use heck::CamelCase; use openssl::rand::rand_bytes; use pulldown_cmark::{html, Event, Options, Parser, Tag}; use rocket::{ http::uri::Uri, response::{Flash, Redirect}, }; use std::borrow::Cow; use std::collections::HashSet; use syntect::html::ClassedHTMLGenerator; use syntect::parsing::SyntaxSet; /// Generates an hexadecimal representation of 32 bytes of random data pub fn random_hex() -> String { let mut bytes = [0; 32]; rand_bytes(&mut bytes).expect("Error while generating client id"); bytes .iter() .fold(String::new(), |res, byte| format!("{}{:x}", res, byte)) } /// Remove non alphanumeric characters and CamelCase a string pub fn make_actor_id(name: &str) -> String { name.to_camel_case() .chars() .filter(|c| c.is_alphanumeric()) .collect() } /** * Redirects to the login page with a given message. * * Note that the message should be translated before passed to this function. */ pub fn requires_login>>(message: &str, url: T) -> Flash { Flash::new( Redirect::to(format!("/login?m={}", Uri::percent_encode(message))), "callback", url.into().to_string(), ) } #[derive(Debug)] enum State { Mention, Hashtag, Word, Ready, } fn to_inline(tag: Tag) -> Tag { match tag { Tag::Header(_) | Tag::Table(_) | Tag::TableHead | Tag::TableRow | Tag::TableCell => { Tag::Paragraph } Tag::Image(url, title) => Tag::Link(url, title), t => t, } } struct HighlighterContext { content: Vec, } fn highlight_code<'a>( context: &mut Option, evt: Event<'a>, ) -> Option>> { match evt { Event::Start(Tag::CodeBlock(lang)) => { if lang.is_empty() { Some(vec![Event::Start(Tag::CodeBlock(lang))]) } else { *context = Some(HighlighterContext { content: vec![] }); Some(vec![Event::Start(Tag::CodeBlock(lang))]) } } Event::End(Tag::CodeBlock(x)) => { let mut result = vec![]; if let Some(ctx) = context.take() { let syntax_set = SyntaxSet::load_defaults_newlines(); let syntax = syntax_set.find_syntax_by_token(&x).unwrap_or_else(|| { syntax_set .find_syntax_by_name(&x) .unwrap_or_else(|| syntax_set.find_syntax_plain_text()) }); let mut html = ClassedHTMLGenerator::new(&syntax, &syntax_set); for line in ctx.content { html.parse_html_for_line(&line); } let q = html.finalize(); result.push(Event::Html(q.into())); } result.push(Event::End(Tag::CodeBlock(x))); *context = None; Some(result) } Event::Text(t) => { if let Some(mut c) = context.take() { c.content.push(t.to_string()); *context = Some(c); Some(vec![]) } else { Some(vec![Event::Text(t)]) } } _ => Some(vec![evt]), } } fn flatten_text<'a>(state: &mut Option, evt: Event<'a>) -> Option>> { let (s, res) = match evt { Event::Text(txt) => match state.take() { Some(mut prev_txt) => { prev_txt.push_str(&txt); (Some(prev_txt), vec![]) } None => (Some(txt.into_owned()), vec![]), }, e => match state.take() { Some(prev) => (None, vec![Event::Text(Cow::Owned(prev)), e]), None => (None, vec![e]), }, }; *state = s; Some(res) } fn inline_tags<'a>( (state, inline): &mut (Vec>, bool), evt: Event<'a>, ) -> Option> { if *inline { let new_evt = match evt { Event::Start(t) => { let tag = to_inline(t); state.push(tag.clone()); Event::Start(tag) } Event::End(t) => match state.pop() { Some(other) => Event::End(other), None => Event::End(t), }, e => e, }; Some(new_evt) } else { Some(evt) } } pub type MediaProcessor<'a> = Box<'a + Fn(i32) -> Option<(String, Option)>>; fn process_image<'a, 'b>( evt: Event<'a>, inline: bool, processor: &Option>, ) -> Event<'a> { if let Some(ref processor) = *processor { match evt { Event::Start(Tag::Image(id, title)) => { if let Some((url, cw)) = id.parse::().ok().and_then(processor.as_ref()) { if inline || cw.is_none() { Event::Start(Tag::Image(Cow::Owned(url), title)) } else { // there is a cw, and where are not inline Event::Html(Cow::Owned(format!( r#""#, )) } } else { Event::End(Tag::Image(id, title)) } } e => e, } } else { evt } } /// Returns (HTML, mentions, hashtags) pub fn md_to_html<'a>( md: &str, base_url: Option<&str>, inline: bool, media_processor: Option>, ) -> (String, HashSet, HashSet) { let base_url = if let Some(base_url) = base_url { format!("//{}/", base_url) } else { "/".to_owned() }; let parser = Parser::new_ext(md, Options::all()); let (parser, mentions, hashtags): (Vec, Vec, Vec) = parser // Flatten text because pulldown_cmark break #hashtag in two individual text elements .scan(None, flatten_text) .flatten() .scan(None, highlight_code) .flatten() .map(|evt| process_image(evt, inline, &media_processor)) // Ignore headings, images, and tables if inline = true .scan((vec![], inline), inline_tags) .scan(false, |in_code, evt| match evt { Event::Start(Tag::CodeBlock(_)) | Event::Start(Tag::Code) => { *in_code = true; Some((vec![evt], vec![], vec![])) } Event::End(Tag::CodeBlock(_)) | Event::End(Tag::Code) => { *in_code = false; Some((vec![evt], vec![], vec![])) } Event::Text(txt) => { let (evts, _, _, _, new_mentions, new_hashtags) = txt.chars().fold( (vec![], State::Ready, String::new(), 0, vec![], vec![]), |(mut events, state, mut text_acc, n, mut mentions, mut hashtags), c| { match state { State::Mention => { let char_matches = c.is_alphanumeric() || "@.-_".contains(c); if char_matches && (n < (txt.chars().count() - 1)) { text_acc.push(c); (events, State::Mention, text_acc, n + 1, mentions, hashtags) } else { if char_matches { text_acc.push(c) } let mention = text_acc; let short_mention = mention.splitn(1, '@').nth(0).unwrap_or(""); let link = Tag::Link( format!("{}@/{}/", base_url, &mention).into(), short_mention.to_owned().into(), ); mentions.push(mention.clone()); events.push(Event::Start(link.clone())); events.push(Event::Text(format!("@{}", &short_mention).into())); events.push(Event::End(link)); ( events, State::Ready, c.to_string(), n + 1, mentions, hashtags, ) } } State::Hashtag => { let char_matches = c.is_alphanumeric() || "-_".contains(c); if char_matches && (n < (txt.chars().count() - 1)) { text_acc.push(c); (events, State::Hashtag, text_acc, n + 1, mentions, hashtags) } else { if char_matches { text_acc.push(c); } let hashtag = text_acc; let link = Tag::Link( format!("{}tag/{}", base_url, &hashtag.to_camel_case()) .into(), hashtag.to_owned().into(), ); hashtags.push(hashtag.clone()); events.push(Event::Start(link.clone())); events.push(Event::Text(format!("#{}", &hashtag).into())); events.push(Event::End(link)); ( events, State::Ready, c.to_string(), n + 1, mentions, hashtags, ) } } State::Ready => { if !*in_code && c == '@' { events.push(Event::Text(text_acc.into())); ( events, State::Mention, String::new(), n + 1, mentions, hashtags, ) } else if !*in_code && c == '#' { events.push(Event::Text(text_acc.into())); ( events, State::Hashtag, String::new(), n + 1, mentions, hashtags, ) } else if c.is_alphanumeric() { text_acc.push(c); if n >= (txt.chars().count() - 1) { // Add the text after at the end, even if it is not followed by a mention. events.push(Event::Text(text_acc.clone().into())) } (events, State::Word, text_acc, n + 1, mentions, hashtags) } else { text_acc.push(c); if n >= (txt.chars().count() - 1) { // Add the text after at the end, even if it is not followed by a mention. events.push(Event::Text(text_acc.clone().into())) } (events, State::Ready, text_acc, n + 1, mentions, hashtags) } } State::Word => { text_acc.push(c); if c.is_alphanumeric() { if n >= (txt.chars().count() - 1) { // Add the text after at the end, even if it is not followed by a mention. events.push(Event::Text(text_acc.clone().into())) } (events, State::Word, text_acc, n + 1, mentions, hashtags) } else { if n >= (txt.chars().count() - 1) { // Add the text after at the end, even if it is not followed by a mention. events.push(Event::Text(text_acc.clone().into())) } (events, State::Ready, text_acc, n + 1, mentions, hashtags) } } } }, ); Some((evts, new_mentions, new_hashtags)) } _ => Some((vec![evt], vec![], vec![])), }) .fold( (vec![], vec![], vec![]), |(mut parser, mut mention, mut hashtag), (mut p, mut m, mut h)| { parser.append(&mut p); mention.append(&mut m); hashtag.append(&mut h); (parser, mention, hashtag) }, ); let parser = parser.into_iter(); let mentions = mentions.into_iter().map(|m| String::from(m.trim())); let hashtags = hashtags.into_iter().map(|h| String::from(h.trim())); // TODO: fetch mentionned profiles in background, if needed let mut buf = String::new(); html::push_html(&mut buf, parser); (buf, mentions.collect(), hashtags.collect()) } #[cfg(test)] mod tests { use super::*; #[test] fn test_mentions() { let tests = vec![ ("nothing", vec![]), ("@mention", vec!["mention"]), ("@mention@instance.tld", vec!["mention@instance.tld"]), ("@many @mentions", vec!["many", "mentions"]), ("@start with a mentions", vec!["start"]), ("mention at @end", vec!["end"]), ("between parenthesis (@test)", vec!["test"]), ("with some punctuation @test!", vec!["test"]), (" @spaces ", vec!["spaces"]), ("@is_a@mention", vec!["is_a@mention"]), ("not_a@mention", vec![]), ("`@helo`", vec![]), ("```\n@hello\n```", vec![]), ]; for (md, mentions) in tests { assert_eq!( md_to_html(md, None, false, None).1, mentions .into_iter() .map(|s| s.to_string()) .collect::>() ); } } #[test] fn test_hashtags() { let tests = vec![ ("nothing", vec![]), ("#hashtag", vec!["hashtag"]), ("#many #hashtags", vec!["many", "hashtags"]), ("#start with a hashtag", vec!["start"]), ("hashtag at #end", vec!["end"]), ("between parenthesis (#test)", vec!["test"]), ("with some punctuation #test!", vec!["test"]), (" #spaces ", vec!["spaces"]), ("not_a#hashtag", vec![]), ]; for (md, mentions) in tests { assert_eq!( md_to_html(md, None, false, None).2, mentions .into_iter() .map(|s| s.to_string()) .collect::>() ); } } #[test] fn test_inline() { assert_eq!( md_to_html("# Hello", None, false, None).0, String::from("

Hello

\n") ); assert_eq!( md_to_html("# Hello", None, true, None).0, String::from("

Hello

\n") ); } }