refactor the parser

Cargo.lock

@@ -1243,6 +1243,7 @@ name = "common"
 version = "1.0.0-beta"
 dependencies = [
  "anyhow",
+ "bech32",
  "chrono",
  "dirs 5.0.1",
  "futures",

crates/chat/src/message.rs

@@ -1,6 +1,7 @@
 use std::hash::Hash;
+use std::ops::Range;
 
-use common::EventUtils;
+use common::{EventUtils, NostrParser};
 use nostr_sdk::prelude::*;
 
 /// New message.
@@ -91,6 +92,18 @@ impl PartialOrd for Message {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct Mention {
+    pub public_key: PublicKey,
+    pub range: Range<usize>,
+}
+
+impl Mention {
+    pub fn new(public_key: PublicKey, range: Range<usize>) -> Self {
+        Self { public_key, range }
+    }
+}
+
 /// Rendered message.
 #[derive(Debug, Clone)]
 pub struct RenderedMessage {
@@ -102,7 +115,7 @@ pub struct RenderedMessage {
     /// Message created time as unix timestamp
     pub created_at: Timestamp,
     /// List of mentioned public keys in the message
-    pub mentions: Vec<PublicKey>,
+    pub mentions: Vec<Mention>,
     /// List of event of the message this message is a reply to
     pub replies_to: Vec<EventId>,
 }
@@ -184,20 +197,17 @@ impl Hash for RenderedMessage {
 }
 
 /// Extracts all mentions (public keys) from a content string.
-fn extract_mentions(content: &str) -> Vec<PublicKey> {
+fn extract_mentions(content: &str) -> Vec<Mention> {
     let parser = NostrParser::new();
     let tokens = parser.parse(content);
 
     tokens
-        .filter_map(|token| match token {
-            Token::Nostr(nip21) => match nip21 {
-                Nip21::Pubkey(pubkey) => Some(pubkey),
-                Nip21::Profile(profile) => Some(profile.public_key),
-                _ => None,
-            },
+        .filter_map(|token| match token.value {
+            Nip21::Pubkey(public_key) => Some(Mention::new(public_key, token.range)),
+            Nip21::Profile(profile) => Some(Mention::new(profile.public_key, token.range)),
             _ => None,
         })
-        .collect::<Vec<_>>()
+        .collect()
 }
 
 /// Extracts all reply (ids) from the event tags.

crates/chat_ui/src/lib.rs

@@ -702,7 +702,7 @@ impl ChatPanel {
                     let text = self
                         .rendered_texts_by_id
                         .entry(rendered.id)
-                        .or_insert_with(|| RenderedText::new(&rendered.content, &[]))
+                        .or_insert_with(|| RenderedText::new(&rendered.content, &rendered.mentions))
                         .element(ix.into(), window, cx);
 
                     self.render_text_message(ix, rendered, text, cx)

crates/chat_ui/src/text.rs

@@ -1,6 +1,7 @@
 use std::ops::Range;
 use std::sync::Arc;
 
+use chat::Mention;
 use common::RangeExt;
 use gpui::{
     AnyElement, App, ElementId, FontStyle, FontWeight, HighlightStyle, InteractiveText,
@@ -24,11 +25,6 @@ impl From<HighlightStyle> for Highlight {
     }
 }
 
-#[derive(Debug)]
-pub struct Mention {
-    pub range: Range<usize>,
-}
-
 #[derive(Default)]
 pub struct RenderedText {
     pub text: SharedString,
@@ -96,7 +92,10 @@ impl RenderedText {
                                 }
                             }
                             Highlight::Mention => HighlightStyle {
-                                font_weight: Some(FontWeight::BOLD),
+                                underline: Some(UnderlineStyle {
+                                    thickness: 1.0.into(),
+                                    ..Default::default()
+                                }),
                                 ..Default::default()
                             },
                             Highlight::Highlight(highlight) => *highlight,

crates/common/Cargo.toml

@@ -19,3 +19,4 @@ log.workspace = true
 
 dirs = "5.0"
 qrcode = "0.14.1"
+bech32 = "0.11.1"

crates/common/src/lib.rs

@@ -1,11 +1,13 @@
 pub use debounced_delay::*;
 pub use display::*;
 pub use event::*;
+pub use parser::*;
 pub use paths::*;
 pub use range::*;
 
 mod debounced_delay;
 mod display;
 mod event;
+mod parser;
 mod paths;
 mod range;

crates/common/src/parser.rs

@@ -0,0 +1,210 @@
+use std::ops::Range;
+
+use nostr::prelude::*;
+
+const BECH32_SEPARATOR: u8 = b'1';
+const SCHEME_WITH_COLON: &str = "nostr:";
+
+/// Nostr parsed token with its range in the original text
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Token {
+    /// The parsed NIP-21 URI
+    ///
+    /// <https://github.com/nostr-protocol/nips/blob/master/21.md>
+    pub value: Nip21,
+    /// The range of this token in the original text
+    pub range: Range<usize>,
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Match {
+    start: usize,
+    end: usize,
+}
+
+/// Nostr parser
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct NostrParser;
+
+impl Default for NostrParser {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl NostrParser {
+    /// Create new parser
+    pub const fn new() -> Self {
+        Self
+    }
+
+    /// Parse text
+    pub fn parse<'a>(&self, text: &'a str) -> NostrParserIter<'a> {
+        NostrParserIter::new(text)
+    }
+}
+
+struct FindMatches<'a> {
+    bytes: &'a [u8],
+    pos: usize,
+}
+
+impl<'a> FindMatches<'a> {
+    fn new(text: &'a str) -> Self {
+        Self {
+            bytes: text.as_bytes(),
+            pos: 0,
+        }
+    }
+
+    fn try_parse_nostr_uri(&mut self) -> Option<Match> {
+        let start = self.pos;
+        let bytes = self.bytes;
+        let len = bytes.len();
+
+        // Check if we have "nostr:" prefix
+        if len - start < SCHEME_WITH_COLON.len() {
+            return None;
+        }
+
+        // Check for "nostr:" prefix (case-insensitive)
+        let scheme_prefix = &bytes[start..start + SCHEME_WITH_COLON.len()];
+        if !scheme_prefix.eq_ignore_ascii_case(SCHEME_WITH_COLON.as_bytes()) {
+            return None;
+        }
+
+        // Skip the scheme
+        let pos = start + SCHEME_WITH_COLON.len();
+
+        // Parse bech32 entity
+        let mut has_separator = false;
+        let mut end = pos;
+
+        while end < len {
+            let byte = bytes[end];
+
+            // Check for bech32 separator
+            if byte == BECH32_SEPARATOR && !has_separator {
+                has_separator = true;
+                end += 1;
+                continue;
+            }
+
+            // Check if character is valid for bech32
+            if !byte.is_ascii_alphanumeric() {
+                break;
+            }
+
+            end += 1;
+        }
+
+        // Must have at least one character after separator
+        if !has_separator || end <= pos + 1 {
+            return None;
+        }
+
+        // Update position
+        self.pos = end;
+
+        Some(Match { start, end })
+    }
+}
+
+impl Iterator for FindMatches<'_> {
+    type Item = Match;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while self.pos < self.bytes.len() {
+            // Try to parse nostr URI
+            if let Some(mat) = self.try_parse_nostr_uri() {
+                return Some(mat);
+            }
+
+            // Skip one character if no match found
+            self.pos += 1;
+        }
+
+        None
+    }
+}
+
+enum HandleMatch {
+    Token(Token),
+    Recursion,
+}
+
+pub struct NostrParserIter<'a> {
+    /// The original text
+    text: &'a str,
+    /// Matches found
+    matches: FindMatches<'a>,
+    /// A pending match
+    pending_match: Option<Match>,
+    /// Last match end index
+    last_match_end: usize,
+}
+
+impl<'a> NostrParserIter<'a> {
+    fn new(text: &'a str) -> Self {
+        Self {
+            text,
+            matches: FindMatches::new(text),
+            pending_match: None,
+            last_match_end: 0,
+        }
+    }
+
+    fn handle_match(&mut self, mat: Match) -> HandleMatch {
+        // Update last match end
+        self.last_match_end = mat.end;
+
+        // Extract the matched string
+        let data: &str = &self.text[mat.start..mat.end];
+
+        // Parse NIP-21 URI
+        match Nip21::parse(data) {
+            Ok(uri) => HandleMatch::Token(Token {
+                value: uri,
+                range: mat.start..mat.end,
+            }),
+            // If the nostr URI parsing is invalid, skip it
+            Err(_) => HandleMatch::Recursion,
+        }
+    }
+}
+
+impl<'a> Iterator for NostrParserIter<'a> {
+    type Item = Token;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // Handle a pending match
+        if let Some(pending_match) = self.pending_match.take() {
+            return match self.handle_match(pending_match) {
+                HandleMatch::Token(token) => Some(token),
+                HandleMatch::Recursion => self.next(),
+            };
+        }
+
+        match self.matches.next() {
+            Some(mat) => {
+                // Skip any text before this match
+                if mat.start > self.last_match_end {
+                    // Update pending match
+                    // This will be handled at next iteration, in `handle_match` method.
+                    self.pending_match = Some(mat);
+
+                    // Skip the text before the match
+                    self.last_match_end = mat.start;
+                    return self.next();
+                }
+
+                // Handle match
+                match self.handle_match(mat) {
+                    HandleMatch::Token(token) => Some(token),
+                    HandleMatch::Recursion => self.next(),
+                }
+            }
+            None => None,
+        }
+    }
+}