wp_update_plugins( array $extra_stats = array() )

function wp_update_plugins( $extra_stats = array() ) {
	if ( wp_installing() ) {
		return;
	}

	// include an unmodified $wp_version
	include( ABSPATH . WPINC . '/version.php' );

	// If running blog-side, bail unless we've not checked in the last 12 hours
	if ( !function_exists( 'get_plugins' ) )
		require_once( ABSPATH . 'wp-admin/includes/plugin.php' );

	$plugins = get_plugins();
	$translations = wp_get_installed_translations( 'plugins' );

	$active  = get_option( 'active_plugins', array() );
	$current = get_site_transient( 'update_plugins' );
	if ( ! is_object($current) )
		$current = new stdClass;

	$new_option = new stdClass;
	$new_option->last_checked = time();

	$doing_cron = wp_doing_cron();

	// Check for update on a different schedule, depending on the page.
	switch ( current_filter() ) {
		case 'upgrader_process_complete' :
			$timeout = 0;
			break;
		case 'load-update-core.php' :
			$timeout = MINUTE_IN_SECONDS;
			break;
		case 'load-plugins.php' :
		case 'load-update.php' :
			$timeout = HOUR_IN_SECONDS;
			break;
		default :
			if ( $doing_cron ) {
				$timeout = 2 * HOUR_IN_SECONDS;
			} else {
				$timeout = 12 * HOUR_IN_SECONDS;
			}
	}

	$time_not_changed = isset( $current->last_checked ) && $timeout > ( time() - $current->last_checked );

	if ( $time_not_changed && ! $extra_stats ) {
		$plugin_changed = false;
		foreach ( $plugins as $file => $p ) {
			$new_option->checked[ $file ] = $p['Version'];

			if ( !isset( $current->checked[ $file ] ) || strval($current->checked[ $file ]) !== strval($p['Version']) )
				$plugin_changed = true;
		}

		if ( isset ( $current->response ) && is_array( $current->response ) ) {
			foreach ( $current->response as $plugin_file => $update_details ) {
				if ( ! isset($plugins[ $plugin_file ]) ) {
					$plugin_changed = true;
					break;
				}
			}
		}

		// Bail if we've checked recently and if nothing has changed
		if ( ! $plugin_changed ) {
			return;
		}
	}

	// Update last_checked for current to prevent multiple blocking requests if request hangs
	$current->last_checked = time();
	set_site_transient( 'update_plugins', $current );

	$to_send = compact( 'plugins', 'active' );

	$locales = array_values( get_available_languages() );

	/**
	 * Filters the locales requested for plugin translations.
	 *
	 * @since WP-3.7.0
	 * @since WP-4.5.0 The default value of the `$locales` parameter changed to include all locales.
	 *
	 * @param array $locales Plugin locales. Default is all available locales of the site.
	 */
	$locales = apply_filters( 'plugins_update_check_locales', $locales );
	$locales = array_unique( $locales );

	if ( $doing_cron ) {
		$timeout = 30;
	} else {
		// Three seconds, plus one extra second for every 10 plugins
		$timeout = 3 + (int) ( count( $plugins ) / 10 );
	}

	$options = array(
		'timeout' => $timeout,
		'body' => array(
			'plugins'      => wp_json_encode( $to_send ),
			'translations' => wp_json_encode( $translations ),
			'locale'       => wp_json_encode( $locales ),
			'all'          => wp_json_encode( true ),
		),
		'user-agent' => classicpress_user_agent(),
	);

	if ( $extra_stats ) {
		$options['body']['update_stats'] = wp_json_encode( $extra_stats );
	}

	$url = 'https://api.wordpress.org/plugins/update-check/1.1/';

	$raw_response = wp_remote_post( $url, $options );
	if ( is_wp_error( $raw_response ) ) {
		trigger_error(
			sprintf(
				/* translators: %s: support forums URL */
				__( 'An unexpected error occurred. Something may be wrong with WordPress.org or this server&#8217;s configuration. If you continue to have problems, please try the <a href="%s">support forums</a>.' ),
				__( 'https://forums.classicpress.net/c/support' )
			) . ' ' . __( '(WordPress could not establish a secure connection to WordPress.org. Please contact your server administrator.)' ),
			headers_sent() || WP_DEBUG ? E_USER_WARNING : E_USER_NOTICE
		);

		// Retry request
		$raw_response = wp_remote_post( $url, $options );
	}

	if ( is_wp_error( $raw_response ) || 200 != wp_remote_retrieve_response_code( $raw_response ) ) {
		return;
	}

	$response = json_decode( wp_remote_retrieve_body( $raw_response ), true );
	foreach ( $response['plugins'] as &$plugin ) {
		$plugin = (object) $plugin;
		if ( isset( $plugin->compatibility ) ) {
			$plugin->compatibility = (object) $plugin->compatibility;
			foreach ( $plugin->compatibility as &$data ) {
				$data = (object) $data;
			}
		}
	}
	unset( $plugin, $data );
	foreach ( $response['no_update'] as &$plugin ) {
		$plugin = (object) $plugin;
	}
	unset( $plugin );

	if ( is_array( $response ) ) {
		$new_option->response = $response['plugins'];
		$new_option->translations = $response['translations'];
		// TODO: Perhaps better to store no_update in a separate transient with an expiry?
		$new_option->no_update = $response['no_update'];
	} else {
		$new_option->response = array();
		$new_option->translations = array();
		$new_option->no_update = array();
	}

	set_site_transient( 'update_plugins', $new_option );
}