checkpoint

Gameboard.ShogiUI.Sockets.ServiceModels/Api/GetSession.cs

@@ -1,16 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using System.Collections.Generic;
-
-namespace Gameboard.ShogiUI.Sockets.ServiceModels.Api
-{
-  public class GetSessionResponse
-  {
-    public Game Game { get; set; }
-    /// <summary>
-    /// The perspective on the game of the requesting user.
-    /// </summary>
-    public WhichPerspective PlayerPerspective { get; set; }
-    public BoardState BoardState { get; set; }
-    public IList<Move> MoveHistory { get; set; }
-  }
-}

Gameboard.ShogiUI.Sockets.ServiceModels/Api/GetSessions.cs

@@ -5,7 +5,7 @@ namespace Gameboard.ShogiUI.Sockets.ServiceModels.Api
 {
   public class GetSessionsResponse
   {
-    public Collection<Game> PlayerHasJoinedSessions { get; set; }
+    public Collection<Session> PlayerHasJoinedSessions { get; set; }
-    public Collection<Game> AllOtherSessions { get; set; }
+    public Collection<Session> AllOtherSessions { get; set; }
   }
 }

Gameboard.ShogiUI.Sockets.ServiceModels/Socket/CreateGame.cs

@@ -6,7 +6,7 @@ namespace Gameboard.ShogiUI.Sockets.ServiceModels.Socket
   public class CreateGameResponse : IResponse
   {
     public string Action { get; }
-    public Game Game { get; set; }
+    public Session Game { get; set; }
 
     /// <summary>
     /// The player who created the game.

Gameboard.ShogiUI.Sockets.ServiceModels/Types/BoardState.cs

@@ -8,7 +8,7 @@ namespace Gameboard.ShogiUI.Sockets.ServiceModels.Types
     public Dictionary<string, Piece?> Board { get; set; } = new Dictionary<string, Piece?>();
     public IReadOnlyCollection<Piece> Player1Hand { get; set; } = Array.Empty<Piece>();
     public IReadOnlyCollection<Piece> Player2Hand { get; set; } = Array.Empty<Piece>();
-    public WhichPerspective? PlayerInCheck { get; set; }
+    public WhichPlayer? PlayerInCheck { get; set; }
-    public WhichPerspective WhoseTurn { get; set; }
+    public WhichPlayer WhoseTurn { get; set; }
   }
 }

Gameboard.ShogiUI.Sockets.ServiceModels/Types/Game.cs

@@ -1,38 +0,0 @@
-using System.Collections.Generic;
-
-namespace Gameboard.ShogiUI.Sockets.ServiceModels.Types
-{
-	public class Game
-	{
-		public string Player1 { get; set; }
-		public string? Player2 { get; set; }
-		public string GameName { get; set; } = string.Empty;
-
-		/// <summary>
-		/// Players[0] is the session owner, Players[1] is the other person.
-		/// </summary>
-		public IReadOnlyList<string> Players
-		{
-			get
-			{
-				var list = new List<string>(2) { Player1 };
-				if (!string.IsNullOrEmpty(Player2)) list.Add(Player2);
-				return list;
-			}
-		}
-
-		/// <summary>
-		/// Constructor for serialization.
-		/// </summary>
-		public Game()
-		{
-		}
-
-		public Game(string gameName, string player1, string? player2 = null)
-		{
-			GameName = gameName;
-			Player1 = player1;
-			Player2 = player2;
-		}
-	}
-}

Gameboard.ShogiUI.Sockets.ServiceModels/Types/Piece.cs

@@ -4,6 +4,6 @@
   {
     public bool IsPromoted { get; set; }
     public WhichPiece WhichPiece { get; set; }
-    public WhichPerspective Owner { get; set; }
+    public WhichPlayer Owner { get; set; }
   }
 }

Gameboard.ShogiUI.Sockets.ServiceModels/Types/Session.cs

@@ -0,0 +1,10 @@
+namespace Gameboard.ShogiUI.Sockets.ServiceModels.Types
+{
+	public class Session
+	{
+		public string Player1 { get; set; }
+		public string? Player2 { get; set; }
+		public string GameName { get; set; }
+		public BoardState BoardState { get; set; }
+	}
+}

Gameboard.ShogiUI.Sockets.ServiceModels/Types/WhichPerspective.cs

@@ -1,9 +1,8 @@
 namespace Gameboard.ShogiUI.Sockets.ServiceModels.Types
 {
-	public enum WhichPerspective
+	public enum WhichPlayer
 	{
 		Player1,
-		Player2,
+		Player2
-		Spectator
 	}
 }

Gameboard.ShogiUI.Sockets.sln

@@ -13,13 +13,11 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Gameboard.ShogiUI.UnitTests
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Benchmarking", "Benchmarking\Benchmarking.csproj", "{DADFF5D6-581F-4D69-845D-53ABD6ABF62F}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PathFinding", "PathFinding\PathFinding.csproj", "{A0AC8C5A-6ADA-45C6-BD1E-EB1061213E47}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Gameboard.ShogiUI.xUnitTests", "Gameboard.ShogiUI.xUnitTests\Gameboard.ShogiUI.xUnitTests.csproj", "{12530716-C11E-40CE-9F71-CCCC243F03E1}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Shogi.Domain", "Shogi.Domain\Shogi.Domain.csproj", "{0211B1E4-20F0-4058-AAC4-3845D19910AF}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Shogi.Domain.UnitTests", "Shogi.Domain.UnitTests\Shogi.Domain.UnitTests.csproj", "{F256989E-B6AF-4731-9DB4-88991C40B2CE}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Shogi.Domain.UnitTests", "Shogi.Domain.UnitTests\Shogi.Domain.UnitTests.csproj", "{F256989E-B6AF-4731-9DB4-88991C40B2CE}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -43,10 +41,6 @@ Global
 		{DADFF5D6-581F-4D69-845D-53ABD6ABF62F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{DADFF5D6-581F-4D69-845D-53ABD6ABF62F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{DADFF5D6-581F-4D69-845D-53ABD6ABF62F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{A0AC8C5A-6ADA-45C6-BD1E-EB1061213E47}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{A0AC8C5A-6ADA-45C6-BD1E-EB1061213E47}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{A0AC8C5A-6ADA-45C6-BD1E-EB1061213E47}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{A0AC8C5A-6ADA-45C6-BD1E-EB1061213E47}.Release|Any CPU.Build.0 = Release|Any CPU
 		{12530716-C11E-40CE-9F71-CCCC243F03E1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{12530716-C11E-40CE-9F71-CCCC243F03E1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{12530716-C11E-40CE-9F71-CCCC243F03E1}.Release|Any CPU.ActiveCfg = Release|Any CPU

Gameboard.ShogiUI.Sockets/Controllers/GameController.cs

@@ -1,5 +1,4 @@
-using Gameboard.ShogiUI.Sockets.Extensions;
+using Gameboard.ShogiUI.Sockets.Managers;
-using Gameboard.ShogiUI.Sockets.Managers;
 using Gameboard.ShogiUI.Sockets.Repositories;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Api;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
@@ -7,10 +6,8 @@ using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
-using System.Security.Claims;
 using System.Threading.Tasks;
 
 namespace Gameboard.ShogiUI.Sockets.Controllers
@@ -169,25 +166,48 @@ namespace Gameboard.ShogiUI.Sockets.Controllers
 				return NotFound();
 			}
 
-			var playerPerspective = WhichPerspective.Spectator;
+			var playerPerspective = session.Player2Name == user.Id
-			if (session.Player1.Id == user.Id)
+				? WhichPlayer.Player2
-			{
+				: WhichPlayer.Player1;
-				playerPerspective = WhichPerspective.Player1;
-			}
-			else if (session.Player2?.Id == user.Id)
-			{
-				playerPerspective = WhichPerspective.Player2;
-			}
 
-			communicationManager.SubscribeToGame(session, user!.Id);
+			var response = new Session
-			var response = new GetSessionResponse()
 			{
-				Game = new Models.SessionMetadata(session).ToServiceModel(),
+				BoardState = new BoardState
-				BoardState = session.Shogi.ToServiceModel(),
+				{
-				MoveHistory = session.Shogi.MoveHistory.Select(_ => _.ToServiceModel()).ToList(),
+					Board = null,
-				PlayerPerspective = playerPerspective
+					Player1Hand = session.Player1Hand.Select(MapPiece).ToList(),
+					Player2Hand = session.Player2Hand.Select(MapPiece).ToList(),
+					PlayerInCheck = session.InCheck.HasValue ? Map(session.InCheck.Value) : null
+				},
+				GameName = session.Name,
+				Player1 = session.Player1Name,
+				Player2 = session.Player2Name
 			};
-			return new JsonResult(response);
+			return this.Ok(response);
+
+			static WhichPlayer Map(Shogi.Domain.WhichPlayer whichPlayer)
+			{
+				return whichPlayer == Shogi.Domain.WhichPlayer.Player1
+					? WhichPlayer.Player1
+					: WhichPlayer.Player2;
+			}
+			static Piece MapPiece(Shogi.Domain.Pieces.Piece piece)
+			{
+				var owner = Map(piece.Owner);
+				var whichPiece = piece.WhichPiece switch
+				{
+					Shogi.Domain.WhichPiece.King => WhichPiece.King,
+					Shogi.Domain.WhichPiece.GoldGeneral => WhichPiece.GoldGeneral,
+					Shogi.Domain.WhichPiece.SilverGeneral => WhichPiece.SilverGeneral,
+					Shogi.Domain.WhichPiece.Bishop => WhichPiece.Bishop,
+					Shogi.Domain.WhichPiece.Rook => WhichPiece.Rook,
+					Shogi.Domain.WhichPiece.Knight => WhichPiece.Knight,
+					Shogi.Domain.WhichPiece.Lance => WhichPiece.Lance,
+					Shogi.Domain.WhichPiece.Pawn => WhichPiece.Pawn,
+					_ => throw new ArgumentException($"Unknown value for {nameof(WhichPiece)}")
+				};
+				return new Piece { IsPromoted = piece.IsPromoted, Owner = owner, WhichPiece = whichPiece };
+			}
 		}
 
 		[HttpGet]
@@ -207,8 +227,8 @@ namespace Gameboard.ShogiUI.Sockets.Controllers
 
 			return new GetSessionsResponse
 			{
-				PlayerHasJoinedSessions = new Collection<Game>(sessionsJoinedByUser),
+				PlayerHasJoinedSessions = new Collection<Session>(sessionsJoinedByUser),
-				AllOtherSessions = new Collection<Game>(sessionsNotJoinedByUser)
+				AllOtherSessions = new Collection<Session>(sessionsNotJoinedByUser)
 			};
 		}
 

Gameboard.ShogiUI.Sockets/Controllers/SocketController.cs

@@ -1,6 +1,5 @@
 using Gameboard.ShogiUI.Sockets.Extensions;
 using Gameboard.ShogiUI.Sockets.Managers;
-using Gameboard.ShogiUI.Sockets.Models;
 using Gameboard.ShogiUI.Sockets.Repositories;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Api;
 using Microsoft.AspNetCore.Authentication;
@@ -56,7 +55,7 @@ namespace Gameboard.ShogiUI.Sockets.Controllers
 			var userId = User?.UserId();
 			if (!string.IsNullOrEmpty(userId))
 			{
-				connectionManager.UnsubscribeFromBroadcastAndGames(userId);
+				connectionManager.Unsubscribe(userId);
 			}
 			
 			await signoutTask;

Gameboard.ShogiUI.Sockets/Extensions/ModelExtensions.cs

@@ -1,63 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using System.Text;
-using System.Text.RegularExpressions;
-
-namespace Gameboard.ShogiUI.Sockets.Extensions
-{
-	public static class ModelExtensions
-  {
-    public static string GetShortName(this Models.Piece self)
-    {
-      var name = self.WhichPiece switch
-      {
-        WhichPiece.King => " K ",
-        WhichPiece.GoldGeneral => " G ",
-        WhichPiece.SilverGeneral => self.IsPromoted ? "^S " : " S ",
-        WhichPiece.Bishop => self.IsPromoted ? "^B " : " B ",
-        WhichPiece.Rook => self.IsPromoted ? "^R " : " R ",
-        WhichPiece.Knight => self.IsPromoted ? "^k " : " k ",
-        WhichPiece.Lance => self.IsPromoted ? "^L " : " L ",
-        WhichPiece.Pawn => self.IsPromoted ? "^P " : " P ",
-        _ => " ? ",
-      };
-      if (self.Owner == WhichPerspective.Player2)
-        name = Regex.Replace(name, @"([^\s]+)\s", "$1.");
-      return name;
-    }
-
-    public static string PrintStateAsAscii(this Models.Shogi self)
-    {
-      var builder = new StringBuilder();
-      builder.Append("               Player 2(.)");
-      builder.AppendLine();
-      for (var y = 8; y >= 0; y--)
-      {
-        builder.Append("- ");
-        for (var x = 0; x < 8; x++) builder.Append("- - ");
-        builder.Append("- -");
-        builder.AppendLine();
-        builder.Append('|');
-        for (var x = 0; x < 9; x++)
-        {
-          var piece = self.Board[x, y];
-          if (piece == null)
-          {
-            builder.Append("   ");
-          }
-          else
-          {
-            builder.AppendFormat("{0}", piece.GetShortName());
-          }
-          builder.Append('|');
-        }
-        builder.AppendLine();
-      }
-      builder.Append("- ");
-      for (var x = 0; x < 8; x++) builder.Append("- - ");
-      builder.Append("- -");
-      builder.AppendLine();
-      builder.Append("               Player 1");
-      return builder.ToString();
-    }
-  }
-}

Gameboard.ShogiUI.Sockets/Gameboard.ShogiUI.Sockets.csproj

@@ -21,9 +21,12 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Gameboard.ShogiUI.Sockets.ServiceModels\Gameboard.ShogiUI.Sockets.ServiceModels.csproj" />
-    <ProjectReference Include="..\PathFinding\PathFinding.csproj" />
     <ProjectReference Include="..\Shogi.Domain\Shogi.Domain.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Folder Include="Services\Utility\" />
+  </ItemGroup>
+
 
 </Project>

Gameboard.ShogiUI.Sockets/Managers/SocketConnectionManager.cs

@@ -1,5 +1,4 @@
 using Gameboard.ShogiUI.Sockets.Extensions;
-using Gameboard.ShogiUI.Sockets.Models;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
@@ -14,12 +13,8 @@ namespace Gameboard.ShogiUI.Sockets.Managers
 	public interface ISocketConnectionManager
 	{
 		Task BroadcastToAll(IResponse response);
-		//Task BroadcastToGame(string gameName, IResponse response);
+		void Subscribe(WebSocket socket, string playerName);
-		//Task BroadcastToGame(string gameName, IResponse forPlayer1, IResponse forPlayer2);
+		void Unsubscribe(string playerName);
-		void SubscribeToGame(Session session, string playerName);
-		void SubscribeToBroadcast(WebSocket socket, string playerName);
-		void UnsubscribeFromBroadcastAndGames(string playerName);
-		void UnsubscribeFromGame(string gameName, string playerName);
 		Task BroadcastToPlayers(IResponse response, params string?[] playerNames);
 	}
 
@@ -31,59 +26,23 @@ namespace Gameboard.ShogiUI.Sockets.Managers
 		/// <summary>Dictionary key is player name.</summary>
 		private readonly ConcurrentDictionary<string, WebSocket> connections;
 		/// <summary>Dictionary key is game name.</summary>
-		private readonly ConcurrentDictionary<string, Session> sessions;
 		private readonly ILogger<SocketConnectionManager> logger;
 
 		public SocketConnectionManager(ILogger<SocketConnectionManager> logger)
 		{
 			this.logger = logger;
 			connections = new ConcurrentDictionary<string, WebSocket>();
-			sessions = new ConcurrentDictionary<string, Session>();
 		}
 
-		public void SubscribeToBroadcast(WebSocket socket, string playerName)
+		public void Subscribe(WebSocket socket, string playerName)
 		{
 			connections.TryRemove(playerName, out var _);
 			connections.TryAdd(playerName, socket);
 		}
 
-		public void UnsubscribeFromBroadcastAndGames(string playerName)
+		public void Unsubscribe(string playerName)
 		{
 			connections.TryRemove(playerName, out _);
-			foreach (var kvp in sessions)
-			{
-				var sessionName = kvp.Key;
-				UnsubscribeFromGame(sessionName, playerName);
-			}
-		}
-
-		/// <summary>
-		/// Unsubscribes the player from their current game, then subscribes to the new game.
-		/// </summary>
-		public void SubscribeToGame(Session session, string playerName)
-		{
-			// Unsubscribe from any other games
-			foreach (var kvp in sessions)
-			{
-				var gameNameKey = kvp.Key;
-				UnsubscribeFromGame(gameNameKey, playerName);
-			}
-
-			// Subscribe
-			if (connections.TryGetValue(playerName, out var socket))
-			{
-				var s = sessions.GetOrAdd(session.Name, session);
-				s.Subscriptions.TryAdd(playerName, socket);
-			}
-		}
-
-		public void UnsubscribeFromGame(string gameName, string playerName)
-		{
-			if (sessions.TryGetValue(gameName, out var s))
-			{
-				s.Subscriptions.TryRemove(playerName, out _);
-				if (s.Subscriptions.IsEmpty) sessions.TryRemove(gameName, out _);
-			}
 		}
 
 		public async Task BroadcastToPlayers(IResponse response, params string?[] playerNames)
@@ -113,15 +72,15 @@ namespace Gameboard.ShogiUI.Sockets.Managers
 
 					tasks.Add(socket.SendTextAsync(message));
 				}
-				catch (WebSocketException webSocketException)
+				catch (WebSocketException)
 				{
 					logger.LogInformation("Tried sending a message to socket connection for user [{user}], but found the connection has closed.", kvp.Key);
-					UnsubscribeFromBroadcastAndGames(kvp.Key);
+					Unsubscribe(kvp.Key);
 				}
-				catch (Exception exception)
+				catch
 				{
 					logger.LogInformation("Tried sending a message to socket connection for user [{user}], but found the connection has closed.", kvp.Key);
-					UnsubscribeFromBroadcastAndGames(kvp.Key);
+					Unsubscribe(kvp.Key);
 				}
 			}
 			try
@@ -129,34 +88,11 @@ namespace Gameboard.ShogiUI.Sockets.Managers
 				var task = Task.WhenAll(tasks);
 				return task;
 			}
-			catch (Exception e)
+			catch
 			{
 				Console.WriteLine("Yo");
 			}
 			return Task.FromResult(0);
 		}
-
-		//public Task BroadcastToGame(string gameName, IResponse forPlayer1, IResponse forPlayer2)
-		//{
-		//  if (sessions.TryGetValue(gameName, out var session))
-		//  {
-		//    var serialized1 = JsonConvert.SerializeObject(forPlayer1);
-		//    var serialized2 = JsonConvert.SerializeObject(forPlayer2);
-		//    return Task.WhenAll(
-		//      session.SendToPlayer1(serialized1),
-		//      session.SendToPlayer2(serialized2));
-		//  }
-		//  return Task.CompletedTask;
-		//}
-
-		//public Task BroadcastToGame(string gameName, IResponse messageForAllPlayers)
-		//{
-		//  if (sessions.TryGetValue(gameName, out var session))
-		//  {
-		//    var serialized = JsonConvert.SerializeObject(messageForAllPlayers);
-		//    return session.Broadcast(serialized);
-		//  }
-		//  return Task.CompletedTask;
-		//}
 	}
 }

Gameboard.ShogiUI.Sockets/Models/MoveSets.cs

@@ -1,95 +0,0 @@
-using PathFinding;
-using System.Collections.Generic;
-
-namespace Gameboard.ShogiUI.Sockets.Models
-{
-  public static class MoveSets
-  {
-    public static readonly List<PathFinding.Move> King = new(8)
-    {
-      new PathFinding.Move(Direction.Up),
-      new PathFinding.Move(Direction.Left),
-      new PathFinding.Move(Direction.Right),
-      new PathFinding.Move(Direction.Down),
-      new PathFinding.Move(Direction.UpLeft),
-      new PathFinding.Move(Direction.UpRight),
-      new PathFinding.Move(Direction.DownLeft),
-      new PathFinding.Move(Direction.DownRight)
-    };
-
-    public static readonly List<PathFinding.Move> Bishop = new(4)
-    {
-      new PathFinding.Move(Direction.UpLeft, Distance.MultiStep),
-      new PathFinding.Move(Direction.UpRight, Distance.MultiStep),
-      new PathFinding.Move(Direction.DownLeft, Distance.MultiStep),
-      new PathFinding.Move(Direction.DownRight, Distance.MultiStep)
-    };
-
-    public static readonly List<PathFinding.Move> PromotedBishop = new(8)
-    {
-      new PathFinding.Move(Direction.Up),
-      new PathFinding.Move(Direction.Left),
-      new PathFinding.Move(Direction.Right),
-      new PathFinding.Move(Direction.Down),
-      new PathFinding.Move(Direction.UpLeft, Distance.MultiStep),
-      new PathFinding.Move(Direction.UpRight, Distance.MultiStep),
-      new PathFinding.Move(Direction.DownLeft, Distance.MultiStep),
-      new PathFinding.Move(Direction.DownRight, Distance.MultiStep)
-    };
-
-    public static readonly List<PathFinding.Move> GoldGeneral = new(6)
-    {
-      new PathFinding.Move(Direction.Up),
-      new PathFinding.Move(Direction.UpLeft),
-      new PathFinding.Move(Direction.UpRight),
-      new PathFinding.Move(Direction.Left),
-      new PathFinding.Move(Direction.Right),
-      new PathFinding.Move(Direction.Down)
-    };
-
-    public static readonly List<PathFinding.Move> Knight = new(2)
-    {
-      new PathFinding.Move(Direction.KnightLeft),
-      new PathFinding.Move(Direction.KnightRight)
-    };
-
-    public static readonly List<PathFinding.Move> Lance = new(1)
-    {
-      new PathFinding.Move(Direction.Up, Distance.MultiStep),
-    };
-
-    public static readonly List<PathFinding.Move> Pawn = new(1)
-    {
-      new PathFinding.Move(Direction.Up)
-    };
-
-    public static readonly List<PathFinding.Move> Rook = new(4)
-    {
-      new PathFinding.Move(Direction.Up, Distance.MultiStep),
-      new PathFinding.Move(Direction.Left, Distance.MultiStep),
-      new PathFinding.Move(Direction.Right, Distance.MultiStep),
-      new PathFinding.Move(Direction.Down, Distance.MultiStep)
-    };
-
-    public static readonly List<PathFinding.Move> PromotedRook = new(8)
-    {
-      new PathFinding.Move(Direction.Up, Distance.MultiStep),
-      new PathFinding.Move(Direction.Left, Distance.MultiStep),
-      new PathFinding.Move(Direction.Right, Distance.MultiStep),
-      new PathFinding.Move(Direction.Down, Distance.MultiStep),
-      new PathFinding.Move(Direction.UpLeft),
-      new PathFinding.Move(Direction.UpRight),
-      new PathFinding.Move(Direction.DownLeft),
-      new PathFinding.Move(Direction.DownRight)
-    };
-
-    public static readonly List<PathFinding.Move> SilverGeneral = new(4)
-    {
-      new PathFinding.Move(Direction.Up),
-      new PathFinding.Move(Direction.UpLeft),
-      new PathFinding.Move(Direction.UpRight),
-      new PathFinding.Move(Direction.DownLeft),
-      new PathFinding.Move(Direction.DownRight)
-    };
-  }
-}

Gameboard.ShogiUI.Sockets/Models/Piece.cs

@@ -1,70 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using PathFinding;
-using System.Diagnostics;
-
-namespace Gameboard.ShogiUI.Sockets.Models
-{
-  [DebuggerDisplay("{WhichPiece} {Owner}")]
-  public class Piece : IPlanarElement
-  {
-    public WhichPiece WhichPiece { get; }
-    public WhichPerspective Owner { get; private set; }
-    public bool IsPromoted { get; private set; }
-    public bool IsUpsideDown => Owner == WhichPerspective.Player2;
-
-    public Piece(WhichPiece piece, WhichPerspective owner, bool isPromoted = false)
-    {
-      WhichPiece = piece;
-      Owner = owner;
-      IsPromoted = isPromoted;
-    }
-    public Piece(Piece piece) : this(piece.WhichPiece, piece.Owner, piece.IsPromoted)
-    {
-    }
-
-    public bool CanPromote => !IsPromoted
-      && WhichPiece != WhichPiece.King
-      && WhichPiece != WhichPiece.GoldGeneral;
-
-    public void ToggleOwnership()
-    {
-      Owner = Owner == WhichPerspective.Player1
-        ? WhichPerspective.Player2
-        : WhichPerspective.Player1;
-    }
-
-    public void Promote() => IsPromoted = CanPromote;
-
-    public void Demote() => IsPromoted = false;
-
-    public void Capture()
-    {
-      ToggleOwnership();
-      Demote();
-    }
-
-    // TODO: There is no reason to make "new" MoveSets every time this property is accessed.
-    public MoveSet MoveSet => WhichPiece switch
-    {
-      WhichPiece.King => new MoveSet(this, MoveSets.King),
-      WhichPiece.GoldGeneral => new MoveSet(this, MoveSets.GoldGeneral),
-      WhichPiece.SilverGeneral => new MoveSet(this, IsPromoted ? MoveSets.GoldGeneral : MoveSets.SilverGeneral),
-      WhichPiece.Bishop => new MoveSet(this, IsPromoted ? MoveSets.PromotedBishop : MoveSets.Bishop),
-      WhichPiece.Rook => new MoveSet(this, IsPromoted ? MoveSets.PromotedRook : MoveSets.Rook),
-      WhichPiece.Knight => new MoveSet(this, IsPromoted ? MoveSets.GoldGeneral : MoveSets.Knight),
-      WhichPiece.Lance => new MoveSet(this, IsPromoted ? MoveSets.GoldGeneral : MoveSets.Lance),
-      WhichPiece.Pawn => new MoveSet(this, IsPromoted ? MoveSets.GoldGeneral : MoveSets.Pawn),
-      _ => throw new System.NotImplementedException()
-    };
-
-    public ServiceModels.Types.Piece ToServiceModel()
-    {
-      return new ServiceModels.Types.Piece
-      {
-        IsPromoted = IsPromoted,
-        Owner = Owner,
-        WhichPiece = WhichPiece
-      };
-    }
-  }
-}

Gameboard.ShogiUI.Sockets/Models/Session.cs

@@ -1,38 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using Newtonsoft.Json;
-using System.Collections.Concurrent;
-using System.Net.WebSockets;
-
-namespace Gameboard.ShogiUI.Sockets.Models
-{
-	public class Session
-	{
-		// TODO: Separate subscriptions to the Session from the Session.
-		[JsonIgnore] public ConcurrentDictionary<string, WebSocket> Subscriptions { get; }
-		public string Name { get; }
-		public User Player1 { get; }
-		public User? Player2 { get; private set; }
-		public bool IsPrivate { get; }
-
-		// TODO: Don't retain the entire rules system within the Session model. It just needs the board state after rules are applied.
-		public Shogi Shogi { get; }
-
-		public Session(string name, bool isPrivate, Shogi shogi, User player1, User? player2 = null)
-		{
-			Subscriptions = new ConcurrentDictionary<string, WebSocket>();
-
-			Name = name;
-			Player1 = player1;
-			Player2 = player2;
-			IsPrivate = isPrivate;
-			Shogi = shogi;
-		}
-
-		public void SetPlayer2(User user)
-		{
-			Player2 = user;
-		}
-
-		public Game ToServiceModel() => new(Name, Player1.DisplayName, Player2?.DisplayName);
-	}
-}

Gameboard.ShogiUI.Sockets/Models/SessionMetadata.cs

@@ -32,6 +32,6 @@
 
 		public bool IsSeated(User user) => user.Id == Player1.Id || user.Id == Player2?.Id;
 
-		public ServiceModels.Types.Game ToServiceModel() => new(Name, Player1.DisplayName, Player2?.DisplayName);
+		public ServiceModels.Types.Session ToServiceModel() => new(Name, Player1.DisplayName, Player2?.DisplayName);
 	}
 }

Gameboard.ShogiUI.Sockets/Models/Shogi.cs

@@ -1,463 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using Gameboard.ShogiUI.Sockets.Utilities;
-using PathFinding;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Numerics;
-
-namespace Gameboard.ShogiUI.Sockets.Models
-{
-	/// <summary>
-	/// Facilitates Shogi board state transitions, cognisant of Shogi rules.
-	/// The board is always from Player1's perspective.
-	/// [0,0] is the lower-left position, [8,8] is the higher-right position
-	/// </summary>
-	public class Shogi
-	{
-		private delegate void MoveSetCallback(Piece piece, Vector2 position);
-		private readonly PathFinder2D<Piece> pathFinder;
-		private Shogi? validationBoard;
-		private Vector2 player1King;
-		private Vector2 player2King;
-		private List<Piece> Hand => WhoseTurn == WhichPerspective.Player1 ? Player1Hand : Player2Hand;
-		public List<Piece> Player1Hand { get; }
-		public List<Piece> Player2Hand { get; }
-		public CoordsToNotationCollection Board { get; } //TODO: Hide this being a getter method
-		public List<Move> MoveHistory { get; }
-		public WhichPerspective WhoseTurn => MoveHistory.Count % 2 == 0 ? WhichPerspective.Player1 : WhichPerspective.Player2;
-		public WhichPerspective? InCheck { get; private set; }
-		public bool IsCheckmate { get; private set; }
-
-		public string Error { get; private set; }
-
-		public Shogi()
-		{
-			Board = new CoordsToNotationCollection();
-			MoveHistory = new List<Move>(20);
-			Player1Hand = new List<Piece>();
-			Player2Hand = new List<Piece>();
-			pathFinder = new PathFinder2D<Piece>(Board, 9, 9);
-			player1King = new Vector2(4, 0);
-			player2King = new Vector2(4, 8);
-			Error = string.Empty;
-
-			InitializeBoardState();
-		}
-
-		public Shogi(IList<Move> moves) : this()
-		{
-			for (var i = 0; i < moves.Count; i++)
-			{
-				if (!Move(moves[i]))
-				{
-					// Todo: Add some smarts to know why a move was invalid. In check? Piece not found? etc.
-					throw new InvalidOperationException($"Unable to construct ShogiBoard with the given move at index {i}. {Error}");
-				}
-			}
-		}
-
-		private Shogi(Shogi toCopy)
-		{
-			Board = new CoordsToNotationCollection();
-			foreach (var kvp in toCopy.Board)
-			{
-				Board[kvp.Key] = kvp.Value == null ? null : new Piece(kvp.Value);
-			}
-
-			pathFinder = new PathFinder2D<Piece>(Board, 9, 9);
-			MoveHistory = new List<Move>(toCopy.MoveHistory);
-			Player1Hand = new List<Piece>(toCopy.Player1Hand);
-			Player2Hand = new List<Piece>(toCopy.Player2Hand);
-			player1King = toCopy.player1King;
-			player2King = toCopy.player2King;
-			Error = toCopy.Error;
-		}
-
-		public bool Move(Move move)
-		{
-			var otherPlayer = WhoseTurn == WhichPerspective.Player1 ? WhichPerspective.Player2 : WhichPerspective.Player1;
-			var moveSuccess = TryMove(move);
-
-			if (!moveSuccess)
-			{
-				return false;
-			}
-
-			// Evaluate check
-			if (EvaluateCheckAfterMove(move, otherPlayer))
-			{
-				InCheck = otherPlayer;
-				IsCheckmate = EvaluateCheckmate();
-			}
-			else
-			{
-				InCheck = null;
-			}
-			return true;
-		}
-		/// <summary>
-		/// Attempts a given move. Returns false if the move is illegal.
-		/// </summary>
-		private bool TryMove(Move move)
-		{
-			// Try making the move in a "throw away" board.
-			if (validationBoard == null)
-			{
-				validationBoard = new Shogi(this);
-			}
-
-			var isValid = move.PieceFromHand.HasValue
-				? validationBoard.PlaceFromHand(move)
-				: validationBoard.PlaceFromBoard(move);
-			if (!isValid)
-			{
-				// Surface the error description.
-				Error = validationBoard.Error;
-				// Invalidate the "throw away" board.
-				validationBoard = null;
-				return false;
-			}
-			// If already in check, assert the move that resulted in check no longer results in check.
-			if (InCheck == WhoseTurn)
-			{
-				if (validationBoard.EvaluateCheckAfterMove(MoveHistory[^1], WhoseTurn))
-				{
-					// Sneakily using this.WhoseTurn instead of validationBoard.WhoseTurn;
-					return false;
-				}
-			}
-
-			// The move is valid and legal; update board state.
-			if (move.PieceFromHand.HasValue) PlaceFromHand(move);
-			else PlaceFromBoard(move);
-			return true;
-		}
-		/// <returns>True if the move was successful.</returns>
-		private bool PlaceFromHand(Move move)
-		{
-			var index = Hand.FindIndex(p => p.WhichPiece == move.PieceFromHand);
-			if (index < 0)
-			{
-				Error = $"{move.PieceFromHand} does not exist in the hand.";
-				return false;
-			}
-			if (Board[move.To] != null)
-			{
-				Error = $"Illegal move - attempting to capture while playing a piece from the hand.";
-				return false;
-			}
-
-			switch (move.PieceFromHand!.Value)
-			{
-				case WhichPiece.Knight:
-					{
-						// Knight cannot be placed onto the farthest two ranks from the hand.
-						if ((WhoseTurn == WhichPerspective.Player1 && move.To.Y > 6)
-							|| (WhoseTurn == WhichPerspective.Player2 && move.To.Y < 2))
-						{
-							Error = $"Knight has no valid moves after placed.";
-							return false;
-						}
-						break;
-					}
-				case WhichPiece.Lance:
-				case WhichPiece.Pawn:
-					{
-						// Lance and Pawn cannot be placed onto the farthest rank from the hand.
-						if ((WhoseTurn == WhichPerspective.Player1 && move.To.Y == 8)
-							|| (WhoseTurn == WhichPerspective.Player2 && move.To.Y == 0))
-						{
-							Error = $"{move.PieceFromHand} has no valid moves after placed.";
-							return false;
-						}
-						break;
-					}
-			}
-
-			// Mutate the board.
-			Board[move.To] = Hand[index];
-			Hand.RemoveAt(index);
-			MoveHistory.Add(move);
-
-			return true;
-		}
-		/// <returns>True if the move was successful.</returns>
-		private bool PlaceFromBoard(Move move)
-		{
-			var fromPiece = Board[move.From!.Value];
-			if (fromPiece == null)
-			{
-				Error = $"No piece exists at {nameof(move)}.{nameof(move.From)}.";
-				return false; // Invalid move
-			}
-			if (fromPiece.Owner != WhoseTurn)
-			{
-				Error = "Not allowed to move the opponents piece";
-				return false; // Invalid move; cannot move other players pieces.
-			}
-			if (IsPathable(move.From.Value, move.To) == false)
-			{
-				Error = $"Illegal move for {fromPiece.WhichPiece}. {nameof(move)}.{nameof(move.To)} is not part of the move-set.";
-				return false; // Invalid move; move not part of move-set.
-			}
-
-			var captured = Board[move.To];
-			if (captured != null)
-			{
-				if (captured.Owner == WhoseTurn) return false; // Invalid move; cannot capture your own piece.
-				captured.Capture();
-				Hand.Add(captured);
-			}
-
-			//Mutate the board.
-			if (move.IsPromotion)
-			{
-				if (WhoseTurn == WhichPerspective.Player1 && (move.To.Y > 5 || move.From.Value.Y > 5))
-				{
-					fromPiece.Promote();
-				}
-				else if (WhoseTurn == WhichPerspective.Player2 && (move.To.Y < 3 || move.From.Value.Y < 3))
-				{
-					fromPiece.Promote();
-				}
-			}
-			Board[move.To] = fromPiece;
-			Board[move.From!.Value] = null;
-			if (fromPiece.WhichPiece == WhichPiece.King)
-			{
-				if (fromPiece.Owner == WhichPerspective.Player1)
-				{
-					player1King.X = move.To.X;
-					player1King.Y = move.To.Y;
-				}
-				else if (fromPiece.Owner == WhichPerspective.Player2)
-				{
-					player2King.X = move.To.X;
-					player2King.Y = move.To.Y;
-				}
-			}
-			MoveHistory.Add(move);
-			return true;
-		}
-
-		private bool IsPathable(Vector2 from, Vector2 to)
-		{
-			var piece = Board[from];
-			if (piece == null) return false;
-
-			var isObstructed = false;
-			var isPathable = pathFinder.PathTo(from, to, (other, position) =>
-			{
-				if (other.Owner == piece.Owner) isObstructed = true;
-			});
-			return !isObstructed && isPathable;
-		}
-
-		#region Rules Validation
-		private bool EvaluateCheckAfterMove(Move move, WhichPerspective WhichPerspective)
-		{
-			if (WhichPerspective == InCheck) return true; // If we already know the player is in check, don't bother.
-
-			var isCheck = false;
-			var kingPosition = WhichPerspective == WhichPerspective.Player1 ? player1King : player2King;
-
-			// Check if the move put the king in check.
-			if (pathFinder.PathTo(move.To, kingPosition)) return true;
-
-			if (move.From.HasValue)
-			{
-				// Get line equation from king through the now-unoccupied location.
-				var direction = Vector2.Subtract(kingPosition, move.From!.Value);
-				var slope = Math.Abs(direction.Y / direction.X);
-				// If absolute slope is 45°, look for a bishop along the line.
-				// If absolute slope is 0° or 90°, look for a rook along the line.
-				// if absolute slope is 0°, look for lance along the line.
-				if (float.IsInfinity(slope))
-				{
-					// if slope of the move is also infinity...can skip this?
-					pathFinder.LinePathTo(kingPosition, direction, (piece, position) =>
-					{
-						if (piece.Owner != WhichPerspective)
-						{
-							switch (piece.WhichPiece)
-							{
-								case WhichPiece.Rook:
-									isCheck = true;
-									break;
-								case WhichPiece.Lance:
-									if (!piece.IsPromoted) isCheck = true;
-									break;
-							}
-						}
-					});
-				}
-				else if (slope == 1)
-				{
-					pathFinder.LinePathTo(kingPosition, direction, (piece, position) =>
-					{
-						if (piece.Owner != WhichPerspective && piece.WhichPiece == WhichPiece.Bishop)
-						{
-							isCheck = true;
-						}
-					});
-				}
-				else if (slope == 0)
-				{
-					pathFinder.LinePathTo(kingPosition, direction, (piece, position) =>
-					{
-						if (piece.Owner != WhichPerspective && piece.WhichPiece == WhichPiece.Rook)
-						{
-							isCheck = true;
-						}
-					});
-				}
-			}
-			else
-			{
-				// TODO: Check for illegal move from hand. It is illegal to place from the hand such that you check-mate your opponent.
-				// Go read the shogi rules to be sure this is true.
-			}
-
-			return isCheck;
-		}
-		private bool EvaluateCheckmate()
-		{
-			if (!InCheck.HasValue) return false;
-
-			// Assume true and try to disprove.
-			var isCheckmate = true;
-			Board.ForEachNotNull((piece, from) => // For each piece...
-			{
-				// Short circuit
-				if (!isCheckmate) return;
-
-				if (piece.Owner == InCheck) // ...owned by the player in check...
-				{
-					// ...evaluate if any move gets the player out of check.
-					pathFinder.PathEvery(from, (other, position) =>
-				{
-					if (validationBoard == null) validationBoard = new Shogi(this);
-					var moveToTry = new Move(from, position);
-					var moveSuccess = validationBoard.TryMove(moveToTry);
-					if (moveSuccess)
-					{
-						validationBoard = null;
-						if (!EvaluateCheckAfterMove(moveToTry, InCheck.Value))
-						{
-							isCheckmate = false;
-						}
-					}
-				});
-				}
-			});
-			return isCheckmate;
-		}
-		#endregion
-
-		private void InitializeBoardState()
-		{
-			Board["A1"] = new Piece(WhichPiece.Lance, WhichPerspective.Player1);
-			Board["B1"] = new Piece(WhichPiece.Knight, WhichPerspective.Player1);
-			Board["C1"] = new Piece(WhichPiece.SilverGeneral, WhichPerspective.Player1);
-			Board["D1"] = new Piece(WhichPiece.GoldGeneral, WhichPerspective.Player1);
-			Board["E1"] = new Piece(WhichPiece.King, WhichPerspective.Player1);
-			Board["F1"] = new Piece(WhichPiece.GoldGeneral, WhichPerspective.Player1);
-			Board["G1"] = new Piece(WhichPiece.SilverGeneral, WhichPerspective.Player1);
-			Board["H1"] = new Piece(WhichPiece.Knight, WhichPerspective.Player1);
-			Board["I1"] = new Piece(WhichPiece.Lance, WhichPerspective.Player1);
-
-			Board["A2"] = null;
-			Board["B2"] = new Piece(WhichPiece.Bishop, WhichPerspective.Player1);
-			Board["C2"] = null;
-			Board["D2"] = null;
-			Board["E2"] = null;
-			Board["F2"] = null;
-			Board["G2"] = null;
-			Board["H2"] = new Piece(WhichPiece.Rook, WhichPerspective.Player1);
-			Board["I2"] = null;
-
-			Board["A3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["B3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["C3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["D3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["E3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["F3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["G3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["H3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-			Board["I3"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player1);
-
-			Board["A4"] = null;
-			Board["B4"] = null;
-			Board["C4"] = null;
-			Board["D4"] = null;
-			Board["E4"] = null;
-			Board["F4"] = null;
-			Board["G4"] = null;
-			Board["H4"] = null;
-			Board["I4"] = null;
-
-			Board["A5"] = null;
-			Board["B5"] = null;
-			Board["C5"] = null;
-			Board["D5"] = null;
-			Board["E5"] = null;
-			Board["F5"] = null;
-			Board["G5"] = null;
-			Board["H5"] = null;
-			Board["I5"] = null;
-
-			Board["A6"] = null;
-			Board["B6"] = null;
-			Board["C6"] = null;
-			Board["D6"] = null;
-			Board["E6"] = null;
-			Board["F6"] = null;
-			Board["G6"] = null;
-			Board["H6"] = null;
-			Board["I6"] = null;
-
-			Board["A7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["B7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["C7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["D7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["E7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["F7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["G7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["H7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-			Board["I7"] = new Piece(WhichPiece.Pawn, WhichPerspective.Player2);
-
-			Board["A8"] = null;
-			Board["B8"] = new Piece(WhichPiece.Rook, WhichPerspective.Player2);
-			Board["C8"] = null;
-			Board["D8"] = null;
-			Board["E8"] = null;
-			Board["F8"] = null;
-			Board["G8"] = null;
-			Board["H8"] = new Piece(WhichPiece.Bishop, WhichPerspective.Player2);
-			Board["I8"] = null;
-
-			Board["A9"] = new Piece(WhichPiece.Lance, WhichPerspective.Player2);
-			Board["B9"] = new Piece(WhichPiece.Knight, WhichPerspective.Player2);
-			Board["C9"] = new Piece(WhichPiece.SilverGeneral, WhichPerspective.Player2);
-			Board["D9"] = new Piece(WhichPiece.GoldGeneral, WhichPerspective.Player2);
-			Board["E9"] = new Piece(WhichPiece.King, WhichPerspective.Player2);
-			Board["F9"] = new Piece(WhichPiece.GoldGeneral, WhichPerspective.Player2);
-			Board["G9"] = new Piece(WhichPiece.SilverGeneral, WhichPerspective.Player2);
-			Board["H9"] = new Piece(WhichPiece.Knight, WhichPerspective.Player2);
-			Board["I9"] = new Piece(WhichPiece.Lance, WhichPerspective.Player2);
-		}
-
-		public BoardState ToServiceModel()
-		{
-			return new BoardState
-			{
-				Board = Board.ToDictionary(kvp => kvp.Key, kvp => kvp.Value?.ToServiceModel()),
-				PlayerInCheck = InCheck,
-				WhoseTurn = WhoseTurn,
-				Player1Hand = Player1Hand.Select(_ => _.ToServiceModel()).ToList(),
-				Player2Hand = Player2Hand.Select(_ => _.ToServiceModel()).ToList()
-			};
-		}
-	}
-}

Gameboard.ShogiUI.Sockets/Repositories/CouchModels/BoardStateDocument.cs

@@ -1,8 +1,7 @@
-using Gameboard.ShogiUI.Sockets.Utilities;
+using Shogi.Domain;
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Numerics;
 
 namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
 {
@@ -35,31 +34,19 @@ namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
 			Player2Hand = Array.Empty<Piece>();
 		}
 
-    public BoardStateDocument(string sessionName, Models.Shogi shogi)
+		public BoardStateDocument(string sessionName, Session shogi)
 			: base($"{sessionName}-{DateTime.Now:O}", WhichDocumentType.BoardState)
 		{
+			static Piece MapPiece(Shogi.Domain.Pieces.Piece piece)
+			{
+				return new Piece { IsPromoted = piece.IsPromoted, Owner = piece.Owner, WhichPiece = piece.WhichPiece };
+			}
+
 			Name = sessionName;
-      Board = new Dictionary<string, Piece?>(81, StringComparer.OrdinalIgnoreCase);
+			Board = shogi.BoardState.ToDictionary(kvp => kvp.Key, kvp => kvp.Value == null ? null : MapPiece(kvp.Value));
 
-      for (var x = 0; x < 9; x++)
+			Player1Hand = shogi.Player1Hand.Select(piece => MapPiece(piece)).ToArray();
-        for (var y = 0; y < 9; y++)
+			Player2Hand = shogi.Player2Hand.Select(piece => MapPiece(piece)).ToArray();
-        {
-          var position = new Vector2(x, y);
-          var piece = shogi.Board[y, x];
-
-          if (piece != null)
-          {
-            var positionNotation = NotationHelper.ToBoardNotation(position);
-            Board[positionNotation] = new Piece(piece);
-          }
-        }
-
-      Player1Hand = shogi.Player1Hand.Select(model => new Piece(model)).ToArray();
-      Player2Hand = shogi.Player2Hand.Select(model => new Piece(model)).ToArray();
-      if (shogi.MoveHistory.Count > 0)
-      {
-        Move = new Move(shogi.MoveHistory[^1]);
-      }
 		}
 	}
 }

Gameboard.ShogiUI.Sockets/Repositories/CouchModels/Move.cs

@@ -1,5 +1,4 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
+using Shogi.Domain;
-using System.Numerics;
 
 namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
 {
@@ -29,28 +28,5 @@ namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
     {
       To = string.Empty;
     }
-
-    public Move(Models.Move move)
-    {
-      if (move.From.HasValue)
-      {
-        From = ToBoardNotation(move.From.Value);
-      }
-      IsPromotion = move.IsPromotion;
-      To = ToBoardNotation(move.To);
-      PieceFromHand = move.PieceFromHand;
-    }
-
-    private static readonly char A = 'A';
-    private static string ToBoardNotation(Vector2 vector)
-    {
-      var file = (char)(vector.X + A);
-      var rank = vector.Y + 1;
-      return $"{file}{rank}";
-    }
-
-    public Models.Move ToDomainModel() => PieceFromHand.HasValue
-      ? new(PieceFromHand.Value, To)
-      : new(From!, To, IsPromotion);
   }
 }

Gameboard.ShogiUI.Sockets/Repositories/CouchModels/Piece.cs

@@ -1,27 +1,11 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
+using Shogi.Domain;
 
 namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
 {
 	public class Piece
 	{
 		public bool IsPromoted { get; set; }
-    public WhichPerspective Owner { get; set; }
+		public WhichPlayer Owner { get; set; }
 		public WhichPiece WhichPiece { get; set; }
-
-    /// <summary>
-    /// Default constructor and setters are for deserialization.
-    /// </summary>
-    public Piece()
-    {
-    }
-
-    public Piece(Models.Piece piece)
-    {
-      IsPromoted = piece.IsPromoted;
-      Owner = piece.Owner;
-      WhichPiece = piece.WhichPiece;
-    }
-
-    public Models.Piece ToDomainModel() => new(WhichPiece, Owner, IsPromoted);
 	}
 }

Gameboard.ShogiUI.Sockets/Repositories/CouchModels/SessionDocument.cs

@@ -1,6 +1,4 @@
-using System.Collections.Generic;
+namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
-
-namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
 {
 	public class SessionDocument : CouchDocument
   {
@@ -8,7 +6,6 @@ namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
     public string Player1Id { get; set; }
     public string? Player2Id { get; set; }
     public bool IsPrivate { get; set; }
-    public IList<BoardStateDocument> History { get; set; }
 
     /// <summary>
     /// Default constructor and setters are for deserialization.
@@ -18,17 +15,6 @@ namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
       Name = string.Empty;
       Player1Id = string.Empty;
       Player2Id = string.Empty;
-      History = new List<BoardStateDocument>(0);
-    }
-
-    public SessionDocument(Models.Session session)
-      : base(session.Name, WhichDocumentType.Session)
-    {
-      Name = session.Name;
-      Player1Id = session.Player1.Id;
-      Player2Id = session.Player2?.Id;
-      IsPrivate = session.IsPrivate;
-      History = new List<BoardStateDocument>(0);
     }
 
     public SessionDocument(Models.SessionMetadata sessionMetaData)
@@ -38,7 +24,6 @@ namespace Gameboard.ShogiUI.Sockets.Repositories.CouchModels
       Player1Id = sessionMetaData.Player1.Id;
       Player2Id = sessionMetaData.Player2?.Id;
       IsPrivate = sessionMetaData.IsPrivate;
-      History = new List<BoardStateDocument>(0);
     }
   }
 }

Gameboard.ShogiUI.Sockets/Repositories/GameboardRepository.cs

@@ -4,6 +4,7 @@ using Microsoft.AspNetCore.Http.Extensions;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Shogi.Domain;
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
@@ -11,17 +12,16 @@ using System.Linq;
 using System.Net.Http;
 using System.Text;
 using System.Threading.Tasks;
-using System.Web;
 
 namespace Gameboard.ShogiUI.Sockets.Repositories
 {
 	public interface IGameboardRepository
 	{
-    Task<bool> CreateBoardState(Models.Session session);
+		Task<bool> CreateBoardState(Session session);
 		Task<bool> CreateSession(Models.SessionMetadata session);
 		Task<bool> CreateUser(Models.User user);
 		Task<Collection<Models.SessionMetadata>> ReadSessionMetadatas();
-    Task<Models.Session?> ReadSession(string name);
+		Task<Session?> ReadSession(string name);
 		Task<bool> UpdateSession(Models.SessionMetadata session);
 		Task<Models.SessionMetadata?> ReadSessionMetaData(string name);
 		Task<Models.User?> ReadUser(string userName);
@@ -80,8 +80,15 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 			return new Collection<Models.SessionMetadata>(Array.Empty<Models.SessionMetadata>());
 		}
 
-    public async Task<Models.Session?> ReadSession(string name)
+		public async Task<Session?> ReadSession(string name)
 		{
+			static Shogi.Domain.Pieces.Piece? MapPiece(Piece? piece)
+			{
+				return piece == null
+					? null
+					: Shogi.Domain.Pieces.Piece.Create(piece.WhichPiece, piece.Owner, piece.IsPromoted);
+			}
+
 			var queryParams = new QueryBuilder
 			{
 				{ "include_docs", "true" },
@@ -97,11 +104,12 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 			{
 				var group = result.rows;
 				/**
-         * A group contains 3 type of elements.
+         * A group contains multiple elements.
-         * 1) The session metadata.
+         * 0) The session metadata.
-         * 2) User documents of Player1 and Player2.
+         * 1) User documents of Player1.
+         * 2) User documents of Player1.
          *   2.a) If the Player2 document doesn't exist, CouchDB will return the SessionDocument instead :(
-         * 3) BoardState
+         * Everything Else) Snapshots of the boardstate after every player move.
          */
 				var session = group[0].doc.ToObject<SessionDocument>();
 				var player1Doc = group[1].doc.ToObject<UserDocument>();
@@ -109,24 +117,14 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 				var player2Doc = group2DocumentType == WhichDocumentType.User.ToString()
 					? group[2].doc.ToObject<UserDocument>()
 					: null;
-        var moves = group
+				var boardState = group.Last().doc.ToObject<BoardStateDocument>();
-          .Skip(4) // Skip 4 because group[3] will not have a .Move property since it's the first/initial BoardState of the session.
-                   // TODO: Deserialize just the Move property.
-          .Select(row => row.doc.ToObject<BoardStateDocument>())
-          .Select(boardState =>
-          {
-            var move = boardState!.Move!;
-            return move.PieceFromHand.HasValue
-              ? new Models.Move(move.PieceFromHand.Value, move.To)
-              : new Models.Move(move.From!, move.To, move.IsPromotion);
-          })
-          .ToList();
 
-        var shogi = new Models.Shogi(moves);
+				if (session != null && player1Doc != null && boardState != null)
-        if (session != null && player1Doc != null)
 				{
 					var player2 = player2Doc == null ? null : new Models.User(player2Doc);
-          return new Models.Session(session.Name, session.IsPrivate, shogi, new(player1Doc), player2);
+					var metaData = new SessionMetadata(session.Name, session.IsPrivate, player1Doc.DisplayName, player2Doc?.DisplayName);
+					var shogiBoardState = new BoardState(boardState.Board.ToDictionary(kvp => kvp.Key, kvp => MapPiece(kvp.Value)));
+					return new Session(shogiBoardState, metaData);
 				}
 			}
 			return null;
@@ -170,9 +168,16 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 		/// <summary>
 		/// Saves a snapshot of board state and the most recent move.
 		/// </summary>
-    public async Task<bool> CreateBoardState(Models.Session session)
+		public async Task<bool> CreateBoardState(Session session)
 		{
-      var boardStateDocument = new BoardStateDocument(session.Name, session.Shogi);
+			Piece? MapPiece(Shogi.Domain.Pieces.Piece? piece)
+			{
+				return piece == null
+					? null
+					: new Piece { IsPromoted = piece.IsPromoted, Owner = piece.Owner, WhichPiece = piece.WhichPiece };
+			}
+
+			var boardStateDocument = new BoardStateDocument(session.Name, session);
 			var content = new StringContent(JsonConvert.SerializeObject(boardStateDocument), Encoding.UTF8, ApplicationJson);
 			var response = await client.PostAsync(string.Empty, content);
 			return response.IsSuccessStatusCode;
@@ -184,7 +189,7 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 			var sessionContent = new StringContent(JsonConvert.SerializeObject(sessionDocument), Encoding.UTF8, ApplicationJson);
 			var postSessionDocumentTask = client.PostAsync(string.Empty, sessionContent);
 
-      var boardStateDocument = new BoardStateDocument(session.Name, new Models.Shogi());
+			var boardStateDocument = new BoardStateDocument(session.Name, new Session());
 			var boardStateContent = new StringContent(JsonConvert.SerializeObject(boardStateDocument), Encoding.UTF8, ApplicationJson);
 
 			if ((await postSessionDocumentTask).IsSuccessStatusCode)
@@ -288,5 +293,21 @@ namespace Gameboard.ShogiUI.Sockets.Repositories
 			return response.IsSuccessStatusCode;
 		}
 
+		public void ReadMoveHistory()
+		{
+			//TODO: Separate move history into a separate request.
+			//var moves = group
+			//  .Skip(4) // Skip 4 because group[3] will not have a .Move property since it's the first/initial BoardState of the session.
+			//           // TODO: Deserialize just the Move property.
+			//  .Select(row => row.doc.ToObject<BoardStateDocument>())
+			//  .Select(boardState =>
+			//  {
+			//    var move = boardState!.Move!;
+			//    return move.PieceFromHand.HasValue
+			//      ? new Models.Move(move.PieceFromHand.Value, move.To)
+			//      : new Models.Move(move.From!, move.To, move.IsPromotion);
+			//  })
+			//  .ToList();
+		}
 	}
 }

Gameboard.ShogiUI.Sockets/Services/SocketService.cs

@@ -5,7 +5,6 @@ using Gameboard.ShogiUI.Sockets.Managers.ClientActionHandlers;
 using Gameboard.ShogiUI.Sockets.Repositories;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
 using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-using Gameboard.ShogiUI.Sockets.Services.Utility;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
@@ -74,7 +73,7 @@ namespace Gameboard.ShogiUI.Sockets.Services
       }
       var socket = await context.WebSockets.AcceptWebSocketAsync();
 
-      communicationManager.SubscribeToBroadcast(socket, userName);
+      communicationManager.Subscribe(socket, userName);
       while (socket.State == WebSocketState.Open)
       {
         try
@@ -82,7 +81,7 @@ namespace Gameboard.ShogiUI.Sockets.Services
           var message = await socket.ReceiveTextAsync();
           if (string.IsNullOrWhiteSpace(message)) continue;
           logger.LogInformation("Request \n{0}\n", message);
-          var request = JsonConvert.DeserializeObject<Request>(message);
+          var request = JsonConvert.DeserializeObject<IRequest>(message);
           if (request == null || !Enum.IsDefined(typeof(ClientAction), request.Action))
           {
             await socket.SendTextAsync("Error: Action not recognized.");
@@ -114,7 +113,7 @@ namespace Gameboard.ShogiUI.Sockets.Services
           logger.LogInformation("Probably tried writing to a closed socket.");
           logger.LogError(ex.Message);
         }
-        communicationManager.UnsubscribeFromBroadcastAndGames(userName);
+        communicationManager.Unsubscribe(userName);
       }
     }
 

Gameboard.ShogiUI.Sockets/Services/Utility/JsonRequest.cs

@@ -1,15 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
-
-namespace Gameboard.ShogiUI.Sockets.Services.Utility
-{
-  public class JsonRequest
-  {
-    public IRequest Request { get; private set; }
-    public string Json { get; private set; }
-    public JsonRequest(IRequest request, string json)
-    {
-      Request = request;
-      Json = json;
-    }
-  }
-}

Gameboard.ShogiUI.Sockets/Services/Utility/Request.cs

@@ -1,10 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
-using Gameboard.ShogiUI.Sockets.ServiceModels.Types;
-
-namespace Gameboard.ShogiUI.Sockets.Services.Utility
-{
-  public class Request : IRequest
-  {
-    public ClientAction Action { get; set; }
-  }
-}

Gameboard.ShogiUI.Sockets/Services/Utility/Response.cs

@@ -1,9 +0,0 @@
-using Gameboard.ShogiUI.Sockets.ServiceModels.Socket;
-
-namespace Gameboard.ShogiUI.Sockets.Services.Utility
-{
-  public class Response : IResponse
-  {
-    public string Action { get; set; }
-  }
-}

Gameboard.ShogiUI.Sockets/Utilities/CoordsToNotationCollection.cs

@@ -1,48 +0,0 @@
-using Gameboard.ShogiUI.Sockets.Models;
-using PathFinding;
-using System;
-using System.Collections.Generic;
-using System.Numerics;
-
-namespace Gameboard.ShogiUI.Sockets.Utilities
-{
-  public class CoordsToNotationCollection : Dictionary<string, Piece?>, IPlanarCollection<Piece>
-  {
-    public delegate void ForEachDelegate(Piece element, Vector2 position);
-
-    public CoordsToNotationCollection() : base(81, StringComparer.OrdinalIgnoreCase)
-    {
-    }
-
-    public CoordsToNotationCollection(Dictionary<string, Piece?> board) : base(board, StringComparer.OrdinalIgnoreCase)
-    {
-    }
-
-    public Piece? this[Vector2 vector]
-    {
-      get => this[NotationHelper.ToBoardNotation(vector)];
-      set => this[NotationHelper.ToBoardNotation(vector)] = value;
-    }
-
-    public Piece? this[int x, int y]
-    {
-      get => this[NotationHelper.ToBoardNotation(x, y)];
-      set => this[NotationHelper.ToBoardNotation(x, y)] = value;
-    }
-
-
-    public void ForEachNotNull(ForEachDelegate callback)
-    {
-      for (var x = 0; x < 9; x++)
-      {
-        for (var y = 0; y < 9; y++)
-        {
-          var position = new Vector2(x, y);
-          var elem = this[position];
-          if (elem != null)
-            callback(elem, position);
-        }
-      }
-    }
-  }
-}

Gameboard.ShogiUI.Sockets/Utilities/NotationHelper.cs

@@ -1,36 +0,0 @@
-using System;
-using System.Numerics;
-using System.Text.RegularExpressions;
-
-namespace Gameboard.ShogiUI.Sockets.Utilities
-{
-  public static class NotationHelper
-  {
-    private static readonly string BoardNotationRegex = @"(?<file>[a-iA-I])(?<rank>[1-9])";
-    private static readonly char A = 'A';
-
-    public static string ToBoardNotation(Vector2 vector)
-    {
-      return ToBoardNotation((int)vector.X, (int)vector.Y);
-    }
-    public static string ToBoardNotation(int x, int y)
-    {
-      var file = (char)(x + A);
-      var rank = y + 1;
-      return $"{file}{rank}";
-    }
-
-    public static Vector2 FromBoardNotation(string notation)
-    {
-      notation = notation.ToUpper();
-      if (Regex.IsMatch(notation, BoardNotationRegex))
-      {
-        var match = Regex.Match(notation, BoardNotationRegex);
-        char file = match.Groups["file"].Value[0];
-        int rank = int.Parse(match.Groups["rank"].Value);
-        return new Vector2(file - A, rank - 1);
-      }
-      throw new ArgumentException($"Board notation not recognized. Notation given: {notation}");
-    }
-  }
-}

Gameboard.ShogiUI.UnitTests/Rules/ShogiBoardShould.cs

@@ -3,7 +3,7 @@ using Gameboard.ShogiUI.Sockets.Models;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System.Linq;
 using System.Numerics;
-using WhichPerspective = Gameboard.ShogiUI.Sockets.ServiceModels.Types.WhichPerspective;
+using WhichPerspective = Gameboard.ShogiUI.Sockets.ServiceModels.Types.WhichPlayer;
 using WhichPiece = Gameboard.ShogiUI.Sockets.ServiceModels.Types.WhichPiece;
 namespace Gameboard.ShogiUI.UnitTests.Rules
 {

Gameboard.ShogiUI.xUnitTests/CoordsToNotationCollectionShould.cs

@@ -1,41 +0,0 @@
-using AutoFixture;
-using FluentAssertions;
-using Gameboard.ShogiUI.Sockets.Models;
-using Gameboard.ShogiUI.Sockets.Utilities;
-using Xunit;
-
-namespace Gameboard.ShogiUI.xUnitTests
-{
-  public class CoordsToNotationCollectionShould
-  {
-    private readonly Fixture fixture;
-    private readonly CoordsToNotationCollection collection;
-    public CoordsToNotationCollectionShould()
-    {
-      fixture = new Fixture();
-      collection = new CoordsToNotationCollection();
-    }
-
-    [Fact]
-    public void TranslateCoordinatesToNotation()
-    {
-      // Arrange
-      collection[0, 0] = fixture.Create<Piece>();
-      collection[4, 4] = fixture.Create<Piece>();
-      collection[8, 8] = fixture.Create<Piece>();
-      collection[2, 2] = fixture.Create<Piece>();
-
-      // Assert
-      collection["A1"].Should().BeSameAs(collection[0, 0]);
-      collection["E5"].Should().BeSameAs(collection[4, 4]);
-      collection["I9"].Should().BeSameAs(collection[8, 8]);
-      collection["C3"].Should().BeSameAs(collection[2, 2]);
-    }
-
-    [Fact]
-    public void Yep()
-    {
-
-    }
-  }
-}

Gameboard.ShogiUI.xUnitTests/GameShould.cs

@@ -9,7 +9,7 @@ namespace Gameboard.ShogiUI.xUnitTests
     [Fact]
     public void DiscardNullPLayers()
     {
-      var game = new Game("Test", "P1", null);
+      var game = new Session("Test", "P1", null);
 
       game.Players.Count.Should().Be(1);
     }

Gameboard.ShogiUI.xUnitTests/ShogiShould.cs

@@ -1,621 +0,0 @@
-using FluentAssertions;
-using FluentAssertions.Execution;
-using Gameboard.ShogiUI.Sockets.Extensions;
-using Gameboard.ShogiUI.Sockets.Models;
-using System.Linq;
-using Xunit;
-using Xunit.Abstractions;
-using WhichPiece = Gameboard.ShogiUI.Sockets.ServiceModels.Types.WhichPiece;
-using WhichPerspective = Gameboard.ShogiUI.Sockets.ServiceModels.Types.WhichPerspective;
-using ShogiModel = Gameboard.ShogiUI.Sockets.Models.Shogi;
-
-namespace Gameboard.ShogiUI.xUnitTests
-{
-	public class ShogiShould
-	{
-		private readonly ITestOutputHelper output;
-		public ShogiShould(ITestOutputHelper output)
-		{
-			this.output = output;
-		}
-
-		[Fact]
-		public void InitializeBoardState()
-		{
-			// Act
-			var board = new ShogiModel().Board;
-
-			// Assert
-			board["A1"].WhichPiece.Should().Be(WhichPiece.Lance);
-			board["A1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["A1"].IsPromoted.Should().Be(false);
-			board["B1"].WhichPiece.Should().Be(WhichPiece.Knight);
-			board["B1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["B1"].IsPromoted.Should().Be(false);
-			board["C1"].WhichPiece.Should().Be(WhichPiece.SilverGeneral);
-			board["C1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["C1"].IsPromoted.Should().Be(false);
-			board["D1"].WhichPiece.Should().Be(WhichPiece.GoldGeneral);
-			board["D1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["D1"].IsPromoted.Should().Be(false);
-			board["E1"].WhichPiece.Should().Be(WhichPiece.King);
-			board["E1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["E1"].IsPromoted.Should().Be(false);
-			board["F1"].WhichPiece.Should().Be(WhichPiece.GoldGeneral);
-			board["F1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["F1"].IsPromoted.Should().Be(false);
-			board["G1"].WhichPiece.Should().Be(WhichPiece.SilverGeneral);
-			board["G1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["G1"].IsPromoted.Should().Be(false);
-			board["H1"].WhichPiece.Should().Be(WhichPiece.Knight);
-			board["H1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["H1"].IsPromoted.Should().Be(false);
-			board["I1"].WhichPiece.Should().Be(WhichPiece.Lance);
-			board["I1"].Owner.Should().Be(WhichPerspective.Player1);
-			board["I1"].IsPromoted.Should().Be(false);
-
-			board["A2"].Should().BeNull();
-			board["B2"].WhichPiece.Should().Be(WhichPiece.Bishop);
-			board["B2"].Owner.Should().Be(WhichPerspective.Player1);
-			board["B2"].IsPromoted.Should().Be(false);
-			board["C2"].Should().BeNull();
-			board["D2"].Should().BeNull();
-			board["E2"].Should().BeNull();
-			board["F2"].Should().BeNull();
-			board["G2"].Should().BeNull();
-			board["H2"].WhichPiece.Should().Be(WhichPiece.Rook);
-			board["H2"].Owner.Should().Be(WhichPerspective.Player1);
-			board["H2"].IsPromoted.Should().Be(false);
-			board["I2"].Should().BeNull();
-
-			board["A3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["A3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["A3"].IsPromoted.Should().Be(false);
-			board["B3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["B3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["B3"].IsPromoted.Should().Be(false);
-			board["C3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["C3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["C3"].IsPromoted.Should().Be(false);
-			board["D3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["D3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["D3"].IsPromoted.Should().Be(false);
-			board["E3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["E3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["E3"].IsPromoted.Should().Be(false);
-			board["F3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["F3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["F3"].IsPromoted.Should().Be(false);
-			board["G3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["G3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["G3"].IsPromoted.Should().Be(false);
-			board["H3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["H3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["H3"].IsPromoted.Should().Be(false);
-			board["I3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["I3"].Owner.Should().Be(WhichPerspective.Player1);
-			board["I3"].IsPromoted.Should().Be(false);
-
-			board["A4"].Should().BeNull();
-			board["B4"].Should().BeNull();
-			board["C4"].Should().BeNull();
-			board["D4"].Should().BeNull();
-			board["E4"].Should().BeNull();
-			board["F4"].Should().BeNull();
-			board["G4"].Should().BeNull();
-			board["H4"].Should().BeNull();
-			board["I4"].Should().BeNull();
-
-			board["A5"].Should().BeNull();
-			board["B5"].Should().BeNull();
-			board["C5"].Should().BeNull();
-			board["D5"].Should().BeNull();
-			board["E5"].Should().BeNull();
-			board["F5"].Should().BeNull();
-			board["G5"].Should().BeNull();
-			board["H5"].Should().BeNull();
-			board["I5"].Should().BeNull();
-
-			board["A6"].Should().BeNull();
-			board["B6"].Should().BeNull();
-			board["C6"].Should().BeNull();
-			board["D6"].Should().BeNull();
-			board["E6"].Should().BeNull();
-			board["F6"].Should().BeNull();
-			board["G6"].Should().BeNull();
-			board["H6"].Should().BeNull();
-			board["I6"].Should().BeNull();
-
-			board["A7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["A7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["A7"].IsPromoted.Should().Be(false);
-			board["B7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["B7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["B7"].IsPromoted.Should().Be(false);
-			board["C7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["C7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["C7"].IsPromoted.Should().Be(false);
-			board["D7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["D7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["D7"].IsPromoted.Should().Be(false);
-			board["E7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["E7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["E7"].IsPromoted.Should().Be(false);
-			board["F7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["F7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["F7"].IsPromoted.Should().Be(false);
-			board["G7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["G7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["G7"].IsPromoted.Should().Be(false);
-			board["H7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["H7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["H7"].IsPromoted.Should().Be(false);
-			board["I7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			board["I7"].Owner.Should().Be(WhichPerspective.Player2);
-			board["I7"].IsPromoted.Should().Be(false);
-
-			board["A8"].Should().BeNull();
-			board["B8"].WhichPiece.Should().Be(WhichPiece.Rook);
-			board["B8"].Owner.Should().Be(WhichPerspective.Player2);
-			board["B8"].IsPromoted.Should().Be(false);
-			board["C8"].Should().BeNull();
-			board["D8"].Should().BeNull();
-			board["E8"].Should().BeNull();
-			board["F8"].Should().BeNull();
-			board["G8"].Should().BeNull();
-			board["H8"].WhichPiece.Should().Be(WhichPiece.Bishop);
-			board["H8"].Owner.Should().Be(WhichPerspective.Player2);
-			board["H8"].IsPromoted.Should().Be(false);
-			board["I8"].Should().BeNull();
-
-			board["A9"].WhichPiece.Should().Be(WhichPiece.Lance);
-			board["A9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["A9"].IsPromoted.Should().Be(false);
-			board["B9"].WhichPiece.Should().Be(WhichPiece.Knight);
-			board["B9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["B9"].IsPromoted.Should().Be(false);
-			board["C9"].WhichPiece.Should().Be(WhichPiece.SilverGeneral);
-			board["C9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["C9"].IsPromoted.Should().Be(false);
-			board["D9"].WhichPiece.Should().Be(WhichPiece.GoldGeneral);
-			board["D9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["D9"].IsPromoted.Should().Be(false);
-			board["E9"].WhichPiece.Should().Be(WhichPiece.King);
-			board["E9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["E9"].IsPromoted.Should().Be(false);
-			board["F9"].WhichPiece.Should().Be(WhichPiece.GoldGeneral);
-			board["F9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["F9"].IsPromoted.Should().Be(false);
-			board["G9"].WhichPiece.Should().Be(WhichPiece.SilverGeneral);
-			board["G9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["G9"].IsPromoted.Should().Be(false);
-			board["H9"].WhichPiece.Should().Be(WhichPiece.Knight);
-			board["H9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["H9"].IsPromoted.Should().Be(false);
-			board["I9"].WhichPiece.Should().Be(WhichPiece.Lance);
-			board["I9"].Owner.Should().Be(WhichPerspective.Player2);
-			board["I9"].IsPromoted.Should().Be(false);
-		}
-
-		[Fact]
-		public void InitializeBoardStateWithMoves()
-		{
-			var moves = new[]
-			{
-          // P1 Pawn
-        new Move("A3", "A4")
-			};
-			var shogi = new ShogiModel(moves);
-			shogi.Board["A3"].Should().BeNull();
-			shogi.Board["A4"].WhichPiece.Should().Be(WhichPiece.Pawn);
-		}
-
-		[Fact]
-		public void AllowValidMoves_AfterCheck()
-		{
-			// Arrange
-			var moves = new[]
-			{
-          // P1 Pawn
-          new Move("C3", "C4"),
-          // P2 Pawn
-          new Move("G7", "G6"),
-          // P1 Bishop puts P2 in check
-          new Move("B2", "G7"),
-			};
-			var shogi = new ShogiModel(moves);
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-
-			// Act - P2 is able to un-check theirself.
-			/// P2 King moves out of check
-			var moveSuccess = shogi.Move(new Move("E9", "E8"));
-
-			// Assert
-			using var _ = new AssertionScope();
-			moveSuccess.Should().BeTrue();
-			shogi.InCheck.Should().BeNull();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_MoveFromEmptyPosition()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-			shogi.Board["D5"].Should().BeNull();
-
-			// Act
-			var moveSuccess = shogi.Move(new Move("D5", "D6"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.Board["D5"].Should().BeNull();
-			shogi.Board["D6"].Should().BeNull();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_MoveToCurrentPosition()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-
-			// Act - P1 "moves" pawn to the position it already exists at.
-			var moveSuccess = shogi.Move(new Move("A3", "A3"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.Board["A3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			shogi.Player1Hand.Should().BeEmpty();
-			shogi.Player2Hand.Should().BeEmpty();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_MoveSet()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-
-			// Act - Move Lance illegally
-			var moveSuccess = shogi.Move(new Move("A1", "D5"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.Board["A1"].WhichPiece.Should().Be(WhichPiece.Lance);
-			shogi.Board["A5"].Should().BeNull();
-			shogi.Player1Hand.Should().BeEmpty();
-			shogi.Player2Hand.Should().BeEmpty();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_Ownership()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-			shogi.WhoseTurn.Should().Be(WhichPerspective.Player1);
-			shogi.Board["A7"].Owner.Should().Be(WhichPerspective.Player2);
-
-			// Act - Move Player2 Pawn when it is Player1 turn.
-			var moveSuccess = shogi.Move(new Move("A7", "A6"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.Board["A7"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			shogi.Board["A6"].Should().BeNull();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_MoveThroughAllies()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-
-			// Act - Move P1 Lance through P1 Pawn.
-			var moveSuccess = shogi.Move(new Move("A1", "A5"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.Board["A1"].WhichPiece.Should().Be(WhichPiece.Lance);
-			shogi.Board["A3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			shogi.Board["A5"].Should().BeNull();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_CaptureAlly()
-		{
-			// Arrange
-			var shogi = new ShogiModel();
-
-			// Act - P1 Knight tries to capture P1 Pawn.
-			var moveSuccess = shogi.Move(new Move("B1", "C3"));
-
-			// Arrange
-			moveSuccess.Should().BeFalse();
-			shogi.Board["B1"].WhichPiece.Should().Be(WhichPiece.Knight);
-			shogi.Board["C3"].WhichPiece.Should().Be(WhichPiece.Pawn);
-			shogi.Player1Hand.Should().BeEmpty();
-			shogi.Player2Hand.Should().BeEmpty();
-		}
-
-		[Fact]
-		public void PreventInvalidMoves_Check()
-		{
-			// Arrange
-			var moves = new[]
-			{
-          // P1 Pawn
-          new Move("C3", "C4"),
-          // P2 Pawn
-          new Move("G7", "G6"),
-          // P1 Bishop puts P2 in check
-          new Move("B2", "G7")
-			};
-			var shogi = new ShogiModel(moves);
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-
-			// Act - P2 moves Lance while in check.
-			var moveSuccess = shogi.Move(new Move("I9", "I8"));
-
-			// Assert
-			moveSuccess.Should().BeFalse();
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-			shogi.Board["I9"].WhichPiece.Should().Be(WhichPiece.Lance);
-			shogi.Board["I8"].Should().BeNull();
-		}
-
-		[Fact]
-		public void PreventInvalidDrops_MoveSet()
-		{
-			// Arrange
-			var moves = new[]
-			{
-          // P1 Pawn
-          new Move("C3", "C4"),
-          // P2 Pawn
-          new Move("I7", "I6"),
-          // P1 Bishop takes P2 Pawn.
-          new Move("B2", "G7"),
-          // P2 Gold, block check from P1 Bishop.
-          new Move("F9", "F8"),
-          // P1 Bishop takes P2 Bishop, promotes so it can capture P2 Knight and P2 Lance
-          new Move("G7", "H8", true),
-          // P2 Pawn again
-          new Move("I6", "I5"),
-          // P1 Bishop takes P2 Knight
-          new Move("H8", "H9"),
-          // P2 Pawn again
-          new Move("I5", "I4"),
-          // P1 Bishop takes P2 Lance
-          new Move("H9", "I9"),
-          // P2 Pawn captures P1 Pawn
-          new Move("I4", "I3")
-				};
-			var shogi = new ShogiModel(moves);
-			shogi.Player1Hand.Count.Should().Be(4);
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Knight);
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Lance);
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Pawn);
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Bishop);
-			shogi.WhoseTurn.Should().Be(WhichPerspective.Player1);
-
-			// Act | Assert - Illegally placing Knight from the hand in farthest row.
-			shogi.Board["H9"].Should().BeNull();
-			var dropSuccess = shogi.Move(new Move(WhichPiece.Knight, "H9"));
-			dropSuccess.Should().BeFalse();
-			shogi.Board["H9"].Should().BeNull();
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Knight);
-
-			// Act | Assert - Illegally placing Knight from the hand in second farthest row.
-			shogi.Board["H8"].Should().BeNull();
-			dropSuccess = shogi.Move(new Move(WhichPiece.Knight, "H8"));
-			dropSuccess.Should().BeFalse();
-			shogi.Board["H8"].Should().BeNull();
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Knight);
-
-			// Act | Assert - Illegally place Lance from the hand.
-			shogi.Board["H9"].Should().BeNull();
-			dropSuccess = shogi.Move(new Move(WhichPiece.Knight, "H9"));
-			dropSuccess.Should().BeFalse();
-			shogi.Board["H9"].Should().BeNull();
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Lance);
-
-			// Act | Assert - Illegally place Pawn from the hand.
-			shogi.Board["H9"].Should().BeNull();
-			dropSuccess = shogi.Move(new Move(WhichPiece.Pawn, "H9"));
-			dropSuccess.Should().BeFalse();
-			shogi.Board["H9"].Should().BeNull();
-			shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Pawn);
-
-			// Act | Assert - Illegally place Pawn from the hand in a row which already has an unpromoted Pawn.
-			// TODO
-		}
-
-		[Fact]
-		public void PreventInvalidDrop_Check()
-		{
-			// Arrange
-			var moves = new[]
-			{
-          // P1 Pawn
-          new Move("C3", "C4"),
-          // P2 Pawn
-          new Move("G7", "G6"),
-          // P1 Pawn, arbitrary move.
-          new Move("A3", "A4"),
-          // P2 Bishop takes P1 Bishop
-          new Move("H8", "B2"),
-          // P1 Silver takes P2 Bishop
-          new Move("C1", "B2"),
-          // P2 Pawn, arbtrary move
-          new Move("A7", "A6"),
-          // P1 drop Bishop, place P2 in check
-          new Move(WhichPiece.Bishop, "G7")
-			};
-			var shogi = new ShogiModel(moves);
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-			shogi.Player2Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Bishop);
-			shogi.Board["E5"].Should().BeNull();
-
-			// Act - P2 places a Bishop while in check.
-			var dropSuccess = shogi.Move(new Move(WhichPiece.Bishop, "E5"));
-
-			// Assert
-			dropSuccess.Should().BeFalse();
-			shogi.Board["E5"].Should().BeNull();
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-			shogi.Player2Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Bishop);
-		}
-
-		[Fact]
-		public void PreventInvalidDrop_Capture()
-		{
-			// Arrange
-			var moves = new[]
-			{
-        // P1 Pawn
-        new Move("C3", "C4"),
-        // P2 Pawn
-        new Move("G7", "G6"),
-        // P1 Bishop capture P2 Bishop
-        new Move("B2", "H8"),
-        // P2 Pawn
-        new Move("G6", "G5")
-			};
-			var shogi = new ShogiModel(moves);
-			using (new AssertionScope())
-			{
-				shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Bishop);
-				shogi.Board["I9"].Should().NotBeNull();
-				shogi.Board["I9"].WhichPiece.Should().Be(WhichPiece.Lance);
-				shogi.Board["I9"].Owner.Should().Be(WhichPerspective.Player2);
-			}
-
-			// Act - P1 tries to place a piece where an opponent's piece resides.
-			var dropSuccess = shogi.Move(new Move(WhichPiece.Bishop, "I9"));
-
-			// Assert
-			using (new AssertionScope())
-			{
-				dropSuccess.Should().BeFalse();
-				shogi.Player1Hand.Should().ContainSingle(_ => _.WhichPiece == WhichPiece.Bishop);
-				shogi.Board["I9"].Should().NotBeNull();
-				shogi.Board["I9"].WhichPiece.Should().Be(WhichPiece.Lance);
-				shogi.Board["I9"].Owner.Should().Be(WhichPerspective.Player2);
-			}
-		}
-
-		[Fact]
-		public void Check()
-		{
-			// Arrange
-			var moves = new[]
-			{
-        // P1 Pawn
-        new Move("C3", "C4"),
-        // P2 Pawn
-        new Move("G7", "G6"),
-			};
-			var shogi = new ShogiModel(moves);
-
-			// Act - P1 Bishop, check
-			shogi.Move(new Move("B2", "G7"));
-
-			// Assert
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-		}
-
-		[Fact]
-		public void Promote()
-		{
-			// Arrange
-			var moves = new[]
-			{
-        // P1 Pawn
-        new Move("C3", "C4" ),
-        // P2 Pawn
-        new Move("G7", "G6" )
-			};
-			var shogi = new ShogiModel(moves);
-
-			// Act - P1 moves across promote threshold.
-			var moveSuccess = shogi.Move(new Move("B2", "G7", true));
-
-			// Assert
-			using (new AssertionScope())
-			{
-				moveSuccess.Should().BeTrue();
-				shogi.Board["B2"].Should().BeNull();
-				shogi.Board["G7"].Should().NotBeNull();
-				shogi.Board["G7"].WhichPiece.Should().Be(WhichPiece.Bishop);
-				shogi.Board["G7"].Owner.Should().Be(WhichPerspective.Player1);
-				shogi.Board["G7"].IsPromoted.Should().BeTrue();
-			}
-		}
-
-		[Fact]
-		public void CheckMate()
-		{
-			// Arrange
-			var moves = new[]
-			{
-          // P1 Rook
-          new Move("H2", "E2"),
-          // P2 Gold
-          new Move("F9", "G8"),
-          // P1 Pawn
-          new Move("E3", "E4"),
-          // P2 other Gold
-          new Move("D9", "C8"),
-          // P1 same Pawn
-          new Move("E4", "E5"),
-          // P2 Pawn
-          new Move("E7", "E6"),
-          // P1 Pawn takes P2 Pawn
-          new Move("E5", "E6"),
-          // P2 King
-          new Move("E9", "E8"),
-          // P1 Pawn promotes, threatens P2 King
-          new Move("E6", "E7", true),
-          // P2 King retreat
-          new Move("E8", "E9"),
-				};
-			var shogi = new ShogiModel(moves);
-			output.WriteLine(shogi.PrintStateAsAscii());
-
-			// Act - P1 Pawn wins by checkmate.
-			var moveSuccess = shogi.Move(new Move("E7", "E8"));
-			output.WriteLine(shogi.PrintStateAsAscii());
-
-			// Assert - checkmate
-			moveSuccess.Should().BeTrue();
-			shogi.IsCheckmate.Should().BeTrue();
-			shogi.InCheck.Should().Be(WhichPerspective.Player2);
-		}
-
-		[Fact]
-		public void Capture()
-		{
-			// Arrange
-			var moves = new[]
-			{
-					new Move("C3", "C4"),
-					new Move("G7", "G6")
-				};
-			var shogi = new ShogiModel(moves);
-
-			// Act - P1 Bishop captures P2 Bishop
-			var moveSuccess = shogi.Move(new Move("B2", "H8"));
-
-			// Assert
-			moveSuccess.Should().BeTrue();
-			shogi.Board["B2"].Should().BeNull();
-			shogi.Board["H8"].WhichPiece.Should().Be(WhichPiece.Bishop);
-			shogi.Board["H8"].Owner.Should().Be(WhichPerspective.Player1);
-			shogi.Board.Values
-				.Where(p => p != null)
-				.Should().ContainSingle(piece => piece.WhichPiece == WhichPiece.Bishop);
-
-			shogi.Player1Hand
-				.Should()
-				.ContainSingle(p => p.WhichPiece == WhichPiece.Bishop && p.Owner == WhichPerspective.Player1);
-		}
-	}
-}

Shogi.Domain.UnitTests/NotationShould.cs

@@ -0,0 +1,27 @@
+using FluentAssertions;
+using System.Numerics;
+using Xunit;
+
+namespace Shogi.Domain.UnitTests
+{
+	public class NotationShould
+	{
+		[Fact]
+		public void ConvertFromNotationToVector()
+		{
+			Notation.FromBoardNotation("A1").Should().Be(new Vector2(0, 0));
+			Notation.FromBoardNotation("E5").Should().Be(new Vector2(4, 4));
+			Notation.FromBoardNotation("I9").Should().Be(new Vector2(8, 8));
+			Notation.FromBoardNotation("C3").Should().Be(new Vector2(2, 2));
+		}
+
+		[Fact]
+		public void ConvertFromVectorToNotation()
+		{
+			Notation.ToBoardNotation(new Vector2(0, 0)).Should().Be("A1");
+			Notation.ToBoardNotation(new Vector2(4, 4)).Should().Be("E5");
+			Notation.ToBoardNotation(new Vector2(8, 8)).Should().Be("I9");
+			Notation.ToBoardNotation(new Vector2(2, 2)).Should().Be("C3");
+		}
+	}
+}

Shogi.Domain.UnitTests/ShogiBoardStateShould.cs

@@ -9,7 +9,7 @@ namespace Shogi.Domain.UnitTests
 		public void InitializeBoardState()
 		{
 			// Act
-			var board = new ShogiBoardState();
+			var board = new BoardState();
 
 			// Assert
 			board["A1"]?.WhichPiece.Should().Be(WhichPiece.Lance);

Shogi.Domain.UnitTests/ShogiShould.cs

@@ -18,8 +18,8 @@ namespace Shogi.Domain.UnitTests
 		public void MoveAPieceToAnEmptyPosition()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			board["A4"].Should().BeNull();
 			var expectedPiece = board["A3"];
 			expectedPiece.Should().NotBeNull();
@@ -36,8 +36,8 @@ namespace Shogi.Domain.UnitTests
 		public void AllowValidMoves_AfterCheck()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			// P1 Pawn
 			shogi.Move("C3", "C4", false);
 			// P2 Pawn
@@ -61,8 +61,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_MoveFromEmptyPosition()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			board["D5"].Should().BeNull();
 
 			// Act
@@ -80,8 +80,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_MoveToCurrentPosition()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			var expectedPiece = board["A3"];
 
 			// Act - P1 "moves" pawn to the position it already exists at.
@@ -101,8 +101,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_MoveSet()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			var expectedPiece = board["A1"];
 			expectedPiece!.WhichPiece.Should().Be(WhichPiece.Lance);
 
@@ -124,8 +124,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_Ownership()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			var expectedPiece = board["A7"];
 			expectedPiece!.Owner.Should().Be(WhichPlayer.Player2);
 			board.WhoseTurn.Should().Be(WhichPlayer.Player1);
@@ -146,8 +146,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_MoveThroughAllies()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			var lance = board["A1"];
 			var pawn = board["A3"];
 			lance!.Owner.Should().Be(pawn!.Owner);
@@ -169,8 +169,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_CaptureAlly()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			var knight = board["B1"];
 			var pawn = board["C3"];
 			knight!.Owner.Should().Be(pawn!.Owner);
@@ -193,8 +193,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidMoves_Check()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			// P1 Pawn
 			shogi.Move("C3", "C4", false);
 			// P2 Pawn
@@ -222,8 +222,8 @@ namespace Shogi.Domain.UnitTests
 		public void PreventInvalidDrops_MoveSet()
 		{
 			// Arrange
-			var board = new ShogiBoardState();
+			var board = new BoardState();
-			var shogi = new Shogi(board);
+			var shogi = new Session(board);
 			// P1 Pawn
 			shogi.Move("C3", "C4", false);
 			// P2 Pawn
@@ -361,8 +361,8 @@ namespace Shogi.Domain.UnitTests
 		public void Check()
 		{
 			// Arrange
-			var boardState = new ShogiBoardState();
+			var boardState = new BoardState();
-			var shogi = new Shogi(boardState);
+			var shogi = new Session(boardState);
 			// P1 Pawn
 			shogi.Move("C3", "C4", false);
 			// P2 Pawn
@@ -379,8 +379,8 @@ namespace Shogi.Domain.UnitTests
 		public void Promote()
 		{
 			// Arrange
-			var boardState = new ShogiBoardState();
+			var boardState = new BoardState();
-			var shogi = new Shogi(boardState);
+			var shogi = new Session(boardState);
 			// P1 Pawn
 			shogi.Move("C3", "C4", false);
 			// P2 Pawn
@@ -404,8 +404,8 @@ namespace Shogi.Domain.UnitTests
 		public void Capture()
 		{
 			// Arrange
-			var boardState = new ShogiBoardState();
+			var boardState = new BoardState();
-			var shogi = new Shogi(boardState);
+			var shogi = new Session(boardState);
 			var p1Bishop = boardState["B2"];
 			p1Bishop!.WhichPiece.Should().Be(WhichPiece.Bishop);
 			shogi.Move("C3", "C4", false);
@@ -428,8 +428,8 @@ namespace Shogi.Domain.UnitTests
 		public void CheckMate()
 		{
 			// Arrange
-			var boardState = new ShogiBoardState();
+			var boardState = new BoardState();
-			var shogi = new Shogi(boardState);
+			var shogi = new Session(boardState);
 			// P1 Rook
 			shogi.Move("H2", "E2", false);
 			// P2 Gold

Shogi.Domain/BoardState.cs

@@ -1,22 +1,26 @@
 using Shogi.Domain.Pieces;
-using System.Text.RegularExpressions;
 using BoardTile = System.Collections.Generic.KeyValuePair<System.Numerics.Vector2, Shogi.Domain.Pieces.Piece>;
 
 namespace Shogi.Domain
 {
-	// TODO: Avoid extending dictionary. Use composition instead.
+	public class BoardState
-	// Then validation can occur when assigning a piece to a position.
-	public class ShogiBoardState
 	{
-		private static readonly string BoardNotationRegex = @"(?<file>[A-I])(?<rank>[1-9])";
-		private static readonly char A = 'A';
 		public delegate void ForEachDelegate(Piece element, Vector2 position);
 		/// <summary>
 		/// Key is position notation, such as "E4".
 		/// </summary>
 		private readonly Dictionary<string, Piece?> board;
 
-		public ShogiBoardState()
+
+		public BoardState(Dictionary<string, Piece?> state)
+		{
+			board = state;
+			Player1Hand = new List<Piece>();
+			Player2Hand = new List<Piece>();
+			PreviousMoveTo = Vector2.Zero;
+		}
+
+		public BoardState()
 		{
 			board = new Dictionary<string, Piece?>(81, StringComparer.OrdinalIgnoreCase);
 			InitializeBoardState();
@@ -25,13 +29,14 @@ namespace Shogi.Domain
 			PreviousMoveTo = Vector2.Zero;
 		}
 
+		public Dictionary<string, Piece?> State => board;
 		public List<Piece> ActivePlayerHand => WhoseTurn == WhichPlayer.Player1 ? Player1Hand : Player2Hand;
-		public Vector2 Player1KingPosition => FromBoardNotation(this.board.Where(kvp => kvp.Value != null).Single(kvp =>
+		public Vector2 Player1KingPosition => Notation.FromBoardNotation(this.board.Where(kvp => kvp.Value != null).Single(kvp =>
 		{
 			var piece = kvp.Value;
 			return piece!.IsKing() && piece!.Owner == WhichPlayer.Player1;
 		}).Key);
-		public Vector2 Player2KingPosition => FromBoardNotation(this.board.Where(kvp => kvp.Value != null).Single(kvp =>
+		public Vector2 Player2KingPosition => Notation.FromBoardNotation(this.board.Where(kvp => kvp.Value != null).Single(kvp =>
 		{
 			var piece = kvp.Value;
 			return piece!.IsKing() && piece!.Owner == WhichPlayer.Player2;
@@ -47,12 +52,12 @@ namespace Shogi.Domain
 		/// <summary>
 		/// Copy constructor.
 		/// </summary>
-		public ShogiBoardState(ShogiBoardState other) : this()
+		public BoardState(BoardState other) : this()
 		{
 			foreach (var kvp in other.board)
 			{
 				// Replace copy constructor with static factory method in Piece.cs
-				board[kvp.Key] = kvp.Value == null ? null : Piece.Create(kvp.Value);
+				board[kvp.Key] = kvp.Value == null ? null : Piece.CreateCopy(kvp.Value);
 			}
 			WhoseTurn = other.WhoseTurn;
 			InCheck = other.InCheck;
@@ -71,14 +76,14 @@ namespace Shogi.Domain
 
 		public Piece? this[Vector2 vector]
 		{
-			get => this[ToBoardNotation(vector)];
+			get => this[Notation.ToBoardNotation(vector)];
-			set => this[ToBoardNotation(vector)] = value;
+			set => this[Notation.ToBoardNotation(vector)] = value;
 		}
 
 		public Piece? this[int x, int y]
 		{
-			get => this[ToBoardNotation(x, y)];
+			get => this[Notation.ToBoardNotation(x, y)];
-			set => this[ToBoardNotation(x, y)] = value;
+			set => this[Notation.ToBoardNotation(x, y)] = value;
 		}
 
 		internal void RememberAsMostRecentMove(Vector2 from, Vector2 to)
@@ -111,7 +116,7 @@ namespace Shogi.Domain
 
 		internal List<BoardTile> GetTilesOccupiedBy(WhichPlayer whichPlayer) => board
 			.Where(kvp => kvp.Value?.Owner == whichPlayer)
-			.Select(kvp => new BoardTile(FromBoardNotation(kvp.Key), kvp.Value!))
+			.Select(kvp => new BoardTile(Notation.FromBoardNotation(kvp.Key), kvp.Value!))
 			.ToList();
 
 		internal void Capture(Vector2 to)
@@ -144,27 +149,6 @@ namespace Shogi.Domain
 			}
 			return null;
 		}
-		public static string ToBoardNotation(Vector2 vector)
-		{
-			return ToBoardNotation((int)vector.X, (int)vector.Y);
-		}
-		private static string ToBoardNotation(int x, int y)
-		{
-			var file = (char)(x + A);
-			var rank = y + 1;
-			return $"{file}{rank}";
-		}
-		public static Vector2 FromBoardNotation(string notation)
-		{
-			if (Regex.IsMatch(notation, BoardNotationRegex))
-			{
-				var match = Regex.Match(notation, BoardNotationRegex, RegexOptions.IgnoreCase);
-				char file = match.Groups["file"].Value[0];
-				int rank = int.Parse(match.Groups["rank"].Value);
-				return new Vector2(file - A, rank - 1);
-			}
-			throw new ArgumentException($"Board notation not recognized. Notation given: {notation}");
-		}
 
 		private void InitializeBoardState()
 		{

Shogi.Domain/Notation.cs

@@ -0,0 +1,33 @@
+using System.Text.RegularExpressions;
+
+namespace Shogi.Domain
+{
+	public static class Notation
+	{
+		private static readonly string BoardNotationRegex = @"(?<file>[A-I])(?<rank>[1-9])";
+		private static readonly char A = 'A';
+
+		public static string ToBoardNotation(Vector2 vector)
+		{
+			return ToBoardNotation((int)vector.X, (int)vector.Y);
+		}
+
+		public static string ToBoardNotation(int x, int y)
+		{
+			var file = (char)(x + A);
+			var rank = y + 1;
+			return $"{file}{rank}";
+		}
+		public static Vector2 FromBoardNotation(string notation)
+		{
+			if (Regex.IsMatch(notation, BoardNotationRegex))
+			{
+				var match = Regex.Match(notation, BoardNotationRegex, RegexOptions.IgnoreCase);
+				char file = match.Groups["file"].Value[0];
+				int rank = int.Parse(match.Groups["rank"].Value);
+				return new Vector2(file - A, rank - 1);
+			}
+			throw new ArgumentException($"Board notation not recognized. Notation given: {notation}");
+		}
+	}
+}

Shogi.Domain/Pieces/Piece.cs

@@ -9,7 +9,7 @@ namespace Shogi.Domain.Pieces
 		/// <summary>
 		/// Creates a clone of an existing piece.
 		/// </summary>
-		public static Piece Create(Piece piece) => Create(piece.WhichPiece, piece.Owner, piece.IsPromoted);
+		public static Piece CreateCopy(Piece piece) => Create(piece.WhichPiece, piece.Owner, piece.IsPromoted);
 		public static Piece Create(WhichPiece piece, WhichPlayer owner, bool isPromoted = false)
 		{
 			return piece switch
@@ -25,8 +25,6 @@ namespace Shogi.Domain.Pieces
 				_ => throw new ArgumentException($"Unknown {nameof(WhichPiece)} when cloning a {nameof(Piece)}.")
 			};
 		}
-
-		// TODO: MoveSet doesn't account for Player2's pieces which are upside-down.
 		public abstract IEnumerable<Path> MoveSet { get; }
 		public WhichPiece WhichPiece { get; }
 		public WhichPlayer Owner { get; private set; }

Shogi.Domain/Session.cs

@@ -8,21 +8,38 @@ namespace Shogi.Domain
 	/// The board is always from Player1's perspective.
 	/// [0,0] is the lower-left position, [8,8] is the higher-right position
 	/// </summary>
-	public sealed class Shogi
+	public sealed class Session
 	{
-		private readonly ShogiBoardState boardState;
+		private readonly Tuple<string, string> Players;
+		private readonly BoardState boardState;
 		private readonly StandardRules rules;
+		private readonly SessionMetadata metadata;
 
-		public Shogi() : this(new ShogiBoardState())
+		public Session() : this(new BoardState())
 		{
 		}
 
-		public Shogi(ShogiBoardState board)
+		public Session(BoardState state) : this(state, new SessionMetadata(string.Empty, false, string.Empty, string.Empty))
 		{
-			this.rules = new StandardRules(board);
-			this.boardState = board;
 		}
 
+		public Session(BoardState state, SessionMetadata metadata)
+		{
+			rules = new StandardRules(state);
+			boardState = state;
+			this.metadata = metadata;
+			Players = new(string.Empty, string.Empty);
+		}
+
+		public string Name => metadata.Name;
+		public string Player1Name => metadata.Player1;
+		public string? Player2Name => metadata.Player2;
+		public IDictionary<string, Piece?> BoardState => boardState.State;
+		public IList<Piece> Player1Hand => boardState.Player1Hand;
+		public IList<Piece> Player2Hand => boardState.Player2Hand;
+		public WhichPlayer? InCheck => boardState.InCheck;
+		public bool IsCheckMate => boardState.IsCheckmate;
+
 		/// <summary>
 		/// Move a piece from a board position to another board position, potentially capturing an opponents piece. Respects all rules of the game.
 		/// </summary>
@@ -33,7 +50,7 @@ namespace Shogi.Domain
 		/// <exception cref="InvalidOperationException"></exception>
 		public void Move(string from, string to, bool isPromotion)
 		{
-			var simulationState = new ShogiBoardState(boardState);
+			var simulationState = new BoardState(boardState);
 			var simulation = new StandardRules(simulationState);
 			var moveResult = simulation.Move(from, to, isPromotion);
 			if (!moveResult.Success)
@@ -83,7 +100,7 @@ namespace Shogi.Domain
 				throw new InvalidOperationException("Illegal placement of piece from the hand. Destination is not empty.");
 			}
 
-			var toVector = ShogiBoardState.FromBoardNotation(to);
+			var toVector = Notation.FromBoardNotation(to);
 			switch (pieceInHand)
 			{
 				case WhichPiece.Knight:
@@ -109,7 +126,7 @@ namespace Shogi.Domain
 					}
 			}
 
-			var tempBoard = new ShogiBoardState(boardState);
+			var tempBoard = new BoardState(boardState);
 			var simulation = new StandardRules(tempBoard);
 			var moveResult = simulation.Move(pieceInHand, to);
 			if (!moveResult.Success)

Shogi.Domain/SessionMetadata.cs

@@ -0,0 +1,26 @@
+namespace Shogi.Domain
+{
+	/// <summary>
+	/// A representation of a Session without the board and game-rules.
+	/// </summary>
+	public class SessionMetadata
+	{
+		public string Name { get; }
+		public string Player1 { get; }
+		public string? Player2 { get; private set; }
+		public bool IsPrivate { get; }
+
+		public SessionMetadata(string name, bool isPrivate, string player1, string? player2 = null)
+		{
+			Name = name;
+			IsPrivate = isPrivate;
+			Player1 = player1;
+			Player2 = player2;
+		}
+
+		public void SetPlayer2(string user)
+		{
+			Player2 = user;
+		}
+	}
+}

Shogi.Domain/StandardRules.cs

@@ -6,9 +6,9 @@ namespace Shogi.Domain
 {
 	internal class StandardRules
 	{
-		private readonly ShogiBoardState boardState;
+		private readonly BoardState boardState;
 
-		internal StandardRules(ShogiBoardState board)
+		internal StandardRules(BoardState board)
 		{
 			boardState = board;
 		}
@@ -22,8 +22,8 @@ namespace Shogi.Domain
 		/// <returns>A <see cref="MoveResult" /> describing the success or failure of the move.</returns>
 		internal MoveResult Move(string fromNotation, string toNotation, bool isPromotionRequested = false)
 		{
-			var from = ShogiBoardState.FromBoardNotation(fromNotation);
+			var from = Notation.FromBoardNotation(fromNotation);
-			var to = ShogiBoardState.FromBoardNotation(toNotation);
+			var to = Notation.FromBoardNotation(toNotation);
 			var fromPiece = boardState[from];
 			if (fromPiece == null)
 			{
@@ -69,7 +69,7 @@ namespace Shogi.Domain
 		/// <returns>A <see cref="MoveResult" /> describing the success or failure of the simulation.</returns>
 		internal MoveResult Move(WhichPiece pieceInHand, string toNotation)
 		{
-			var to = ShogiBoardState.FromBoardNotation(toNotation);
+			var to = Notation.FromBoardNotation(toNotation);
 			var index = boardState.ActivePlayerHand.FindIndex(p => p.WhichPiece == pieceInHand);
 			if (index == -1)
 			{
@@ -130,7 +130,7 @@ namespace Shogi.Domain
 			// Get line equation from king through the now-unoccupied location.
 			var direction = Vector2.Subtract(kingPosition, boardState.PreviousMoveFrom);
 			var slope = Math.Abs(direction.Y / direction.X);
-			var path = ShogiBoardState.GetPathAlongDirectionFromStartToEdgeOfBoard(boardState.PreviousMoveFrom, Vector2.Normalize(direction));
+			var path = BoardState.GetPathAlongDirectionFromStartToEdgeOfBoard(boardState.PreviousMoveFrom, Vector2.Normalize(direction));
 			var threat = boardState.QueryFirstPieceInPath(path);
 			if (threat == null || threat.Owner == previousMovedPiece.Owner) return false;
 			// If absolute slope is 45°, look for a bishop along the line.
@@ -253,7 +253,7 @@ namespace Shogi.Domain
 			var path = tile.Value.GetPathFromStartToEnd(tile.Key, lineOfSightTarget);
 			return path
 				.SkipLast(1)
-				.All(position => boardState[ShogiBoardState.ToBoardNotation(position)] == null);
+				.All(position => boardState[Notation.ToBoardNotation(position)] == null);
 		}
 	}
 }