Add support for Activitypub JSON

assets/css/activitypub-embed.css

@@ -0,0 +1,106 @@
+/**
+ * ActivityPub embed styles.
+ */
+
+.activitypub-embed {
+	background: #fff;
+	border: 1px solid #e6e6e6;
+	border-radius: 12px;
+	margin: 1em 0;
+	padding: 0;
+	max-width: 100%;
+	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+}
+
+.activitypub-embed-header {
+	padding: 15px;
+	display: flex;
+	align-items: center;
+	gap: 10px;
+}
+
+.activitypub-embed-header img {
+	width: 48px;
+	height: 48px;
+	border-radius: 50%;
+}
+
+.activitypub-embed-header-text {
+	flex-grow: 1;
+}
+
+.activitypub-embed-header-text h2 {
+	color: #000;
+	font-size: 15px;
+	font-weight: 600;
+	margin: 0;
+	padding: 0;
+}
+
+.activitypub-embed-header-text .ap-account {
+	color: #687684;
+	font-size: 14px;
+	text-decoration: none;
+}
+
+.activitypub-embed-content {
+	padding: 0 15px 15px;
+}
+
+.activitypub-embed-content .ap-title {
+	font-size: 23px;
+	font-weight: 600;
+	margin: 0 0 10px;
+	padding: 0;
+	color: #000;
+}
+
+.activitypub-embed-content .ap-subtitle {
+	font-size: 15px;
+	color: #000;
+	margin: 0 0 15px;
+}
+
+.activitypub-embed-content .ap-preview {
+	border: 1px solid #e6e6e6;
+	border-radius: 8px;
+	overflow: hidden;
+}
+
+.activitypub-embed-content .ap-preview img {
+	width: 100%;
+	height: auto;
+	display: block;
+}
+
+.activitypub-embed-content .ap-preview-text {
+	padding: 15px;
+}
+
+.activitypub-embed-meta {
+	padding: 15px;
+	border-top: 1px solid #e6e6e6;
+	color: #687684;
+	font-size: 13px;
+	display: flex;
+	gap: 15px;
+}
+
+.activitypub-embed-meta .ap-stat {
+	display: flex;
+	align-items: center;
+	gap: 5px;
+}
+
+.activitypub-embed-meta a.ap-stat {
+	text-decoration: none;
+}
+
+.activitypub-embed-meta strong {
+	font-weight: 600;
+	color: #000;
+}
+
+.activitypub-embed-meta .ap-stat-label {
+	color: #687684;
+}

includes/functions.php

@@ -1597,15 +1597,138 @@ function is_self_ping( $id ) {
 /**
  * Get the embed of a URL.
  *
- * This function supports oEmbed URLs, but it is planned to also
- * support ActivityPub in the future.
- *
- * @todo Add ActivityPub support.
+ * This function supports both ActivityPub JSON and oEmbed URLs.
+ * It first tries to fetch ActivityPub JSON, and if that fails,
+ * falls back to oEmbed.
  *
  * @param string $url The URL to get the embed of.
  *
  * @return string|false The embed of the URL or false if not found.
  */
 function embed_get( $url ) {
-	return wp_oembed_get( $url );
+	if ( ! \get_the_ID() ) {
+		return false;
+	}
+
+	// Create unique transient keys for both HTTP calls.
+	$main_transient_key = '_activitypub_embed_' . md5( $url );
+	$embed              = \get_transient( $main_transient_key );
+
+	if ( false === $embed ) {
+		$response = Http::get( $url );
+		if ( \wp_remote_retrieve_response_code( $response ) === 200 ) {
+			$embed = \json_decode( \wp_remote_retrieve_body( $response ), true );
+			\set_transient( $main_transient_key, $embed, DAY_IN_SECONDS );
+		} else {
+			return \wp_oembed_get( $url );
+		}
+	}
+
+	if ( $embed ) {
+		$author_name = isset( $embed['attributedTo'] ) ? $embed['attributedTo'] : '';
+		$author_url  = $author_name;
+		$avatar_url  = isset( $embed['icon']['url'] ) ? $embed['icon']['url'] : '';
+
+		// If we don't have an avatar URL but we have an author URL, try to fetch it.
+		if ( ! $avatar_url && $author_url ) {
+			$author_transient_key = '_activitypub_author_' . md5( $author_url );
+			$author               = \get_transient( $author_transient_key );
+
+			if ( false === $author ) {
+				$author_response = Http::get( $author_url );
+				if ( \wp_remote_retrieve_response_code( $author_response ) === 200 ) {
+					$author = \json_decode( \wp_remote_retrieve_body( $author_response ), true );
+					\set_transient( $author_transient_key, $author, DAY_IN_SECONDS );
+				}
+			}
+
+			if ( $author ) {
+				if ( isset( $author['icon']['url'] ) ) {
+					$avatar_url = $author['icon']['url'];
+				}
+				if ( isset( $author['name'] ) ) {
+					$author_name = $author['name'];
+				}
+			}
+		}
+
+		$published = isset( $embed['published'] ) ? \gmdate( get_option( 'date_format' ) . ', ' . get_option( 'time_format' ), \strtotime( $embed['published'] ) ) : '';
+		$title     = isset( $embed['name'] ) ? $embed['name'] : '';
+		$content   = isset( $embed['content'] ) ? $embed['content'] : '';
+		$boosts    = isset( $embed['shares']['totalItems'] ) ? (int) $embed['shares']['totalItems'] : 0;
+		$favorites = isset( $embed['likes']['totalItems'] ) ? (int) $embed['likes']['totalItems'] : 0;
+
+		$image = '';
+		if ( isset( $embed['image']['url'] ) ) {
+			$image = $embed['image']['url'];
+		} elseif ( isset( $embed['attachment'] ) ) {
+			foreach ( $embed['attachment'] as $attachment ) {
+				if ( isset( $attachment['type'] ) && 'Document' === $attachment['type'] ) {
+					$image = $attachment['url'];
+					break;
+				}
+			}
+		}
+
+		ob_start();
+		?>
+		<div class="activitypub-embed">
+			<div class="activitypub-embed-header">
+				<?php if ( $avatar_url ) : ?>
+					<img src="<?php echo \esc_url( $avatar_url ); ?>" alt="" />
+				<?php endif; ?>
+				<div class="activitypub-embed-header-text">
+					<h2><?php echo \esc_html( $author_name ); ?></h2>
+					<?php if ( $author_url ) : ?>
+						<a href="<?php echo \esc_url( $author_url ); ?>" class="ap-account"><?php echo \esc_html( $author_url ); ?></a>
+					<?php endif; ?>
+				</div>
+			</div>
+
+			<div class="activitypub-embed-content">
+				<?php if ( $title ) : ?>
+					<h3 class="ap-title"><?php echo \esc_html( $title ); ?></h3>
+				<?php endif; ?>
+
+				<?php if ( $content ) : ?>
+					<div class="ap-subtitle"><?php echo \wp_kses_post( $content ); ?></div>
+				<?php endif; ?>
+
+				<?php if ( $image ) : ?>
+					<div class="ap-preview">
+						<img src="<?php echo \esc_url( $image ); ?>" alt="" />
+					</div>
+				<?php endif; ?>
+			</div>
+
+			<div class="activitypub-embed-meta">
+				<?php if ( $published ) : ?>
+					<a href="<?php echo \esc_url( $url ); ?>" class="ap-stat ap-date"><?php echo \esc_html( $published ); ?></a>
+				<?php endif; ?>
+
+				<span class="ap-stat">
+					<?php
+					/* translators: %s: number of boosts */
+					printf( \esc_html__( '%s boosts', 'activitypub' ), '<strong>' . \esc_html( $boosts ) . '</strong>' );
+					?>
+				</span>
+
+				<span class="ap-stat">
+					<?php
+					/* translators: %s: number of favorites */
+					printf( \esc_html__( '%s favorites', 'activitypub' ), '<strong>' . \esc_html( $favorites ) . '</strong>' );
+					?>
+				</span>
+			</div>
+		</div>
+		<?php
+		$output = ob_get_clean();
+
+		if ( $output ) {
+			\wp_enqueue_style( 'activitypub-embed', ACTIVITYPUB_PLUGIN_URL . 'assets/css/activitypub-embed.css', array(), ACTIVITYPUB_PLUGIN_VERSION );
+			return $output;
+		}
+	}
+
+	return \wp_oembed_get( $url );
 }