From a653c6350d6d5ddc76d86040271df142a3ad237c Mon Sep 17 00:00:00 2001
From: Michael <heluecht@pirati.ca>
Date: Thu, 29 Sep 2022 16:04:33 +0000
Subject: [PATCH] Support for quoted links is added

---
 src/Protocol/ActivityPub/Processor.php | 38 ++++++++++++++++++++++++++
 src/Protocol/ActivityPub/Receiver.php  | 18 ++++++++++++
 src/Util/JsonLD.php                    |  2 ++
 static/litepub-0.1.jsonld              |  6 +++-
 4 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index 6fcce4a3ab..f75e6189b8 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -848,6 +848,10 @@ class Processor
 			}
 			$item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 			$item['raw-body'] = $item['body'] = $content;
+
+			if (!empty($activity['quote-url'])) {
+				$item['body'] .= self::addSharedData($activity['quote-url']);
+			}
 		}
 
 		self::storeFromBody($item);
@@ -866,6 +870,40 @@ class Processor
 		return $item;
 	}
 
+	/**
+	 * Add a share block for the given quote link
+	 *
+	 * @param string $url
+	 * @return string
+	 */
+	private static function addSharedData(string $url): string
+	{
+		$id = Item::fetchByLink($url);
+		if (empty($id)) {
+			return '';
+		}
+
+		$shared_item = Post::selectFirst(['author-name', 'author-link', 'author-avatar', 'plink', 'created', 'guid', 'title', 'body'], ['id' => $id]);
+		if (!DBA::isResult($shared_item)) {
+			return '';
+		}
+
+		$prefix = BBCode::getShareOpeningTag(
+			$shared_item['author-name'],
+			$shared_item['author-link'],
+			$shared_item['author-avatar'],
+			$shared_item['plink'],
+			$shared_item['created'],
+			$shared_item['guid']
+		);
+
+		if (!empty($shared_item['title'])) {
+			$prefix .= '[h3]' . $shared_item['title'] . "[/h3]\n";
+		}
+
+		return $prefix . $shared_item['body'] . '[/share]';
+	}
+
 	/**
 	 * Store hashtags and mentions
 	 *
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index c161ce4d11..a410c35258 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -1916,6 +1916,24 @@ class Receiver
 			$object_data['attachments'] = array_merge($object_data['attachments'], self::processAttachmentUrls($object['as:url'] ?? []));
 		}
 
+		// Support for quoted posts (Pleroma, Fedibird and Misskey)
+		$object_data['quote-url'] = JsonLD::fetchElement($object, 'as:quoteUrl', '@value');
+		if (empty($object_data['quote-url'])) {
+			$object_data['quote-url'] = JsonLD::fetchElement($object, 'fedibird:quoteUri', '@value');
+		}
+		if (empty($object_data['quote-url'])) {
+			$object_data['quote-url'] = JsonLD::fetchElement($object, 'misskey:_misskey_quote', '@value');
+		}
+
+		// Misskey adds some data to the standard "content" value for quoted posts for backwards compatibility.
+		// Their own "_misskey_content" value does then contain the content without this extra data.
+		if (!empty($object_data['quote-url'])) {
+			$misskey_content = JsonLD::fetchElement($object, 'misskey:_misskey_content', '@value');
+			if (!empty($misskey_content)) {
+				$object_data['content'] = $misskey_content;
+			}
+		}
+
 		// For page types we expect that the alternate url posts to some page.
 		// So we add this to the attachments if it differs from the id.
 		// Currently only Lemmy is using the page type.
diff --git a/src/Util/JsonLD.php b/src/Util/JsonLD.php
index 947274134c..25ce74fcc7 100644
--- a/src/Util/JsonLD.php
+++ b/src/Util/JsonLD.php
@@ -157,6 +157,8 @@ class JsonLD
 			'sc' => (object)['@id' => 'http://schema.org#', '@type' => '@id'],
 			'pt' => (object)['@id' => 'https://joinpeertube.org/ns#', '@type' => '@id'],
 			'mobilizon' => (object)['@id' => 'https://joinmobilizon.org/ns#', '@type' => '@id'],
+			'fedibird' => (object)['@id' => 'http://fedibird.com/ns#', '@type' => '@id'],
+			'misskey' => (object)['@id' => 'https://misskey-hub.net/ns#', '@type' => '@id'],
 		];
 
 		$orig_json = $json;
diff --git a/static/litepub-0.1.jsonld b/static/litepub-0.1.jsonld
index e7722cf726..16c22ff0f6 100644
--- a/static/litepub-0.1.jsonld
+++ b/static/litepub-0.1.jsonld
@@ -17,6 +17,7 @@
             "ostatus": "http://ostatus.org#",
             "schema": "http://schema.org#",
             "toot": "http://joinmastodon.org/ns#",
+            "fedibird": "http://fedibird.com/ns#",
             "value": "schema:value",
             "sensitive": "as:sensitive",
             "litepub": "http://litepub.social/ns#",
@@ -26,6 +27,8 @@
                 "@id": "litepub:listMessage",
                 "@type": "@id"
             },
+            "quoteUrl": "as:quoteUrl",
+            "quoteUri": "fedibird:quoteUri",
             "oauthRegistrationEndpoint": {
                 "@id": "litepub:oauthRegistrationEndpoint",
                 "@type": "@id"
@@ -35,7 +38,8 @@
             "alsoKnownAs": {
                 "@id": "as:alsoKnownAs",
                 "@type": "@id"
-            }
+            },
+            "vcard": "http://www.w3.org/2006/vcard/ns#"
         }
     ]
 }