Add a whitespace

Cargo.lock

@@ -19,6 +19,22 @@ dependencies = [
  "tokio-util",
 ]
 
+[[package]]
+name = "actix-cors"
+version = "0.6.0-beta.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4f1bd0e31c745df129f0e94efd374d21f2a455bcc386c15d78ed9a9e7d4dd50"
+dependencies = [
+ "actix-service",
+ "actix-utils",
+ "actix-web",
+ "derive_more",
+ "futures-util",
+ "log",
+ "once_cell",
+ "smallvec",
+]
+
 [[package]]
 name = "actix-http"
 version = "3.0.0-beta.17"
@@ -258,6 +274,7 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 name = "chess"
 version = "0.1.0"
 dependencies = [
+ "actix-cors",
  "actix-web",
  "serde",
  "serde_repr",

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+actix-cors = "0.6.0-beta.8"
 actix-web = { version = "4.0.0-beta.18", default-features = false }
 serde = { version = "1", features = ["derive"] }
 serde_repr = "0.1"

src/api_types.rs

@@ -0,0 +1,270 @@
+//! Everything in this file is part of the public JSON api
+//!
+//! Adding methods on types is fine, but modifying structure breaks compatibility
+
+use uuid::Uuid;
+
+#[derive(
+    Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+#[serde(transparent)]
+pub(crate) struct GameId {
+    inner: Uuid,
+}
+
+#[derive(
+    Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+pub(crate) struct Piece {
+    pub(crate) kind: PieceKind,
+    pub(crate) color: Color,
+}
+
+#[derive(
+    Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+pub(crate) struct Coordinates {
+    pub(crate) file: File,
+    pub(crate) rank: Rank,
+}
+
+#[derive(serde::Deserialize, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct Move {
+    pub(crate) piece: Piece,
+    pub(crate) from: Coordinates,
+    pub(crate) to: Coordinates,
+    pub(crate) game_id: GameId,
+}
+
+#[derive(serde::Deserialize, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct Start {
+    pub(crate) player_color: Color,
+}
+
+#[derive(serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct GameStart {
+    pub(crate) board: Vec<(File, Rank, PieceKind, Color)>,
+    pub(crate) game_id: GameId,
+}
+
+#[derive(
+    Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+#[serde(rename_all = "camelCase")]
+pub(crate) enum Color {
+    Black,
+    White,
+}
+
+#[derive(
+    Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+#[serde(rename_all = "camelCase")]
+pub(crate) enum PieceKind {
+    Pawn,
+    Rook,
+    Knight,
+    Bishop,
+    Queen,
+    King,
+}
+
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    Hash,
+    serde_repr::Deserialize_repr,
+    serde_repr::Serialize_repr,
+)]
+#[repr(u8)]
+pub(crate) enum Rank {
+    One = 1,
+    Two = 2,
+    Three = 3,
+    Four = 4,
+    Five = 5,
+    Six = 6,
+    Seven = 7,
+    Eight = 8,
+}
+
+#[derive(
+    Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
+)]
+#[serde(rename_all = "camelCase")]
+pub(crate) enum File {
+    A,
+    B,
+    C,
+    D,
+    E,
+    F,
+    G,
+    H,
+}
+
+impl GameId {
+    pub(crate) fn new() -> Self {
+        GameId {
+            inner: Uuid::new_v4(),
+        }
+    }
+}
+
+impl Color {
+    pub(crate) fn is_white(self) -> bool {
+        matches!(self, Self::White)
+    }
+
+    pub(crate) fn is_black(self) -> bool {
+        matches!(self, Self::Black)
+    }
+}
+
+impl Rank {
+    pub(crate) fn next(self) -> Option<Self> {
+        match self {
+            Self::One => Some(Self::Two),
+            Self::Two => Some(Self::Three),
+            Self::Three => Some(Self::Four),
+            Self::Four => Some(Self::Five),
+            Self::Five => Some(Self::Six),
+            Self::Six => Some(Self::Seven),
+            Self::Seven => Some(Self::Eight),
+            Self::Eight => None,
+        }
+    }
+
+    pub(crate) fn prev(self) -> Option<Self> {
+        match self {
+            Self::One => None,
+            Self::Two => Some(Self::One),
+            Self::Three => Some(Self::Two),
+            Self::Four => Some(Self::Three),
+            Self::Five => Some(Self::Four),
+            Self::Six => Some(Self::Five),
+            Self::Seven => Some(Self::Six),
+            Self::Eight => Some(Self::Seven),
+        }
+    }
+
+    pub(crate) fn diff(self, other: Self) -> Option<u8> {
+        if self > other {
+            Some(self.to_number() - other.to_number())
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn absolute_diff(self, other: Self) -> u8 {
+        self.diff(other).or_else(|| other.diff(self)).unwrap_or(0)
+    }
+
+    pub(crate) fn to_number(self) -> u8 {
+        match self {
+            Self::One => 0,
+            Self::Two => 1,
+            Self::Three => 2,
+            Self::Four => 3,
+            Self::Five => 4,
+            Self::Six => 5,
+            Self::Seven => 6,
+            Self::Eight => 7,
+        }
+    }
+
+    pub(crate) fn from_number(value: u8) -> Option<Self> {
+        match value {
+            0 => Some(Self::One),
+            1 => Some(Self::Two),
+            2 => Some(Self::Three),
+            3 => Some(Self::Four),
+            4 => Some(Self::Five),
+            5 => Some(Self::Six),
+            6 => Some(Self::Seven),
+            7 => Some(Self::Eight),
+            _ => None,
+        }
+    }
+}
+
+impl File {
+    pub(crate) fn next(self) -> Option<Self> {
+        match self {
+            Self::A => Some(Self::B),
+            Self::B => Some(Self::C),
+            Self::C => Some(Self::D),
+            Self::D => Some(Self::E),
+            Self::E => Some(Self::F),
+            Self::F => Some(Self::G),
+            Self::G => Some(Self::H),
+            Self::H => None,
+        }
+    }
+
+    pub(crate) fn prev(self) -> Option<Self> {
+        match self {
+            Self::A => None,
+            Self::B => Some(Self::A),
+            Self::C => Some(Self::B),
+            Self::D => Some(Self::C),
+            Self::E => Some(Self::D),
+            Self::F => Some(Self::E),
+            Self::G => Some(Self::F),
+            Self::H => Some(Self::G),
+        }
+    }
+
+    pub(crate) fn diff(self, other: Self) -> Option<u8> {
+        if self > other {
+            Some(self.to_number() - other.to_number())
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn absolute_diff(self, other: Self) -> u8 {
+        self.diff(other).or_else(|| other.diff(self)).unwrap_or(0)
+    }
+
+    pub(crate) fn to_number(self) -> u8 {
+        match self {
+            Self::A => 0,
+            Self::B => 1,
+            Self::C => 2,
+            Self::D => 3,
+            Self::E => 4,
+            Self::F => 5,
+            Self::G => 6,
+            Self::H => 7,
+        }
+    }
+
+    pub(crate) fn from_number(value: u8) -> Option<Self> {
+        match value {
+            0 => Some(Self::A),
+            1 => Some(Self::B),
+            2 => Some(Self::C),
+            3 => Some(Self::D),
+            4 => Some(Self::E),
+            5 => Some(Self::F),
+            6 => Some(Self::G),
+            7 => Some(Self::H),
+            _ => None,
+        }
+    }
+}
+
+impl std::fmt::Display for GameId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(&self.inner, f)
+    }
+}

src/board_state.rs

@@ -0,0 +1,236 @@
+use crate::api_types::{Color, Coordinates, File, Move, Piece, PieceKind, Rank};
+use std::collections::HashMap;
+
+#[derive(Clone, Debug)]
+struct CastleState {
+    can_king_castle: bool,
+    can_queen_castle: bool,
+}
+
+#[derive(Default)]
+struct SideEffects {
+    en_passant: Option<Coordinates>,
+    king_castle_invalidated: bool,
+    queen_castle_invalidated: bool,
+}
+
+#[derive(Clone, Debug, Default)]
+pub(crate) struct BoardState {
+    inner: HashMap<Coordinates, Piece>,
+    white_state: CastleState,
+    black_state: CastleState,
+    en_passant: Option<Coordinates>,
+}
+
+impl BoardState {
+    pub(crate) fn starting_positions() -> Self {
+        let mut this = Self::default();
+
+        for (file, rank, kind, color) in INITIAL_PIECES {
+            this.inner
+                .insert(Coordinates { file, rank }, Piece { kind, color });
+        }
+
+        this
+    }
+
+    pub(crate) fn to_serializable(&self) -> Vec<(File, Rank, PieceKind, Color)> {
+        self.inner
+            .iter()
+            .map(|(coordinates, piece)| {
+                (coordinates.file, coordinates.rank, piece.kind, piece.color)
+            })
+            .collect()
+    }
+
+    pub(crate) fn handle(&mut self, action: Move) {
+        let mut proposed = self.clone();
+
+        let moving_color = action.piece.color;
+
+        if let Some(piece) = proposed.inner.remove(&action.from) {
+            // not allowed to move mismatched piece
+            if piece != action.piece {
+                return;
+            }
+
+            let opt = piece.can_move_to(&action.from, &action.to, &proposed);
+
+            if let Some(side_effects) = opt {
+                proposed.apply_side_effects(moving_color, side_effects);
+                proposed.inner.insert(action.to, piece);
+            } else {
+                proposed.inner.insert(action.from, piece);
+            }
+        }
+
+        if proposed.is_in_check(moving_color) {
+            return;
+        }
+
+        *self = proposed;
+    }
+
+    fn apply_side_effects(&mut self, color: Color, side_effects: SideEffects) {
+        self.en_passant = side_effects.en_passant;
+
+        if color.is_white() {
+            if side_effects.king_castle_invalidated {
+                self.white_state.can_king_castle = false;
+            }
+            if side_effects.queen_castle_invalidated {
+                self.white_state.can_queen_castle = false;
+            }
+        } else {
+            if side_effects.king_castle_invalidated {
+                self.black_state.can_king_castle = false;
+            }
+            if side_effects.queen_castle_invalidated {
+                self.black_state.can_queen_castle = false;
+            }
+        }
+    }
+
+    fn is_in_check(&self, color: Color) -> bool {
+        let king = Piece {
+            kind: PieceKind::King,
+            color,
+        };
+
+        let king_opt = self.inner.iter().find(|(_, piece)| **piece == king);
+
+        if let Some((king_coords, _)) = king_opt {
+            self.inner
+                .iter()
+                .filter(|(_, piece)| piece.color != color)
+                .any(|(coords, piece)| piece.can_move_to(coords, king_coords, self).is_some())
+        } else {
+            false
+        }
+    }
+}
+
+impl Piece {
+    fn can_move_to(
+        &self,
+        from: &Coordinates,
+        to: &Coordinates,
+        state: &BoardState,
+    ) -> Option<SideEffects> {
+        match self.kind {
+            PieceKind::Pawn if self.color.is_white() && to.rank > from.rank => {
+                self.check_pawn(from, to, state, Rank::Two, Rank::next)
+            }
+            PieceKind::Pawn if self.color.is_black() && to.rank < from.rank => {
+                self.check_pawn(from, to, state, Rank::Seven, Rank::prev)
+            }
+            _ => None,
+        }
+    }
+
+    fn check_pawn(
+        &self,
+        from: &Coordinates,
+        to: &Coordinates,
+        state: &BoardState,
+        en_passant_rank: Rank,
+        forward: impl Fn(Rank) -> Option<Rank>,
+    ) -> Option<SideEffects> {
+        let rank_diff = to.rank.absolute_diff(from.rank);
+        let file_diff = to.file.absolute_diff(from.file);
+
+        let mut side_effects = SideEffects::default();
+
+        // move forward 1 or two steps as long as not blocked
+        if file_diff == 0 && ((rank_diff == 2 && from.rank == en_passant_rank) || rank_diff == 1) {
+            let mut path_rank = from.rank;
+
+            while let Some(rank) = forward(path_rank) {
+                let block_check = Coordinates {
+                    rank,
+                    file: to.file,
+                };
+
+                if state.inner.contains_key(&block_check) {
+                    return None;
+                }
+
+                if rank == to.rank {
+                    break;
+                }
+
+                // set en_passant to cell directly behind pawn
+                side_effects.en_passant = Some(block_check);
+
+                path_rank = rank;
+            }
+
+            return Some(side_effects);
+        }
+
+        // pawn capture move
+        if file_diff == 1 && rank_diff == 1 {
+            // check for real capture
+            if let Some(piece) = state.inner.get(to) {
+                if piece.color != self.color {
+                    return Some(side_effects);
+                } else {
+                    return None;
+                }
+            }
+
+            // check en_passant
+            if let Some(coords) = &state.en_passant {
+                if coords == to {
+                    return Some(side_effects);
+                }
+            }
+        }
+
+        None
+    }
+}
+
+impl Default for CastleState {
+    fn default() -> Self {
+        Self {
+            can_king_castle: true,
+            can_queen_castle: true,
+        }
+    }
+}
+
+const INITIAL_PIECES: [(File, Rank, PieceKind, Color); 32] = [
+    (File::A, Rank::One, PieceKind::Rook, Color::White),
+    (File::B, Rank::One, PieceKind::Knight, Color::White),
+    (File::C, Rank::One, PieceKind::Bishop, Color::White),
+    (File::D, Rank::One, PieceKind::Queen, Color::White),
+    (File::E, Rank::One, PieceKind::King, Color::White),
+    (File::F, Rank::One, PieceKind::Bishop, Color::White),
+    (File::G, Rank::One, PieceKind::Knight, Color::White),
+    (File::H, Rank::One, PieceKind::Rook, Color::White),
+    (File::A, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::B, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::C, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::D, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::E, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::F, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::G, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::H, Rank::Two, PieceKind::Pawn, Color::White),
+    (File::A, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::B, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::C, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::D, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::E, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::F, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::G, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::H, Rank::Seven, PieceKind::Pawn, Color::Black),
+    (File::A, Rank::Eight, PieceKind::Rook, Color::Black),
+    (File::B, Rank::Eight, PieceKind::Knight, Color::Black),
+    (File::C, Rank::Eight, PieceKind::Bishop, Color::Black),
+    (File::D, Rank::Eight, PieceKind::Queen, Color::Black),
+    (File::E, Rank::Eight, PieceKind::King, Color::Black),
+    (File::F, Rank::Eight, PieceKind::Bishop, Color::Black),
+    (File::G, Rank::Eight, PieceKind::Knight, Color::Black),
+    (File::H, Rank::Eight, PieceKind::Rook, Color::Black),
+];

src/init_tracing.rs

@@ -1,9 +1,6 @@
 use tracing::subscriber::set_global_default;
 use tracing_log::LogTracer;
-use tracing_subscriber::filter::Targets;
-use tracing_subscriber::fmt::format::FmtSpan;
-use tracing_subscriber::prelude::__tracing_subscriber_SubscriberExt;
-use tracing_subscriber::Registry;
+use tracing_subscriber::{filter::Targets, fmt::format::FmtSpan, layer::SubscriberExt, Registry};
 
 pub(crate) fn init_tracing() -> Result<(), Box<dyn std::error::Error>> {
     LogTracer::init()?;

src/main.rs

@@ -1,242 +1,23 @@
-use actix_web::web::{Data, Json};
-use actix_web::{App, HttpResponse, HttpServer};
-use std::collections::HashMap;
-use std::sync::{Arc, Mutex};
-use std::time::Duration;
+use actix_cors::Cors;
+use actix_web::{
+    web::{Data, Json},
+    App, HttpResponse, HttpServer,
+};
+use std::{
+    collections::HashMap,
+    sync::{Arc, Mutex},
+    time::Duration,
+};
 use tokio::sync::mpsc::Sender;
+use tracing::Instrument;
 use tracing_actix_web::TracingLogger;
-use uuid::Uuid;
 
+mod api_types;
+mod board_state;
 mod init_tracing;
 
-const INITIAL_PIECES: [(File, Rank, PieceKind, Color); 32] = [
-    (File::A, Rank::One, PieceKind::Rook, Color::White),
-    (File::B, Rank::One, PieceKind::Knight, Color::White),
-    (File::C, Rank::One, PieceKind::Bishop, Color::White),
-    (File::D, Rank::One, PieceKind::Queen, Color::White),
-    (File::E, Rank::One, PieceKind::King, Color::White),
-    (File::F, Rank::One, PieceKind::Bishop, Color::White),
-    (File::G, Rank::One, PieceKind::Knight, Color::White),
-    (File::H, Rank::One, PieceKind::Rook, Color::White),
-    (File::A, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::B, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::C, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::D, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::E, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::F, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::G, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::H, Rank::Two, PieceKind::Pawn, Color::White),
-    (File::A, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::B, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::C, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::D, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::E, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::F, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::G, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::H, Rank::Seven, PieceKind::Pawn, Color::Black),
-    (File::A, Rank::Eight, PieceKind::Rook, Color::Black),
-    (File::B, Rank::Eight, PieceKind::Knight, Color::Black),
-    (File::C, Rank::Eight, PieceKind::Bishop, Color::Black),
-    (File::D, Rank::Eight, PieceKind::Queen, Color::Black),
-    (File::E, Rank::Eight, PieceKind::King, Color::Black),
-    (File::F, Rank::Eight, PieceKind::Bishop, Color::Black),
-    (File::G, Rank::Eight, PieceKind::Knight, Color::Black),
-    (File::H, Rank::Eight, PieceKind::Rook, Color::Black),
-];
-
-#[derive(
-    Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize,
-)]
-#[serde(transparent)]
-struct GameId {
-    inner: Uuid,
-}
-
-impl GameId {
-    fn new() -> Self {
-        GameId {
-            inner: Uuid::new_v4(),
-        }
-    }
-}
-
-#[derive(Clone, serde::Deserialize, serde::Serialize)]
-struct Piece {
-    kind: PieceKind,
-    color: Color,
-}
-
-#[derive(serde::Deserialize, serde::Serialize)]
-struct Coordinates {
-    file: File,
-    rank: Rank,
-}
-
-#[derive(serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-struct Move {
-    piece: Piece,
-    from: Coordinates,
-    to: Coordinates,
-    game_id: GameId,
-}
-
-#[derive(serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-struct Start {
-    player_color: Color,
-}
-
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-enum Color {
-    Black,
-    White,
-}
-
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-enum PieceKind {
-    Pawn,
-    Rook,
-    Knight,
-    Bishop,
-    Queen,
-    King,
-}
-
-#[derive(
-    Clone,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Hash,
-    serde_repr::Deserialize_repr,
-    serde_repr::Serialize_repr,
-)]
-#[repr(u8)]
-enum Rank {
-    One = 1,
-    Two = 2,
-    Three = 3,
-    Four = 4,
-    Five = 5,
-    Six = 6,
-    Seven = 7,
-    Eight = 8,
-}
-
-impl Rank {
-    fn to_number(&self) -> u8 {
-        match self {
-            Self::One => 0,
-            Self::Two => 1,
-            Self::Three => 2,
-            Self::Four => 3,
-            Self::Five => 4,
-            Self::Six => 5,
-            Self::Seven => 6,
-            Self::Eight => 7,
-        }
-    }
-
-    fn from_number(value: u8) -> Option<Self> {
-        match value {
-            0 => Some(Self::One),
-            1 => Some(Self::Two),
-            2 => Some(Self::Three),
-            3 => Some(Self::Four),
-            4 => Some(Self::Five),
-            5 => Some(Self::Six),
-            6 => Some(Self::Seven),
-            7 => Some(Self::Eight),
-            _ => None,
-        }
-    }
-}
-
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-enum File {
-    A,
-    B,
-    C,
-    D,
-    E,
-    F,
-    G,
-    H,
-}
-
-impl File {
-    fn to_number(&self) -> u8 {
-        match self {
-            Self::A => 0,
-            Self::B => 1,
-            Self::C => 2,
-            Self::D => 3,
-            Self::E => 4,
-            Self::F => 5,
-            Self::G => 6,
-            Self::H => 7,
-        }
-    }
-
-    fn from_number(value: u8) -> Option<Self> {
-        match value {
-            0 => Some(Self::A),
-            1 => Some(Self::B),
-            2 => Some(Self::C),
-            3 => Some(Self::D),
-            4 => Some(Self::E),
-            5 => Some(Self::F),
-            6 => Some(Self::G),
-            7 => Some(Self::H),
-            _ => None,
-        }
-    }
-}
-
-#[derive(Clone, Default)]
-struct FileState {
-    inner: HashMap<Rank, Piece>,
-}
-
-#[derive(Clone, Default)]
-struct BoardState {
-    inner: HashMap<File, FileState>,
-}
-
-impl BoardState {
-    fn starting_positions() -> Self {
-        let mut this = Self::default();
-
-        for (file, rank, kind, color) in INITIAL_PIECES {
-            let rank_entry = this.inner.entry(file).or_default();
-
-            rank_entry.inner.insert(rank, Piece { kind, color });
-        }
-
-        this
-    }
-
-    fn to_serializable(&self) -> Vec<(File, Rank, PieceKind, Color)> {
-        self.inner
-            .iter()
-            .flat_map(|(file, ranks)| {
-                ranks.inner.iter().map(|(rank, piece)| {
-                    (
-                        file.clone(),
-                        rank.clone(),
-                        piece.kind.clone(),
-                        piece.color.clone(),
-                    )
-                })
-            })
-            .collect()
-    }
-}
+use api_types::{GameId, GameStart, Move, Start};
+use board_state::BoardState;
 
 struct Reply {
     board_state: BoardState,
@@ -247,13 +28,6 @@ struct MoveSession {
     reply: tokio::sync::oneshot::Sender<Reply>,
 }
 
-#[derive(serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-struct GameStart {
-    board: Vec<(File, Rank, PieceKind, Color)>,
-    game_id: GameId,
-}
-
 #[derive(Clone, Debug)]
 struct GameData {
     sender: Sender<MoveSession>,
@@ -264,13 +38,17 @@ struct GameState {
     inner: Arc<Mutex<HashMap<GameId, GameData>>>,
 }
 
+struct GameDropper(GameState, GameId);
+
 impl GameState {
     fn data_for_id(&self, game_id: &GameId) -> Option<GameData> {
         self.inner.lock().unwrap().get(game_id).cloned()
     }
-}
 
-struct GameDropper(GameState, GameId);
+    fn save_data(&self, game_id: GameId, data: GameData) {
+        self.inner.lock().unwrap().insert(game_id, data);
+    }
+}
 
 impl Drop for GameDropper {
     fn drop(&mut self) {
@@ -278,55 +56,52 @@ impl Drop for GameDropper {
     }
 }
 
-async fn start(start: Json<Start>, game_state: Data<GameState>) -> HttpResponse {
+async fn start(Json(start): Json<Start>, game_state: Data<GameState>) -> HttpResponse {
     let game_id = GameId::new();
 
-    let (tx, mut rx) = tokio::sync::mpsc::channel(1);
-
-    let initial_board_state = BoardState::starting_positions();
-
-    let board_state = initial_board_state.clone();
     let game_dropper = GameDropper((**game_state).clone(), game_id.clone());
 
-    let game_data = GameData { sender: tx };
+    let (sender, mut rx) = tokio::sync::mpsc::channel(1);
 
-    game_state
-        .inner
-        .lock()
-        .unwrap()
-        .insert(game_id.clone(), game_data);
+    game_state.save_data(game_id.clone(), GameData { sender });
 
-    actix_web::rt::spawn(async move {
-        while let Ok(Some(msg)) =
-            actix_web::rt::time::timeout(Duration::from_secs(60 * 5), rx.recv()).await
-        {
-            /* do stuff */
+    let game_span = tracing::info_span!(
+        parent: None,
+        "Game Session",
+        game.id = %game_id,
+    );
 
-            let _ = msg.reply.send(Reply {
-                board_state: board_state.clone(),
-            });
+    let mut board_state = BoardState::starting_positions();
+    let serializable = board_state.to_serializable();
+
+    actix_web::rt::spawn(
+        async move {
+            while let Ok(Some(msg)) =
+                actix_web::rt::time::timeout(Duration::from_secs(60 * 5), rx.recv()).await
+            {
+                board_state.handle(msg.action);
+
+                let _ = msg.reply.send(Reply {
+                    board_state: board_state.clone(),
+                });
+            }
+
+            drop(game_dropper);
         }
-
-        drop(game_dropper);
-    });
+        .instrument(game_span),
+    );
 
     HttpResponse::Ok().json(GameStart {
-        board: initial_board_state.to_serializable(),
+        board: serializable,
         game_id,
     })
 }
 
-async fn make_move(action: Json<Move>, game_state: Data<GameState>) -> HttpResponse {
-    if let Some(data) = game_state.data_for_id(&action.0.game_id) {
-        let (tx, rx) = tokio::sync::oneshot::channel();
+async fn make_move(Json(action): Json<Move>, game_state: Data<GameState>) -> HttpResponse {
+    if let Some(data) = game_state.data_for_id(&action.game_id) {
+        let (reply, rx) = tokio::sync::oneshot::channel();
 
-        let res = data
-            .sender
-            .send(MoveSession {
-                action: action.into_inner(),
-                reply: tx,
-            })
-            .await;
+        let res = data.sender.send(MoveSession { action, reply }).await;
 
         if res.is_err() {
             return HttpResponse::InternalServerError().finish();
@@ -346,10 +121,18 @@ async fn make_move(action: Json<Move>, game_state: Data<GameState>) -> HttpRespo
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
     init_tracing::init_tracing()?;
 
-    HttpServer::new(|| {
+    let game_state = GameState::default();
+
+    HttpServer::new(move || {
         App::new()
-            .app_data(Data::new(GameState::default()))
+            .app_data(Data::new(game_state.clone()))
             .wrap(TracingLogger::default())
+            .wrap(
+                Cors::default()
+                    .allow_any_origin()
+                    .allow_any_header()
+                    .allow_any_method(),
+            )
             .route("/start", actix_web::web::post().to(start))
             .route("/move", actix_web::web::post().to(make_move))
     })