Add support for on-demand involvement

Fixes https://github.com/etkecc/baibot/issues/15

src/conversation/matrix/entity.rs

@@ -1,10 +1,13 @@
 use regex::Regex;
 
+use mxlink::matrix_sdk::ruma::OwnedUserId;
+
 #[derive(Clone)]
 pub struct MatrixMessage {
-    pub sender_id: String,
+    pub sender_id: OwnedUserId,
     pub message_type: MatrixMessageType,
     pub message_text: String,
+    pub mentioned_users: Vec<OwnedUserId>,
 }
 
 #[derive(Clone)]
@@ -13,26 +16,42 @@ pub enum MatrixMessageType {
     Notice,
 }
 
-#[derive(Default, Clone)]
+#[derive(Clone)]
 pub struct MatrixMessageProcessingParams {
-    pub(crate) bot_user_id: String,
-    pub(crate) allowed_users: Vec<Regex>,
+    pub(crate) bot_user_id: OwnedUserId,
 
-    // If non-empty, these prefixes will be stripped when processing the message
-    pub(crate) first_message_stripped_prefixes: Vec<String>,
+    /// The prefixes that will be stripped when processing the messages in the context (thread or reply chain),
+    /// which are found to be mentioning the bot user (`bot_user_id`).
+    pub(crate) bot_user_prefixes_to_strip: Vec<String>,
+
+    /// The prefixes that will be stripped when processing the 1st message in the context (thread or reply chain).
+    pub(crate) first_message_prefixes_to_strip: Vec<String>,
+
+    /// A list of users whose messages are allowed.
+    /// If None, all messages are allowed.
+    /// If Some, only messages from the allowed users (and the bot itself, `bot_user_id`) are allowed.
+    pub(crate) allowed_users: Option<Vec<Regex>>,
 }
 
 impl MatrixMessageProcessingParams {
-    pub fn new(bot_user_id: String, allowed_users: Vec<Regex>) -> Self {
+    pub fn new(bot_user_id: OwnedUserId, allowed_users: Option<Vec<Regex>>) -> Self {
         Self {
             bot_user_id,
+            bot_user_prefixes_to_strip: vec![],
+
+            first_message_prefixes_to_strip: vec![],
+
             allowed_users,
-            ..Default::default()
         }
     }
 
-    pub fn with_first_message_stripped_prefixes(mut self, value: Vec<String>) -> Self {
-        self.first_message_stripped_prefixes = value;
+    pub fn with_bot_user_prefixes_to_strip(mut self, value: Vec<String>) -> Self {
+        self.bot_user_prefixes_to_strip = value;
+        self
+    }
+
+    pub fn with_first_message_prefixes_to_strip(mut self, value: Vec<String>) -> Self {
+        self.first_message_prefixes_to_strip = value;
         self
     }
 }