using FluentAssertions;
using Microsoft.Extensions.Time.Testing;
using SIGCM2.Application.Common;

namespace SIGCM2.Application.Tests.Common;

/// <summary>
/// SUITE-BE-CLOCK — UDT-011 T300.10
/// Unit tests for TimeProviderArgentinaExtensions.GetArgentinaToday.
/// Uses FakeTimeProvider for deterministic UTC control.
/// </summary>
public sealed class TimeProviderArgentinaExtensionsTests
{
    /// <summary>
    /// 22:30 ART del 30/04 = 01:30 UTC del 01/05.
    /// UTC lleva al día siguiente, ART debe ser el día anterior.
    /// </summary>
    [Fact]
    public void GetArgentinaToday_A22_30UTCdel01Mayo_Retorna30AbrilArgentina()
    {
        // 22:30 ART del 30/04 = 01:30 UTC del 01/05
        var fake = new FakeTimeProvider();
        fake.SetUtcNow(new DateTimeOffset(2026, 5, 1, 1, 30, 0, TimeSpan.Zero));

        var result = fake.GetArgentinaToday();

        result.Should().Be(new DateOnly(2026, 4, 30));
    }

    /// <summary>
    /// 00:30 ART del 01/05 = 03:30 UTC del 01/05.
    /// Ambos UTC y ART son el mismo día civil.
    /// </summary>
    [Fact]
    public void GetArgentinaToday_A00_30ARTdel01Mayo_Retorna01MayoArgentina()
    {
        // 00:30 ART del 01/05 = 03:30 UTC del 01/05
        var fake = new FakeTimeProvider();
        fake.SetUtcNow(new DateTimeOffset(2026, 5, 1, 3, 30, 0, TimeSpan.Zero));

        var result = fake.GetArgentinaToday();

        result.Should().Be(new DateOnly(2026, 5, 1));
    }

    /// <summary>
    /// Fin de mes en año bisiesto: 22:30 ART del 28/02/2024 = 01:30 UTC del 29/02/2024.
    /// UTC cae en día bisiesto 29/02, ART debe devolver 28/02.
    /// </summary>
    [Fact]
    public void GetArgentinaToday_BisiestoEnFinDeMesArgentina_RetornaCorrectoAR()
    {
        // 22:30 ART del 28/02/2024 (año bisiesto) = 01:30 UTC del 29/02/2024
        var fake = new FakeTimeProvider();
        fake.SetUtcNow(new DateTimeOffset(2024, 2, 29, 1, 30, 0, TimeSpan.Zero));

        var result = fake.GetArgentinaToday();

        result.Should().Be(new DateOnly(2024, 2, 28));
    }

    /// <summary>
    /// Cruce de año: 22:30 ART del 31/12/2026 = 01:30 UTC del 01/01/2027.
    /// UTC es año nuevo, ART debe ser el 31/12 del año anterior.
    /// </summary>
    [Fact]
    public void GetArgentinaToday_FinDeAnio_22_30ARTdel31Dic_Retorna31Dic()
    {
        // 22:30 ART del 31/12/2026 = 01:30 UTC del 01/01/2027
        var fake = new FakeTimeProvider();
        fake.SetUtcNow(new DateTimeOffset(2027, 1, 1, 1, 30, 0, TimeSpan.Zero));

        var result = fake.GetArgentinaToday();

        result.Should().Be(new DateOnly(2026, 12, 31));
    }
}