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()
}