_year_url( $domain, $path ) {
 		"%.{$domain}"
 	) );
 
-	return $latest ? 'https://' . $latest->domain . $latest->path : false;
+	return $latest;
 }
 
 /**

public_html/wp-content/themes/wporg-flagship-landing/.stylelintrc

@@ -0,0 +1,18 @@
+{
+	"extends": "@wordpress/stylelint-config",
+	"rules": {
+		"max-line-length": null,
+		"no-duplicate-selectors": null,
+		"no-descending-specificity": null,
+		"rule-empty-line-before": [
+			"always-multi-line",
+			{
+				"except": [
+					"first-nested",
+					"after-single-line-comment"
+				]
+			}
+		],
+		"selector-class-pattern": null
+	}
+}

public_html/wp-content/themes/wporg-flagship-landing/README.md

@@ -0,0 +1,3 @@
+# wporg-flagship-landing
+
+You must run the `build` task for this to be recognized as a valid theme by WP.