Manage when user leave during connection.

src/bin/client.rs

@@ -1,4 +1,6 @@
 extern crate ctrlc;
+use clichess::RecvPositionError;
+use serde_json::json;
 use shakmaty::fen::Fen;
 use shakmaty::{Chess, Color, Outcome, Position, Setup};
 use std::io;
@@ -7,7 +9,6 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time;
-use serde_json::json;
 
 struct Client {
     player: clichess::Player,
@@ -17,12 +18,6 @@ struct Client {
     server_message: Arc<Mutex<String>>,
 }
 
-enum RecvPositionError {
-    UserCanceledError,
-    CommunicationError,
-    ParsePositionError,
-}
-
 fn main() {
     let running = setupctrlc();
     let username = std::env::args().nth(1).expect("no name given");
@@ -56,8 +51,10 @@ fn main() {
         server_message: server_message.clone(),
     };
 
-    let role = prompt_user_for_role(&client, &mut stream);
-    client.player.role = role.clone();
+    match prompt_user_for_role(&client, &mut stream) {
+        Some(role) => client.player.role = role.clone(),
+        None => return,
+    };
     println!(
         "Hello, {} !\n\r You're playing with the {} pieces",
         client.player.username,
@@ -218,8 +215,8 @@ fn parse_position(string: &str) -> Chess {
     position
 }
 
-fn prompt_user_for_role(client: &Client, stream: &mut UnixStream) -> clichess::UserRole {
-    let mut role: clichess::UserRole;
+fn prompt_user_for_role(client: &Client, stream: &mut UnixStream) -> Option<clichess::UserRole> {
+    let mut role = None;
     loop {
         println!("fetching roles from server...");
         let available_roles = fetch_available_roles(client);
@@ -241,14 +238,18 @@ fn prompt_user_for_role(client: &Client, stream: &mut UnixStream) -> clichess::U
         println!("{}", prompt);
         //wait for user to give a correct answer.
         let input = String::from(read_user_input(client).trim());
+        if input.trim() == "exit" {
+            clichess::write_to_stream(stream, String::from("exit")).unwrap();
+            break;
+        }
         match clichess::parse_to_role(&input) {
-            Ok(r) => role = r,
+            Ok(r) => role = Some(r),
             Err(e) => {
                 println!("{}", e);
                 continue;
             }
         };
-        if !available_roles.contains(&role) {
+        if role.is_some() && !available_roles.contains(&role.expect("role is some")) {
             println!("Sorry, this side is not available.");
             continue;
         }

src/bin/server.rs

@@ -1,5 +1,6 @@
 use clichess;
 use clichess::Player;
+use clichess::RecvPositionError;
 use clichess::UserRole;
 use serde_json::Value;
 use shakmaty::{fen, Chess, Color, Setup};
@@ -49,9 +50,20 @@ fn main() {
 }
 
 fn handle_player(mut stream: UnixStream, server: Server) {
+    match initialize_client(&mut stream, &server) {
+        Ok((player, player_turn)) => main_loop(&mut stream, &server, player, player_turn),
+        Err(e) => println!("User id {} could not be initialized: {}", server.id, e),
+    };
+    player_disconnected();
+}
+
+fn initialize_client(
+    stream: &mut UnixStream,
+    server: &Server,
+) -> Result<(Player, Color), RecvPositionError> {
     //create player
-    let player = create_player(&server, &mut stream);
-    let mut player_turn: Color;
+    let player = create_player(server, stream)?;
+    let player_turn: Color;
     //send current position to the player
     println!(
         "server {}, send current position to the player...",
@@ -60,15 +72,19 @@ fn handle_player(mut stream: UnixStream, server: Server) {
     {
         let chess = server.chess_position.lock().unwrap();
         player_turn = chess.turn();
-        clichess::write_to_stream(&mut stream, fen::fen(&*chess)).unwrap();
+        clichess::write_to_stream(stream, fen::fen(&*chess)).unwrap();
     }
     println!("server {}, current position to the player sent", server.id);
+    Ok((player, player_turn))
+}
+
+fn main_loop(stream: &mut UnixStream, server: &Server, player: Player, mut player_turn: Color) {
     loop {
         if clichess::is_player_turn(&player, player_turn) {
             //let go of the lock while waiting for user input.
             println!("server {}, waiting for player move..", server.id);
             let input;
-            match clichess::read_line_from_stream(&stream) {
+            match clichess::read_line_from_stream(stream) {
                 Ok(i) => input = i,
                 Err(e) => {
                     println!("Error while getting user input: {}", e);
@@ -93,7 +109,7 @@ fn handle_player(mut stream: UnixStream, server: Server) {
                         cvar_buffer.1.notify_one();
                     }
                 }
-                clichess::write_to_stream(&mut stream, chessfen).unwrap();
+                clichess::write_to_stream(stream, chessfen).unwrap();
                 player_turn = chess.turn();
             }
         } else {
@@ -105,7 +121,7 @@ fn handle_player(mut stream: UnixStream, server: Server) {
                     buffer = cvar.wait(buffer).unwrap();
                 }
                 println!("server id: {}, sending {}", server.id, buffer);
-                match clichess::write_to_stream(&mut stream, buffer.clone()) {
+                match clichess::write_to_stream(stream, buffer.clone()) {
                     Ok(()) => buffer.clear(),
                     Err(e) => {
                         println!("{}", e);
@@ -117,10 +133,9 @@ fn handle_player(mut stream: UnixStream, server: Server) {
             }
         }
     }
-    println!("Player disconnected.")
 }
 
-fn create_player(server: &Server, stream: &mut UnixStream) -> Player {
+fn create_player(server: &Server, stream: &mut UnixStream) -> Result<Player, RecvPositionError> {
     println!("Creating player {}...", server.id);
     //get player name and pubkey
     let username_pubkey_json =
@@ -130,7 +145,7 @@ fn create_player(server: &Server, stream: &mut UnixStream) -> Player {
     let public_key = username_pubkey_value["pubkey"].to_string();
     println!("got username: {}", username);
     println!("got pubkey: {}", public_key);
-    let role = receive_user_role(server, stream);
+    let role = receive_user_role(server, stream)?;
     let mut players = server.players.lock().unwrap();
     let player = Player {
         role,
@@ -139,10 +154,13 @@ fn create_player(server: &Server, stream: &mut UnixStream) -> Player {
     };
     players.insert(server.id, (player.clone(), server.receiving_buffer.clone()));
     println!("Created player {}", server.id);
-    player
+    Ok(player)
 }
 
-fn receive_user_role(server: &Server, stream: &mut UnixStream) -> UserRole {
+fn receive_user_role(
+    server: &Server,
+    stream: &mut UnixStream,
+) -> Result<UserRole, RecvPositionError> {
     let mut chosen_role: UserRole;
     loop {
         //send available roles
@@ -152,9 +170,16 @@ fn receive_user_role(server: &Server, stream: &mut UnixStream) -> UserRole {
         //receive chosen role
         let chosen_role_str =
             clichess::read_line_from_stream(stream).expect("Player closed connection.");
+        if chosen_role_str == "exit" {
+            return Err(RecvPositionError::UserCanceledError);
+        }
         println!("Client id {} has chosen {}", server.id, chosen_role_str);
-        chosen_role =
-            clichess::parse_to_role(&chosen_role_str).expect("Client did not send parsable role.");
+        let chosen_role_parse = clichess::parse_to_role(&chosen_role_str);
+
+        if chosen_role_parse.is_err() {
+            return Err(RecvPositionError::ParsePositionError);
+        }
+        chosen_role = chosen_role_parse.unwrap();
         //check if role is still available after the choice
         {
             let mut available_roles_after_choice =
@@ -183,7 +208,7 @@ fn receive_user_role(server: &Server, stream: &mut UnixStream) -> UserRole {
             }
         }
     }
-    chosen_role
+    Ok(chosen_role)
 }
 
 fn compute_available_roles_to_str(server: &Server) -> String {
@@ -201,3 +226,7 @@ fn compute_available_roles_to_str(server: &Server) -> String {
         .collect();
     available_roles_str.join(",")
 }
+
+fn player_disconnected() {
+    println!("Player disconnected.");
+}

src/lib.rs

@@ -8,7 +8,6 @@ use std::io;
 use std::io::prelude::*;
 use std::io::{BufReader, Write};
 use std::os::unix::net::UnixStream;
-use std::ops::Add;
 
 #[derive(Clone)]
 pub struct Player {
@@ -38,6 +37,27 @@ impl fmt::Display for UserRole {
     }
 }
 
+pub enum RecvPositionError {
+    UserCanceledError,
+    CommunicationError,
+    ParsePositionError,
+}
+
+impl fmt::Display for RecvPositionError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                RecvPositionError::CommunicationError =>
+                    "Error during the communication between client and server.",
+                RecvPositionError::ParsePositionError => "Error when parsing current position.",
+                RecvPositionError::UserCanceledError => "Cancelled by user.",
+            }
+        )
+    }
+}
+
 struct SquareToPrint {
     color: String,
     background_color: String,
@@ -205,7 +225,7 @@ pub fn parse_to_role(s: &str) -> Result<UserRole, String> {
         "w" => Ok(UserRole::White),
         "b" => Ok(UserRole::Black),
         "s" => Ok(UserRole::Spectator),
-        _ => Err(String::from("Please enter a valid answer."))
+        _ => Err(String::from("Please enter a valid answer.")),
     }
 }
 
@@ -213,7 +233,7 @@ pub fn role_to_str(r: &UserRole) -> String {
     String::from(match *r {
         UserRole::White => "w",
         UserRole::Black => "b",
-        UserRole::Spectator => "s"
+        UserRole::Spectator => "s",
     })
 }