From a65678343a38e5b480a5faad3cf2486f0117d235 Mon Sep 17 00:00:00 2001
From: Baptiste Fouques <baptiste@bat.fr.eu.org>
Date: Mon, 16 Jan 2023 17:08:06 +0100
Subject: [PATCH] Add auxilary functions

---
 chess_uci/src/lib.rs       | 78 +++++++++++++++++++++++++-------------
 chess_uci_demo/src/main.rs |  2 +-
 2 files changed, 53 insertions(+), 27 deletions(-)

diff --git a/chess_uci/src/lib.rs b/chess_uci/src/lib.rs
index da288b0..381edeb 100644
--- a/chess_uci/src/lib.rs
+++ b/chess_uci/src/lib.rs
@@ -32,8 +32,8 @@ use chess::{Game, Board, ChessMove};
 /// uci.push_raw("quit\n");
 /// ```
 pub struct UciEngine<Fi: Read, Fo: Write> {
-    source: BufReader<Fi>,
-    destination: Fo,
+    source: Option<BufReader<Fi>>,
+    destination: Option<Fo>,
     uciok: bool,
     id: Id,
     initial: Board,
@@ -45,9 +45,9 @@ impl<Fi: Read, Fo:  Write> UciEngine<Fi, Fo> {
     /// Create new game manager
     ///
     /// Requires line by line input and output streams to communicate with uci engine
-    pub fn new(source: Fi, destination: Fo) -> UciEngine<Fi, Fo> {
+    pub fn new(source: Option<Fi>, destination: Option<Fo>) -> UciEngine<Fi, Fo> {
         UciEngine::<Fi, Fo>{
-            source: BufReader::new(source),
+            source: if let Some(source) = source {Some(BufReader::new(source))} else {None},
             destination,
             id: Id::new(),
             uciok: false,
@@ -148,45 +148,71 @@ impl<Fi: Read, Fo:  Write> UciEngine<Fi, Fo> {
     /// Retrieve a line from the uci engine input stream and parse it
     pub fn pull(&mut self) {
 
-        let mut command = String::new();
-        match self.source.read_line(&mut command) {
-            Ok(0) => self.terminate("Chess engine closed connection."),
-            Ok(_) => {
-                info!("← {}", command);
-                self.exec(&command)
-            },
-            Err(reason) => warn!("Unable to read from engine: {reason}"),
+        if let Some(source) = &mut self.source {
+            let mut command = String::new();
+            match source.read_line(&mut command) {
+                Ok(0) => self.terminate("Chess engine closed connection."),
+                Ok(_) => {
+                    info!("← {}", command);
+                    self.exec(&command)
+                },
+                Err(reason) => warn!("Unable to read from engine: {reason}"),
+            }
+        } else {
+            info!("❌ No connected uci engine");
         }
     }
 
     /// Read a line from the uci engine input stream (do not parse)
     pub fn pull_raw(&mut self) -> Option<String> {
-        let mut data = String::new();
-        match self.source.read_line(&mut data) {
-            Ok(0) => {self.terminate("Chess engine closed connection."); None},
-            Ok(_) => {info!("↜ {}", data); Some(data.clone())},
-            Err(reason) => {warn!("Unable to read from engine: {reason}"); None},
+        if let Some(source) = &mut self.source {
+            let mut data = String::new();
+            match source.read_line(&mut data) {
+                Ok(0) => {self.terminate("Chess engine closed connection."); None},
+                Ok(_) => {info!("↜ {}", data); Some(data.clone())},
+                Err(reason) => {warn!("Unable to read from engine: {reason}"); None},
+            }
+        } else {
+            info!("❌ No connected uci engine");
+            None
         }
     }
 
     /// Push a Uci Gui command to the engine
     fn push(&mut self, command: GuiCommand) {
-        let command_str = command.to_string();
-        match self.destination.write(&command_str.as_bytes()){
-            Ok(n) if n == command_str.len() => info!("→ gui: {command_str}"),
-            Ok(n) => warn!("⚠ gui: {command_str} truncated at {n}"),
-            Err(reason) => warn!("Unable to send command {command_str}: {reason}"),
+        if let Some(destination) = &mut self.destination {
+            let command_str = command.to_string();
+            match destination.write(&command_str.as_bytes()){
+                Ok(n) if n == command_str.len() => info!("→ gui: {command_str}"),
+                Ok(n) => warn!("⚠ gui: {command_str} truncated at {n}"),
+                Err(reason) => warn!("Unable to send command {command_str}: {reason}"),
+            }
+        } else {
+            info!("❌ No connected uci engine");
         }
     }
 
     /// Push string (not a game manager integrated command) to the Uci engine output stream
     pub fn push_raw(&mut self, data: &str){
-        match self.destination.write(data.as_bytes()) {
-            Ok(n) if n == data.len() => info!("↝ raw: {data}"),
-            Ok(n) => warn!("⚠ raw: {data} truncated at {n}"),
-            Err(reason) => warn!("Unable to send raw {data}: {reason}"),
+        if let Some(destination) = &mut self.destination {
+            match destination.write(data.as_bytes()) {
+                Ok(n) if n == data.len() => info!("↝ raw: {data}"),
+                Ok(n) => warn!("⚠ raw: {data} truncated at {n}"),
+                Err(reason) => warn!("Unable to send raw {data}: {reason}"),
+            }
+        } else {
+            info!("❌ No connected uci engine");
         }
     }
 }
 
+use chess::{Square, Piece, Color};
+impl<Fi: Read, Fo:  Write> UciEngine<Fi, Fo> {
+    pub fn piece_on(&self, square: Square) -> Option<Piece> {
+        self.game.current_position().piece_on(square)
+    }
+    pub fn color_on(&self, square: Square) -> Option<Color> {
+        self.game.current_position().color_on(square)
+    }
+}
 //  LocalWords:  uci
diff --git a/chess_uci_demo/src/main.rs b/chess_uci_demo/src/main.rs
index db3cd31..2ee41bb 100644
--- a/chess_uci_demo/src/main.rs
+++ b/chess_uci_demo/src/main.rs
@@ -22,7 +22,7 @@ pub fn main(){
         };
 
     let (sf_in,sf_out) = (process.stdin.expect("Program stdin"), process.stdout.expect("Program stdout"));
-    let mut uci = UciEngine::new(sf_out, sf_in);
+    let mut uci = UciEngine::new(Some(sf_out), Some(sf_in));
     uci.init();
 
     println!("Engine: {} \nby: {}",