using FluentAssertions;
using Marathon.Domain.Backtesting;

namespace Marathon.Domain.Tests.Backtesting;

public sealed class SavedStrategyTests
{
    private static BacktestStrategy AnyStrategy() => BacktestStrategy.Default;

    [Fact]
    public void Create_AssignsIdentity_AndRecentTimestamp()
    {
        var s = SavedStrategy.Create("My preset", AnyStrategy());

        s.Id.Should().NotBe(Guid.Empty);
        s.Name.Should().Be("My preset");
        s.Strategy.Should().Be(AnyStrategy());
        // Offset-agnostic instant comparison — robust to however MoscowTime is sourced.
        s.CreatedAt.Should().BeCloseTo(DateTimeOffset.UtcNow, TimeSpan.FromMinutes(1));
    }

    [Theory]
    [InlineData("  Spaced  ", "Spaced")]
    [InlineData("\tTabbed\n", "Tabbed")]
    public void Constructor_TrimsName(string input, string expected)
    {
        SavedStrategy.Create(input, AnyStrategy()).Name.Should().Be(expected);
    }

    [Theory]
    [InlineData("")]
    [InlineData("   ")]
    public void Constructor_Throws_When_NameBlank(string blank)
    {
        var act = () => SavedStrategy.Create(blank, AnyStrategy());
        act.Should().Throw<ArgumentException>();
    }

    [Fact]
    public void Constructor_Throws_When_NameExceedsMax()
    {
        var tooLong = new string('x', SavedStrategy.MaxNameLength + 1);
        var act = () => SavedStrategy.Create(tooLong, AnyStrategy());
        act.Should().Throw<ArgumentException>();
    }

    [Fact]
    public void Constructor_Accepts_NameAtMaxLength()
    {
        var maxName = new string('x', SavedStrategy.MaxNameLength);
        SavedStrategy.Create(maxName, AnyStrategy()).Name.Should().HaveLength(SavedStrategy.MaxNameLength);
    }

    [Fact]
    public void With_SwapsStrategy_KeepingIdentityAndName()
    {
        var s = SavedStrategy.Create("Preset", AnyStrategy());
        var tweaked = new BacktestStrategy(1000m, 0.6m, StakeRule.Flat, 50m, 0.02m, 0.25m);

        var updated = s with { Strategy = tweaked };

        updated.Id.Should().Be(s.Id);
        updated.Name.Should().Be("Preset");
        updated.CreatedAt.Should().Be(s.CreatedAt);
        updated.Strategy.MinScore.Should().Be(0.6m);
    }
}