<?php
namespace Activitypub\Collection;
use WP_Error;
use Exception;
use WP_Term_Query;
use Activitypub\Http;
use Activitypub\Webfinger;
use Activitypub\Model\Activity;
use Activitypub\Model\Follower;
use function Activitypub\is_tombstone;
use function Activitypub\get_remote_metadata_by_actor;
/**
* ActivityPub Followers Collection
*
* @author Matthias Pfefferle
*/
class Followers {
const TAXONOMY = 'activitypub-followers';
/**
* Register WordPress hooks/actions and register Taxonomy
*
* @return void
*/
public static function init() {
// register "followers" taxonomy
self::register_taxonomy();
\add_action( 'activitypub_inbox_follow', array( self::class, 'handle_follow_request' ), 10, 2 );
\add_action( 'activitypub_inbox_undo', array( self::class, 'handle_undo_request' ), 10, 2 );
\add_action( 'activitypub_followers_post_follow', array( self::class, 'send_follow_response' ), 10, 4 );
}
/**
* Register the "Followers" Taxonomy
*
* @return void
*/
public static function register_taxonomy() {
$args = array(
'labels' => array(
'name' => _x( 'Followers', 'taxonomy general name', 'activitypub' ),
'singular_name' => _x( 'Followers', 'taxonomy singular name', 'activitypub' ),
'menu_name' => __( 'Followers', 'activitypub' ),
),
'hierarchical' => false,
'show_ui' => false,
'show_in_menu' => false,
'show_in_nav_menus' => false,
'show_admin_column' => false,
'query_var' => false,
'rewrite' => false,
'public' => false,
'capabilities' => array(
'edit_terms' => null,
),
);
register_taxonomy( self::TAXONOMY, 'user', $args );
register_taxonomy_for_object_type( self::TAXONOMY, 'user' );
register_term_meta(
self::TAXONOMY,
'name',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
return sanitize_user( $value );
},
)
);
register_term_meta(
self::TAXONOMY,
'username',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
return sanitize_user( $value, true );
},
)
);
register_term_meta(
self::TAXONOMY,
'avatar',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
return '';
}
return esc_url_raw( $value );
},
)
);
register_term_meta(
self::TAXONOMY,
'inbox',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
throw new Exception( '"inbox" has to be a valid URL' );
}
return esc_url_raw( $value );
},
)
);
register_term_meta(
self::TAXONOMY,
'shared_inbox',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
return null;
}
return esc_url_raw( $value );
},
)
);
register_term_meta(
self::TAXONOMY,
'updated_at',
array(
'type' => 'string',
'single' => true,
'sanitize_callback' => function( $value ) {
if ( ! is_numeric( $value ) && (int) $value !== $value ) {
$value = \time();
}
return $value;
},
)
);
register_term_meta(
self::TAXONOMY,
'errors',
array(
'type' => 'string',
'single' => false,
'sanitize_callback' => function( $value ) {
if ( ! is_string( $value ) ) {
throw new Exception( 'Error message is no valid string' );
}
return esc_sql( $value );
},
)
);
do_action( 'activitypub_after_register_taxonomy' );
}
/**
* Handle the "Follow" Request
*
* @param array $object The JSON "Follow" Activity
* @param int $user_id The ID of the ID of the WordPress User
*
* @return void
*/
public static function handle_follow_request( $object, $user_id ) {
// save follower
$follower = self::add_follower( $user_id, $object['actor'] );
do_action( 'activitypub_followers_post_follow', $object['actor'], $object, $user_id, $follower );
}
/**
* Handle "Unfollow" requests
*
* @param array $object The JSON "Undo" Activity
* @param int $user_id The ID of the ID of the WordPress User
*/
public static function handle_undo_request( $object, $user_id ) {
if (
isset( $object['object'] ) &&
isset( $object['object']['type'] ) &&
'Follow' === $object['object']['type']
) {
self::remove_follower( $user_id, $object['actor'] );
}
}
/**
* Add new Follower
*
* @param int $user_id The ID of the WordPress User
* @param string $actor The Actor URL
*
* @return array|WP_Error The Follower (WP_Term array) or an WP_Error
*/
public static function add_follower( $user_id, $actor ) {
$meta = get_remote_metadata_by_actor( $actor );
if ( empty( $meta ) || ! is_array( $meta ) || is_wp_error( $meta ) ) {
return $meta;
}
$follower = new Follower( $actor );
$follower->from_meta( $meta );
$follower->upsert();
$result = wp_set_object_terms( $user_id, $follower->get_actor(), self::TAXONOMY, true );
if ( is_wp_error( $result ) ) {
return $result;
} else {
return $follower;
}
}
/**
* Remove a Follower
*
* @param int $user_id The ID of the WordPress User
* @param string $actor The Actor URL
*
* @return bool|WP_Error True on success, false or WP_Error on failure.
*/
public static function remove_follower( $user_id, $actor ) {
return wp_remove_object_terms( $user_id, $actor, self::TAXONOMY );
}
/**
* Remove a Follower
*
* @param int $user_id The ID of the WordPress User
* @param string $actor The Actor URL
*
* @return \Activitypub\Model\Follower The Follower object
*/
public static function get_follower( $user_id, $actor ) {
$terms = new WP_Term_Query(
array(
'name' => $actor,
'taxonomy' => self::TAXONOMY,
'hide_empty' => false,
'object_ids' => $user_id,
'number' => 1,
)
);
$term = $terms->get_terms();
if ( is_array( $term ) && ! empty( $term ) ) {
$term = reset( $term );
return new Follower( $term->name );
}
return null;
}
/**
* Send Accept response
*
* @param string $actor The Actor URL
* @param array $object The Activity object
* @param int $user_id The ID of the WordPress User
* @param Activitypub\Model\Follower $follower The Follower object
*
* @return void
*/
public static function send_follow_response( $actor, $object, $user_id, $follower ) {
if ( is_wp_error( $follower ) ) {
// it is not even possible to send a "Reject" because
// we can not get the Remote-Inbox
return;
}
if ( isset( $object['user_id'] ) ) {
unset( $object['user_id'] );
unset( $object['@context'] );
}
// get inbox
$inbox = $follower->get_inbox();
// send "Accept" activity
$activity = new Activity( 'Accept' );
$activity->set_object( $object );
$activity->set_actor( \get_author_posts_url( $user_id ) );
$activity->set_to( $actor );
$activity->set_id( \get_author_posts_url( $user_id ) . '#follow-' . \preg_replace( '~^https?://~', '', $actor ) );
$activity = $activity->to_simple_json();
$response = Http::post( $inbox, $activity, $user_id );
}
/**
* Get the Followers of a given user
*
* @param int $user_id The ID of the WordPress User
* @param string $output The output format, supported ARRAY_N, OBJECT and ACTIVITYPUB_OBJECT
* @param int $number Limts the result
* @param int $offset Offset
*
* @return array The Term list of Followers, the format depends on $output
*/
public static function get_followers( $user_id, $number = null, $offset = null, $args = array() ) {
$defaults = array(
'taxonomy' => self::TAXONOMY,
'hide_empty' => false,
'object_ids' => $user_id,
'number' => $number,
'offset' => $offset,
'orderby' => 'id',
'order' => 'ASC',
);
$args = wp_parse_args( $args, $defaults );
$terms = new WP_Term_Query( $args );
$items = array();
foreach ( $terms->get_terms() as $follower ) {
$items[] = new Follower( $follower->name ); // phpcs:ignore
}
return $items;
}
/**
* Count the total number of followers
*
* @param int $user_id The ID of the WordPress User
*
* @return int The number of Followers
*/
public static function count_followers( $user_id ) {
return count( self::get_followers( $user_id ) );
}
/**
* Returns all Inboxes fo a Users Followers
*
* @param int $user_id The ID of the WordPress User
*
* @return array The list of Inboxes
*/
public static function get_inboxes( $user_id ) {
// get all Followers of a ID of the WordPress User
$terms = new WP_Term_Query(
array(
'taxonomy' => self::TAXONOMY,
'hide_empty' => false,
'object_ids' => $user_id,
'fields' => 'ids',
'meta_query' => array(
array(
'key' => 'inbox',
'compare' => 'EXISTS',
),
),
)
);
$terms = $terms->get_terms();
if ( ! $terms ) {
return array();
}
global $wpdb;
$results = $wpdb->get_col(
$wpdb->prepare(
"SELECT DISTINCT meta_value FROM {$wpdb->termmeta}
WHERE term_id IN (" . implode( ', ', array_fill( 0, count( $terms ), '%d' ) ) . ")
AND meta_key = 'shared_inbox'
AND meta_value IS NOT NULL",
$terms
)
);
return array_filter( $results );
}
/**
* Get all Followers that have not been updated for a given time
*
* @param enum $output The output format, supported ARRAY_N, OBJECT and ACTIVITYPUB_OBJECT.
* @param int $number Limits the result.
* @param int $older_than The time in seconds.
*
* @return mixed The Term list of Followers, the format depends on $output.
*/
public static function get_outdated_followers( $number = 50, $older_than = 604800 ) {
$args = array(
'taxonomy' => self::TAXONOMY,
'number' => $number,
'meta_key' => 'updated_at',
'orderby' => 'meta_value_num',
'order' => 'DESC',
'meta_query' => array(
array(
'key' => 'updated_at',
'value' => time() - $older_than,
'type' => 'numeric',
'compare' => '<=',
),
),
);
$terms = new WP_Term_Query( $args );
$items = array();
foreach ( $terms->get_terms() as $follower ) {
$items[] = new Follower( $follower->name ); // phpcs:ignore
}
return $items;
}
/**
* Get all Followers that had errors
*
* @param enum $output The output format, supported ARRAY_N, OBJECT and ACTIVITYPUB_OBJECT
* @param integer $number The number of Followers to return.
*
* @return mixed The Term list of Followers, the format depends on $output.
*/
public static function get_faulty_followers( $number = 10 ) {
$args = array(
'taxonomy' => self::TAXONOMY,
'number' => $number,
'meta_query' => array(
array(
'key' => 'errors',
'compare' => 'EXISTS',
),
),
);
$terms = new WP_Term_Query( $args );
$items = array();
foreach ( $terms->get_terms() as $follower ) {
$items[] = new Follower( $follower->name ); // phpcs:ignore
}
return $items;
}
}