From 18e6865b68e12a8293d09033d587d7c57f3aeda2 Mon Sep 17 00:00:00 2001
From: Youwen Wu <youwenw@gmail.com>
Date: Mon, 16 Jun 2025 10:36:27 -0700
Subject: [PATCH] feat: add regex option for username_display

---
 src/config.rs | 21 +++++++++++++++++++++
 src/tests.rs  |  1 +
 2 files changed, 22 insertions(+)

diff --git a/src/config.rs b/src/config.rs
index b712c73..26da1e3 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -397,6 +397,9 @@ pub enum UserDisplayStyle {
     // it can wind up being the Matrix username if there are display name collisions in the room,
     // in order to avoid any confusion.
     DisplayName,
+
+    // Acts like Username, except when the username matches given regex, then acts like DisplayName
+    Regex,
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
@@ -566,6 +569,7 @@ pub struct TunableValues {
     pub typing_notice_display: bool,
     pub users: UserOverrides,
     pub username_display: UserDisplayStyle,
+    pub username_display_regex: Option<String>,
     pub message_user_color: bool,
     pub default_room: Option<String>,
     pub open_command: Option<Vec<String>>,
@@ -592,6 +596,7 @@ pub struct Tunables {
     pub typing_notice_display: Option<bool>,
     pub users: Option<UserOverrides>,
     pub username_display: Option<UserDisplayStyle>,
+    pub username_display_regex: Option<String>,
     pub message_user_color: Option<bool>,
     pub default_room: Option<String>,
     pub open_command: Option<Vec<String>>,
@@ -622,6 +627,7 @@ impl Tunables {
             typing_notice_display: self.typing_notice_display.or(other.typing_notice_display),
             users: merge_maps(self.users, other.users),
             username_display: self.username_display.or(other.username_display),
+            username_display_regex: self.username_display_regex.or(other.username_display_regex),
             message_user_color: self.message_user_color.or(other.message_user_color),
             default_room: self.default_room.or(other.default_room),
             open_command: self.open_command.or(other.open_command),
@@ -650,6 +656,7 @@ impl Tunables {
             typing_notice_display: self.typing_notice_display.unwrap_or(true),
             users: self.users.unwrap_or_default(),
             username_display: self.username_display.unwrap_or_default(),
+            username_display_regex: self.username_display_regex,
             message_user_color: self.message_user_color.unwrap_or(false),
             default_room: self.default_room,
             open_command: self.open_command,
@@ -1042,6 +1049,20 @@ impl ApplicationSettings {
                     Cow::Borrowed(user_id.as_str())
                 }
             },
+            (None, UserDisplayStyle::Regex) => {
+                let re = regex::Regex::new(
+                    &self.tunables.username_display_regex.clone().unwrap_or("*".into()),
+                )
+                .unwrap();
+
+                if !re.is_match(user_id.as_str()) {
+                    Cow::Borrowed(user_id.as_str())
+                } else if let Some(display) = info.display_names.get(user_id) {
+                    Cow::Borrowed(display.as_str())
+                } else {
+                    Cow::Borrowed(user_id.as_str())
+                }
+            },
         };
 
         Span::styled(name, style)
diff --git a/src/tests.rs b/src/tests.rs
index 52cb859..ef6f82c 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -189,6 +189,7 @@ pub fn mock_tunables() -> TunableValues {
         open_command: None,
         external_edit_file_suffix: String::from(".md"),
         username_display: UserDisplayStyle::Username,
+        username_display_regex: Some(String::from(".*")),
         message_user_color: false,
         mouse: Default::default(),
         notifications: Notifications {