maraphon-app/tests/Marathon.Application.Tests/UseCases/RunBacktestUseCaseTests.cs

using FluentAssertions;
using Marathon.Application.Abstractions;
using Marathon.Application.UseCases;
using Marathon.Domain.Backtesting;
using Marathon.Domain.Entities;
using Marathon.Domain.Enums;
using Marathon.Domain.ValueObjects;
using Microsoft.Extensions.Logging.Abstractions;
using NSubstitute;

namespace Marathon.Application.Tests.UseCases;

/// <summary>
/// Tests the orchestration: anomaly + event + result join + parse + delegate to
/// the simulator. The simulator's own correctness is covered in
/// Marathon.Domain.Tests.
/// </summary>
public sealed class RunBacktestUseCaseTests
{
    private static readonly TimeSpan MoscowOffset = TimeSpan.FromHours(3);
    private static readonly DateTimeOffset BaseTime =
        new(2026, 5, 10, 18, 0, 0, MoscowOffset);

    private readonly IAnomalyRepository _anomalies = Substitute.For<IAnomalyRepository>();
    private readonly IEventRepository _events = Substitute.For<IEventRepository>();
    private readonly IResultRepository _results = Substitute.For<IResultRepository>();

    private RunBacktestUseCase CreateSut() =>
        new(_anomalies, _events, _results, NullLogger<RunBacktestUseCase>.Instance);

    private const string FlipEvidence = """
        {
          "suspensionGapSeconds": 90,
          "preSuspension": {
            "capturedAt": "2026-05-10T18:00:00+03:00",
            "p1": 0.55, "pDraw": 0.20, "p2": 0.25,
            "rate1": 1.8, "rateDraw": 4.5, "rate2": 4.0
          },
          "postSuspension": {
            "capturedAt": "2026-05-10T18:02:30+03:00",
            "p1": 0.25, "pDraw": 0.20, "p2": 0.55,
            "rate1": 4.0, "rateDraw": 4.5, "rate2": 1.8
          }
        }
        """;

    private static Anomaly MakeAnomaly(EventId eventId, decimal score = 0.55m, string? evidence = null) =>
        new(Guid.NewGuid(), eventId, BaseTime, AnomalyKind.SuspensionFlip,
            score, evidence ?? FlipEvidence);

    private static Event MakeEvent(EventId id) =>
        new(id, new SportCode(11), "BY", "L1", "Cat", BaseTime, "Team A", "Team B");

    private static BacktestStrategy DefaultStrategy(decimal minScore = 0.30m) =>
        new(StartingBankroll: 1000m, MinScore: minScore,
            StakeRule: StakeRule.Flat,
            FlatStake: 100m, PercentOfBankroll: 0.02m, KellyFraction: 0.25m);

    [Fact]
    public async Task Should_ReturnEmptyResult_When_NoAnomaliesExist()
    {
        _anomalies.ListAsync(Arg.Any<CancellationToken>())
            .Returns(Array.Empty<Anomaly>().ToList().AsReadOnly());

        var result = await CreateSut().ExecuteAsync(DefaultStrategy(), CancellationToken.None);

        result.BetsPlaced.Should().Be(0);
        result.FinalBankroll.Should().Be(1000m);
    }

    [Fact]
    public async Task Should_SimulateBet_When_AnomalyHasResult()
    {
        // Anomaly with result, Side2 (post-flip favourite) wins → +100.
        var id = new EventId("event-1");
        _anomalies.ListAsync(Arg.Any<CancellationToken>())
            .Returns(new[] { MakeAnomaly(id, score: 0.55m) }.ToList().AsReadOnly());
        _events.GetAsync(id, Arg.Any<CancellationToken>()).Returns(MakeEvent(id));
        _results.GetAsync(id, Arg.Any<CancellationToken>())
            .Returns(new EventResult(id, 0, 2, Side.Side2, DateTimeOffset.UtcNow));

        var result = await CreateSut().ExecuteAsync(DefaultStrategy(), CancellationToken.None);

        result.BetsPlaced.Should().Be(1);
        result.Wins.Should().Be(1);
        result.NetProfit.Should().Be(80m,
            "stake 100 at rate 1.8 — win pays 180, profit 80");
    }

    [Fact]
    public async Task Should_FilterOut_AnomaliesWithoutResults()
    {
        var graded = new EventId("graded");
        var ungraded = new EventId("ungraded");
        _anomalies.ListAsync(Arg.Any<CancellationToken>())
            .Returns(new[] { MakeAnomaly(graded), MakeAnomaly(ungraded) }.ToList().AsReadOnly());

        _events.GetAsync(graded, Arg.Any<CancellationToken>()).Returns(MakeEvent(graded));
        _events.GetAsync(ungraded, Arg.Any<CancellationToken>()).Returns(MakeEvent(ungraded));

        _results.GetAsync(graded, Arg.Any<CancellationToken>())
            .Returns(new EventResult(graded, 0, 2, Side.Side2, DateTimeOffset.UtcNow));
        _results.GetAsync(ungraded, Arg.Any<CancellationToken>())
            .Returns((EventResult?)null);

        var result = await CreateSut().ExecuteAsync(DefaultStrategy(), CancellationToken.None);

        // Only the graded anomaly should reach the simulator — the ungraded one is filtered out
        // before the simulator, so it does NOT appear in result.Skipped.
        (result.BetsPlaced + result.Skipped).Should().Be(1);
    }

    [Fact]
    public async Task Should_FilterOut_AnomaliesWithMalformedEvidence()
    {
        var id = new EventId("bad-evidence");
        _anomalies.ListAsync(Arg.Any<CancellationToken>())
            .Returns(new[] { MakeAnomaly(id, evidence: "{not json") }.ToList().AsReadOnly());

        _events.GetAsync(id, Arg.Any<CancellationToken>()).Returns(MakeEvent(id));
        _results.GetAsync(id, Arg.Any<CancellationToken>())
            .Returns(new EventResult(id, 0, 2, Side.Side2, DateTimeOffset.UtcNow));

        var result = await CreateSut().ExecuteAsync(DefaultStrategy(), CancellationToken.None);

        result.BetsPlaced.Should().Be(0);
        result.Skipped.Should().Be(0,
            "malformed evidence is filtered before the simulator — not counted as a strategy skip");
    }
}