From 95bc5557f8e6ad7439177b26af7e0f77c5c783a2 Mon Sep 17 00:00:00 2001
From: Jeremy Dormitzer <jeremy.dormitzer@gmail.com>
Date: Sun, 9 Sep 2018 18:48:14 -0600
Subject: [PATCH] [WIP] Begin to implement delivery

---
 inc/deliver.php | 82 +++++++++++++++++++++++++++++++++++++++++++++++++
 inc/outbox.php  |  4 ++-
 2 files changed, 85 insertions(+), 1 deletion(-)
 create mode 100644 inc/deliver.php

diff --git a/inc/deliver.php b/inc/deliver.php
new file mode 100644
index 0000000..523f6f5
--- /dev/null
+++ b/inc/deliver.php
@@ -0,0 +1,82 @@
+<?php
+namespace deliver;
+
+function deliver_activity( $activity ) {
+    $recipients = array();
+    for ( $field as array( 'to', 'bto', 'cc', 'bcc', 'audience' ) ) {
+        $recipients = array_merge(
+            $recipients, retrieve_recipients_for_field( $field, $activity )
+        );
+    }
+    $recipients = array_unique( $recipients );
+    if ( array_key_exists( 'actor', $activity ) ) {
+        $recipients = remove_actor_inbox_from_recipients( $activity['actor'], $recipients );
+    }
+    post_activity_to_inboxes( $activity, $recipients );
+}
+
+function remove_actor_inbox_from_recipients( $actor, $recipients ) {
+    if ( array_key_exists( 'inbox', $actor ) ) {
+        $key = array_search( $actor['inbox'], $recipients );
+        if ( $key ) {
+            unset $recipients[$key];
+        }
+    }
+    return $recipients;
+}
+
+function retrieve_recipients_for_field( $field, $activity ) {
+    $recipients = array();
+    if ( array_key_exists( $field, $activity ) ) {
+        foreach ( $url as $activity[$field] ) {
+            $recipients = array_merge( $recipients, retrieve_recipients( $url ) );
+        }
+    }
+    return $recipients;
+}
+
+function retrieve_recipients( $url ) {
+    // TODO add an arg to keep track of recursion and cut off after 30 recursions
+    $response_body = wp_remote_retrieve_body( wp_remote_get ( $url ) );
+    // possible responses:
+    //  - actor json
+    //  - collection
+    if ( !array_key_exists( 'type', $response_body ) ) {
+        return new \WP_Error(
+            'invalid_object', __( 'Expected an object type', 'activitypub' )
+        );
+    }
+    switch ( $response_body['type'] ) {
+    case 'Collection':
+    case 'OrderedCollection':
+        $items = array();
+        $recipients = array();
+        if ( array_key_exists( 'items', $response_body ) ) {
+            $items = $response_body['items'];
+        } else if ( array_key_exists( 'orderedItems', $response_body ) ) {
+            $items = $response_body['orderedItems'];
+        }
+        if ( count( $items ) > 0 ) {
+            // recursive case: call retrieve_recipients on each $item
+            // merge the results and return them
+            foreach ( $items as $item ) {
+                // TODO what will $item look like? Could be an actor JSON, or just a URL?
+                $recipients[] = retrieve_recipients( $item );
+            }
+        }
+        return $recipients;
+    default: // an actor
+        if ( array_key_exists( 'inbox', $response_body ) ) {
+            return array( $response_body['inbox'] );
+        }
+        return array();
+    }
+}
+
+function post_activity_to_inboxes( $activity, $recipients ) {
+    foreach ( $inbox as $recipients ) {
+        // TODO
+        wp_remote_post();
+    }
+}
+?>
diff --git a/inc/outbox.php b/inc/outbox.php
index 39f895d..af0719d 100644
--- a/inc/outbox.php
+++ b/inc/outbox.php
@@ -13,6 +13,7 @@ When an Activity is received (i.e. POSTed) to an Actor's outbox, the server must
 namespace outbox;
 
 require_once plugin_dir_path( __FILE__ ) . '/activities.php';
+require_once plugin_dir_path( __FILE__ ) . '/deliver.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/create.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/update.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/delete.php';
@@ -86,7 +87,8 @@ function handle_activity( $actor, $activity ) {
 }
 
 function deliver_activity( $activity ) {
-    // TODO
+    // TODO deliver activity, then strip bto and bcc
+    \deliver\deliver_activity( $activity );
 }
 
 function persist_activity( $actor, $activity ) {