using FluentAssertions;
using Marathon.Application.Abstractions;
using Marathon.Application.Configuration;
using Marathon.Application.UseCases;
using Marathon.Domain.Entities;
using Marathon.Domain.Enums;
using Marathon.Domain.ValueObjects;
using Marathon.Infrastructure.Configuration;
using Marathon.Infrastructure.Workers;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using NSubstitute;
using NSubstitute.ExceptionExtensions;

namespace Marathon.Infrastructure.Tests.Workers;

/// <summary>
/// Tests for <see cref="LiveOddsPoller"/>.
/// Uses real <see cref="PullLiveOddsUseCase"/> backed by NSubstitute interfaces,
/// so the poller's DI scope resolution is exercised end-to-end.
/// </summary>
public sealed class LiveOddsPollerTests
{
    private static readonly TimeSpan MoscowOffset = TimeSpan.FromHours(3);

    private static OddsSnapshot MakeSnapshot(EventId eventId) =>
        new(eventId, DateTimeOffset.UtcNow, OddsSource.Live, new List<Bet>
        {
            new(MatchScope.Instance, BetType.Win, Side.Side1, null, new OddsRate(1.80m)),
        });

    /// <summary>
    /// Builds a DI ServiceProvider wiring a real <see cref="PullLiveOddsUseCase"/>
    /// against the provided interface substitutes.
    /// </summary>
    private static IServiceProvider BuildServiceProvider(
        IOddsScraper scraper,
        IEventRepository eventRepo,
        ISnapshotRepository snapshotRepo)
    {
        var services = new ServiceCollection();
        services.AddScoped(_ => scraper);
        services.AddScoped(_ => eventRepo);
        services.AddScoped(_ => snapshotRepo);
        services.AddScoped(sp =>
            new PullLiveOddsUseCase(
                sp.GetRequiredService<IOddsScraper>(),
                sp.GetRequiredService<IEventRepository>(),
                sp.GetRequiredService<ISnapshotRepository>(),
                StaticThrottle(),
                NullLogger<PullLiveOddsUseCase>.Instance));

        return services.BuildServiceProvider();
    }

    private static IOptionsMonitor<ScrapingThrottle> StaticThrottle()
    {
        var monitor = Substitute.For<IOptionsMonitor<ScrapingThrottle>>();
        monitor.CurrentValue.Returns(new ScrapingThrottle { MaxConcurrentRequests = 1 });
        return monitor;
    }

    private static IOptionsMonitor<WorkerOptions> BuildOptions(
        bool enabled = true,
        int intervalSeconds = 0)
    {
        var opts = new WorkerOptions
        {
            LivePollerEnabled       = enabled,
            LivePollIntervalSeconds = intervalSeconds,
        };
        var monitor = Substitute.For<IOptionsMonitor<WorkerOptions>>();
        monitor.CurrentValue.Returns(opts);
        return monitor;
    }

    [Fact]
    public async Task Should_InvokeUseCase_When_PollerIsEnabled()
    {
        // Arrange — scraper returns 1 event; snapshot succeeds
        var eventId = new EventId("10000001");
        var ev = new Event(eventId, new SportCode(6), "BY", "league-1", "Group",
            new DateTimeOffset(2026, 5, 10, 18, 0, 0, MoscowOffset), "A", "B");

        var scraper      = Substitute.For<IOddsScraper>();
        var eventRepo    = Substitute.For<IEventRepository>();
        var snapshotRepo = Substitute.For<ISnapshotRepository>();

        // Use case discovers live events via ScrapeLiveAsync (NOT ListAsync)
        scraper.ScrapeLiveAsync(Arg.Any<CancellationToken>())
            .Returns(new List<Event> { ev }.AsReadOnly());
        eventRepo.GetAsync(eventId, Arg.Any<CancellationToken>())
            .Returns(ev);
        scraper.ScrapeEventOddsAsync(
                Arg.Is<Event>(e => e.Id == eventId), OddsSource.Live, Arg.Any<CancellationToken>())
            .Returns(MakeSnapshot(eventId));

        var sp     = BuildServiceProvider(scraper, eventRepo, snapshotRepo);
        var opts   = BuildOptions(enabled: true, intervalSeconds: 0);
        var poller = new LiveOddsPoller(sp, opts, NullLogger<LiveOddsPoller>.Instance);

        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(3));

        // Act
        await poller.StartAsync(cts.Token);
        await Task.Delay(300); // allow at least one cycle
        await poller.StopAsync(CancellationToken.None);

        // Assert — snapshot was added at least once
        await snapshotRepo.Received().AddAsync(Arg.Any<OddsSnapshot>(), Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task Should_NotInvokeUseCase_When_PollerIsDisabled()
    {
        // Arrange
        var scraper      = Substitute.For<IOddsScraper>();
        var eventRepo    = Substitute.For<IEventRepository>();
        var snapshotRepo = Substitute.For<ISnapshotRepository>();

        var sp     = BuildServiceProvider(scraper, eventRepo, snapshotRepo);
        var opts   = BuildOptions(enabled: false, intervalSeconds: 0);
        var poller = new LiveOddsPoller(sp, opts, NullLogger<LiveOddsPoller>.Instance);

        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(2));

        // Act
        await poller.StartAsync(cts.Token);
        await Task.Delay(300);
        await poller.StopAsync(CancellationToken.None);

        // Assert — no snapshot attempts while disabled
        await snapshotRepo.DidNotReceive().AddAsync(Arg.Any<OddsSnapshot>(), Arg.Any<CancellationToken>());
        await scraper.DidNotReceive().ScrapeLiveAsync(Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task Should_ContinueRunning_When_UseCaseThrowsException()
    {
        // Arrange — ListAsync always throws; poller must survive
        var scraper      = Substitute.For<IOddsScraper>();
        var eventRepo    = Substitute.For<IEventRepository>();
        var snapshotRepo = Substitute.For<ISnapshotRepository>();

        // Use case calls ScrapeLiveAsync first; if it throws, the cycle returns 0
        // without hitting the repo. To exercise the "poller survives failures"
        // path, make ScrapeLiveAsync itself throw.
        scraper.ScrapeLiveAsync(Arg.Any<CancellationToken>())
            .ThrowsAsync(new InvalidOperationException("listing unavailable"));

        var sp     = BuildServiceProvider(scraper, eventRepo, snapshotRepo);
        var opts   = BuildOptions(enabled: true, intervalSeconds: 0);
        var poller = new LiveOddsPoller(sp, opts, NullLogger<LiveOddsPoller>.Instance);

        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(2));

        // Act — start, let failures occur, stop cleanly
        await poller.StartAsync(cts.Token);
        await Task.Delay(400);

        var stopAct = async () => await poller.StopAsync(CancellationToken.None);

        // Assert — StopAsync must not propagate the exception
        await stopAct.Should().NotThrowAsync();

        // Scraper was hit at least once (poller cycled at least one iteration).
        // The use case swallows ScrapeLiveAsync exceptions and returns 0, so the
        // poller's catch block is not triggered — but it still cycles.
        await scraper.Received().ScrapeLiveAsync(Arg.Any<CancellationToken>());
    }
}