game is playable through netcat

Cargo.lock

@@ -48,6 +48,7 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 name = "connect4"
 version = "0.1.0"
 dependencies = [
+ "bytes",
  "tokio",
 ]
 

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+bytes = "1.7.2"
 tokio = { version = "1.38.0", features = [
     "rt-multi-thread",
     "macros",

src/connect4.rs

@@ -118,22 +118,25 @@ impl GameState {
         return score;
     }
 
-    pub fn display(&self) {
+    pub fn to_string(&self) -> String {
+        let mut string = String::new();
         for irow in (0..NROWS).rev() {
-            print!("\n ");
+            string += " ";
             for icol in 0..NCOLS {
                 let idx = irow + 7 * icol;
                 
                 if (self.bitboards[0] >> idx) & 1 != 0 {
-                    print!("● ");
+                    string += "● ";
                 } else if (self.bitboards[1] >> idx) & 1 != 0 {
-                    print!("○ ");
+                    string += "○ ";
                 } else {
-                    print!("· ");
+                    string += "· ";
                 }
             }
+            string += "\n";
         }
-        print!("\n 1 2 3 4 5 6 7\n\n");
+        string += " 1 2 3 4 5 6 7\n\n";
+        string
     }
 }
 

src/game_server.rs

@@ -1,31 +1,89 @@
-
+use bytes::BytesMut;
-use std::f32::consts::E;
 
 use tokio::{
-    // AsyncWriteExt trait provides asynchronous write methods like write_all
     io::{AsyncReadExt, AsyncWriteExt},
-    net::{TcpListener, TcpStream},
+    net::TcpStream,
 };
 
-use crate::connect4::GameState;
+use crate::connect4;
-
-/// The Server struct holds the tokio TcpListener which listens for
-/// incoming TCP connections.
 #[derive(Debug)]
-pub struct GameServer {
+pub struct GameServer {}
-}
 
 impl GameServer {
-    pub async fn handle(socket: &mut TcpStream, game_state: GameState) {
+    pub async fn handle(socket: &mut TcpStream) -> Result<(), String> {
-        match socket.write_all("Hello!!".as_bytes()).await {
+        send_text("Connect 4\nChoose your difficulty [1-9]: ", socket).await?;
-            Ok(_) => {println!("socket socketed successfully")},
+
-            Err(e) => {println!("socket didn't socket: {e}")},
+        let depth = get_one_char(b"123456789", socket).await? - b'0';
-        }
+
-        loop {
+        println!("Difficulty: {depth}");
-            match socket.read_i8().await {
+
-                Ok(read) => {println!("read: {read}")},
+        let mut board = connect4::GameState::new();
-                Err(_) => {break},
+
+        let mut end_score: i64 = -1;
+
+        while end_score == -1 {
+            
+            match board.counter % 2 == 0 {
+                true => {
+                    send_text(format!("Move {}:\n", board.counter).as_str(), socket).await?;
+                    send_text(board.to_string().as_str(), socket).await?;
+                    
+                    send_text("Choose column: ", socket).await?;
+                    let mut player_move = get_one_char(b"1234567", socket).await? - b'0';
+                    while !board.move_is_valid((player_move - 1).into()) {
+                        send_text("Illegal move.\nChoose column: ", socket).await?;
+                        player_move = get_one_char(b"1234567", socket).await? - b'0';
+                    }
+
+                    board.make_move((player_move - 1).into());
+                    end_score = board.end_state_reached();
+                    send_text("\n", socket).await?;
+                },
+                false => {
+                    let best_move = connect4::get_minimax_move(&mut board, depth.into());
+
+                    board.make_move(best_move);
+                    end_score = board.end_state_reached();
+                }
             }
         }
+
+        if end_score == 0 {
+            send_text( "It's a Tie\n\n", socket).await?;
+        } else if end_score > 0 {
+            send_text("White (●) Won!\n\n", socket).await?;
+        } else {
+            send_text("Black (○) Won!\n\n", socket).await?;
+        }
+        
+        send_text(&board.to_string(), socket).await?;
+
+        Ok(())
+    }
+}
+
+async fn get_one_char(allowed: &[u8], socket: &mut TcpStream) -> Result<u8, String> {
+    let mut buffer = BytesMut::with_capacity(100);
+    loop {
+        match socket.read_buf(&mut buffer).await {
+            Ok(0) => return Err(format!("socket disconnected")),
+            Ok(read) => {
+                println!("read {read} bytes: {:?}", buffer);
+                for byte in &buffer {
+                    if allowed.contains(byte) {
+                        return Ok(*byte);
+                    }
+                }
+                buffer.clear();
+            }
+            Err(e) => return Err(format!("socket error while reading a digit: {e}")),
+        }
+    }
+}
+
+async fn send_text(text: &str, socket: &mut TcpStream) -> Result<(), String> {
+    match socket.write_all(text.as_bytes()).await {
+        Ok(_) => Ok(()),
+        Err(e) => Err(format!("socket error while sending text: {e}")),
     }
 }

src/main.rs

@@ -1,4 +1,3 @@
-use connect4::GameState;
 use game_server::GameServer;
 use tokio::net::TcpListener;
 
@@ -7,21 +6,20 @@ mod game_server;
 
 #[tokio::main]
 async fn main() {
-    let addr = format!("127.0.0.1:{}", 6379);
+    let addr = format!("127.0.0.1:{}", 1234);
 
-    let listener = match TcpListener::bind(&addr).await {
+    let listener = TcpListener::bind(&addr)
-        Ok(tcp_listener) => {
+        .await
-            println!("TCP listener started on port 6379");
+        .expect(format!("Could not bind the TCP listener to {}", &addr).as_str());
-            tcp_listener
-        }
-        Err(e) => panic!("Could not bind the TCP listener to {}. Err: {}", &addr, e),
-    };
 
     loop {
         match listener.accept().await {
             Ok((mut socket, _)) => {
                 tokio::spawn(async move {
-                    GameServer::handle(&mut socket, GameState::new()).await;
+                    match GameServer::handle(&mut socket).await {
+                        Ok(_) => {println!("Game finished")},
+                        Err(e) => {println!("Game failed with error: {e}")},
+                    };
                 });
             }
             Err(e) => {
@@ -30,28 +28,5 @@ async fn main() {
         }
     }
 
-    let mut board = connect4::GameState::new();
-    let depth = 7;
     
-    let mut end_score: i64 = -1;
-
-    while end_score == -1 {
-        println!("Move {}:", board.counter);
-        board.display();
-        let best_move = connect4::get_minimax_move(&mut board, depth);
-
-        board.make_move(best_move);
-        end_score = board.end_state_reached();
-    }
-
-    println!("Move {}:", board.counter);
-    board.display();
-
-    if end_score == 0 {
-        println!("It's a Tie");
-    } else if end_score > 0 {
-        println!("White (●) Won!");
-    } else {
-        println!("Black (○) Won!");
-    }
 }