//! Contains functions and structures useful to the general web server

use std::collections::{HashSet, VecDeque};

use tokio::sync::{broadcast, Mutex};

/// Our shared state
#[derive(Debug)]
pub struct State {
	/// Contains the history of the last 100 messages sent
	pub message_history: Mutex<VecDeque<String>>,

	/// Channel used to send messages to all connected clients.
	pub tx: broadcast::Sender<String>,

	/// We require unique usernames. This tracks which usernames have been
	/// taken.
	pub user_set: Mutex<HashSet<String>>,
}

/// Doc
pub async fn check_username(state: &State, string: &mut String, name: &str) {
	let mut user_set = state.user_set.lock().await;

	let name = name.trim();

	if !name.is_empty() && !user_set.contains(name) {
		user_set.insert(name.to_owned());

		drop(user_set);

		string.push_str(name);
	}
}