1 use crate::post::SiteMetadata;
2 use encoding::{all::encodings, DecoderTrap};
3 use lemmy_utils::{settings::structs::Settings, version::VERSION, LemmyError, REQWEST_TIMEOUT};
4 use percent_encoding::{utf8_percent_encode, NON_ALPHANUMERIC};
5 use reqwest_middleware::ClientWithMiddleware;
6 use serde::Deserialize;
11 /// Fetches the post link html tags (like title, description, image, etc)
12 #[tracing::instrument(skip_all)]
13 pub async fn fetch_site_metadata(
14 client: &ClientWithMiddleware,
16 ) -> Result<SiteMetadata, LemmyError> {
17 info!("Fetching site metadata for url: {}", url);
20 .timeout(REQWEST_TIMEOUT)
24 // Can't use .text() here, because it only checks the content header, not the actual bytes
25 // https://github.com/LemmyNet/lemmy/issues/1964
26 let html_bytes = response.bytes().await.map_err(LemmyError::from)?.to_vec();
28 let tags = html_to_site_metadata(&html_bytes)?;
33 fn html_to_site_metadata(html_bytes: &[u8]) -> Result<SiteMetadata, LemmyError> {
34 let html = String::from_utf8_lossy(html_bytes);
36 // Make sure the first line is doctype html
42 .ok_or_else(|| LemmyError::from_message("No lines in html"))?
45 if !first_line.starts_with("<!doctype html>") {
46 return Err(LemmyError::from_message(
47 "Site metadata page fetch is not DOCTYPE html",
51 let mut page = HTML::from_string(html.to_string(), None)?;
53 // If the web page specifies that it isn't actually UTF-8, re-decode the received bytes with the
54 // proper encoding. If the specified encoding cannot be found, fall back to the original UTF-8
56 if let Some(charset) = page.meta.get("charset") {
57 if charset.to_lowercase() != "utf-8" {
58 if let Some(encoding_ref) = encodings().iter().find(|e| e.name() == charset) {
59 if let Ok(html_with_encoding) = encoding_ref.decode(html_bytes, DecoderTrap::Replace) {
60 page = HTML::from_string(html_with_encoding, None)?;
66 let page_title = page.title;
67 let page_description = page.description;
69 let og_description = page
73 .map(|t| t.to_string());
78 .map(|t| t.to_string());
83 .and_then(|ogo| Url::parse(&ogo.url).ok());
85 let title = og_title.or(page_title);
86 let description = og_description.or(page_description);
97 #[derive(Deserialize, Debug, Clone)]
98 pub(crate) struct PictrsResponse {
99 files: Vec<PictrsFile>,
103 #[derive(Deserialize, Debug, Clone)]
104 pub(crate) struct PictrsFile {
107 delete_token: String,
110 #[tracing::instrument(skip_all)]
111 pub(crate) async fn fetch_pictrs(
112 client: &ClientWithMiddleware,
115 ) -> Result<PictrsResponse, LemmyError> {
116 if let Some(pictrs_url) = settings.pictrs_url.to_owned() {
117 is_image_content_type(client, image_url).await?;
119 let fetch_url = format!(
120 "{}/image/download?url={}",
122 utf8_percent_encode(image_url.as_str(), NON_ALPHANUMERIC) // TODO this might not be needed
125 let response = client
127 .timeout(REQWEST_TIMEOUT)
131 let response: PictrsResponse = response.json().await.map_err(LemmyError::from)?;
133 if response.msg == "ok" {
136 Err(LemmyError::from_message(&response.msg))
139 Err(LemmyError::from_message("pictrs_url not set up in config"))
143 /// Both are options, since the URL might be either an html page, or an image
144 /// Returns the SiteMetadata, and a Pictrs URL, if there is a picture associated
145 #[tracing::instrument(skip_all)]
146 pub async fn fetch_site_data(
147 client: &ClientWithMiddleware,
150 ) -> (Option<SiteMetadata>, Option<Url>) {
154 // Ignore errors, since it may be an image, or not have the data.
155 // Warning, this may ignore SSL errors
156 let metadata_option = fetch_site_metadata(client, url).await.ok();
158 // Fetch pictrs thumbnail
159 let pictrs_hash = match &metadata_option {
160 Some(metadata_res) => match &metadata_res.image {
161 // Metadata, with image
162 // Try to generate a small thumbnail if there's a full sized one from post-links
163 Some(metadata_image) => fetch_pictrs(client, settings, metadata_image)
165 .map(|r| r.files[0].file.to_owned()),
166 // Metadata, but no image
167 None => fetch_pictrs(client, settings, url)
169 .map(|r| r.files[0].file.to_owned()),
171 // No metadata, try to fetch the URL as an image
172 None => fetch_pictrs(client, settings, url)
174 .map(|r| r.files[0].file.to_owned()),
177 // The full urls are necessary for federation
178 let pictrs_thumbnail = pictrs_hash
181 "{}/pictrs/image/{}",
182 settings.get_protocol_and_hostname(),
190 (metadata_option, pictrs_thumbnail)
192 None => (None, None),
196 #[tracing::instrument(skip_all)]
197 async fn is_image_content_type(client: &ClientWithMiddleware, url: &Url) -> Result<(), LemmyError> {
198 let response = client
200 .timeout(REQWEST_TIMEOUT)
206 .ok_or_else(|| LemmyError::from_message("No Content-Type header"))?
208 .starts_with("image/")
212 Err(LemmyError::from_message("Not an image type."))
216 pub fn build_user_agent(settings: &Settings) -> String {
220 settings.get_protocol_and_hostname()
226 use crate::request::{build_user_agent, fetch_site_metadata, SiteMetadata};
227 use lemmy_utils::settings::structs::Settings;
230 // These helped with testing
232 async fn test_site_metadata() {
233 let settings = Settings::init().unwrap();
234 let client = reqwest::Client::builder()
235 .user_agent(build_user_agent(&settings))
239 let sample_url = Url::parse("https://gitlab.com/IzzyOnDroid/repo/-/wikis/FAQ").unwrap();
240 let sample_res = fetch_site_metadata(&client, &sample_url).await.unwrap();
243 title: Some("FAQ · Wiki · IzzyOnDroid / repo · GitLab".to_string()),
245 "The F-Droid compatible repo at https://apt.izzysoft.de/fdroid/".to_string()
248 Url::parse("https://gitlab.com/uploads/-/system/project/avatar/4877469/iod_logo.png")
256 let youtube_url = Url::parse("https://www.youtube.com/watch?v=IquO_TcMZIQ").unwrap();
257 let youtube_res = fetch_site_metadata(&client, &youtube_url).await.unwrap();
260 title: Some("A Hard Look at Rent and Rent Seeking with Michael Hudson & Pepe Escobar".to_string()),
261 description: Some("An interactive discussion on wealth inequality and the “Great Game” on the control of natural resources.In this webinar organized jointly by the Henry George...".to_string()),
262 image: Some(Url::parse("https://i.ytimg.com/vi/IquO_TcMZIQ/maxresdefault.jpg").unwrap()),
268 // fn test_pictshare() {
269 // let res = fetch_pictshare("https://upload.wikimedia.org/wikipedia/en/2/27/The_Mandalorian_logo.jpg");
270 // assert!(res.is_ok());
271 // let res_other = fetch_pictshare("https://upload.wikimedia.org/wikipedia/en/2/27/The_Mandalorian_logo.jpgaoeu");
272 // assert!(res_other.is_err());