Refactored converting row column coordinates to value

3 files changed, 113 insertions, 48 deletions

diff --git a/model/src/board.rs b/model/src/board.rs
index e852063..d7cc69f 100644
--- a/model/src/board.rs
+++ b/model/src/board.rs
@@ -1,5 +1,5 @@
 use crate::possible_moves::PossibleMoves;
-use crate::{Piece, PieceColor};
+use crate::{Piece, PieceColor, SquareCoordinate};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use std::hash::{Hash, Hasher};
@@ -124,26 +124,6 @@ impl CheckersBitBoard {
 		self.turn
 	}
 
-	/// Get the piece at the given square
-	///
-	/// # Arguments
-	///
-	/// * `value` - The square to get the piece from
-	///
-	/// # Panics
-	///
-	/// Panics if value >= 32
-	const fn get(self, value: usize) -> Option<Piece> {
-		if self.piece_at(value) {
-			Some(Piece::new(
-				unsafe { self.king_at_unchecked(value) },
-				unsafe { self.color_at_unchecked(value) },
-			))
-		} else {
-			None
-		}
-	}
-
 	/// Gets the piece at a given row column coordinate
 	///
 	/// # Arguments
@@ -151,38 +131,22 @@ impl CheckersBitBoard {
 	/// * `row` - The row. The a file is row 0
 	/// * `col` - The column. The first rank is column 0
 	pub fn get_at_row_col(self, row: usize, col: usize) -> Option<Piece> {
-		if row < 8 && col < 8 {
-			if row % 2 == 0 {
-				if col % 2 == 0 {
-					let value = ((18 - ((col / 2) * 6)) + ((row / 2) * 8)) % 32;
-					self.get(value)
+		if row > 32 || col > 32 {
+			None
+		} else {
+			let value = SquareCoordinate::new(row as u8, col as u8).to_value();
+			if let Some(value) = value {
+				if self.piece_at(value) {
+					Some(Piece::new(
+						unsafe { self.king_at_unchecked(value) },
+						unsafe { self.color_at_unchecked(value) },
+					))
 				} else {
 					None
 				}
 			} else {
-				if col % 2 == 1 {
-					let column_value = match col {
-						1 => 19,
-						3 => 13,
-						5 => 7,
-						7 => 1,
-						_ => unreachable!(),
-					};
-					let row_value = match row {
-						1 => 0,
-						3 => 8,
-						5 => 16,
-						7 => 24,
-						_ => unreachable!(),
-					};
-					let value = (column_value + row_value) % 32;
-					self.get(value)
-				} else {
-					None
-				}
+				None
 			}
-		} else {
-			None
 		}
 	}
 
diff --git a/model/src/coordinates.rs b/model/src/coordinates.rs
new file mode 100644
index 0000000..34dcdcf
--- /dev/null
+++ b/model/src/coordinates.rs
@@ -0,0 +1,99 @@
+use std::fmt::{Display, Formatter};
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub struct SquareCoordinate {
+	rank: u8,
+	file: u8,
+}
+
+impl SquareCoordinate {
+	pub(crate) fn new(rank: u8, file: u8) -> Self {
+		if rank > 32 {
+			panic!("A Square cannot have a rank greater than 32. Got {}", rank)
+		} else if file > 32 {
+			panic!("A Square cannot have a file greater than 32. Got {}", file)
+		} else {
+			Self { rank, file }
+		}
+	}
+
+	pub fn from_value(value: usize) -> Self {
+		static VALUE_COORDINATE_MAP: [SquareCoordinate; 32] = [
+			SquareCoordinate { rank: 0, file: 6 },
+			SquareCoordinate { rank: 1, file: 7 },
+			SquareCoordinate { rank: 4, file: 0 },
+			SquareCoordinate { rank: 5, file: 1 },
+			SquareCoordinate { rank: 6, file: 2 },
+			SquareCoordinate { rank: 7, file: 3 },
+			SquareCoordinate { rank: 0, file: 4 },
+			SquareCoordinate { rank: 1, file: 5 },
+			SquareCoordinate { rank: 2, file: 6 },
+			SquareCoordinate { rank: 3, file: 7 },
+			SquareCoordinate { rank: 6, file: 0 },
+			SquareCoordinate { rank: 7, file: 1 },
+			SquareCoordinate { rank: 0, file: 2 },
+			SquareCoordinate { rank: 1, file: 3 },
+			SquareCoordinate { rank: 2, file: 4 },
+			SquareCoordinate { rank: 3, file: 5 },
+			SquareCoordinate { rank: 4, file: 6 },
+			SquareCoordinate { rank: 5, file: 7 },
+			SquareCoordinate { rank: 0, file: 0 },
+			SquareCoordinate { rank: 1, file: 1 },
+			SquareCoordinate { rank: 2, file: 2 },
+			SquareCoordinate { rank: 3, file: 3 },
+			SquareCoordinate { rank: 4, file: 4 },
+			SquareCoordinate { rank: 5, file: 5 },
+			SquareCoordinate { rank: 6, file: 6 },
+			SquareCoordinate { rank: 7, file: 7 },
+			SquareCoordinate { rank: 2, file: 0 },
+			SquareCoordinate { rank: 3, file: 1 },
+			SquareCoordinate { rank: 4, file: 2 },
+			SquareCoordinate { rank: 5, file: 3 },
+			SquareCoordinate { rank: 6, file: 4 },
+			SquareCoordinate { rank: 7, file: 5 },
+		];
+
+		VALUE_COORDINATE_MAP[value]
+	}
+
+	pub fn to_value(self) -> Option<usize> {
+		if self.rank % 2 == 0 {
+			if self.file % 2 == 0 {
+				Some(((18 - ((self.file / 2) * 6)) + ((self.rank / 2) * 8)) as usize % 32)
+			} else {
+				None
+			}
+		} else {
+			if self.file % 2 == 1 {
+				let column_value = match self.file {
+					1 => 19,
+					3 => 13,
+					5 => 7,
+					7 => 1,
+					_ => unreachable!(),
+				};
+				let row_value = match self.file {
+					1 => 0,
+					3 => 8,
+					5 => 16,
+					7 => 24,
+					_ => unreachable!(),
+				};
+				Some((column_value + row_value) % 32)
+			} else {
+				None
+			}
+		}
+	}
+}
+
+impl Display for SquareCoordinate {
+	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+		write!(
+			f,
+			"{}{}",
+			char::from_u32((self.file + b'a') as u32).unwrap(),
+			self.rank + 1
+		)
+	}
+}
diff --git a/model/src/lib.rs b/model/src/lib.rs
index 1e1b364..61ab2cc 100644
--- a/model/src/lib.rs
+++ b/model/src/lib.rs
@@ -1,11 +1,13 @@
 mod board;
 mod color;
+mod coordinates;
 mod moves;
 mod piece;
 mod possible_moves;
 
 pub use board::CheckersBitBoard;
 pub use color::PieceColor;
+pub use coordinates::SquareCoordinate;
 pub use moves::Move;
 pub use piece::Piece;
 pub use possible_moves::PossibleMoves;