use super::{find_nostr_url_pos, NostrBech32, NostrUrl};
use lazy_static::lazy_static;
use linkify::{LinkFinder, LinkKind};
use regex::Regex;
/// This is like `Range<usize>`, except we impl offset() on it
/// This is like linkify::Span, except we impl offset() on it and don't need
/// the as_str() or kind() functions.
#[derive(Clone, Copy, Debug)]
pub struct Span {
start: usize,
end: usize,
}
impl Span {
/// Modify a span by offsetting it from the start by `offset` bytes
pub fn offset(&mut self, offset: usize) {
self.start += offset;
self.end += offset;
}
}
/// A segment of content
#[derive(Clone, Debug)]
pub enum ContentSegment {
/// A Nostr URL
NostrUrl(NostrUrl),
/// A reference to an event tag by index
TagReference(usize),
/// A hyperlink
Hyperlink(Span),
/// Plain text
Plain(Span),
}
/// A sequence of content segments
#[derive(Clone, Debug)]
pub struct ShatteredContent {
/// The sequence of `ContentSegment`s
pub segments: Vec<ContentSegment>,
/// The original content (the allocated string)
/// `Range`s within segments refer to this
pub allocated: String,
}
impl ShatteredContent {
/// Break content into meaningful segments
///
/// This avoids reallocation
pub fn new(content: String) -> ShatteredContent {
let segments = shatter_content_1(&content);
ShatteredContent {
segments,
allocated: content,
}
}
/// View a slice of the original content as specified in a Span
#[allow(clippy::string_slice)] // the Span is trusted
pub fn slice<'a>(&'a self, span: &Span) -> Option<&'a str> {
if self.allocated.is_char_boundary(span.start) && self.allocated.is_char_boundary(span.end)
{
Some(&self.allocated[span.start..span.end])
} else {
None
}
}
}
/// Break content into a linear sequence of `ContentSegment`s
#[allow(clippy::string_slice)] // start/end from find_nostr_url_pos is trusted
fn shatter_content_1(mut content: &str) -> Vec<ContentSegment> {
let mut segments: Vec<ContentSegment> = Vec::new();
let mut offset: usize = 0; // used to adjust Span ranges
// Pass 1 - `NostrUrl`s
while let Some((start, end)) = find_nostr_url_pos(content) {
let mut inner_segments = shatter_content_2(&content[..start]);
apply_offset(&mut inner_segments, offset);
segments.append(&mut inner_segments);
// The Nostr Bech32 itself
if let Some(nbech) = NostrBech32::try_from_string(&content[start + 6..end]) {
segments.push(ContentSegment::NostrUrl(NostrUrl(nbech)));
} else {
segments.push(ContentSegment::Plain(Span { start, end }));
}
offset += end;
content = &content[end..];
}
// The stuff after it
let mut inner_segments = shatter_content_2(content);
apply_offset(&mut inner_segments, offset);
segments.append(&mut inner_segments);
segments
}
// Pass 2 - `TagReference`s
#[allow(clippy::string_slice)] // Regex positions are trusted
fn shatter_content_2(content: &str) -> Vec<ContentSegment> {
lazy_static! {
static ref TAG_RE: Regex = Regex::new(r"(\#\[\d+\])").unwrap();
}
let mut segments: Vec<ContentSegment> = Vec::new();
let mut pos = 0;
for mat in TAG_RE.find_iter(content) {
let mut inner_segments = shatter_content_3(&content[pos..mat.start()]);
apply_offset(&mut inner_segments, pos);
segments.append(&mut inner_segments);
// If panics on unwrap, something is wrong with Regex.
let u: usize = content[mat.start() + 2..mat.end() - 1].parse().unwrap();
segments.push(ContentSegment::TagReference(u));
pos = mat.end();
}
let mut inner_segments = shatter_content_3(&content[pos..]);
apply_offset(&mut inner_segments, pos);
segments.append(&mut inner_segments);
segments
}
fn shatter_content_3(content: &str) -> Vec<ContentSegment> {
let mut segments: Vec<ContentSegment> = Vec::new();
for span in LinkFinder::new().kinds(&[LinkKind::Url]).spans(content) {
if span.kind().is_some() {
segments.push(ContentSegment::Hyperlink(Span {
start: span.start(),
end: span.end(),
}));
} else if !span.as_str().is_empty() {
segments.push(ContentSegment::Plain(Span {
start: span.start(),
end: span.end(),
}));
}
}
segments
}
fn apply_offset(segments: &mut [ContentSegment], offset: usize) {
for segment in segments.iter_mut() {
match segment {
ContentSegment::Hyperlink(span) => span.offset(offset),
ContentSegment::Plain(span) => span.offset(offset),
_ => {}
}
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_shatter_content() {
let content_str = "My friend #[0] wrote me this note: nostr:note10ttnuuvcs29y3k23gwrcurw2ksvgd7c2rrqlfx7urmt5m963vhss8nja90 and it might have referred to https://github.com/Giszmo/nostr.info/blob/master/assets/js/main.js";
let content = content_str.to_string();
let pieces = ShatteredContent::new(content);
assert_eq!(pieces.segments.len(), 6);
assert!(matches!(pieces.segments[0], ContentSegment::Plain(..)));
assert!(matches!(
pieces.segments[1],
ContentSegment::TagReference(..)
));
assert!(matches!(pieces.segments[2], ContentSegment::Plain(..)));
assert!(matches!(pieces.segments[3], ContentSegment::NostrUrl(..)));
assert!(matches!(pieces.segments[4], ContentSegment::Plain(..)));
assert!(matches!(pieces.segments[5], ContentSegment::Hyperlink(..)));
let content_str = r#"This is a test of NIP-27 posting support referencing this note nostr:nevent1qqsqqqq9wh98g4u6e480vyp6p4w3ux2cd0mxn2rssq0w5cscsgzp2ksprpmhxue69uhkzapwdehhxarjwahhy6mn9e3k7mf0qyt8wumn8ghj7etyv4hzumn0wd68ytnvv9hxgtcpremhxue69uhkummnw3ez6ur4vgh8wetvd3hhyer9wghxuet59uq3kamnwvaz7tmwdaehgu3wd45kketyd9kxwetj9e3k7mf0qy2hwumn8ghj7mn0wd68ytn00p68ytnyv4mz7qgnwaehxw309ahkvenrdpskjm3wwp6kytcpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz9mhwden5te0wfjkccte9ehx7um5wghxyctwvshszxthwden5te0wfjkccte9eekummjwsh8xmmrd9skctcnmzajy and again without the url data nostr:note1qqqq2aw2w3te4n2w7cgr5r2arcv4s6lkdx58pqq7af3p3qsyz4dqns2935
And referencing this person nostr:npub1acg6thl5psv62405rljzkj8spesceyfz2c32udakc2ak0dmvfeyse9p35c and again as an nprofile nostr:nprofile1qqswuyd9ml6qcxd92h6pleptfrcqucvvjy39vg4wx7mv9wm8kakyujgprdmhxue69uhkummnw3ezumtfddjkg6tvvajhytnrdakj7qg7waehxw309ahx7um5wgkhqatz9emk2mrvdaexgetj9ehx2ap0qythwumn8ghj7un9d3shjtnwdaehgu3wd9hxvme0qyt8wumn8ghj7etyv4hzumn0wd68ytnvv9hxgtcpzdmhxue69uhk7enxvd5xz6tw9ec82c30qy2hwumn8ghj7mn0wd68ytn00p68ytnyv4mz7qgcwaehxw309ashgtnwdaehgunhdaexkuewvdhk6tczkvt9n all on the same damn line even (I think)."#;
let content = content_str.to_string();
let pieces = ShatteredContent::new(content);
assert_eq!(pieces.segments.len(), 9);
}
#[test]
fn test_shatter_content_2() {
let content_str =
"Ein wunderschönes langes Wochenende auf der #zitadelle2024 geht zu Ende...
🏰 #einundzwanzig
Hier einige Impressionen mit opsec gewährten Bildern.
Wonderful Long Weekend at a Zitadelle, Here Impressions opsec included
nostr:npub1vwf2mytkyk22x2gcmr9d7k";
let content = content_str.to_string();
let pieces = ShatteredContent::new(content);
assert_eq!(pieces.segments.len(), 2);
assert!(matches!(pieces.segments[0], ContentSegment::Plain(..)));
assert!(matches!(pieces.segments[1], ContentSegment::Plain(..))); // 223 - 256
if let ContentSegment::Plain(span) = pieces.segments[1] {
let _slice = pieces.slice(&span);
}
}
}