wordpress-activitypub/includes/functions.php
2023-07-18 15:02:27 -05:00

353 lines
8.8 KiB
PHP

<?php
namespace Activitypub;
use Activitypub\Http;
use Activitypub\Activity\Activity;
use Activitypub\Collection\Followers;
/**
* Returns the ActivityPub default JSON-context
*
* @return array the activitypub context
*/
function get_context() {
$context = Activity::CONTEXT;
return \apply_filters( 'activitypub_json_context', $context );
}
function safe_remote_post( $url, $body, $user_id ) {
return Http::post( $url, $body, $user_id );
}
function safe_remote_get( $url ) {
return Http::get( $url );
}
/**
* Returns a users WebFinger "resource"
*
* @param int $user_id The User-ID.
*
* @return string The User-Resource.
*/
function get_webfinger_resource( $user_id ) {
return Webfinger::get_user_resource( $user_id );
}
/**
* Requests the Meta-Data from the Actors profile
*
* @param string $actor The Actor URL.
* @param bool $cached If the result should be cached.
*
* @return array The Actor profile as array
*/
function get_remote_metadata_by_actor( $actor, $cached = true ) {
$pre = apply_filters( 'pre_get_remote_metadata_by_actor', false, $actor );
if ( $pre ) {
return $pre;
}
if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $actor ) ) {
$actor = Webfinger::resolve( $actor );
}
if ( ! $actor ) {
return null;
}
if ( is_wp_error( $actor ) ) {
return $actor;
}
$transient_key = 'activitypub_' . $actor;
// only check the cache if needed.
if ( $cached ) {
$metadata = \get_transient( $transient_key );
if ( $metadata ) {
return $metadata;
}
}
if ( ! \wp_http_validate_url( $actor ) ) {
$metadata = new \WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), $actor );
\set_transient( $transient_key, $metadata, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $metadata;
}
$short_timeout = function() {
return 3;
};
add_filter( 'activitypub_remote_get_timeout', $short_timeout );
$response = Http::get( $actor );
remove_filter( 'activitypub_remote_get_timeout', $short_timeout );
if ( \is_wp_error( $response ) ) {
\set_transient( $transient_key, $response, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $response;
}
$metadata = \wp_remote_retrieve_body( $response );
$metadata = \json_decode( $metadata, true );
\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
if ( ! $metadata ) {
$metadata = new \WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), $actor );
\set_transient( $transient_key, $metadata, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $metadata;
}
return $metadata;
}
/**
* Returns the followers of a given user.
*
* @param int $user_id The User-ID.
*
* @return array The followers.
*/
function get_followers( $user_id ) {
return Followers::get_followers( $user_id );
}
/**
* Count the number of followers for a given user.
*
* @param int $user_id The User-ID.
*
* @return int The number of followers.
*/
function count_followers( $user_id ) {
return Followers::count_followers( $user_id );
}
/**
* Examine a url and try to determine the author ID it represents.
*
* Checks are supposedly from the hosted site blog.
*
* @param string $url Permalink to check.
*
* @return int User ID, or 0 on failure.
*/
function url_to_authorid( $url ) {
global $wp_rewrite;
// check if url hase the same host
if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
return 0;
}
// first, check to see if there is a 'author=N' to match against
if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
$id = \absint( $values[1] );
if ( $id ) {
return $id;
}
}
// check to see if we are using rewrite rules
$rewrite = $wp_rewrite->wp_rewrite_rules();
// not using rewrite rules, and 'author=N' method failed, so we're out of options
if ( empty( $rewrite ) ) {
return 0;
}
// generate rewrite rule for the author url
$author_rewrite = $wp_rewrite->get_author_permastruct();
$author_regexp = \str_replace( '%author%', '', $author_rewrite );
// match the rewrite rule with the passed url
if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
$user = \get_user_by( 'slug', $match[2] );
if ( $user ) {
return $user->ID;
}
}
return 0;
}
/**
* Check for Tombstone Objects
*
* @see https://www.w3.org/TR/activitypub/#delete-activity-outbox
*
* @param WP_Error $wp_error A WP_Error-Response of an HTTP-Request
*
* @return boolean true if HTTP-Code is 410 or 404
*/
function is_tombstone( $wp_error ) {
if ( ! is_wp_error( $wp_error ) ) {
return false;
}
if ( in_array( (int) $wp_error->get_error_code(), array( 404, 410 ), true ) ) {
return true;
}
return false;
}
/**
* Get the REST URL relative to this plugin's namespace.
*
* @param string $path Optional. REST route path. Otherwise this plugin's namespaced root.
*
* @return string REST URL relative to this plugin's namespace.
*/
function get_rest_url_by_path( $path = '' ) {
// we'll handle the leading slash.
$path = ltrim( $path, '/' );
$namespaced_path = sprintf( '/%s/%s', ACTIVITYPUB_REST_NAMESPACE, $path );
return \get_rest_url( null, $namespaced_path );
}
/**
* Convert a string from camelCase to snake_case.
*
* @param string $string The string to convert.
*
* @return string The converted string.
*/
function camel_to_snake_case( $string ) {
return strtolower( preg_replace( '/(?<!^)[A-Z]/', '_$0', $string ) );
}
/**
* Convert a string from snake_case to camelCase.
*
* @param string $string The string to convert.
*
* @return string The converted string.
*/
function snake_to_camel_case( $string ) {
return lcfirst( str_replace( '_', '', ucwords( $string, '_' ) ) );
}
/**
* Check if a request is for an ActivityPub request.
*
* @return bool False by default.
*/
function is_activitypub_request() {
global $wp_query;
/*
* ActivityPub requests are currently only made for
* author archives, singular posts, and the homepage.
*/
if ( ! \is_author() && ! \is_singular() && ! \is_home() && ! defined( '\REST_REQUEST' ) ) {
return false;
}
// One can trigger an ActivityPub request by adding ?activitypub to the URL.
global $wp_query;
if ( isset( $wp_query->query_vars['activitypub'] ) ) {
return true;
}
/*
* The other (more common) option to make an ActivityPub request
* is to send an Accept header.
*/
if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
$accept = sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT'] ) );
/*
* $accept can be a single value, or a comma separated list of values.
* We want to support both scenarios,
* and return true when the header includes at least one of the following:
* - application/activity+json
* - application/ld+json
*/
if ( preg_match( '/(application\/(ld\+json|activity\+json))/', $accept ) ) {
return true;
}
}
return false;
}
/**
* This function checks if a user is disabled for ActivityPub.
*
* @param int $user_id The User-ID.
*
* @return boolean True if the user is disabled, false otherwise.
*/
function is_user_disabled( $user_id ) {
$return = false;
switch ( $user_id ) {
// if the user is the application user, it's always enabled.
case \Activitypub\Collection\Users::APPLICATION_USER_ID:
$return = false;
break;
// if the user is the blog user, it's only enabled in single-user mode.
case \Activitypub\Collection\Users::BLOG_USER_ID:
if ( defined( 'ACTIVITYPUB_DISABLE_BLOG_USER' ) ) {
$return = ACTIVITYPUB_DISABLE_BLOG_USER;
break;
}
$return = false;
break;
// if the user is any other user, it's enabled if it can publish posts.
default:
if ( ! \get_user_by( 'id', $user_id ) ) {
$return = true;
break;
}
if ( defined( 'ACTIVITYPUB_DISABLE_USER' ) ) {
$return = ACTIVITYPUB_DISABLE_USER;
break;
}
if ( ! \user_can( $user_id, 'publish_posts' ) ) {
$return = true;
break;
}
$return = false;
break;
}
return apply_filters( 'activitypub_is_user_disabled', $return, $user_id );
}
/**
* Check if the blog is in single-user mode.
*
* @return boolean True if the blog is in single-user mode, false otherwise.
*/
function is_single_user() {
$return = false;
if (
false === ACTIVITYPUB_DISABLE_BLOG_USER &&
true === ACTIVITYPUB_DISABLE_USER
) {
$return = true;
}
return apply_filters( 'activitypub_is_single_user', $return );
}
if ( ! function_exists( 'get_self_link' ) ) {
/**
* Returns the link for the currently displayed feed.
*
* @return string Correct link for the atom:self element.
*/
function get_self_link() {
$host = wp_parse_url( home_url() );
$path = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
return esc_url( apply_filters( 'self_link', set_url_scheme( 'http://' . $host['host'] . $path ) ) );
}
}