armature-websocket 0.2.0

//! Room-based message broadcasting.

use crate::connection::{Connection, ConnectionId};
use crate::error::{WebSocketError, WebSocketResult};
use crate::message::Message;
use dashmap::DashMap;
use std::collections::HashSet;
use std::sync::Arc;

/// Unique identifier for a room.
pub type RoomId = String;

/// A room for grouping WebSocket connections.
#[derive(Debug)]
pub struct Room {
    /// Room identifier
    pub id: RoomId,
    /// Connection IDs in this room
    members: DashMap<ConnectionId, ()>,
}

impl Room {
    /// Create a new room.
    pub fn new(id: RoomId) -> Self {
        Self {
            id,
            members: DashMap::new(),
        }
    }

    /// Add a connection to the room.
    pub fn join(&self, connection_id: ConnectionId) {
        self.members.insert(connection_id, ());
    }

    /// Remove a connection from the room.
    pub fn leave(&self, connection_id: &str) -> bool {
        self.members.remove(connection_id).is_some()
    }

    /// Check if a connection is in the room.
    pub fn contains(&self, connection_id: &str) -> bool {
        self.members.contains_key(connection_id)
    }

    /// Get the number of connections in the room.
    pub fn len(&self) -> usize {
        self.members.len()
    }

    /// Check if the room is empty.
    pub fn is_empty(&self) -> bool {
        self.members.is_empty()
    }

    /// Get all connection IDs in the room.
    pub fn members(&self) -> Vec<ConnectionId> {
        self.members.iter().map(|r| r.key().clone()).collect()
    }
}

/// Manages rooms and their members.
pub struct RoomManager {
    /// All rooms
    rooms: DashMap<RoomId, Arc<Room>>,
    /// Mapping of connection ID to room IDs
    connection_rooms: DashMap<ConnectionId, HashSet<RoomId>>,
    /// All connections
    connections: DashMap<ConnectionId, Connection>,
}

impl RoomManager {
    /// Create a new room manager.
    pub fn new() -> Self {
        Self {
            rooms: DashMap::new(),
            connection_rooms: DashMap::new(),
            connections: DashMap::new(),
        }
    }

    /// Register a connection.
    pub fn register_connection(&self, connection: Connection) {
        let id = connection.id.clone();
        self.connections.insert(id.clone(), connection);
        self.connection_rooms.insert(id, HashSet::new());
    }

    /// Unregister a connection and remove it from all rooms.
    pub fn unregister_connection(&self, connection_id: &str) {
        if let Some((_, room_ids)) = self.connection_rooms.remove(connection_id) {
            for room_id in room_ids {
                if let Some(room) = self.rooms.get(&room_id) {
                    room.leave(connection_id);
                }
                // Atomically remove room if empty (avoids TOCTOU race)
                self.rooms.remove_if(&room_id, |_, room| room.is_empty());
            }
        }
        self.connections.remove(connection_id);
    }

    /// Get a connection by ID.
    pub fn get_connection(&self, connection_id: &str) -> Option<Connection> {
        self.connections.get(connection_id).map(|c| c.clone())
    }

    /// Create a room if it doesn't exist.
    pub fn create_room(&self, room_id: RoomId) -> Arc<Room> {
        self.rooms
            .entry(room_id.clone())
            .or_insert_with(|| Arc::new(Room::new(room_id)))
            .clone()
    }

    /// Get a room by ID.
    pub fn get_room(&self, room_id: &str) -> Option<Arc<Room>> {
        self.rooms.get(room_id).map(|r| r.clone())
    }

    /// Delete a room.
    pub fn delete_room(&self, room_id: &str) -> bool {
        if let Some((_, room)) = self.rooms.remove(room_id) {
            // Remove room from all connection's room sets
            for member_id in room.members() {
                if let Some(mut rooms) = self.connection_rooms.get_mut(&member_id) {
                    rooms.remove(room_id);
                }
            }
            true
        } else {
            false
        }
    }

    /// Join a connection to a room.
    pub fn join_room(&self, connection_id: &str, room_id: &str) -> WebSocketResult<()> {
        if !self.connections.contains_key(connection_id) {
            return Err(WebSocketError::ConnectionNotFound(connection_id.to_string()));
        }

        let room = self.create_room(room_id.to_string());
        room.join(connection_id.to_string());

        if let Some(mut rooms) = self.connection_rooms.get_mut(connection_id) {
            rooms.insert(room_id.to_string());
        }

        Ok(())
    }

    /// Remove a connection from a room.
    pub fn leave_room(&self, connection_id: &str, room_id: &str) -> WebSocketResult<()> {
        if let Some(room) = self.rooms.get(room_id) {
            room.leave(connection_id);
        }

        if let Some(mut rooms) = self.connection_rooms.get_mut(connection_id) {
            rooms.remove(room_id);
        }

        // Atomically remove room if empty (avoids TOCTOU race)
        self.rooms.remove_if(room_id, |_, room| room.is_empty());

        Ok(())
    }

    /// Broadcast a message to all connections in a room.
    pub fn broadcast_to_room(&self, room_id: &str, message: Message) -> WebSocketResult<usize> {
        let room = self
            .rooms
            .get(room_id)
            .ok_or_else(|| WebSocketError::RoomNotFound(room_id.to_string()))?;

        let mut sent_count = 0;
        for member_id in room.members() {
            if let Some(conn) = self.connections.get(&member_id) {
                if conn.send(message.clone()).is_ok() {
                    sent_count += 1;
                }
            }
        }

        Ok(sent_count)
    }

    /// Broadcast a message to all connections in a room except one.
    pub fn broadcast_to_room_except(
        &self,
        room_id: &str,
        message: Message,
        except_id: &str,
    ) -> WebSocketResult<usize> {
        let room = self
            .rooms
            .get(room_id)
            .ok_or_else(|| WebSocketError::RoomNotFound(room_id.to_string()))?;

        let mut sent_count = 0;
        for member_id in room.members() {
            if member_id != except_id {
                if let Some(conn) = self.connections.get(&member_id) {
                    if conn.send(message.clone()).is_ok() {
                        sent_count += 1;
                    }
                }
            }
        }

        Ok(sent_count)
    }

    /// Broadcast a message to all connections.
    pub fn broadcast_all(&self, message: Message) -> usize {
        let mut sent_count = 0;
        for conn in self.connections.iter() {
            if conn.send(message.clone()).is_ok() {
                sent_count += 1;
            }
        }
        sent_count
    }

    /// Get all room IDs.
    pub fn room_ids(&self) -> Vec<RoomId> {
        self.rooms.iter().map(|r| r.key().clone()).collect()
    }

    /// Get all connection IDs.
    pub fn connection_ids(&self) -> Vec<ConnectionId> {
        self.connections.iter().map(|c| c.key().clone()).collect()
    }

    /// Get the total number of connections.
    pub fn connection_count(&self) -> usize {
        self.connections.len()
    }

    /// Get the total number of rooms.
    pub fn room_count(&self) -> usize {
        self.rooms.len()
    }
}

impl Default for RoomManager {
    fn default() -> Self {
        Self::new()
    }
}