activitypub / includes / functions-media.php

functions-media.php in ActivityPub trunk, at includes/functions-media.php

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1	<?php
2	/**
3	* Media functions file.
4	*
5	* Functions for processing remote media (images, audio, video) in ActivityPub content.
6	*
7	* @package Activitypub
8	*/
9
10	namespace Activitypub;
11
12	/**
13	* Check if a URL is a remote URL (not local to this site).
14	*
15	* @param string $url The URL to check.
16	*
17	* @return bool True if the URL is remote, false otherwise.
18	*/
19	function is_remote_url( $url ) {
20	// Must be http/https URL.
21	if ( ! \preg_match( '#^https?://#i', $url ) ) {
22	return false;
23	}
24
25	// Compare hosts to determine if URL is local.
26	$site_host = \wp_parse_url( \home_url(), PHP_URL_HOST );
27	$url_host = \wp_parse_url( $url, PHP_URL_HOST );
28
29	// If hosts match, it's a local URL.
30	if ( $site_host && $url_host && 0 === \strcasecmp( $site_host, $url_host ) ) {
31	return false;
32	}
33
34	// Also check uploads directory with strict prefix match.
35	$upload_dir = \wp_upload_dir();
36	$upload_base = isset( $upload_dir['baseurl'] ) ? \trailingslashit( $upload_dir['baseurl'] ) : '';
37
38	if ( $upload_base && \str_starts_with( $url, $upload_base ) ) {
39	return false;
40	}
41
42	return true;
43	}
44
45	/**
46	* Generate an image block wrapper for a remote image.
47	*
48	* @param string $url The remote image URL.
49	* @param string $img_html The img tag HTML.
50	*
51	* @return string The wrapped image block.
52	*/
53	function generate_image_block( $url, $img_html ) {
54	return \sprintf(
55	'<!-- wp:activitypub/image %s -->%s<!-- /wp:activitypub/image -->',
56	\wp_json_encode( array( 'url' => $url ) ),
57	$img_html
58	);
59	}
60
61	/**
62	* Generate an audio block wrapper for a remote audio file.
63	*
64	* @param string $url The remote audio URL.
65	*
66	* @return string The audio block markup.
67	*/
68	function generate_audio_block( $url ) {
69	return \sprintf(
70	'<!-- wp:activitypub/audio %s --><figure class="wp-block-audio"><audio controls src="%s"></audio></figure><!-- /wp:activitypub/audio -->',
71	\wp_json_encode( array( 'url' => $url ) ),
72	\esc_url( $url )
73	);
74	}
75
76	/**
77	* Generate a video block wrapper for a remote video file.
78	*
79	* @param string $url The remote video URL.
80	*
81	* @return string The video block markup.
82	*/
83	function generate_video_block( $url ) {
84	return \sprintf(
85	'<!-- wp:activitypub/video %s --><figure class="wp-block-video"><video controls src="%s"></video></figure><!-- /wp:activitypub/video -->',
86	\wp_json_encode( array( 'url' => $url ) ),
87	\esc_url( $url )
88	);
89	}
90
91	/**
92	* Process remote images in content and from attachments.
93	*
94	* Wraps remote `<img>` tags with activitypub/image blocks for lazy caching,
95	* and appends any attachments not already present in the content.
96	*
97	* @param string $content The content to process.
98	* @param array $attachments Optional. Array of attachments with 'url' and 'alt' keys.
99	*
100	* @return string The content with wrapped images and appended attachments.
101	*/
102	function process_remote_images( $content, $attachments = array() ) {
103	if ( empty( $content ) && empty( $attachments ) ) {
104	return $content;
105	}
106
107	// Track URLs we've seen to avoid duplicates.
108	$seen_urls = array();
109
110	// Process existing images in content.
111	if ( ! empty( $content ) && false !== \strpos( $content, '<img' ) ) {
112	$processor = new \WP_HTML_Tag_Processor( $content );
113
114	// Mark remote images for wrapping using a data attribute.
115	while ( $processor->next_tag( 'IMG' ) ) {
116	$src = $processor->get_attribute( 'src' );
117
118	if ( $src && is_remote_url( $src ) && ! isset( $seen_urls[ $src ] ) ) {
119	$processor->set_attribute( 'data-activitypub-wrap', '1' );
120	$seen_urls[ $src ] = true;
121	}
122	}
123
124	$content = $processor->get_updated_html();
125
126	// Wrap marked images, skipping those already in image blocks.
127	$content = \preg_replace_callback(
128	'/<!-- wp:activitypub\/image[^>]-->.?<!-- \/wp:activitypub\/image -->(SKIP)(?!)\|<img\s+([^>])data-activitypub-wrap="1"([^>]*)>/is',
129	function ( $matches ) {
130	if ( empty( $matches[1] ) && empty( $matches[2] ) ) {
131	return $matches[0]; // Skipped block.
132	}
133
134	// Reconstruct img tag without the marker attribute.
135	$img_html = '<img ' . \trim( $matches[1] . $matches[2] ) . '>';
136
137	// Extract src URL from the img tag.
138	if ( \preg_match( '/src=["\']([^"\']+)["\']/', $img_html, $src_match ) ) {
139	return generate_image_block( $src_match[1], $img_html );
140	}
141
142	return $matches[0];
143	},
144	$content
145	);
146	}
147
148	// Append attachments not already in content.
149	if ( ! empty( $attachments ) ) {
150	foreach ( $attachments as $attachment ) {
151	$url = $attachment['url'] ?? '';
152	if ( empty( $url ) \|\| isset( $seen_urls[ $url ] ) ) {
153	continue;
154	}
155
156	// Also check if URL appears in content (in case it wasn't in an img tag).
157	if ( false !== \strpos( $content, $url ) ) {
158	continue;
159	}
160
161	$alt = ! empty( $attachment['alt'] ) ? \esc_attr( $attachment['alt'] ) : '';
162	$img_tag = $alt
163	? \sprintf( '<img src="%s" alt="%s" />', \esc_url( $url ), $alt )
164	: \sprintf( '<img src="%s" />', \esc_url( $url ) );
165
166	$content .= "\n\n" . generate_image_block( $url, $img_tag );
167	$seen_urls[ $url ] = true;
168	}
169	}
170
171	return $content;
172	}
173
174	/**
175	* Process remote media in content and from attachments.
176	*
177	* Delegates image attachments to process_remote_images() and appends
178	* audio/video attachments as their respective block types.
179	*
180	* @param string $content The content to process.
181	* @param array $attachments Optional. Array of attachments with 'url', 'alt', and 'type' keys.
182	*
183	* @return string The content with wrapped images and appended audio/video blocks.
184	*/
185	function process_remote_media( $content, $attachments = array() ) {
186	// Separate attachments by type.
187	$image_attachments = array();
188	$media_attachments = array();
189
190	foreach ( $attachments as $attachment ) {
191	$type = $attachment['type'] ?? 'image';
192
193	if ( 'audio' === $type \|\| 'video' === $type ) {
194	$media_attachments[] = $attachment;
195	} else {
196	$image_attachments[] = $attachment;
197	}
198	}
199
200	// Delegate image attachments to existing handler.
201	$content = process_remote_images( $content, $image_attachments );
202
203	// Append audio/video blocks.
204	foreach ( $media_attachments as $attachment ) {
205	$url = $attachment['url'] ?? '';
206	if ( empty( $url ) ) {
207	continue;
208	}
209
210	// Skip if URL already appears in content.
211	if ( false !== \strpos( $content, $url ) ) {
212	continue;
213	}
214
215	$type = $attachment['type'];
216
217	if ( 'audio' === $type ) {
218	$content .= "\n\n" . generate_audio_block( $url );
219	} elseif ( 'video' === $type ) {
220	$content .= "\n\n" . generate_video_block( $url );
221	}
222	}
223
224	return $content;
225	}
226