cargo fmt

src/client.rs

@@ -0,0 +1,117 @@
+// ---------------
+// Module overview
+// ---------------
+//
+// DiscordInfo: describes a Discord user's information
+//
+// ClientInfo:  describes a client's identifying information,
+//              both for websocket and Discord connections.
+//              Webscoket connections have the option to store
+//              DiscordInfo as well for verified connections.
+//
+// Client:      describes a client, holding ClientInfo and Rc<Room>
+
+use crate::room::Room;
+
+use simple_websockets::{Message, Responder};
+use std::cell::RefCell;
+use std::cmp::{Eq, PartialEq};
+use std::hash::{Hash, Hasher};
+use std::rc::Rc;
+
+pub struct DiscordInfo {
+    pub username: String,
+    pub discriminator: u16,
+    pub id: u64,
+}
+
+impl PartialEq for DiscordInfo {
+    fn eq(&self, other: &Self) -> bool {
+        self.id == other.id
+    }
+}
+
+impl Eq for DiscordInfo {}
+
+pub enum ClientInfo {
+    Ws {
+        id: u64,
+        responder: Responder,
+        discord_info: Option<DiscordInfo>,
+    },
+    Discord {
+        discord_info: DiscordInfo,
+    },
+}
+
+impl ClientInfo {
+    fn id(&self) -> u64 {
+        match self {
+            Self::Ws {
+                id, discord_info, ..
+            } => match discord_info {
+                // Discord-verified websocket connection
+                Some(discord_info) => discord_info.id,
+                // Anonymous websocket connection
+                None => *id,
+            },
+            // Discord connection
+            Self::Discord { discord_info } => discord_info.id,
+        }
+    }
+}
+
+impl PartialEq for ClientInfo {
+    fn eq(&self, other: &Self) -> bool {
+        self.id() == other.id()
+    }
+}
+
+impl Eq for ClientInfo {}
+
+impl Hash for ClientInfo {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.id().hash(state)
+    }
+}
+
+pub struct Client {
+    info: ClientInfo,
+    pub room: Rc<RefCell<Room>>,
+}
+
+impl Client {
+    pub fn new(info: ClientInfo, room: Rc<RefCell<Room>>) -> Self {
+        Self { info, room }
+    }
+
+    pub fn id(&self) -> u64 {
+        match self.info {
+            ClientInfo::Ws { id, .. } => id,
+            ClientInfo::Discord { .. } => unimplemented!("no id for Discord connections"),
+        }
+    }
+
+    pub fn send(&self, message: Message) -> bool {
+        match &self.info {
+            ClientInfo::Ws { responder, .. } => responder.send(message),
+            ClientInfo::Discord { .. } => {
+                unimplemented!("no networking implementation for Discord connections")
+            }
+        }
+    }
+}
+
+impl PartialEq for Client {
+    fn eq(&self, other: &Self) -> bool {
+        self.info.eq(&other.info)
+    }
+}
+
+impl Eq for Client {}
+
+impl Hash for Client {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.info.hash(state)
+    }
+}

src/database.rs

@@ -1,8 +1,8 @@
-use crate::Word;
+use crate::word::Word;
 
 use derive_more::From;
+use rusqlite::{params, Connection, Result};
 use std::path::PathBuf;
-use rusqlite::{Connection, Result, params};
 
 pub struct Database {
     conn: Connection,
@@ -15,16 +15,23 @@ pub enum DatabaseCreationError {
     IoError(std::io::Error),
 }
 
+#[derive(Default)]
+pub enum DatabaseType {
+    #[default]
+    InMemory,
+    OnDisk(String),
+}
+
+#[derive(Default)]
+pub struct DatabaseSettings {
+    pub db_type: DatabaseType,
+}
+
 impl Database {
-    pub fn new(
-        testing: bool,
-    ) -> Result<Self, DatabaseCreationError> {
-        let conn = if testing {
-            Connection::open_in_memory()
-        } else {
-            let path = PathBuf::from("shiritori.db");
-            //fs::create_dir_all(path.parent().unwrap())?;
-            Connection::open(path)
+    pub fn new(settings: DatabaseSettings) -> Result<Self, DatabaseCreationError> {
+        let conn = match settings.db_type {
+            DatabaseType::InMemory => Connection::open_in_memory(),
+            DatabaseType::OnDisk(path) => Connection::open(PathBuf::from(path)),
         }?;
         conn.execute(
             "CREATE TABLE IF NOT EXISTS word (
@@ -39,10 +46,11 @@ impl Database {
             .prepare("SELECT id FROM word ORDER BY id DESC LIMIT 1")?
             .query_map(params![], |row| row.get(0))?
             .collect::<Result<Vec<i64>>>()?
-            .first() {
-                Some(id) => *id,
-                None => 0, // first database entry is id 1
-            };
+            .first()
+        {
+            Some(id) => *id,
+            None => 0, // first database entry is id 1
+        };
         Ok(Self { conn, last_word_id })
     }
 
@@ -63,10 +71,7 @@ impl Database {
     pub fn add_word(&mut self, word: &Word) -> Result<()> {
         self.conn.execute(
             "INSERT INTO word (word, reading) VALUES (?1, ?2)",
-            params![
-                word.word,
-                word.reading,
-            ],
+            params![word.word, word.reading,],
         )?;
         self.last_word_id += 1;
         Ok(())

src/dictionary.rs

@@ -1,8 +1,9 @@
 use wana_kana::{ConvertJapanese, IsJapaneseStr};
 
-pub fn lookup(input: &str) -> Option<&jisho::Entry> {
+fn raw_lookup(input: &str) -> Option<&jisho::Entry> {
     let input = input.trim();
-    jisho::lookup(input).into_iter().find(|&word| (
+    jisho::lookup(input).into_iter().find(|&word| {
+        (
             // If input has no kanji,
             // we can just compare the input to the reading verbatim
             // ensuring both are hiragana
@@ -11,5 +12,32 @@ pub fn lookup(input: &str) -> Option<&jisho::Entry> {
             // is verbosely the same.
             // However, this will cause problems for some words.
             // For example, 照り焼き will be accepted but 照焼 won't.
-            (input == word.kanji)))
+            (input == word.kanji)
+        )
+    })
+}
+
+pub fn lookup(query: &str) -> Option<jisho::Entry> {
+    match raw_lookup(&query) {
+        Some(result) => Some(result.clone()),
+        None => {
+            if query.is_hiragana() {
+                // looking up ごりら doesn't return ゴリラ
+                // jisho::lookup for some reason refers to input string,
+                // so cloning is required
+                match raw_lookup(&query.to_katakana()) {
+                    Some(entry) => Some(entry.clone()),
+                    None => None,
+                }
+            } else if query.is_katakana() {
+                // looking up シリトリ doesn't return 尻取り
+                match raw_lookup(&query.to_hiragana()) {
+                    Some(entry) => Some(entry.clone()),
+                    None => None,
+                }
+            } else {
+                None
+            }
+        }
+    }
 }

src/main.rs

@@ -1,18 +1,21 @@
+mod client;
 mod database;
-pub use database::*;
-
 mod dictionary;
-pub use dictionary::*;
-
+mod response;
+mod room;
 mod server;
-pub use server::*;
-
+mod utils;
 mod word;
-pub use word::*;
+
+use crate::server::{Server, ServerSettings};
 
 fn main() {
-    const PORT: u16 = 8080;
-    let mut server = Server::new(PORT, true)
-        .unwrap_or_else(|error| panic!("Failed to start server at port {PORT}: {:?}", error));
+    let settings = ServerSettings::default();
+    let mut server = Server::new(&settings).unwrap_or_else(|error| {
+        panic!(
+            "Failed to start server at port {}: {:?}",
+            settings.port, error
+        )
+    });
     server.run();
 }

src/response.rs

@@ -0,0 +1,62 @@
+use crate::word::Word;
+
+use serde::Serialize;
+use simple_websockets::Message;
+
+#[derive(Serialize)]
+pub struct MessageResponse {
+    event: String,
+    data: MessageResponseData,
+}
+
+impl MessageResponse {
+    pub fn to_message(&self) -> Message {
+        Message::Text(serde_json::to_string(&self).unwrap())
+    }
+}
+
+#[derive(Serialize)]
+#[serde(untagged)]
+pub enum MessageResponseData {
+    Greeting {
+        id: u64,
+        next_mora: Option<String>,
+    },
+    Word {
+        author: u64,
+        word: Word,
+        next_mora: String,
+    },
+    History {
+        words: Vec<Word>,
+    },
+    PlayerCount {
+        players: u64,
+    },
+    Error {
+        message: String,
+    },
+}
+
+impl MessageResponseData {
+    pub fn get_name(&self) -> String {
+        String::from(match self {
+            Self::Greeting { .. } => "greeting",
+            Self::Word { .. } => "word",
+            Self::History { .. } => "history",
+            Self::PlayerCount { .. } => "playerCount",
+            Self::Error { .. } => "error",
+        })
+    }
+
+    pub fn into_response(self) -> MessageResponse {
+        MessageResponse {
+            event: self.get_name(),
+            data: self,
+        }
+    }
+
+    pub fn into_message(self) -> Message {
+        self.into_response().to_message()
+    }
+}

src/room.rs

@@ -0,0 +1,107 @@
+// ---------------
+// Module overview
+// ---------------
+//
+// RoomSettings: Stores database settings for room.
+//               In future, could store passphrase, etc.
+//
+// Room:         Game state abstracted away from any networking.
+//               Any events that aren't game-related are handled by Server.
+
+use crate::database::{Database, DatabaseCreationError, DatabaseSettings};
+use crate::dictionary::lookup;
+use crate::response::MessageResponseData;
+use crate::utils::{get_final_mora, get_starting_mora};
+use crate::word::Word;
+
+use wana_kana::{ConvertJapanese, IsJapaneseStr};
+
+#[derive(Default)]
+pub struct RoomSettings {
+    pub database_settings: DatabaseSettings,
+}
+
+pub struct Room {
+    database: Database,
+    next_mora: Option<String>,
+    last_client_id: Option<u64>,
+}
+
+impl Room {
+    pub fn new(settings: RoomSettings) -> Result<Self, DatabaseCreationError> {
+        Ok(Self {
+            database: Database::new(settings.database_settings)?,
+            next_mora: None,
+            last_client_id: None,
+        })
+    }
+
+    pub fn next_mora(&self) -> &Option<String> {
+        &self.next_mora
+    }
+
+    pub fn get_history(&self) -> rusqlite::Result<Vec<Word>> {
+        self.database
+            .load_words_before(self.database.last_word_id + 1)
+    }
+
+    // Err(&str) will be converted to MessageResponseData::Error
+    pub fn handle_query(
+        &mut self,
+        query: &str,
+        client_id: u64,
+    ) -> Result<MessageResponseData, &str> {
+        // Ensure query isn't from last player
+        if Some(client_id) == self.last_client_id {
+            return Err("It's not your turn!");
+        };
+
+        // Ensure query is in Japanese
+        let query = query.to_string();
+        let query = if query.is_japanese() {
+            query
+        } else {
+            let kana = query.to_kana();
+            if kana.is_japanese() {
+                kana
+            } else {
+                return Err("Not Japanese!");
+            }
+        };
+
+        // Look up word in dictionary
+        let dictionary_result = lookup(&query);
+
+        // Send result
+        match dictionary_result {
+            Some(entry) => {
+                if entry
+                    .reading
+                    .chars()
+                    .last()
+                    .unwrap()
+                    .to_string()
+                    .to_hiragana()
+                    == "ん"
+                {
+                    Err("Can't end with ん!")
+                } else if self.next_mora.is_none()
+                    || get_starting_mora(&entry.reading).eq(self.next_mora.as_deref().unwrap())
+                {
+                    let word: Word = entry.clone().into();
+                    self.next_mora = Some(get_final_mora(&word.reading));
+                    self.database.add_word(&word).unwrap(); // TODO: replace .unwrap() with ?
+                    self.last_client_id = Some(client_id);
+                    Ok(MessageResponseData::Word {
+                        author: client_id,
+                        word,
+                        next_mora: self.next_mora.as_deref().unwrap().to_owned(),
+                    })
+                } else {
+                    Err("Wrong starting mora!")
+                }
+            }
+            None => Err("Not in dictionary!"),
+        }
+    }
+}

src/server.rs

@@ -1,79 +1,13 @@
-use crate::DatabaseCreationError;
-use crate::lookup;
-use crate::Word;
-use crate::Database;
+use crate::client::{Client, ClientInfo};
+use crate::database::{DatabaseCreationError, DatabaseSettings, DatabaseType};
+use crate::response::MessageResponseData;
+use crate::room::{Room, RoomSettings};
 
-use simple_websockets::{Event, Responder, Message, EventHub};
-use std::collections::HashMap;
-use serde::Serialize;
-use wana_kana::{ConvertJapanese, IsJapaneseStr};
 use derive_more::From;
-
-#[derive(Serialize)]
-struct MessageResponse {
-    event: String,
-    data: MessageResponseData,
-}
-
-impl MessageResponse {
-    fn to_message(&self) -> Message {
-        Message::Text(serde_json::to_string(&self).unwrap())
-    }
-}
-
-#[derive(Serialize)]
-#[serde(untagged)]
-enum MessageResponseData {
-    Greeting {
-        id: u64,
-        next_mora: Option<String>,
-    },
-    Word {
-        author: u64,
-        word: Word,
-        next_mora: String,
-    },
-    History {
-        words: Vec<Word>,
-    },
-    PlayerCount {
-        players: u64,
-    },
-    Error {
-        message: String,
-    },
-}
-
-impl MessageResponseData {
-    fn get_name(&self) -> String {
-        String::from(match self {
-            Self::Greeting { .. } => "greeting",
-            Self::Word { .. } => "word",
-            Self::History { .. } => "history",
-            Self::PlayerCount { .. } => "playerCount",
-            Self::Error { .. } => "error",
-        })
-    }
-
-    fn into_response(self) -> MessageResponse {
-        MessageResponse {
-            event: self.get_name(),
-            data: self,
-        }
-    }
-
-    fn into_message(self) -> Message {
-        self.into_response().to_message()
-    }
-}
-
-pub struct Server {
-    event_hub: EventHub,
-    database: Database,
-    clients: HashMap<u64, Responder>,
-    next_mora: Option<String>,
-    last_client_id: Option<u64>,
-}
+use simple_websockets::{Event, EventHub, Message, Responder};
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::rc::Rc;
 
 #[derive(From, Debug)]
 pub enum ServerCreationError {
@@ -86,196 +20,203 @@ pub enum ServerError {
     DatabaseError(rusqlite::Error),
 }
 
-fn get_starting_mora(word: &str) -> String {
-    if word.is_empty() {
-        return String::from("");
-    }
-    let word = word.to_hiragana();
-    let mut iter = word.chars();
-    let starting_char = iter.next().unwrap();
-    let second_char = iter.next().unwrap();
-    match second_char {
-        'ゃ' | 'ゅ' | 'ょ' => format!("{starting_char}{second_char}"),
-        _ => starting_char.to_string(),
-    }
+pub struct ServerSettings {
+    pub port: u16,
+    pub testing: bool,
 }
 
-// Trim off lengtheners and non-kana that are irrelevant to shiritori
-// TODO: Use slices
-fn trim_irrelevant_chars(word: &str) -> String {
-    let mut iter = word.chars().rev().peekable();
-    while let Some(c) = iter.peek() {
-        if *c == 'ー' || !c.to_string().is_kana() {
-            iter.next();
-        } else {
-            break;
+impl Default for ServerSettings {
+    fn default() -> Self {
+        Self {
+            port: 8080,
+            testing: true,
         }
     }
-    iter.rev().collect()
 }
 
-// Get final mora, which could be multiple chars e.g. しゃ
-// TODO: Use slices
-fn get_final_mora(word: &str) -> String {
-    let word = trim_irrelevant_chars(word).to_hiragana();
-    if word.is_empty() {
-        return String::from("");
-    }
-    let mut iter = word.chars().rev();
-    let final_char = iter.next().unwrap();
-    match final_char {
-        'ゃ' | 'ゅ' | 'ょ' => format!("{}{final_char}", match iter.next() {
-            Some(c) => c.to_string(),
-            None => String::from(""),
-        }),
-        _ => final_char.to_string(),
-    }
+pub struct Server {
+    event_hub: EventHub,
+    lobby: Rc<RefCell<Room>>,
+    rooms: HashMap<String, Room>,
+    clients: HashMap<u64, Client>,
 }
 
 impl Server {
-    pub fn new(port: u16, testing: bool) -> Result<Self, ServerCreationError> {
-        Ok(Server {
-            event_hub: simple_websockets::launch(port)?,
-            database: Database::new(testing)?,
+    pub fn new(settings: &ServerSettings) -> Result<Self, ServerCreationError> {
+        Ok(Self {
+            event_hub: simple_websockets::launch(settings.port)?,
+            lobby: Rc::new(RefCell::new(Room::new(RoomSettings {
+                database_settings: DatabaseSettings {
+                    db_type: match settings.testing {
+                        true => DatabaseType::InMemory,
+                        false => DatabaseType::OnDisk("shiritori.sb".to_string()),
+                    },
+                },
+                ..Default::default()
+            })?)),
+            rooms: HashMap::new(),
             clients: HashMap::new(),
-            next_mora: None,
-            last_client_id: None,
         })
     }
 
+    pub fn get_client(&self, id: u64) -> Option<&Client> {
+        self.clients.get(&id)
+    }
+
     pub fn run(&mut self) {
         loop {
             match match self.event_hub.poll_event() {
-                Event::Connect(client_id, responder) => self.handle_connection(client_id, responder),
+                Event::Connect(client_id, responder) => {
+                    self.handle_connection(client_id, responder)
+                }
                 Event::Disconnect(client_id) => self.handle_disconnection(client_id),
                 Event::Message(client_id, message) => self.handle_message(client_id, message),
             } {
-                Ok(()) => {},
+                Ok(()) => {}
                 Err(error) => println!("{:?}", error),
             }
         }
     }
 
-    fn broadcast_player_count(&self) {
-        let response = MessageResponseData::PlayerCount { players: self.clients.len() as u64 }.into_response();
-        for (_client, responder) in self.clients.iter() {
-            responder.send(response.to_message());
-        }
+    fn new_client(&mut self, client_id: u64, responder: Responder) -> &Client {
+        let client = Client::new(
+            ClientInfo::Ws {
+                id: client_id,
+                responder,
+                discord_info: None,
+            },
+            self.lobby.clone(),
+        );
+        self.clients.insert(client_id, client);
+        self.clients.get(&client_id).unwrap()
     }
 
-    fn handle_connection(&mut self, client_id: u64, responder: Responder) -> Result<(), ServerError> {
+    fn handle_connection(
+        &mut self,
+        client_id: u64,
+        responder: Responder,
+    ) -> Result<(), ServerError> {
+        // Debug
         println!("A client connected with id #{}", client_id);
-        responder.send(MessageResponseData::Greeting {
-            id: client_id,
-            next_mora: self.next_mora.clone(),
-        }.into_message());
-        responder.send(MessageResponseData::History {
-            words: self.database.load_words_before(self.database.last_word_id + 1)?
-        }.into_message());
-        self.clients.insert(client_id, responder);
-        self.broadcast_player_count();
+
+        {
+            // Initialize client
+            let client = self.new_client(client_id, responder);
+
+            // Get immutable access to room
+            let room = client.room.borrow();
+
+            // Send client greeting
+            client.send(
+                MessageResponseData::Greeting {
+                    id: client_id,
+                    next_mora: room.next_mora().clone(),
+                }
+                .into_message(),
+            );
+
+            // Sent recent message history
+            client.send(
+                MessageResponseData::History {
+                    words: room.get_history()?,
+                }
+                .into_message(),
+            );
+        }
+
+        // Number of clients on Rc<RefCell<Room>> reference counter will be one more
+        self.broadcast_player_count(&self.lobby);
+
         Ok(())
     }
 
     fn handle_disconnection(&mut self, client_id: u64) -> Result<(), ServerError> {
+        // Debug
         println!("Client #{} disconnected.", client_id);
-        self.clients.remove(&client_id);
-        self.broadcast_player_count();
+
+        // Remove client
+        // At this point, client should be dropped
+        let client = self.clients.remove(&client_id).unwrap();
+
+        // Get room
+        let room = client.room;
+
+        // Number of clients on Rc<RefCell<Room>> reference counter will be one less
+        self.broadcast_player_count(&room);
+
         Ok(())
     }
 
+    fn for_client_in_room(&self, room: &Rc<RefCell<Room>>, mut closure: impl FnMut(&Client) -> ()) {
+        for (_id, client) in self
+            .clients
+            .iter()
+            .filter(|(_id, client)| Rc::<RefCell<Room>>::ptr_eq(room, &client.room))
+        {
+            closure(client);
+        }
+    }
+
+    fn client_count_in_room(&self, room: &Rc<RefCell<Room>>) -> usize {
+        let mut count: usize = 0;
+        self.for_client_in_room(room, |_| count += 1);
+        count
+    }
+
+    fn broadcast_player_count(&self, room: &Rc<RefCell<Room>>) {
+        let response = MessageResponseData::PlayerCount {
+            players: self.client_count_in_room(room) as u64,
+        }
+        .into_response();
+        for (_id, client) in self.clients.iter() {
+            client.send(response.to_message());
+        }
+    }
+
+    fn announce_to_room(&self, room: &Rc<RefCell<Room>>, response_data: MessageResponseData) {
+        let response = response_data.into_response();
+        self.for_client_in_room(room, |client| {
+            client.send(response.to_message());
+        });
+    }
+
     fn handle_message(&mut self, client_id: u64, message: Message) -> Result<(), ServerError> {
         // Ignore binary messages
         let message = match message {
-            Message::Text(message) => message,
-            Message::Binary(_) => return Ok(()),
+            Message::Text(message) => {
+                // Debug
+                println!(
+                    "Received a message from client #{}: {:?}",
+                    client_id, message
+                );
+
+                message
+            }
+            Message::Binary(message) => {
+                // Debug
+                println!(
+                    "Received a binary message from client #{}: {:?}",
+                    client_id, message
+                );
+
+                return Ok(());
+            }
         };
 
-        // Debug
-        println!("Received a message from client #{}: {:?}", client_id, message);
+        let client = self.get_client(client_id).unwrap();
 
-        let response = if Some(client_id) == self.last_client_id {
-            MessageResponseData::Error {
-                message: String::from("It's not your turn!"),
-            }
-        } else {
-            let query = if message.is_japanese() {
-                Some(message)
-            } else {
-                let kana = message.to_kana();
-                if kana.is_japanese() {
-                    Some(kana)
-                } else {
-                    None
-                }
-            };
-            // For some reason result will keep a reference to
-            // katakana_query and hiragana_query, meaning that
-            // these need to be kept around as a variable
-            // to prevent them from being dropped.
-            let (katakana_query, hiragana_query) = match &query {
-                Some(query) => (
-                    Some(query.to_katakana()),
-                    Some(query.to_hiragana())
-                ),
-                None => (None, None),
-            };
-            let result = match &query {
-                Some(query) => match lookup(query) {
-                    Some(result) => Some(result),
-                    None => {
-                        if query.is_hiragana() {
-                            // looking up ごりら doesn't return ゴリラ
-                            lookup(katakana_query.as_ref().unwrap())
-                        } else if query.is_katakana() {
-                            // looking up シリトリ doesn't return 尻取り
-                            lookup(hiragana_query.as_ref().unwrap())
-                        } else {
-                            None
-                        }
-                    }
-                },
-                None => None,
-            };
-            match result {
-                Some(entry) => {
-                    if entry.reading.chars().last().unwrap().to_string().to_hiragana() == "ん" {
-                        MessageResponseData::Error {
-                            message: String::from("Can't end with ん!"),
-                        }
-                    } else if self.next_mora.is_none() || get_starting_mora(&entry.reading).eq(self.next_mora.as_deref().unwrap()) {
-                        let word: Word = entry.clone().into();
-                        self.next_mora = Some(get_final_mora(&word.reading));
-                        self.database.add_word(&word)?;
-                        MessageResponseData::Word {
-                            author: client_id,
-                            word,
-                            next_mora: self.next_mora.as_deref().unwrap().to_owned(),
-                        }
-                    } else {
-                        MessageResponseData::Error {
-                            message: String::from("Wrong starting mora!"),
-                        }
+        match client.room.borrow_mut().handle_query(&message, client_id) {
+            // Broadcast new words to all clients in same room
+            Ok(response) => self.announce_to_room(&client.room, response),
+            // Send errors to only this client
+            Err(message) => {
+                client.send(
+                    MessageResponseData::Error {
+                        message: message.to_string(),
                     }
-                }
-                None => MessageResponseData::Error {
-                    message: String::from("Not in dictionary!"),
-                },
+                    .into_message(),
+                );
             }
-        }.into_response();
-
-        match response.data {
-            // Send errors to only this client
-            MessageResponseData::Error { .. } => {
-                self.clients.get(&client_id).unwrap().send(response.to_message());
-            },
-            // Broadcast everything else to all clients
-            _ => {
-                for (_client, responder) in self.clients.iter() {
-                    responder.send(response.to_message());
-                }
-                self.last_client_id = Some(client_id);
-            },
         };
         Ok(())
     }

src/utils.rs

@@ -0,0 +1,50 @@
+use wana_kana::{ConvertJapanese, IsJapaneseStr};
+
+pub fn get_starting_mora(word: &str) -> String {
+    if word.is_empty() {
+        return String::from("");
+    }
+    let word = word.to_hiragana();
+    let mut iter = word.chars();
+    let starting_char = iter.next().unwrap();
+    let second_char = iter.next().unwrap();
+    match second_char {
+        'ゃ' | 'ゅ' | 'ょ' => format!("{starting_char}{second_char}"),
+        _ => starting_char.to_string(),
+    }
+}
+
+// Trim off lengtheners and non-kana that are irrelevant to shiritori
+// TODO: Use slices
+fn trim_irrelevant_chars(word: &str) -> String {
+    let mut iter = word.chars().rev().peekable();
+    while let Some(c) = iter.peek() {
+        if *c == 'ー' || !c.to_string().is_kana() {
+            iter.next();
+        } else {
+            break;
+        }
+    }
+    iter.rev().collect()
+}
+
+// Get final mora, which could be multiple chars e.g. しゃ
+// TODO: Use slices
+pub fn get_final_mora(word: &str) -> String {
+    let word = trim_irrelevant_chars(word).to_hiragana();
+    if word.is_empty() {
+        return String::from("");
+    }
+    let mut iter = word.chars().rev();
+    let final_char = iter.next().unwrap();
+    match final_char {
+        'ゃ' | 'ゅ' | 'ょ' => format!(
+            "{}{final_char}",
+            match iter.next() {
+                Some(c) => c.to_string(),
+                None => String::from(""),
+            }
+        ),
+        _ => final_char.to_string(),
+    }
+}

src/word.rs

@@ -1,6 +1,6 @@
 use chrono::{DateTime, Utc};
-use serde::Serialize;
 use jisho::Entry;
+use serde::Serialize;
 use std::convert::From;
 
 #[derive(Serialize)]