Add utility functions for readability and refactor make_move

src/board/bitboard.rs

@@ -21,6 +21,13 @@ pub const fn square_to_bitboard_wrapping(square: usize) -> Bitboard {
     1_u64.wrapping_shl(square as u32)
 }
 
+pub const fn bitboard_to_coords(bitboard: Bitboard) -> (usize, usize) {
+    match bitboard {
+        0 => (0, 0),
+        _ => (lsb(bitboard) / 8, lsb(bitboard) % 8),
+    }
+}
+
 pub const fn lsb(bitboard: Bitboard) -> usize {
     bitboard.trailing_zeros() as usize
 }

src/board/board.rs

@@ -167,6 +167,18 @@ impl Board {
     pub fn set_state(&mut self, state: State) {
         self.state = state;
     }
+
+    pub fn piece_type_at(&self, square: usize, color: Color) -> Option<PieceType> {
+        let pieces = match color {
+            Color::White => &self.white_pieces,
+            Color::Black => &self.black_pieces,
+        };
+
+        pieces
+            .iter()
+            .find(|p| have_common_bit(p.bitboard, square_to_bitboard(square)))
+            .map(|p| p.piece_type)
+    }
 }
 
 impl Default for Board {
@@ -216,6 +228,8 @@ impl PieceType {
 }
 use std::ops::{Index, IndexMut};
 
+use super::bitboard::square_to_bitboard;
+
 impl Index<PieceType> for [Piece] {
     type Output = Piece;
 

src/board/game.rs

@@ -1,7 +1,7 @@
 use crate::board::fen::from_fen;
 use String as FenError;
 
-use super::board::Board;
+use super::board::{Board, Color};
 
 #[derive(Debug, PartialEq, Eq)]
 pub struct Game {
@@ -22,6 +22,10 @@ impl Game {
     pub const fn run(&self) {
         Board::new();
     }
+
+    pub const fn current_player(&self) -> Color {
+        self.board.state.current_player()
+    }
 }
 
 impl Default for Game {

src/board/square.rs

@@ -1,7 +1,3 @@
-use u64 as Bitboard;
-
-use crate::board::bitboard::lsb;
-
 pub struct Square {}
 
 impl Square {
@@ -82,13 +78,6 @@ pub const fn coords_to_square(rank: usize, file: usize) -> usize {
     rank * 8 + file
 }
 
-pub const fn bitboard_to_coords(bitboard: Bitboard) -> (usize, usize) {
-    match bitboard {
-        0 => (0, 0),
-        _ => (lsb(bitboard) / 8, lsb(bitboard) % 8),
-    }
-}
-
 pub fn square_to_algebraic(square: usize) -> String {
     let file = (square % 8) as u8;
     let rank = (square / 8) as u8;

src/board/state.rs

@@ -3,10 +3,10 @@ use crate::{board::board::Color, movegen::r#move::MoveType};
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct State {
     side_to_move: Color,
-    castling_ability: [Castle; 2],
-    en_passant_target_square: Option<usize>,
-    halfmove_clock: u8,
-    fullmove_counter: u8,
+    pub castling_ability: [Castle; 2],
+    pub en_passant_target_square: Option<usize>,
+    pub halfmove_clock: u8,
+    pub fullmove_counter: u8,
 }
 
 impl State {
@@ -40,6 +40,17 @@ impl State {
         self.en_passant_target_square
     }
 
+    pub fn set_en_passant_target_square(&mut self, square: Option<usize>) {
+        self.en_passant_target_square = square;
+    }
+
+    pub const fn castling_ability(&self, color: Color) -> Castle {
+        match color {
+            Color::White => self.castling_ability[0],
+            Color::Black => self.castling_ability[1],
+        }
+    }
+
     pub fn set_castling_ability(&mut self, color: Color, castle: Castle) {
         match color {
             Color::White => self.castling_ability[0] = castle,
@@ -95,26 +106,23 @@ impl State {
         }
     }
 
-    pub fn change_side(&mut self) {
+    pub fn revert_full_move(&mut self, color: Color) {
+        match color {
+            Color::White => (),
+            Color::Black => self.fullmove_counter -= 1,
+        }
+    }
+
+    pub fn change_side(&mut self) -> Color {
         self.side_to_move = match self.side_to_move {
             Color::White => Color::Black,
             Color::Black => Color::White,
-        }
-    }
-
-    pub const fn next_turn(&self) -> Color {
+        };
         self.side_to_move
     }
 
-    pub fn set_en_passant_target_square(&mut self, square: Option<usize>) {
-        self.en_passant_target_square = square;
-    }
-
-    pub const fn castling_ability(&self, color: Color) -> Castle {
-        match color {
-            Color::White => self.castling_ability[0],
-            Color::Black => self.castling_ability[1],
-        }
+    pub const fn current_player(&self) -> Color {
+        self.side_to_move
     }
 }