wordpress-event-bridge-for-activitypub/includes/activitypub/handler/class-create.php

<?php
/**
 * Create handler file.
 *
 * @package Event_Bridge_For_ActivityPub
 */

namespace Event_Bridge_For_ActivityPub\ActivityPub\Handler;

use Activitypub\Collection\Actors;
use Event_Bridge_For_ActivityPub\Setup;

use function Activitypub\is_activity_public;

/**
 * Handle Create requests.
 */
class Create {
	/**
	 * Initialize the class, registering WordPress hooks.
	 */
	public static function init() {
		\add_action(
			'activitypub_inbox_create',
			array( self::class, 'handle_create' ),
			15,
			2
		);
		\add_filter(
			'activitypub_validate_object',
			array( self::class, 'validate_object' ),
			12,
			3
		);
	}

	/**
	 * Handle "Create" requests.
	 *
	 * @param array $activity The activity-object.
	 * @param int   $user_id  The id of the local blog-user.
	 */
	public static function handle_create( $activity, $user_id ) {
		// We only process activities that are target to the application user.
		if ( Actors::APPLICATION_USER_ID !== $user_id ) {
			return;
		}

		// Check if Activity is public or not.
		if ( ! is_activity_public( $activity ) ) {
			return;
		}

		// Check if an object is set.
		if ( ! isset( $activity['object']['type'] ) || 'Event' !== $activity['object']['type'] ) {
			return;
		}

		$transmogrifier_class = Setup::get_transmogrifier();

		if ( ! $transmogrifier_class ) {
			return;
		}

		$transmogrifier = new $transmogrifier_class( $activity['object'] );
		$transmogrifier->create();
	}

	/**
	 * Validate the object.
	 *
	 * @param bool             $valid   The validation state.
	 * @param string           $param   The object parameter.
	 * @param \WP_REST_Request $request The request object.
	 *
	 * @return bool The validation state: true if valid, false if not.
	 */
	public static function validate_object( $valid, $param, $request ) {
		$json_params = $request->get_json_params();

		if ( isset( $json_params['object']['type'] ) && 'Event' === $json_params['object']['type'] ) {
			$valid = true;
		} else {
			return $valid;
		}

		if ( empty( $json_params['type'] ) ) {
			return false;
		}

		if (
			'Create' !== $json_params['type'] || 'Update' !== $json_params['type'] ||
			is_wp_error( $request )
		) {
			return $valid;
		}

		$object = $json_params['object'];

		if ( ! is_array( $object ) ) {
			return false;
		}

		$required = array(
			'id',
		);

		// Limit this as a safety measure.
		add_filter( 'wp_revisions_to_keep', array( 'revisions_to_keep' ) );

		if ( array_intersect( $required, array_keys( $object ) ) !== $required ) {
			return false;
		}

		return $valid;
	}

	/**
	 * Return the number of revisions to keep.
	 *
	 * @return     int   The number of revisions to keep.
	 */
	public static function revisions_to_keep() {
		return 3;
	}
}