From 42e68fffcd713ef1a0fa2debaafe7d0906f71c87 Mon Sep 17 00:00:00 2001
From: Natty <natty.sh.git@gmail.com>
Date: Thu, 26 Oct 2023 21:23:59 +0200
Subject: [PATCH] MMM: Matrix handle parsing

---
 magnetar_mmm_parser/src/lib.rs | 55 ++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/magnetar_mmm_parser/src/lib.rs b/magnetar_mmm_parser/src/lib.rs
index 52c5e84..fc9b06d 100644
--- a/magnetar_mmm_parser/src/lib.rs
+++ b/magnetar_mmm_parser/src/lib.rs
@@ -29,6 +29,7 @@ use unicode_segmentation::UnicodeSegmentation;
 pub enum MentionType {
     Community,
     User,
+    MatrixUser,
 }
 
 impl MentionType {
@@ -36,6 +37,14 @@ impl MentionType {
         match self {
             MentionType::Community => '!',
             MentionType::User => '@',
+            MentionType::MatrixUser => ':',
+        }
+    }
+
+    pub fn separator(&self) -> char {
+        match self {
+            MentionType::Community | MentionType::User => '@',
+            MentionType::MatrixUser => ':',
         }
     }
 }
@@ -1460,7 +1469,6 @@ impl Context {
             return Ok((plain_out, Token::PlainText(plain.into())));
         }
 
-        let start = input;
         let tags = one_of("@!");
         let (input, mention_type) = map(tags, |c| match c {
             '@' => MentionType::User,
@@ -1474,29 +1482,28 @@ impl Context {
         )(input)?;
 
         let before = input;
-        let (_, host) = map(
-            opt(tuple((
-                tag("@"),
-                map(
-                    recognize(many1(alt((alphanumeric1, recognize(one_of("-_.")))))),
-                    Span::into_fragment,
-                ),
-            ))),
-            |maybe_tag_host| maybe_tag_host.map(|(_, host)| host),
-        )(input)?;
+        let (_, host_opt) = opt(tuple((
+            one_of(if matches!(mention_type, MentionType::User) {
+                "@:"
+            } else {
+                "@"
+            }),
+            map(
+                recognize(many1(alt((alphanumeric1, recognize(one_of("-_.")))))),
+                Span::into_fragment,
+            ),
+        )))(input)?;
 
-        let host = host.map(|h| h.trim_end_matches(|c| matches!(c, '.' | '-' | '_')));
+        // Promote tags with a colon separator to Matrix handles
+        let mention_type = if let Some((':', _)) = host_opt {
+            MentionType::MatrixUser
+        } else {
+            mention_type
+        };
+        let host =
+            host_opt.map(|(_, name)| name.trim_end_matches(|c| matches!(c, '.' | '-' | '_')));
         let input = host.map(|c| before.slice(c.len() + 1..)).unwrap_or(before);
 
-        if let (input, Some(_)) =
-            peek(opt(tuple((recognize(tag(":")), alphanumeric1_unicode))))(input)?
-        {
-            return Ok((
-                input,
-                Token::PlainText(start.up_to(&input).into_fragment().into()),
-            ));
-        }
-
         Ok((
             input,
             Token::Mention {
@@ -2182,7 +2189,11 @@ text</center>"#
 
         assert_eq!(
             parse_full("@tag:domain.com"),
-            Token::PlainText("@tag:domain.com".into())
+            Token::Mention {
+                mention_type: crate::MentionType::MatrixUser,
+                name: "tag".into(),
+                host: Some("domain.com".into())
+            },
         );
     }