From 925723143b2a125033ed7e1ead123b15262e589c Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Fri, 23 May 2025 17:18:15 +0300
Subject: [PATCH] Tic-tac-toe

---
 .../TicTacToe.Tests/GlobalSuppressions.cs     |  11 ++
 .../TicTacToe.Tests/TicTacToe.Tests.csproj    |  27 +++++
 .../TicTacToe.Tests/TicTacToeGameTests.cs     |  66 +++++++++++
 TicTacToe/TicTacToe.UI/App.axaml              |  10 ++
 TicTacToe/TicTacToe.UI/App.axaml.cs           |  27 +++++
 TicTacToe/TicTacToe.UI/GlobalSuppressions.cs  |  16 +++
 TicTacToe/TicTacToe.UI/MainWindow.axaml       |  25 ++++
 TicTacToe/TicTacToe.UI/MainWindow.axaml.cs    |  79 +++++++++++++
 TicTacToe/TicTacToe.UI/Program.cs             |  25 ++++
 TicTacToe/TicTacToe.UI/TicTacToe.UI.csproj    |  22 ++++
 TicTacToe/TicTacToe.UI/app.manifest           |  18 +++
 TicTacToe/TicTacToe.sln                       |  34 ++++++
 TicTacToe/TicTacToe/Cell.cs                   |  26 +++++
 TicTacToe/TicTacToe/MoveResult.cs             |  36 ++++++
 TicTacToe/TicTacToe/TicTacToe.csproj          |   9 ++
 TicTacToe/TicTacToe/TicTacToeGame.cs          | 107 ++++++++++++++++++
 16 files changed, 538 insertions(+)
 create mode 100644 TicTacToe/TicTacToe.Tests/GlobalSuppressions.cs
 create mode 100644 TicTacToe/TicTacToe.Tests/TicTacToe.Tests.csproj
 create mode 100644 TicTacToe/TicTacToe.Tests/TicTacToeGameTests.cs
 create mode 100644 TicTacToe/TicTacToe.UI/App.axaml
 create mode 100644 TicTacToe/TicTacToe.UI/App.axaml.cs
 create mode 100644 TicTacToe/TicTacToe.UI/GlobalSuppressions.cs
 create mode 100644 TicTacToe/TicTacToe.UI/MainWindow.axaml
 create mode 100644 TicTacToe/TicTacToe.UI/MainWindow.axaml.cs
 create mode 100644 TicTacToe/TicTacToe.UI/Program.cs
 create mode 100644 TicTacToe/TicTacToe.UI/TicTacToe.UI.csproj
 create mode 100644 TicTacToe/TicTacToe.UI/app.manifest
 create mode 100644 TicTacToe/TicTacToe.sln
 create mode 100644 TicTacToe/TicTacToe/Cell.cs
 create mode 100644 TicTacToe/TicTacToe/MoveResult.cs
 create mode 100644 TicTacToe/TicTacToe/TicTacToe.csproj
 create mode 100644 TicTacToe/TicTacToe/TicTacToeGame.cs

diff --git a/TicTacToe/TicTacToe.Tests/GlobalSuppressions.cs b/TicTacToe/TicTacToe.Tests/GlobalSuppressions.cs
new file mode 100644
index 0000000..5292943
--- /dev/null
+++ b/TicTacToe/TicTacToe.Tests/GlobalSuppressions.cs
@@ -0,0 +1,11 @@
+// <copyright file="GlobalSuppressions.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+// This file is used by Code Analysis to maintain SuppressMessage
+// attributes that are applied to this project.
+// Project-level suppressions either have no target or are given
+// a specific target and scoped to a namespace, type, member, etc.
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1600:Elements should be documented", Justification = "This is project with tests")]
diff --git a/TicTacToe/TicTacToe.Tests/TicTacToe.Tests.csproj b/TicTacToe/TicTacToe.Tests/TicTacToe.Tests.csproj
new file mode 100644
index 0000000..0cfaf2c
--- /dev/null
+++ b/TicTacToe/TicTacToe.Tests/TicTacToe.Tests.csproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageReference Include="NUnit" Version="4.2.2" />
+    <PackageReference Include="NUnit.Analyzers" Version="4.4.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="NUnit.Framework" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../TicTacToe/TicTacToe.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/TicTacToe/TicTacToe.Tests/TicTacToeGameTests.cs b/TicTacToe/TicTacToe.Tests/TicTacToeGameTests.cs
new file mode 100644
index 0000000..467e211
--- /dev/null
+++ b/TicTacToe/TicTacToe.Tests/TicTacToeGameTests.cs
@@ -0,0 +1,66 @@
+// <copyright file="TicTacToeGameTests.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe.Tests;
+
+public class TicTacToeGameTests
+{
+    private TicTacToeGame game;
+
+    [SetUp]
+    public void Setup()
+    {
+        game = new();
+    }
+
+    [Test]
+    public void FirstRow_OfX_Wins()
+    {
+        Assert.That(game.MakeMove(0, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(1, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(1, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(2, 0), Is.EqualTo(MoveResult.XWins));
+    }
+
+    [Test]
+    public void FirstRow_OfO_Wins()
+    {
+        Assert.That(game.MakeMove(0, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(1, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(1, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(2, 2), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(2, 1), Is.EqualTo(MoveResult.OWins));
+    }
+
+    [Test]
+    public void FirstColumn_OfO_Wins()
+    {
+        Assert.That(game.MakeMove(1, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 0), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(1, 2), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(2, 2), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 2), Is.EqualTo(MoveResult.OWins));
+    }
+
+    [Test]
+    public void Diagonal_OfX_Wins()
+    {
+        Assert.That(game.MakeMove(0, 0), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(0, 1), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(1, 1), Is.EqualTo(MoveResult.XTurn));
+        Assert.That(game.MakeMove(1, 2), Is.EqualTo(MoveResult.OTurn));
+
+        Assert.That(game.MakeMove(2, 2), Is.EqualTo(MoveResult.XWins));
+    }
+}
diff --git a/TicTacToe/TicTacToe.UI/App.axaml b/TicTacToe/TicTacToe.UI/App.axaml
new file mode 100644
index 0000000..840b2b0
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/App.axaml
@@ -0,0 +1,10 @@
+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="TicTacToe.UI.App"
+             RequestedThemeVariant="Default">
+             <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
+
+    <Application.Styles>
+        <FluentTheme />
+    </Application.Styles>
+</Application>
\ No newline at end of file
diff --git a/TicTacToe/TicTacToe.UI/App.axaml.cs b/TicTacToe/TicTacToe.UI/App.axaml.cs
new file mode 100644
index 0000000..fb50f3f
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/App.axaml.cs
@@ -0,0 +1,27 @@
+// <copyright file="App.axaml.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe.UI;
+
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+
+public partial class App : Application
+{
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            desktop.MainWindow = new MainWindow();
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+}
diff --git a/TicTacToe/TicTacToe.UI/GlobalSuppressions.cs b/TicTacToe/TicTacToe.UI/GlobalSuppressions.cs
new file mode 100644
index 0000000..d28023d
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/GlobalSuppressions.cs
@@ -0,0 +1,16 @@
+// <copyright file="GlobalSuppressions.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+// This file is used by Code Analysis to maintain SuppressMessage
+// attributes that are applied to this project.
+// Project-level suppressions either have no target or are given
+// a specific target and scoped to a namespace, type, member, etc.
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1600:Elements should be documented", Justification = "Entry point", Scope = "type", Target = "~T:TicTacToe.UI.Program")]
+
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1601:Partial elements should be documented", Justification = "Application class", Scope = "type", Target = "~T:TicTacToe.UI.App")]
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1601:Partial elements should be documented", Justification = "Window class", Scope = "type", Target = "~T:TicTacToe.UI.MainWindow")]
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1600:Elements should be documented", Justification = "Application class", Scope = "type", Target = "~T:TicTacToe.UI.App")]
+[assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1600:Elements should be documented", Justification = "Window class", Scope = "type", Target = "~T:TicTacToe.UI.MainWindow")]
diff --git a/TicTacToe/TicTacToe.UI/MainWindow.axaml b/TicTacToe/TicTacToe.UI/MainWindow.axaml
new file mode 100644
index 0000000..46bd4ec
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/MainWindow.axaml
@@ -0,0 +1,25 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+        x:Class="TicTacToe.UI.MainWindow"
+        Title="TicTacToe.UI"
+        CanResize="false"
+        Width="640"
+        Height="640"
+        Background="#eeeeee">
+
+    <Grid x:Name="mainGrid" ShowGridLines="true">
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="*"></ColumnDefinition>
+            <ColumnDefinition Width="*"></ColumnDefinition>
+            <ColumnDefinition Width="*"></ColumnDefinition>
+        </Grid.ColumnDefinitions>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*"></RowDefinition>
+            <RowDefinition Height="*"></RowDefinition>
+            <RowDefinition Height="*"></RowDefinition>
+        </Grid.RowDefinitions>
+    </Grid>
+</Window>
diff --git a/TicTacToe/TicTacToe.UI/MainWindow.axaml.cs b/TicTacToe/TicTacToe.UI/MainWindow.axaml.cs
new file mode 100644
index 0000000..f99ccae
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/MainWindow.axaml.cs
@@ -0,0 +1,79 @@
+// <copyright file="MainWindow.axaml.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe.UI;
+
+using System.Diagnostics;
+using System.Linq;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using Avalonia.Media;
+using Avalonia.VisualTree;
+using MsBox.Avalonia;
+
+public partial class MainWindow : Window
+{
+    private readonly TicTacToeGame game;
+
+    private bool won = false;
+
+    public MainWindow()
+    {
+        InitializeComponent();
+
+        game = new();
+
+        for (int i = 0; i < 3; i++)
+        {
+            for (int j = 0; j < 3; j++)
+            {
+                var button = new Button()
+                {
+                    HorizontalAlignment = Avalonia.Layout.HorizontalAlignment.Stretch,
+                    VerticalAlignment = Avalonia.Layout.VerticalAlignment.Stretch,
+                    HorizontalContentAlignment = Avalonia.Layout.HorizontalAlignment.Center,
+                    VerticalContentAlignment = Avalonia.Layout.VerticalAlignment.Center,
+                    FontSize = 64,
+                };
+                int row = i;
+                int column = j;
+
+                button.Click += (o, e) => OnClick(button, row, column);
+
+                Grid.SetRow(button, row);
+                Grid.SetColumn(button, column);
+                mainGrid.Children.Add(button);
+            }
+        }
+    }
+
+    private void OnClick(Button button, int row, int column)
+    {
+        if (won)
+        {
+            return;
+        }
+
+        var result = game.MakeMove(column, row);
+
+        var xTurn = result is MoveResult.XTurn or MoveResult.XWins;
+        var oTurn = result is MoveResult.OTurn or MoveResult.OWins;
+
+        if (!xTurn && !oTurn)
+        {
+            return;
+        }
+
+        if (result is MoveResult.XWins or MoveResult.OWins)
+        {
+            won = true;
+            MessageBoxManager
+                .GetMessageBoxStandard("Win!", $"{(result == MoveResult.XWins ? "X" : "O")} has won!")
+                .ShowWindowAsync();
+        }
+
+        button.Content = xTurn ? "X" : "O";
+        button.Foreground = xTurn ? SolidColorBrush.Parse("#f02020") : SolidColorBrush.Parse("#2020f0");
+    }
+}
diff --git a/TicTacToe/TicTacToe.UI/Program.cs b/TicTacToe/TicTacToe.UI/Program.cs
new file mode 100644
index 0000000..de9c834
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/Program.cs
@@ -0,0 +1,25 @@
+// <copyright file="Program.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe.UI;
+
+using System;
+using Avalonia;
+
+public class Program
+{
+    // Initialization code. Don't use any Avalonia, third-party APIs or any
+    // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
+    // yet and stuff might break.
+    [STAThread]
+    public static void Main(string[] args) => BuildAvaloniaApp()
+        .StartWithClassicDesktopLifetime(args);
+
+    // Avalonia configuration, don't remove; also used by visual designer.
+    public static AppBuilder BuildAvaloniaApp()
+        => AppBuilder.Configure<App>()
+            .UsePlatformDetect()
+            .WithInterFont()
+            .LogToTrace();
+}
diff --git a/TicTacToe/TicTacToe.UI/TicTacToe.UI.csproj b/TicTacToe/TicTacToe.UI/TicTacToe.UI.csproj
new file mode 100644
index 0000000..6d4a0b9
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/TicTacToe.UI.csproj
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <BuiltInComInteropSupport>true</BuiltInComInteropSupport>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Avalonia" Version="11.2.7" />
+    <PackageReference Include="Avalonia.Desktop" Version="11.2.7" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="11.2.7" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="11.2.7" />
+    <PackageReference Include="MessageBox.Avalonia" Version="3.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../TicTacToe/TicTacToe.csproj" />
+  </ItemGroup>
+</Project>
diff --git a/TicTacToe/TicTacToe.UI/app.manifest b/TicTacToe/TicTacToe.UI/app.manifest
new file mode 100644
index 0000000..6348f3f
--- /dev/null
+++ b/TicTacToe/TicTacToe.UI/app.manifest
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <!-- This manifest is used on Windows only.
+       Don't remove it as it might cause problems with window transparency and embedded controls.
+       For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
+  <assemblyIdentity version="1.0.0.0" name="TicTacToe.UI.Desktop"/>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- A list of the Windows versions that this application has been tested on
+           and is designed to work with. Uncomment the appropriate elements
+           and Windows will automatically select the most compatible environment. -->
+
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+    </application>
+  </compatibility>
+</assembly>
diff --git a/TicTacToe/TicTacToe.sln b/TicTacToe/TicTacToe.sln
new file mode 100644
index 0000000..70c58b3
--- /dev/null
+++ b/TicTacToe/TicTacToe.sln
@@ -0,0 +1,34 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TicTacToe", "TicTacToe\TicTacToe.csproj", "{13DED376-EA25-47D0-A76A-1C417967F3E3}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TicTacToe.Tests", "TicTacToe.Tests\TicTacToe.Tests.csproj", "{671F028F-5CA0-4D46-94D7-5250C1EBEAEF}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TicTacToe.UI", "TicTacToe.UI\TicTacToe.UI.csproj", "{D1BAFEA2-7EEA-4602-98A0-F639C9265A2D}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{13DED376-EA25-47D0-A76A-1C417967F3E3}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{13DED376-EA25-47D0-A76A-1C417967F3E3}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{13DED376-EA25-47D0-A76A-1C417967F3E3}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{13DED376-EA25-47D0-A76A-1C417967F3E3}.Release|Any CPU.Build.0 = Release|Any CPU
+		{671F028F-5CA0-4D46-94D7-5250C1EBEAEF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{671F028F-5CA0-4D46-94D7-5250C1EBEAEF}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{671F028F-5CA0-4D46-94D7-5250C1EBEAEF}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{671F028F-5CA0-4D46-94D7-5250C1EBEAEF}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D1BAFEA2-7EEA-4602-98A0-F639C9265A2D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D1BAFEA2-7EEA-4602-98A0-F639C9265A2D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D1BAFEA2-7EEA-4602-98A0-F639C9265A2D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D1BAFEA2-7EEA-4602-98A0-F639C9265A2D}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
diff --git a/TicTacToe/TicTacToe/Cell.cs b/TicTacToe/TicTacToe/Cell.cs
new file mode 100644
index 0000000..bfc3698
--- /dev/null
+++ b/TicTacToe/TicTacToe/Cell.cs
@@ -0,0 +1,26 @@
+// <copyright file="Cell.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe;
+
+/// <summary>
+/// Cell on the tic-tac-toe board.
+/// </summary>
+public enum Cell
+{
+    /// <summary>
+    /// Empty cell.
+    /// </summary>
+    Empty,
+
+    /// <summary>
+    /// X cell.
+    /// </summary>
+    X,
+
+    /// <summary>
+    /// O cell.
+    /// </summary>
+    O,
+}
diff --git a/TicTacToe/TicTacToe/MoveResult.cs b/TicTacToe/TicTacToe/MoveResult.cs
new file mode 100644
index 0000000..957b527
--- /dev/null
+++ b/TicTacToe/TicTacToe/MoveResult.cs
@@ -0,0 +1,36 @@
+// <copyright file="MoveResult.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe;
+
+/// <summary>
+/// Result of the move on the tic-tac-toe board.
+/// </summary>
+public enum MoveResult
+{
+    /// <summary>
+    /// X made turn.
+    /// </summary>
+    XTurn,
+
+    /// <summary>
+    /// X made turn.
+    /// </summary>
+    OTurn,
+
+    /// <summary>
+    /// X wins.
+    /// </summary>
+    XWins,
+
+    /// <summary>
+    /// O wins.
+    /// </summary>
+    OWins,
+
+    /// <summary>
+    /// Incorrect move has been made.
+    /// </summary>
+    IncorrectMove,
+}
diff --git a/TicTacToe/TicTacToe/TicTacToe.csproj b/TicTacToe/TicTacToe/TicTacToe.csproj
new file mode 100644
index 0000000..125f4c9
--- /dev/null
+++ b/TicTacToe/TicTacToe/TicTacToe.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/TicTacToe/TicTacToe/TicTacToeGame.cs b/TicTacToe/TicTacToe/TicTacToeGame.cs
new file mode 100644
index 0000000..0382c58
--- /dev/null
+++ b/TicTacToe/TicTacToe/TicTacToeGame.cs
@@ -0,0 +1,107 @@
+// <copyright file="TicTacToeGame.cs" company="Ilya Krivtsov">
+// Copyright (c) Ilya Krivtsov. All rights reserved.
+// </copyright>
+
+namespace TicTacToe;
+
+/// <summary>
+/// The game of tic-tac-toe.
+/// </summary>
+public class TicTacToeGame
+{
+    private readonly Cell[,] cells = new Cell[3, 3];
+
+    private Cell turn;
+
+    private MoveResult? winner = null;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="TicTacToeGame"/> class.
+    /// </summary>
+    public TicTacToeGame()
+    {
+        for (int i = 0; i < 3; i++)
+        {
+            for (int j = 0; j < 3; j++)
+            {
+                cells[i, j] = Cell.Empty;
+            }
+        }
+
+        turn = Cell.X;
+    }
+
+    /// <summary>
+    /// Makes a move and returns <see langword="true"/>, if player won this turn.
+    /// </summary>
+    /// <param name="column">Column on the board to set X or O.</param>
+    /// <param name="row">Row on the board to set X or O.</param>
+    /// <returns><see langword="true"/> if player won the game with this move, <see langword="false"/> otherwise.</returns>
+    public MoveResult MakeMove(int column, int row)
+    {
+        if (winner != null)
+        {
+            return winner.Value;
+        }
+
+        if (column < 0 || column > 2 || row < 0 || row > 2)
+        {
+            return MoveResult.IncorrectMove;
+        }
+
+        if (cells[column, row] != Cell.Empty)
+        {
+            return MoveResult.IncorrectMove;
+        }
+
+        cells[column, row] = turn;
+
+        if (CheckVictory(turn))
+        {
+            winner = turn == Cell.X ? MoveResult.XWins : MoveResult.OWins;
+            return winner.Value;
+        }
+
+        var oldTurn = turn;
+
+        turn = turn == Cell.X ? Cell.O : Cell.X;
+
+        return oldTurn == Cell.X ? MoveResult.XTurn : MoveResult.OTurn;
+    }
+
+    private bool CheckVictory(Cell cell)
+    {
+        if (cell != Cell.X && cell != Cell.O)
+        {
+            return false;
+        }
+
+        for (int y = 0; y < 3; y++)
+        {
+            if (Enumerable.Range(0, 3).All(i => cells[i, y] == cell))
+            {
+                return true;
+            }
+        }
+
+        for (int x = 0; x < 3; x++)
+        {
+            if (Enumerable.Range(0, 3).All(i => cells[x, i] == cell))
+            {
+                return true;
+            }
+        }
+
+        if (Enumerable.Range(0, 3).All(i => cells[i, i] == cell))
+        {
+            return true;
+        }
+
+        if (Enumerable.Range(0, 3).All(i => cells[2 - i, i] == cell))
+        {
+            return true;
+        }
+
+        return false;
+    }
+}