add tag all function

src/state.rs

@@ -0,0 +1,20 @@
+use once_cell::sync::Lazy;
+use std::collections::{HashMap, HashSet};
+use std::sync::RwLock;
+
+static SEEN_USERS: Lazy<RwLock<HashMap<i64, HashSet<String>>>> =
+    Lazy::new(|| RwLock::new(HashMap::new()));
+
+pub fn track_user(chat_id: i64, username: String) {
+    let mut map = SEEN_USERS.write().unwrap();
+    map.entry(chat_id).or_default().insert(username);
+}
+
+pub fn get_tracked_users(chat_id: i64) -> Vec<String> {
+    SEEN_USERS
+        .read()
+        .unwrap()
+        .get(&chat_id)
+        .map(|s| s.iter().cloned().collect())
+        .unwrap_or_default()
+}