checkpoint

Shogi.Api/Application/ShogiApplication.cs

@@ -92,6 +92,7 @@ public class ShogiApplication(
 		if (moveResult.IsSuccess)
 		{
 			await sessionRepository.CreateMove(sessionId, command);
+			await sessionRepository.CreateState(session);
 			await gameHubContext.Emit_PieceMoved(sessionId);
 			return new NoContentResult();
 		}
@@ -128,4 +129,38 @@ public class ShogiApplication(
 
 		return userManager.Users.FirstOrDefault(u => u.Id == userId)?.UserName!;
 	}
+
+	public async Task<IActionResult> ReadSessionSnapshots(string sessionId)
+	{
+		var session = this.ReadSession(sessionId);
+		if (session == null)
+		{
+			return new NotFoundResult();
+		}
+
+		var snapshots = await queryRepository.ReadSessionSnapshots(sessionId);
+
+		var boardStates = snapshots.Select(snap => new Contracts.Types.BoardState
+		{
+			Board = snap.Board.ToDictionary(
+				kvp => kvp.Key,
+				kvp => kvp.Value == null
+					? null
+					: new Contracts.Types.Piece
+					{
+						IsPromoted = kvp.Value.IsPromoted,
+						Owner = (Contracts.Types.WhichPlayer)kvp.Value.Owner,
+						WhichPiece = (Contracts.Types.WhichPiece)kvp.Value.WhichPiece,
+					}),
+			Player1Hand = snap.Player1Hand.Cast<Contracts.Types.WhichPiece>().ToArray(),
+			Player2Hand = snap.Player2Hand.Cast<Contracts.Types.WhichPiece>().ToArray(),
+			PlayerInCheck = snap.PlayerInCheck == null ? null : (Contracts.Types.WhichPlayer)snap.PlayerInCheck,
+			Victor = snap.IsGameOver
+				? snap.PlayerInCheck == Repositories.Dto.SessionState.WhichPlayer.Player1 ? Contracts.Types.WhichPlayer.Player2 : Contracts.Types.WhichPlayer.Player1
+				: null,
+			WhoseTurn = (Contracts.Types.WhichPlayer)snap.WhoseTurn,
+		});
+
+		return new OkObjectResult(boardStates.ToArray());
+	}
 }

Shogi.Api/Controllers/SessionsController.cs

@@ -65,8 +65,8 @@ public class SessionsController(
 			BoardState = new BoardState
 			{
 				Board = session.Board.BoardState.State.ToContract(),
-				Player1Hand = session.Board.BoardState.Player1Hand.ToContract(),
-				Player2Hand = session.Board.BoardState.Player2Hand.ToContract(),
+				Player1Hand = session.Board.BoardState.Player1Hand.Select(p => p.WhichPiece.ToContract()).ToArray(),
+				Player2Hand = session.Board.BoardState.Player2Hand.Select(p => p.WhichPiece.ToContract()).ToArray(),
 				PlayerInCheck = session.Board.BoardState.InCheck?.ToContract(),
 				WhoseTurn = session.Board.BoardState.WhoseTurn.ToContract(),
 				Victor = session.Board.BoardState.IsCheckmate
@@ -118,4 +118,14 @@ public class SessionsController(
 
 		return await application.MovePiece(id, sessionId, command);
 	}
+
+	/// <summary>
+	/// Returns an array of board states, one per player move of the given session, in the same order that player moves occurred.
+	/// </summary>
+	[HttpGet("{sessionId}/History")]
+	[AllowAnonymous]
+	public async Task<IActionResult> GetHistory([FromRoute] string sessionId)
+	{
+		return await application.ReadSessionSnapshots(sessionId);
+	}
 }

Shogi.Api/Extensions/ContractsExtensions.cs

@@ -38,14 +38,6 @@ public static class ContractsExtensions
 		WhichPiece = piece.WhichPiece.ToContract()
 	};
 
-	public static IReadOnlyList<Piece> ToContract(this List<Domain.ValueObjects.Piece> pieces)
-	{
-		return pieces
-			.Select(ToContract)
-			.ToList()
-			.AsReadOnly();
-	}
-
 	public static Dictionary<string, Piece?> ToContract(this ReadOnlyDictionary<string, Domain.ValueObjects.Piece?> boardState) =>
 		boardState.ToDictionary(kvp => kvp.Key, kvp => kvp.Value?.ToContract());
 

Shogi.Api/Repositories/Dto/SessionState/Piece.cs

@@ -0,0 +1,34 @@
+namespace Shogi.Api.Repositories.Dto.SessionState;
+
+public class Piece
+{
+	public bool IsPromoted { get; set; }
+	public WhichPiece WhichPiece { get; set; }
+	public WhichPlayer Owner { get; set; }
+
+	public Piece() { }
+
+	public Piece(Domain.ValueObjects.Piece piece)
+	{
+		IsPromoted = piece.IsPromoted;
+		WhichPiece = piece.WhichPiece switch
+		{
+			Domain.ValueObjects.WhichPiece.Bishop => WhichPiece.Bishop,
+			Domain.ValueObjects.WhichPiece.GoldGeneral => WhichPiece.GoldGeneral,
+			Domain.ValueObjects.WhichPiece.King => WhichPiece.King,
+			Domain.ValueObjects.WhichPiece.SilverGeneral => WhichPiece.SilverGeneral,
+			Domain.ValueObjects.WhichPiece.Rook => WhichPiece.Rook,
+			Domain.ValueObjects.WhichPiece.Knight => WhichPiece.Knight,
+			Domain.ValueObjects.WhichPiece.Lance => WhichPiece.Lance,
+			Domain.ValueObjects.WhichPiece.Pawn => WhichPiece.Pawn,
+			_ => throw new NotImplementedException()
+		};
+
+		Owner = piece.Owner switch
+		{
+			Domain.ValueObjects.WhichPlayer.Player1 => WhichPlayer.Player1,
+			Domain.ValueObjects.WhichPlayer.Player2 => WhichPlayer.Player2,
+			_ => throw new NotImplementedException()
+		};
+	}
+}

Shogi.Api/Repositories/Dto/SessionState/SessionStateDocument.cs

@@ -0,0 +1,69 @@
+namespace Shogi.Api.Repositories.Dto.SessionState;
+
+public class SessionStateDocument
+{
+	public long Id { get; set; }
+
+	public Dictionary<string, Piece?> Board { get; set; }
+
+	public WhichPiece[] Player1Hand { get; set; }
+
+	public WhichPiece[] Player2Hand { get; set; }
+
+	public WhichPlayer? PlayerInCheck { get; set; }
+
+	public WhichPlayer WhoseTurn { get; set; }
+
+	public bool IsGameOver { get; set; }
+
+	public string DocumentVersion { get; set; } = "1";
+
+	public SessionStateDocument() { }
+	public SessionStateDocument(Domain.ValueObjects.BoardState boardState)
+	{
+		this.Board = boardState.State.ToDictionary(
+			kvp => kvp.Key,
+			kvp => kvp.Value == null ? null : new Piece(kvp.Value));
+
+		this.Player1Hand = boardState.Player1Hand
+			.Select(piece => Map(piece.WhichPiece))
+			.ToArray();
+
+		this.Player2Hand = boardState.Player2Hand
+			.Select(piece => Map(piece.WhichPiece))
+			.ToArray();
+
+		this.PlayerInCheck = boardState.InCheck.HasValue
+			? Map(boardState.InCheck.Value)
+			: null;
+
+		this.IsGameOver = boardState.IsCheckmate;
+	}
+
+
+	static WhichPiece Map(Domain.ValueObjects.WhichPiece whichPiece)
+	{
+		return whichPiece switch
+		{
+			Domain.ValueObjects.WhichPiece.Bishop => WhichPiece.Bishop,
+			Domain.ValueObjects.WhichPiece.GoldGeneral => WhichPiece.GoldGeneral,
+			Domain.ValueObjects.WhichPiece.King => WhichPiece.King,
+			Domain.ValueObjects.WhichPiece.SilverGeneral => WhichPiece.SilverGeneral,
+			Domain.ValueObjects.WhichPiece.Rook => WhichPiece.Rook,
+			Domain.ValueObjects.WhichPiece.Knight => WhichPiece.Knight,
+			Domain.ValueObjects.WhichPiece.Lance => WhichPiece.Lance,
+			Domain.ValueObjects.WhichPiece.Pawn => WhichPiece.Pawn,
+			_ => throw new NotImplementedException()
+		};
+	}
+
+	static WhichPlayer Map(Domain.ValueObjects.WhichPlayer whichPlayer)
+	{
+		return whichPlayer switch
+		{
+			Domain.ValueObjects.WhichPlayer.Player1 => WhichPlayer.Player1,
+			Domain.ValueObjects.WhichPlayer.Player2 => WhichPlayer.Player2,
+			_ => throw new NotImplementedException()
+		};
+	}
+}

Shogi.Api/Repositories/Dto/SessionState/WhichPiece.cs

@@ -0,0 +1,13 @@
+namespace Shogi.Api.Repositories.Dto.SessionState;
+
+public enum WhichPiece
+{
+	King,
+	GoldGeneral,
+	SilverGeneral,
+	Bishop,
+	Rook,
+	Knight,
+	Lance,
+	Pawn
+}

Shogi.Api/Repositories/Dto/SessionState/WhichPlayer.cs

@@ -0,0 +1,7 @@
+namespace Shogi.Api.Repositories.Dto.SessionState;
+
+public enum WhichPlayer
+{
+	Player1,
+	Player2
+}

Shogi.Api/Repositories/QueryRepository.cs

@@ -1,7 +1,9 @@
 using Dapper;
 using Shogi.Api.Repositories.Dto;
+using Shogi.Api.Repositories.Dto.SessionState;
 using System.Data;
 using System.Data.SqlClient;
+using System.Text.Json;
 
 namespace Shogi.Api.Repositories;
 
@@ -21,4 +23,27 @@ public class QueryRepository(IConfiguration configuration)
 
 		return await results.ReadAsync<SessionDto>();
 	}
+
+	public async Task<List<SessionStateDocument>> ReadSessionSnapshots(string sessionId)
+	{
+		using var connection = new SqlConnection(this.connectionString);
+		var command = connection.CreateCommand();
+		command.CommandText = "session.ReadStatesBySession";
+		command.CommandType = CommandType.StoredProcedure;
+		command.Parameters.AddWithValue("SessionId", sessionId);
+
+		await using var reader = await command.ExecuteReaderAsync();
+		var documents = new List<SessionStateDocument>(20);
+		while (await reader.ReadAsync())
+		{
+			var json = reader.GetString("Document");
+			var document = JsonSerializer.Deserialize<SessionStateDocument>(json);
+			if (document != null)
+			{
+				documents.Add(document);
+			}
+		}
+
+		return documents;
+	}
 }

Shogi.Api/Repositories/SessionRepository.cs

@@ -1,9 +1,11 @@
 using Dapper;
 using Shogi.Api.Repositories.Dto;
+using Shogi.Api.Repositories.Dto.SessionState;
 using Shogi.Contracts.Api.Commands;
 using Shogi.Domain.Aggregates;
 using System.Data;
 using System.Data.SqlClient;
+using System.Text.Json;
 
 namespace Shogi.Api.Repositories;
 
@@ -81,4 +83,19 @@ public class SessionRepository(IConfiguration configuration)
 				},
 				commandType: CommandType.StoredProcedure);
 	}
+
+	public async Task CreateState(Session session)
+	{
+		var document = new SessionStateDocument(session.Board.BoardState);
+
+		using var connection = new SqlConnection(this.connectionString);
+		await connection.ExecuteAsync(
+			"session.CreateState",
+			new
+			{
+				SessionId = session.Id.ToString(),
+				Document = JsonSerializer.Serialize(document)
+			},
+			commandType: CommandType.StoredProcedure);
+	}
 }

Shogi.Contracts/Types/BoardState.cs

@@ -1,13 +1,12 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 
 namespace Shogi.Contracts.Types;
 
 public class BoardState
 {
-	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 Dictionary<string, Piece?> Board { get; set; } = [];
+	public IReadOnlyCollection<WhichPiece> Player1Hand { get; set; } = [];
+	public IReadOnlyCollection<WhichPiece> Player2Hand { get; set; } = [];
 	public WhichPlayer? PlayerInCheck { get; set; }
 	public WhichPlayer WhoseTurn { get; set; }
 	public WhichPlayer? Victor { get; set; }

Shogi.Contracts/Types/Piece.cs

@@ -1,9 +1,8 @@
-namespace Shogi.Contracts.Types
-{
+namespace Shogi.Contracts.Types;
+
   public class Piece
   {
     public bool IsPromoted { get; set; }
     public WhichPiece WhichPiece { get; set; }
     public WhichPlayer Owner { get; set; }
   }
-}

Shogi.Database/Session/Stored Procedures/CreateState.sql

@@ -0,0 +1,6 @@
+CREATE PROCEDURE [session].[CreateState]
+	@SessionId [session].[SessionSurrogateKey],
+	@Document NVARCHAR(MAX)
+AS
+
+INSERT INTO [session].[State] (SessionId, Document) VALUES (@SessionId, @Document);

Shogi.Database/Session/Stored Procedures/ReadStatesBySession.sql

@@ -0,0 +1,8 @@
+CREATE PROCEDURE [session].[ReadStatesBySession]
+	@SessionId [session].[SessionSurrogateKey]
+AS
+
+SELECT Id, SessionId, Document
+FROM [session].[State]
+WHERE Id = @SessionId
+ORDER BY Id ASC;

Shogi.Database/Session/Tables/State.sql

@@ -0,0 +1,9 @@
+CREATE TABLE [session].[State]
+(
+	[Id] BIGINT NOT NULL PRIMARY KEY IDENTITY, 
+  [SessionId] [session].[SessionSurrogateKey] NOT NULL, 
+  [Document] NVARCHAR(MAX) NOT NULL,
+    
+  CONSTRAINT [FK_State_ToSession] FOREIGN KEY (SessionId) REFERENCES [session].[Session](Id),
+  CONSTRAINT [StateDocument must be JSON] CHECK(ISJSON(Document)=1)
+)

Shogi.Database/Session/Types/SessionSurrogateKey.sql

@@ -1,2 +1,3 @@
-CREATE TYPE [session].[SessionSurrogateKey]
+-- C# Guid
+CREATE TYPE [session].[SessionSurrogateKey]
 	FROM CHAR(36) NOT NULL

Shogi.Database/Shogi.Database.sqlproj

@@ -79,6 +79,9 @@
     <Build Include="Session\Stored Procedures\ReadSessionsMetadata.sql" />
     <Build Include="AspNetUsersId.sql" />
     <Build Include="Session\Functions\MaxNewSessionsPerUser.sql" />
+    <Build Include="Session\Tables\State.sql" />
+    <Build Include="Session\Stored Procedures\CreateState.sql" />
+    <Build Include="Session\Stored Procedures\ReadStatesBySession.sql" />
   </ItemGroup>
   <ItemGroup>
     <PostDeploy Include="Post Deployment\Script.PostDeployment.sql" />

Shogi.Domain/ValueObjects/WhichPlayer.cs

@@ -1,8 +1,7 @@
-namespace Shogi.Domain.ValueObjects
-{
+namespace Shogi.Domain.ValueObjects;
+
 public enum WhichPlayer
 {
 	Player1,
 	Player2
 }
-}

Shogi.UI/Pages/Play/GameBoard/GameBoardPresentation.razor

@@ -2,6 +2,16 @@
 @using System.Text.Json;
 
 <article class="game-board">
+	<!-- Controls -->
+	<header class="controls">
+		<form @onsubmit:preventDefault>
+			<fieldset class="history" disabled=@Yep>
+				<legend>Replay</legend>
+				<button disabled=@Yep>&lt;</button>
+				<button>&gt;</button>
+			</fieldset>
+		</form>
+	</header>
 	<!-- Game board -->
 	<section class="board" data-perspective="@Perspective">
 		@for (var rank = 1; rank < 10; rank++)
@@ -17,7 +27,7 @@
 						 style="grid-area: @position">
 					@if (piece != null)
 					{
-						<GamePiece Piece="piece" Perspective="Perspective" />
+						<GamePiece Piece="piece.WhichPiece" RenderUpsideDown="@(piece.Owner != Perspective)" IsPromoted="piece.IsPromoted" />
 					}
 				</div>
 			}
@@ -57,7 +67,7 @@
 						@foreach (var piece in opponentHand)
 						{
 							<div class="tile">
-								<GamePiece Piece="piece" Perspective="Perspective" />
+								<GamePiece Piece="piece" RenderUpsideDown="true" />
 							</div>
 						}
 					}
@@ -86,12 +96,12 @@
 					<div class="hand">
 						@if (userHand.Any())
 						{
-							@foreach (var piece in userHand)
+							@foreach (var whichPiece in userHand)
 							{
-								<div @onclick="OnClickHandInternal(piece)"
+								<div @onclick="OnClickHandInternal(whichPiece)"
 										 class="tile"
-										 data-selected="@(piece.WhichPiece == SelectedPieceFromHand)">
-									<GamePiece Piece="piece" Perspective="Perspective" />
+										 data-selected="@(whichPiece == SelectedPieceFromHand)">
+									<GamePiece Piece="whichPiece" RenderUpsideDown="false" />
 								</div>
 							}
 						}
@@ -104,6 +114,7 @@
 </article>
 
 @code {
+
 	static readonly string[] Files = new[] { "A", "B", "C", "D", "E", "F", "G", "H", "I" };
 
 	/// <summary>
@@ -116,21 +127,26 @@
 	[Parameter] public WhichPiece? SelectedPieceFromHand { get; set; }
 	// TODO: Exchange these OnClick actions for events like "SelectionChangedEvent" and "MoveFromBoardEvent" and "MoveFromHandEvent".
 	[Parameter] public EventCallback<string> OnClickTile { get; set; }
-	[Parameter] public EventCallback<Piece> OnClickHand { get; set; }
+	[Parameter] public EventCallback<WhichPiece> OnClickHand { get; set; }
 	[Parameter] public EventCallback OnClickJoinGame { get; set; }
 	[Parameter] public bool UseSideboard { get; set; } = true;
+	[Parameter] public IList<BoardState> History { get; set; }
 
-	private IReadOnlyCollection<Piece> opponentHand;
-	private IReadOnlyCollection<Piece> userHand;
+	private bool Yep => History.Count == 0;
+
+	private IReadOnlyCollection<WhichPiece> opponentHand;
+	private IReadOnlyCollection<WhichPiece> userHand;
 	private string? userName;
 	private string? opponentName;
+	private int historyIndex;
 
 	public GameBoardPresentation()
 	{
-		opponentHand = Array.Empty<Piece>();
-		userHand = Array.Empty<Piece>();
+		opponentHand = [];
+		userHand = [];
 		userName = string.Empty;
 		opponentName = string.Empty;
+		History = [];
 	}
 
 	protected override void OnParametersSet()
@@ -138,8 +154,8 @@
 		base.OnParametersSet();
 		if (Session == null)
 		{
-			opponentHand = Array.Empty<Piece>();
-			userHand = Array.Empty<Piece>();
+			opponentHand = [];
+			userHand = [];
 			userName = string.Empty;
 			opponentName = string.Empty;
 		}
@@ -158,17 +174,16 @@
 					? this.Session.Player2 ?? "Empty Seat"
 					: this.Session.Player1;
 		}
+
+
+
+		Console.WriteLine("Count: {0}", History.Count);
 	}
 
 	private bool IsMyTurn => Session?.BoardState.WhoseTurn == Perspective;
-
 	private bool IsPlayerInCheck => Session?.BoardState.PlayerInCheck == Perspective;
-
 	private bool IsOpponentInCheck => Session?.BoardState.PlayerInCheck != null && Session.BoardState.PlayerInCheck != Perspective;
-
 	private bool IsPlayerVictor => Session?.BoardState.Victor == Perspective;
-
-
 	private bool IsOpponentVictor => Session?.BoardState.Victor != null && Session.BoardState.Victor != Perspective;
 
 	private Func<Task> OnClickTileInternal(string position) => () =>
@@ -180,7 +195,7 @@
 		return Task.CompletedTask;
 	};
 
-	private Func<Task> OnClickHandInternal(Piece piece) => () =>
+	private Func<Task> OnClickHandInternal(WhichPiece piece) => () =>
 	{
 		if (IsMyTurn)
 		{

Shogi.UI/Pages/Play/GameBoard/GameboardPresentation.razor.css

@@ -2,7 +2,7 @@
 	--ratio: 0.9;
 	display: grid;
 	grid-template-columns: min-content repeat(9, minmax(2rem, 4rem)) max-content;
-	grid-template-rows: repeat(9, 1fr) auto;
+	grid-template-rows: auto repeat(9, 1fr) auto;
 	background-color: #444;
 	gap: 3px;
 	place-self: center;
@@ -98,6 +98,15 @@
 		padding: 0.5rem;
 	}
 
+	.controls {
+		grid-column: span 11;
+
+		display: flex;
+	}
+
+	.controls .history {
+
+	}
 
 @media all and (max-width: 1000px) {
 	.game-board {

Shogi.UI/Pages/Play/GameBoard/SeatedGameBoard.razor

@@ -136,17 +136,17 @@
 		}
 	}
 
-	void OnClickHand(Piece piece)
+	void OnClickHand(WhichPiece piece)
 	{
 		if (showPromotePrompt) return;
 
 		// Prevent selecting from both the hand and the board.
 		selectedBoardPosition = null;
 
-		selectedPieceFromHand = piece.WhichPiece == selectedPieceFromHand
+		selectedPieceFromHand = piece== selectedPieceFromHand
 				// Deselecting the already-selected piece
 				? selectedPieceFromHand = null
-				: selectedPieceFromHand = piece.WhichPiece;
+				: selectedPieceFromHand = piece;
 
 		StateHasChanged();
 	}

Shogi.UI/Pages/Play/GamePiece.razor

@@ -1,32 +1,41 @@
 @using Shogi.Contracts.Types
 
-<div class="game-piece" title="@HtmlTitle" data-upsidedown="@(Piece?.Owner != Perspective)" data-owner="@Piece?.Owner.ToString()">
-	@switch (Piece?.WhichPiece)
+<div class="game-piece" title="@HtmlTitle" data-upsidedown="@RenderUpsideDown">
+	@switch (Piece)
 	{
+
 		case WhichPiece.Bishop:
 			<Bishop IsPromoted="@IsPromoted" />
 			break;
+
 		case WhichPiece.GoldGeneral:
 			<GoldGeneral />
 			break;
+
 		case WhichPiece.King:
 			<ChallengingKing />
 			break;
+
 		case WhichPiece.Knight:
 			<Knight IsPromoted="@IsPromoted" />
 			break;
+
 		case WhichPiece.Lance:
 			<Lance IsPromoted="@IsPromoted" />
 			break;
+
 		case WhichPiece.Pawn:
 			<Pawn IsPromoted="@IsPromoted" />
 			break;
+
 		case WhichPiece.Rook:
 			<Rook IsPromoted="@IsPromoted" />
 			break;
+
 		case WhichPiece.SilverGeneral:
 			<SilverGeneral IsPromoted="@IsPromoted" />
 			break;
+
 		default:
 			@*render nothing*@
 			break;
@@ -34,15 +43,11 @@
 </div>
 
 @code {
-	[Parameter]
-	public Contracts.Types.Piece? Piece { get; set; }
+	[Parameter][EditorRequired] public WhichPiece? Piece { get; set; }
+	[Parameter] public bool IsPromoted { get; set; } = false;
+	[Parameter] public bool RenderUpsideDown { get; set; }
 
-	[Parameter]
-	public WhichPlayer Perspective { get; set; }
-
-	private bool IsPromoted => Piece != null && Piece.IsPromoted;
-
-	private string HtmlTitle => Piece?.WhichPiece switch
+	private string HtmlTitle => this.Piece switch
 	{
 		WhichPiece.Bishop => "Bishop",
 		WhichPiece.GoldGeneral => "Gold General",

Tests/UnitTests/ShogiShould.cs

@@ -4,13 +4,8 @@ using System.Linq;
 
 namespace UnitTests
 {
-	public class ShogiShould
+	public class ShogiShould(ITestOutputHelper console)
 	{
-		private readonly ITestOutputHelper console;
-		public ShogiShould(ITestOutputHelper console)
-		{
-			this.console = console;
-		}
 
 		[Fact]
 		public void MoveAPieceToAnEmptyPosition()