1 files changed, 99 insertions, 0 deletions
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
+		)
+	}
+}