From 2133fb3cad04335588e95198e1f758813a673f92 Mon Sep 17 00:00:00 2001
From: stefiosif <si.iosifidis@gmail.com>
Date: Sun, 9 Jun 2024 15:21:11 +0300
Subject: [PATCH] Add State struct as part of Board struct

---
 src/board.rs | 25 +++++++++++++++++++------
 src/fen.rs   | 20 +++++++++-----------
 src/game.rs  |  8 +++++---
 3 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/src/board.rs b/src/board.rs
index dcce0bd..27dc7d1 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -5,11 +5,13 @@ use crate::attack::{
     get_bishop_attacks, get_king_attacks, get_knight_attacks, get_pawn_attacks, get_queen_attacks,
     get_rook_attacks,
 };
+use crate::game::State;
 
 #[derive(Debug, PartialEq, Eq)]
 pub struct Board {
-    white_pieces: [Piece; 6],
-    black_pieces: [Piece; 6],
+    pub white_pieces: [Piece; 6],
+    pub black_pieces: [Piece; 6],
+    pub state: State,
 }
 
 impl Board {
@@ -31,6 +33,7 @@ impl Board {
                 Piece::new(0x800000000000000, Kind::Queen, Color::Black),
                 Piece::new(0x1000000000000000, Kind::King, Color::Black),
             ],
+            state: State::new(),
         }
     }
 
@@ -52,6 +55,7 @@ impl Board {
                 Piece::new(0x0, Kind::Queen, Color::Black),
                 Piece::new(0x0, Kind::King, Color::Black),
             ],
+            state: State::new(),
         }
     }
 
@@ -62,11 +66,20 @@ impl Board {
         };
     }
 
-    pub fn get_all_occupancies(&self) -> Bitboard {
-        let white_blockers = self.white_pieces.iter().fold(0, |acc, p| p.bitboard | acc);
-        let black_blockers = self.black_pieces.iter().fold(0, |acc, p| p.bitboard | acc);
+    pub fn set_state(&mut self, state: State) {
+        self.state = state;
+    }
 
-        white_blockers | black_blockers
+    pub fn get_white_occupancies(&self) -> Bitboard {
+        self.white_pieces.iter().fold(0, |acc, p| p.bitboard | acc)
+    }
+
+    pub fn get_black_occupancies(&self) -> Bitboard {
+        self.black_pieces.iter().fold(0, |acc, p| p.bitboard | acc)
+    }
+
+    pub fn get_all_occupancies(&self) -> Bitboard {
+        self.get_white_occupancies() | self.get_black_occupancies()
     }
 
     pub fn is_attacked(&self, sq: usize, opponent_color: Color) -> bool {
diff --git a/src/fen.rs b/src/fen.rs
index 7bd2854..9428f98 100644
--- a/src/fen.rs
+++ b/src/fen.rs
@@ -5,7 +5,7 @@ use String as FenError;
 pub fn from_fen(fen: &str) -> Result<Game, FenError> {
     let fen_parts: Vec<_> = fen.split_whitespace().collect();
 
-    let board = piece_placement(fen_parts[0])?;
+    let mut board = piece_placement(fen_parts[0])?;
 
     let side_to_move = side_to_move(fen_parts[1])?;
 
@@ -17,16 +17,14 @@ pub fn from_fen(fen: &str) -> Result<Game, FenError> {
 
     let fullmove_counter = fullmove_counter(fen_parts[5])?;
 
-    Ok(Game {
-        board,
-        state: State::load_state(
-            side_to_move,
-            castling_ability,
-            en_passant_target_square,
-            halfmove_clock,
-            fullmove_counter,
-        ),
-    })
+    board.set_state(State::load_state(
+        side_to_move,
+        castling_ability,
+        en_passant_target_square,
+        halfmove_clock,
+        fullmove_counter,
+    ));
+    Ok(Game { board })
 }
 
 pub fn piece_placement(pieces: &str) -> Result<Board, FenError> {
diff --git a/src/game.rs b/src/game.rs
index 3b1234f..78284ab 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -7,14 +7,12 @@ use String as FenError;
 #[derive(Debug, PartialEq, Eq)]
 pub struct Game {
     pub board: Board,
-    pub state: State,
 }
 
 impl Game {
     pub const fn new() -> Self {
         Self {
             board: Board::new(),
-            state: State::new(),
         }
     }
 
@@ -33,7 +31,7 @@ impl Default for Game {
     }
 }
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct State {
     side_to_move: Color,
     castling_ability: u8,
@@ -68,6 +66,10 @@ impl State {
             fullmove_counter,
         }
     }
+
+    pub const fn get_en_passant_target_square(&self) -> u8 {
+        self.en_passant_target_square
+    }
 }
 
 use std::fmt;