<?php
namespace Zotlabs\Lib;
/**
* @brief ActivityStreams class.
*
* Parses an ActivityStream JSON string.
*/
class ActivityStreams {
public $raw = null;
public $data = null;
public $valid = false;
public $deleted = false;
public $id = '';
public $parent_id = '';
public $type = '';
public $actor = null;
public $obj = null;
public $tgt = null;
public $origin = null;
public $owner = null;
public $signer = null;
public $ldsig = null;
public $sigok = false;
public $recips = null;
public $raw_recips = null;
/**
* @brief Constructor for ActivityStreams.
*
* Takes a JSON string as parameter, decodes it and sets up this object.
*
* @param string $string
*/
function __construct($string) {
$this->raw = $string;
if(is_array($string)) {
$this->data = $string;
}
else {
$this->data = json_decode($string, true);
}
if($this->data) {
// verify and unpack JSalmon signature if present
if(is_array($this->data) && array_key_exists('signed',$this->data)) {
$ret = JSalmon::verify($this->data);
$tmp = JSalmon::unpack($this->data['data']);
if($ret && $ret['success']) {
if($ret['signer']) {
$saved = json_encode($this->data,JSON_UNESCAPED_SLASHES);
$this->data = $tmp;
$this->data['signer'] = $ret['signer'];
$this->data['signed_data'] = $saved;
if($ret['hubloc']) {
$this->data['hubloc'] = $ret['hubloc'];
}
}
}
}
$this->valid = true;
if(array_key_exists('type',$this->data) && array_key_exists('actor',$this->data) && array_key_exists('object',$this->data)) {
if($this->data['type'] === 'Delete' && $this->data['actor'] === $this->data['object']) {
$this->deleted = $this->data['actor'];
$this->valid = false;
}
}
}
if($this->is_valid()) {
$this->id = $this->get_property_obj('id');
$this->type = $this->get_primary_type();
$this->actor = $this->get_actor('actor','','');
$this->obj = $this->get_compound_property('object');
$this->tgt = $this->get_compound_property('target');
$this->origin = $this->get_compound_property('origin');
$this->recips = $this->collect_recips();
$this->ldsig = $this->get_compound_property('signature');
if($this->ldsig) {
$this->signer = $this->get_compound_property('creator',$this->ldsig);
if($this->signer && is_array($this->signer) && array_key_exists('publicKey',$this->signer) && is_array($this->signer['publicKey']) && $this->signer['publicKey']['publicKeyPem']) {
$this->sigok = LDSignatures::verify($this->data,$this->signer['publicKey']['publicKeyPem']);
}
}
if(! $this->obj) {
$this->obj = $this->data;
$this->type = 'Create';
if(! $this->actor) {
$this->actor = $this->get_actor('attributedTo',$this->obj);
}
}
// fetch recursive or embedded activities
if ($this->obj && is_array($this->obj) && array_key_exists('object',$this->obj)) {
$this->obj['object'] = $this->get_compound_property($this->obj['object']);
}
if($this->obj && is_array($this->obj) && $this->obj['actor'])
$this->obj['actor'] = $this->get_actor('actor',$this->obj);
if($this->tgt && is_array($this->tgt) && $this->tgt['actor'])
$this->tgt['actor'] = $this->get_actor('actor',$this->tgt);
$this->parent_id = $this->get_property_obj('inReplyTo');
if((! $this->parent_id) && is_array($this->obj)) {
$this->parent_id = $this->obj['inReplyTo'];
}
if((! $this->parent_id) && is_array($this->obj)) {
$this->parent_id = $this->obj['id'];
}
}
}
/**
* @brief Return if instantiated ActivityStream is valid.
*
* @return boolean Return true if the JSON string could be decoded.
*/
function is_valid() {
return $this->valid;
}
function set_recips($arr) {
$this->saved_recips = $arr;
}
/**
* @brief Collects all recipients.
*
* @param string $base
* @param string $namespace (optional) default empty
* @return array
*/
function collect_recips($base = '', $namespace = '') {
$x = [];
$fields = [ 'to', 'cc', 'bto', 'bcc', 'audience'];
foreach($fields as $f) {
$y = $this->get_compound_property($f, $base, $namespace);
if($y) {
$x = array_merge($x, $y);
if(! is_array($this->raw_recips))
$this->raw_recips = [];
$this->raw_recips[$f] = $x;
}
}
// not yet ready for prime time
// $x = $this->expand($x,$base,$namespace);
return $x;
}
function expand($arr,$base = '',$namespace = '') {
$ret = [];
// right now use a hardwired recursion depth of 5
for($z = 0; $z < 5; $z ++) {
if(is_array($arr) && $arr) {
foreach($arr as $a) {
if(is_array($a)) {
$ret[] = $a;
}
else {
$x = $this->get_compound_property($a,$base,$namespace);
if($x) {
$ret = array_merge($ret,$x);
}
}
}
}
}
/// @fixme de-duplicate
return $ret;
}
/**
* @brief
*
* @param array $base
* @param string $namespace if not set return empty string
* @return string|NULL
*/
function get_namespace($base, $namespace) {
if(! $namespace)
return '';
$key = null;
foreach( [ $this->data, $base ] as $b ) {
if(! $b)
continue;
if(array_key_exists('@context', $b)) {
if(is_array($b['@context'])) {
foreach($b['@context'] as $ns) {
if(is_array($ns)) {
foreach($ns as $k => $v) {
if($namespace === $v)
$key = $k;
}
}
else {
if($namespace === $ns) {
$key = '';
}
}
}
}
else {
if($namespace === $b['@context']) {
$key = '';
}
}
}
}
return $key;
}
/**
* @brief
*
* @param string $property
* @param array $base (optional)
* @param string $namespace (optional) default empty
* @return NULL|mixed
*/
function get_property_obj($property, $base = '', $namespace = '') {
$prefix = $this->get_namespace($base, $namespace);
if($prefix === null)
return null;
$base = (($base) ? $base : $this->data);
$propname = (($prefix) ? $prefix . ':' : '') . $property;
if(! is_array($base)) {
btlogger('not an array: ' . print_r($base,true));
return null;
}
return ((array_key_exists($propname, $base)) ? $base[$propname] : null);
}
/**
* @brief Fetches a property from an URL.
*
* @param string $url
* @return NULL|mixed
*/
function fetch_property($url) {
return self::fetch($url);
}
static function fetch($url,$channel = null) {
return Activity::fetch($url,$channel);
}
static function is_an_actor($s) {
return(in_array($s,[ 'Application','Group','Organization','Person','Service' ]));
}
/**
* @brief
*
* @param string $property
* @param array $base
* @param string $namespace (optional) default empty
* @return NULL|mixed
*/
function get_actor($property,$base='',$namespace = '') {
$x = $this->get_property_obj($property, $base, $namespace);
if($this->is_url($x)) {
// SECURITY: If we have already stored the actor profile, re-generate it
// from cached data - don't refetch it from the network
$r = q("select * from xchan left join hubloc on xchan_hash = hubloc_hash where hubloc_id_url = '%s' limit 1",
dbesc($x)
);
if($r) {
$y = Activity::encode_person($r[0]);
$y['cached'] = true;
return $y;
}
}
$actor = $this->get_compound_property($property,$base,$namespace,true);
if(is_array($actor) && self::is_an_actor($actor['type'])) {
if(array_key_exists('id',$actor) && (! array_key_exists('inbox',$actor))) {
$actor = $this->fetch_property($actor['id']);
}
return $actor;
}
return null;
}
/**
* @brief
*
* @param string $property
* @param array $base
* @param string $namespace (optional) default empty
* @param boolean $first (optional) default false, if true and result is a sequential array return only the first element
* @return NULL|mixed
*/
function get_compound_property($property, $base = '', $namespace = '', $first = false) {
$x = $this->get_property_obj($property, $base, $namespace);
if($this->is_url($x)) {
$y = $this->fetch_property($x);
if (is_array($y)) {
$x = $y;
}
}
// verify and unpack JSalmon signature if present
if(is_array($x) && array_key_exists('signed',$x)) {
$ret = JSalmon::verify($x);
$tmp = JSalmon::unpack($x['data']);
if($ret && $ret['success']) {
if($ret['signer']) {
$saved = json_encode($x,JSON_UNESCAPED_SLASHES);
$x = $tmp;
$x['signer'] = $ret['signer'];
$x['signed_data'] = $saved;
if($ret['hubloc']) {
$x['hubloc'] = $ret['hubloc'];
}
}
}
}
if($first && is_array($x) && array_key_exists(0,$x)) {
return $x[0];
}
return $x;
}
/**
* @brief Check if string starts with http.
*
* @param string $url
* @return boolean
*/
function is_url($url) {
if(($url) && (! is_array($url)) && (strpos($url, 'http') === 0)) {
return true;
}
return false;
}
/**
* @brief Gets the type property.
*
* @param array $base
* @param string $namespace (optional) default empty
* @return NULL|mixed
*/
function get_primary_type($base = '', $namespace = '') {
if(! $base)
$base = $this->data;
$x = $this->get_property_obj('type', $base, $namespace);
if(is_array($x)) {
foreach($x as $y) {
if(strpos($y, ':') === false) {
return $y;
}
}
}
return $x;
}
function debug() {
$x = var_export($this, true);
return $x;
}
static function is_as_request() {
$x = getBestSupportedMimeType([
'application/ld+json;profile="https://www.w3.org/ns/activitystreams"',
'application/activity+json',
'application/ld+json;profile="http://www.w3.org/ns/activitystreams"'
]);
return(($x) ? true : false);
}
}
