Refactoring after review - v1

Gambling.API.Tests/GamblingTests.cs → Gambling.API.Tests/BetHttpHandlerTests.cs

@@ -1,8 +1,15 @@
 namespace Gambling.API.Tests;
 
 [TestClass]
-public class GamblingTests
+public class BetHttpHandlerTests
 {
+ [TestInitialize]
+ public void Init()
+ {
+
+ }
+
+
  [TestMethod]
  public void WebApplicationIsCreatedWithoutExceptions()
  {
@@ -15,14 +22,14 @@ public void GamblingServiceResolvedFromServiceProvider()
  {
  var serviceProvider = new ServiceCollection().AddGamblingServices().BuildServiceProvider(true);
  using var scope = serviceProvider.CreateAsyncScope();
- var service = scope.ServiceProvider.GetService<GamblingService>();
+ var service = scope.ServiceProvider.GetService<BetHttpHandler>();
  Assert.IsNotNull(service);
  }
 
  [TestMethod]
  public async Task BetLessThanZeroNotAllowed()
  {
- var request = new BetRequest(-5, 0);
+ var request = new BetHttpRequest(-5, 0);
  var response = await MakeMockBetAsync(request);
  Assert.IsNotNull(response);
  var problemResponse = (ProblemHttpResult) response;
@@ -32,7 +39,7 @@ public async Task BetLessThanZeroNotAllowed()
  [TestMethod]
  public async Task BettingOnNumberLessThanZeroNotAllowed()
  {
- var request = new BetRequest(0, -5);
+ var request = new BetHttpRequest(0, -5);
  var response = await MakeMockBetAsync(request);
  var problemResponse = (ProblemHttpResult)response;
  Assert.AreEqual(StatusCodes.Status400BadRequest, problemResponse.StatusCode);
@@ -41,7 +48,7 @@ public async Task BettingOnNumberLessThanZeroNotAllowed()
  [TestMethod]
  public async Task BettingOnNumberBiggerThanNineNotAllowed()
  {
- var request = new BetRequest(0, 10);
+ var request = new BetHttpRequest(0, 10);
  var response = await MakeMockBetAsync(request);
  var problemResponse = (ProblemHttpResult)response;
  Assert.AreEqual(StatusCodes.Status400BadRequest, problemResponse.StatusCode);
@@ -50,24 +57,24 @@ public async Task BettingOnNumberBiggerThanNineNotAllowed()
  [TestMethod]
  public async Task EmptyBetReturnsOkResponse()
  {
- var request = new BetRequest(0, 0);
+ var request = new BetHttpRequest(0, 0);
  var response = await MakeMockBetAsync(request);
- var okResponse = (Ok<BetResponse>)response;
+ var okResponse = (Ok<BetHttpResponse>)response;
  Assert.AreEqual(StatusCodes.Status200OK, okResponse.StatusCode);
  }
 
  [TestMethod]
  public async Task UserHas10KPointsToStartWith()
  {
- var request = new BetRequest(0, 0);
+ var request = new BetHttpRequest(0, 0);
  var response = await MakeMockBetAsyncUnwrap(request);
  Assert.AreEqual(10_000, response.Account);
  }
 
  [TestMethod]
  public async Task ManyUsersStartWith10K()
  {
- var bet = new BetRequest(0, 0);
+ var bet = new BetHttpRequest(0, 0);
  var aliceResponse = await MakeMockBetAsyncUnwrap(bet, "Alice");
  var bobResponse = await MakeMockBetAsyncUnwrap(bet, "Bob");
  var charlieResponse = await MakeMockBetAsyncUnwrap(bet, "Charlie");
@@ -79,7 +86,7 @@ public async Task ManyUsersStartWith10K()
  [TestMethod]
  public async Task WinGives9TimesTheBetAsReward()
  {
- var bet = new BetRequest(200, 3);
+ var bet = new BetHttpRequest(200, 3);
  var response = await MakeWinningBetAsync(bet, "Alice");
  var expectedWin = bet.Points * 9;
  Assert.AreEqual(10_000 + expectedWin, response.Account);
@@ -90,7 +97,7 @@ public async Task WinGives9TimesTheBetAsReward()
  [TestMethod]
  public async Task LosingDeductsPointsFromAccount()
  {
- var bet = new BetRequest(200, 3);
+ var bet = new BetHttpRequest(200, 3);
  var response = await MakeLosingBetAsync(bet, "Henry");
  Assert.AreEqual(10_000 - bet.Points, response.Account);
  Assert.AreEqual($"-{bet.Points}", response.Points);
@@ -100,25 +107,25 @@ public async Task LosingDeductsPointsFromAccount()
  [TestMethod]
  public async Task MultiUserScenarioIsHandled()
  {
- var archieBet = new BetRequest(200, 3);
+ var archieBet = new BetHttpRequest(200, 3);
  var archieResponse = await MakeLosingBetAsync(archieBet, "Archie");
  Assert.AreEqual(10_000 - archieBet.Points, archieResponse.Account);
 
- var bobBet = new BetRequest(700, 5);
+ var bobBet = new BetHttpRequest(700, 5);
  var bobResponse = await MakeWinningBetAsync(bobBet, "Bob");
  Assert.AreEqual(10_000 + bobBet.Points * 9, bobResponse.Account);
 
- var charlieBet = new BetRequest(555, 2);
+ var charlieBet = new BetHttpRequest(555, 2);
  var charlieResponse = await MakeLosingBetAsync(charlieBet, "Charlie");
  Assert.AreEqual(10_000 - charlieBet.Points, charlieResponse.Account);
  }
 
  [TestMethod]
  public async Task BalanceIsPreservedBetweenBets()
  {
- var firstBet = new BetRequest(300, 5);
- var secondBet = new BetRequest(50, 6);
- var thirdBet = new BetRequest(800, 7);
+ var firstBet = new BetHttpRequest(300, 5);
+ var secondBet = new BetHttpRequest(50, 6);
+ var thirdBet = new BetHttpRequest(800, 7);
 
  var firstResponse = await MakeLosingBetAsync(firstBet, "Mortimer");
  var secondResponse = await MakeWinningBetAsync(secondBet, "Mortimer");
@@ -134,35 +141,37 @@ public async Task BalanceIsPreservedBetweenBets()
  Assert.AreEqual(expectedBalanceAfterThirdBet, thirdResponse.Account);
  }
 
- private static async Task<IResult> MakeMockBetAsync(BetRequest request, string? userId = null, int? winningNumber = null)
+ private static async Task<IResult> MakeMockBetAsync(BetHttpRequest httpRequest, string? userId = null, int? winningNumber = null)
  {
  var authService = new MockAuthService(userId ?? "");
- var rngService = new MockRngService(winningNumber ?? 0);
- var gamblingService = new GamblingService(authService, rngService);
- return await gamblingService.BetAsync(request);
+ var betService = new BetService((_, _) => winningNumber ?? 0, new InMemoryBetRepository());
+ var httpHandler = new BetHttpHandler(authService, betService);
+ return await httpHandler.HandleAsync(httpRequest);
  }
 
- private static async Task<BetResponse> MakeMockBetAsyncUnwrap(BetRequest request, string? userId = null, int? winningNumber = null)
+ private static async Task<BetHttpResponse> MakeMockBetAsyncUnwrap(BetHttpRequest httpRequest, string? userId = null, int? winningNumber = null)
  {
- var response = await MakeMockBetAsync(request, userId, winningNumber);
- var okResponse = (Ok<BetResponse>)response;
+ var response = await MakeMockBetAsync(httpRequest, userId, winningNumber);
+ Assert.IsInstanceOfType(response, typeof(Ok<BetHttpResponse>));
+ var okResponse = (Ok<BetHttpResponse>)response;
  return okResponse.Value ?? throw new NullReferenceException("response was null for some reason");
  }
- private static async Task<BetResponse> MakeWinningBetAsync(BetRequest request, string userId)
+
+ private static async Task<BetHttpResponse> MakeWinningBetAsync(BetHttpRequest httpRequest, string userId)
  {
- return await MakeMockBetAsyncUnwrap(request, userId, request.Number);
+ return await MakeMockBetAsyncUnwrap(httpRequest, userId, httpRequest.Number);
  }
 
- private static async Task<BetResponse> MakeLosingBetAsync(BetRequest request, string userId)
+ private static async Task<BetHttpResponse> MakeLosingBetAsync(BetHttpRequest httpRequest, string userId)
  {
- return await MakeMockBetAsyncUnwrap(request, userId, request.Number == 0 ? 1 : 0);
+ return await MakeMockBetAsyncUnwrap(httpRequest, userId, httpRequest.Number == 0 ? 1 : 0);
  }
 
  private class MockRngService : IRandomService
  {
  private readonly int _number;
  public MockRngService(int number) => _number = number;
- public int GetNumber(int min, int max) => _number;
+ public int GetNumber(int min, int toInclusive) => _number;
  }
 
  private class MockAuthService : IAuthService

Gambling.API/Interfaces/IRandomService.cs

@@ -2,5 +2,5 @@
 
 public interface IRandomService
 {
- int GetNumber(int min, int max);
+ int GetNumber(int min, int toInclusive);
 }

Gambling.API/Models/BetHttpRequest.cs

@@ -0,0 +1,23 @@
+namespace Gambling.API.Models;
+
+public record BetHttpRequest(int Points, int Number)
+{
+ private const int MinAllowedNumber = 0;
+ private const int MaxAllowedNumber = 9;
+ public bool IsNotValid(out Dictionary<string, string[]> problems)
+ {
+ problems = new Dictionary<string, string[]>();
+
+ if (Points < 0)
+ {
+ problems.Add(nameof(Points), new[] { "Bet can't be negative" });
+ }
+
+ if (Number is < MinAllowedNumber or > MaxAllowedNumber)
+ {
+ problems.Add(nameof(Number), new[] { $"Winning number must be between {MinAllowedNumber} and {MaxAllowedNumber}" });
+ }
+
+ return problems.Any();
+ }
+}

Gambling.API/Models/BetHttpResponse.cs

@@ -0,0 +1,3 @@
+namespace Gambling.API.Models;
+
+public record BetHttpResponse(int Account, string Status, string Points);

Gambling.API/Program.cs

@@ -1,7 +1,11 @@
 using Microsoft.AspNetCore.Diagnostics;
+using System.Security.Cryptography;
 
 namespace Gambling.API;
 
+
+public delegate int RngFunc(int fromInclusive, int toExclusive);
+
 public static class Program
 {
  private static void Main(string[] args)
@@ -17,16 +21,18 @@ public static WebApplication CreateWebApplication(string[] args)
  var app = builder.Build();
  app.WrapUnhandledExceptionsInProblemDetails();
  app.UseAuthentication();
- app.MapPost("/", async (BetRequest request, GamblingService service) => await service.BetAsync(request));
+ app.MapPost("/api/v1/bet", async (BetHttpRequest request, BetHttpHandler handler) => await handler.HandleAsync(request));
  return app;
  }
 
  public static IServiceCollection AddGamblingServices(this IServiceCollection services)
  {
- services.AddSingleton<IRandomService, CryptoRngService>();
+ services.AddSingleton<RngFunc>(_ => RandomNumberGenerator.GetInt32);
+ services.AddScoped<IBetRepository, InMemoryBetRepository>();
  services.AddScoped<IAuthService, CookiesAuthService>();
- services.AddScoped<GamblingService>();
+ services.AddScoped<BetHttpHandler>();
  services.AddHttpContextAccessor();
+ services.AddScoped<BetService>();
  return services;
  }
 

Gambling.API/Services/BalanceUpdateCommand.cs

@@ -0,0 +1,3 @@
+namespace Gambling.API.Services;
+
+public record BalanceUpdateCommand(string UserId, int BetAmount, int TheoreticalReward, int StartingBalance);

Gambling.API/Services/BalanceUpdateResult.cs

@@ -0,0 +1,3 @@
+namespace Gambling.API.Services;
+
+public record BalanceUpdateResult(bool HadEnoughCredit, int CurrentBalance);

Gambling.API/Services/BetCommand.cs

@@ -0,0 +1,3 @@
+namespace Gambling.API.Services;
+
+public record BetRequest(string UserId, int Points, int Number);

Gambling.API/Services/BetHttpHandler.cs

@@ -0,0 +1,40 @@
+
+namespace Gambling.API.Services;
+
+public class BetHttpHandler
+{
+ private readonly IAuthService _auth;
+ private readonly BetService _service;
+
+ public BetHttpHandler(IAuthService auth, BetService service)
+ {
+ _auth = auth;
+ _service = service;
+ }
+
+ public async Task<IResult> HandleAsync(BetHttpRequest httpRequest)
+ {
+ if (httpRequest.IsNotValid(out var problemDetails))
+ {
+ return Results.ValidationProblem(problemDetails);
+ }
+
+ var userId = await _auth.GetCurrentUserIdAsync();
+ var request = new BetRequest(userId, httpRequest.Points, httpRequest.Number);
+ var betResult = await _service.BetAsync(request);
+ if (!betResult.UserHadEnoughCredit)
+ {
+ return Results.BadRequest("Not enough points on the account!");
+ };
+
+ var response = MapToResponse(betResult);
+ return Results.Ok(response);
+ }
+
+ private static BetHttpResponse MapToResponse(BetResult betResult)
+ {
+ var statusString = betResult.HasWon ? "won" : "lost";
+ var rewardString = betResult.Reward >= 0 ? $"+{betResult.Reward}" : betResult.Reward.ToString();
+ return new BetHttpResponse(betResult.CurrentBalance, statusString, rewardString);
+ }
+}

Gambling.API/Services/BetHttpRequestValidator.cs

@@ -0,0 +1,23 @@
+namespace Gambling.API.Services;
+
+public class BetHttpRequestValidator
+{
+ private const int MinAllowedNumber = 0;
+ private const int MaxAllowedNumber = 9;
+ public bool IsNotValid(BetHttpRequest httpRequest, out Dictionary<string, string[]> problems)
+ {
+ problems = new Dictionary<string, string[]>();
+
+ if (httpRequest.Points < 0)
+ {
+ problems.Add(nameof(httpRequest.Points), new[] { "Bet can't be negative" });
+ }
+
+ if (httpRequest.Number is < MinAllowedNumber or > MaxAllowedNumber)
+ {
+ problems.Add(nameof(httpRequest.Number), new[] { $"Winning number must be between {MinAllowedNumber} and {MaxAllowedNumber}" });
+ }
+
+ return problems.Any();
+ }
+}

Gambling.API/Services/BetResult.cs

@@ -0,0 +1,3 @@
+namespace Gambling.API.Services;
+
+public record BetResult(bool UserHadEnoughCredit, int CurrentBalance, int Reward, bool HasWon);

Gambling.API/Services/BetService.cs

@@ -0,0 +1,27 @@
+namespace Gambling.API.Services;
+
+public class BetService
+{
+ private readonly RngFunc _rngFunc;
+ private readonly IBetRepository _repository;
+ private const int StartingBalance = 10_000;
+ private const int WinPointsMultiplier = 9;
+ private const int MinWinningNumber = 0;
+ private const int MaxWinningNumber = 9;
+
+ public BetService(RngFunc rngFunc, IBetRepository repository)
+ {
+ _rngFunc = rngFunc;
+ _repository = repository;
+ }
+
+ public async Task<BetResult> BetAsync(BetRequest request)
+ {
+ var winningNumber = _rngFunc(MinWinningNumber, MaxWinningNumber + 1);
+ var hasWon = request.Number == winningNumber;
+ var reward = hasWon ? request.Points * WinPointsMultiplier : -request.Points;
+ var updateCommand = new BalanceUpdateCommand(request.UserId, request.Points, reward, StartingBalance);
+ var updateResult = await _repository.UpdateBalance(updateCommand);
+ return new BetResult(updateResult.HadEnoughCredit, updateResult.CurrentBalance, reward, hasWon);
+ }
+}

Gambling.API/Services/CryptoRngService.cs

@@ -4,5 +4,5 @@ namespace Gambling.API.Services;
 
 public class CryptoRngService : IRandomService
 {
- public int GetNumber(int min, int max) => RandomNumberGenerator.GetInt32(min, max);
+ public int GetNumber(int min, int toInclusive) => RandomNumberGenerator.GetInt32(min, toInclusive + 1);
 }