--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/hedgewars-server/src/server/core.rs	Mon Dec 10 22:44:46 2018 +0100
@@ -0,0 +1,158 @@
+use slab;
+use crate::utils;
+use super::{
+    io::HWServerIO,
+    client::HWClient, room::HWRoom, actions, handlers,
+    coretypes::{ClientId, RoomId},
+    actions::{Destination, PendingMessage}
+};
+use crate::protocol::messages::*;
+use rand::{RngCore, thread_rng};
+use base64::{encode};
+use log::*;
+
+type Slab<T> = slab::Slab<T>;
+
+pub struct HWServer {
+    pub clients: Slab<HWClient>,
+    pub rooms: Slab<HWRoom>,
+    pub lobby_id: RoomId,
+    pub output: Vec<(Vec<ClientId>, HWServerMessage)>,
+    pub removed_clients: Vec<ClientId>,
+    pub io: Box<dyn HWServerIO>
+}
+
+impl HWServer {
+    pub fn new(clients_limit: usize, rooms_limit: usize, io: Box<dyn HWServerIO>) -> HWServer {
+        let rooms = Slab::with_capacity(rooms_limit);
+        let clients = Slab::with_capacity(clients_limit);
+        let mut server = HWServer {
+            clients, rooms,
+            lobby_id: 0,
+            output: vec![],
+            removed_clients: vec![],
+            io
+        };
+        server.lobby_id = server.add_room();
+        server
+    }
+
+    pub fn add_client(&mut self) -> ClientId {
+        let key: ClientId;
+        {
+            let entry = self.clients.vacant_entry();
+            key = entry.key();
+            let mut salt = [0u8; 18];
+            thread_rng().fill_bytes(&mut salt);
+
+            let client = HWClient::new(entry.key(), encode(&salt));
+            entry.insert(client);
+        }
+        self.send(key, &Destination::ToSelf, HWServerMessage::Connected(utils::PROTOCOL_VERSION));
+        key
+    }
+
+    pub fn client_lost(&mut self, client_id: ClientId) {
+        actions::run_action(self, client_id,
+                            actions::Action::ByeClient("Connection reset".to_string()));
+    }
+
+    pub fn add_room(&mut self) -> RoomId {
+        let entry = self.rooms.vacant_entry();
+        let key = entry.key();
+        let room = HWRoom::new(entry.key());
+        entry.insert(room);
+        key
+    }
+
+    pub fn handle_msg(&mut self, client_id: ClientId, msg: HWProtocolMessage) {
+        debug!("Handling message {:?} for client {}", msg, client_id);
+        if self.clients.contains(client_id) {
+            handlers::handle(self, client_id, msg);
+        }
+    }
+
+    fn get_recipients(&self, client_id: ClientId, destination: &Destination) -> Vec<ClientId> {
+        let mut ids = match *destination {
+            Destination::ToSelf => vec![client_id],
+            Destination::ToId(id) => vec![id],
+            Destination::ToAll {room_id: Some(id), ..} =>
+                self.room_clients(id),
+            Destination::ToAll {protocol: Some(proto), ..} =>
+                self.protocol_clients(proto),
+            Destination::ToAll {..} =>
+                self.clients.iter().map(|(id, _)| id).collect::<Vec<_>>()
+        };
+        if let Destination::ToAll {skip_self: true, ..} = destination {
+            if let Some(index) = ids.iter().position(|id| *id == client_id) {
+                ids.remove(index);
+            }
+        }
+        ids
+    }
+
+    pub fn send(&mut self, client_id: ClientId, destination: &Destination, message: HWServerMessage) {
+        let ids = self.get_recipients(client_id, &destination);
+        self.output.push((ids, message));
+    }
+
+    pub fn react(&mut self, client_id: ClientId, actions: Vec<actions::Action>) {
+        for action in actions {
+            actions::run_action(self, client_id, action);
+        }
+    }
+
+    pub fn lobby(&self) -> &HWRoom { &self.rooms[self.lobby_id] }
+
+    pub fn has_room(&self, name: &str) -> bool {
+        self.rooms.iter().any(|(_, r)| r.name == name)
+    }
+
+    pub fn find_room(&self, name: &str) -> Option<&HWRoom> {
+        self.rooms.iter().find_map(|(_, r)| Some(r).filter(|r| r.name == name))
+    }
+
+    pub fn find_room_mut(&mut self, name: &str) -> Option<&mut HWRoom> {
+        self.rooms.iter_mut().find_map(|(_, r)| Some(r).filter(|r| r.name == name))
+    }
+
+    pub fn find_client(&self, nick: &str) -> Option<&HWClient> {
+        self.clients.iter().find_map(|(_, c)| Some(c).filter(|c| c.nick == nick))
+    }
+
+    pub fn find_client_mut(&mut self, nick: &str) -> Option<&mut HWClient> {
+        self.clients.iter_mut().find_map(|(_, c)| Some(c).filter(|c| c.nick == nick))
+    }
+
+    pub fn select_clients<F>(&self, f: F) -> Vec<ClientId>
+        where F: Fn(&(usize, &HWClient)) -> bool {
+        self.clients.iter().filter(f)
+            .map(|(_, c)| c.id).collect()
+    }
+
+    pub fn room_clients(&self, room_id: RoomId) -> Vec<ClientId> {
+        self.select_clients(|(_, c)| c.room_id == Some(room_id))
+    }
+
+    pub fn protocol_clients(&self, protocol: u16) -> Vec<ClientId> {
+        self.select_clients(|(_, c)| c.protocol_number == protocol)
+    }
+
+    pub fn other_clients_in_room(&self, self_id: ClientId) -> Vec<ClientId> {
+        let room_id = self.clients[self_id].room_id;
+        self.select_clients(|(id, c)| *id != self_id && c.room_id == room_id )
+    }
+
+    pub fn client_and_room(&mut self, client_id: ClientId) -> (&mut HWClient, Option<&mut HWRoom>) {
+        let c = &mut self.clients[client_id];
+        if let Some(room_id) = c.room_id {
+            (c, Some(&mut self.rooms[room_id]))
+        } else {
+            (c, None)
+        }
+    }
+
+    pub fn room(&mut self, client_id: ClientId) -> Option<&mut HWRoom> {
+        self.client_and_room(client_id).1
+    }
+}