fix(transformers): Add signal mention support

src/transform.rs

@@ -10,6 +10,7 @@ struct SignalMessageBuilder<'a> {
     from: Option<String>,
     message: Option<String>,
     attachments_urls: Vec<String>,
+    mentions: Vec<(usize, usize, String)>, // TODO Add type
     target: Option<&'a String>,
 }
 
@@ -22,16 +23,28 @@ impl<'b> SignalMessageBuilder<'b> {
         self.from = Some(from);
     }
 
-    pub fn attach(&mut self, attach: Vec<String>) {
+    pub fn attach(&mut self, attach: &Vec<String>) {
-        self.attachments_urls.extend_from_slice(&attach);
+        self.attachments_urls.extend_from_slice(attach);
+    }
+
+    pub fn mention(&mut self, mentions: &Vec<(usize, usize, String)>) {
+        self.mentions.extend_from_slice(mentions);
     }
 
     pub fn target(&mut self, channel: Option<&'b String>) {
         self.target = channel;
     }
 
-    pub fn build(self) -> Option<(&'b String, String)>
+    pub fn build(mut self) -> Option<(&'b String, String)>
     {
+        self.mentions.sort_by(|(pos1, _, _), (pos2, _, _)| pos1.cmp(pos2));
+        self.message.as_mut().map(|message| {
+            let mut offset: usize = 0;
+            for (pos, len, name) in self.mentions.into_iter() {
+                message.replace_range((pos + offset)..(pos + offset + len), &name);
+                offset += len;
+            }
+        });
         let attachments_text = self.attachments_urls.join(", ");
         (match (&self.message, attachments_text.len()) {
             (None, 0) => None,
@@ -107,7 +120,7 @@ impl<'a> Bridge<'a> {
                     log::warn!("droped attachment: {a}");
                 }
             }
-            result.attach(attachments_urls);
+            result.attach(&attachments_urls);
         };
         if let Some(Value::String(text)) = message.get("message") {
             result.message(text.clone());