using AvParser.Core.Collecting;
using AvParser.Core.Proxies;
using AvParser.Infrastructure.Storage;
using AvParser.UI.Tests.Fakes;
using AvParser.UI.ViewModels;
using ReactiveUI.Primitives.Concurrency;

namespace AvParser.UI.Tests;

public class DashboardViewModelTests
{
    private sealed class TestPaths : IAppPaths
    {
        public string DataDirectory => Path.Combine(Path.GetTempPath(), "AvParserTests");

        public string SettingsFile => Path.Combine(DataDirectory, "settings.json");

        public string CustomProxiesFile => Path.Combine(DataDirectory, "proxies.custom.json");

        public string ProxyStateFile => Path.Combine(DataDirectory, "proxies.state.json");

        public string LogDirectory => Path.Combine(DataDirectory, "logs");
    }

    private sealed class EmptyServiceProvider : IServiceProvider
    {
        public object? GetService(Type serviceType) => null;
    }

    private sealed class EmptyUserSourceStore : IUserSourceStore
    {
        public event EventHandler? Changed
        {
            add { }
            remove { }
        }

        public IReadOnlyList<AvParser.Core.Collecting.Sources.PatternSourceConfig> List() => [];

        public Task<AvParser.Core.Collecting.Sources.PatternSourceConfig> AddAsync(
            AvParser.Core.Collecting.Sources.PatternSourceConfig config,
            CancellationToken cancellationToken = default
        ) => Task.FromResult(config);

        public Task<bool> UpdateAsync(
            AvParser.Core.Collecting.Sources.PatternSourceConfig config,
            CancellationToken cancellationToken = default
        ) => Task.FromResult(false);

        public Task<bool> RemoveAsync(string id, CancellationToken cancellationToken = default) =>
            Task.FromResult(false);
    }

    private static DashboardViewModel Build(IProxyPool pool) =>
        new(
            new MediaSourceCatalog(new EmptyUserSourceStore()),
            new TestPaths(),
            pool,
            new EmptyServiceProvider(),
            ImmediateSequencer.Instance
        );

    private static ProxyEndpoint Endpoint(string host) => new(ProxyProtocol.Http, host, 8080);

    [Fact]
    public void An_empty_pool_reports_nothing_rather_than_zeroes_dressed_up_as_health()
    {
        using var page = Build(new ProxyPool([], new FakeProxyProbe(), new ProxyOptions()));

        page.ProxyTotal.ShouldBe(0);
        page.HasProxies.ShouldBeFalse();
        page.ProxyLatency.ShouldBeNull();
        page.ProxyRequests.ShouldBeNull();
    }

    [Fact]
    public async Task The_pool_summary_counts_live_and_unchecked_entries()
    {
        var alive = Endpoint("1.2.3.4");
        var dead = Endpoint("5.6.7.8");
        var pool = new ProxyPool(
            [new FakeProxySource([alive, dead])],
            new FakeProxyProbe().Set(alive, alive: true),
            new ProxyOptions()
        );

        using var page = Build(pool);

        await pool.RefreshAsync(TestContext.Current.CancellationToken);
        page.RefreshProxyStats();

        page.ProxyTotal.ShouldBe(2);
        page.HasProxies.ShouldBeTrue();
        // Nothing has been probed yet, so nothing is live however promising the list looks.
        page.ProxyLive.ShouldBe(0);
        page.ProxyUnchecked.ShouldBe(2);

        await pool.SweepAsync(cancellationToken: TestContext.Current.CancellationToken);
        page.RefreshProxyStats();

        page.ProxyLive.ShouldBe(1);
        page.ProxyUnchecked.ShouldBe(0);
        page.ProxyLatency.ShouldNotBeNull().ShouldContain("20");
    }

    [Fact]
    public async Task Real_requests_show_up_as_a_success_rate()
    {
        var endpoint = Endpoint("1.2.3.4");
        var pool = new ProxyPool(
            [new FakeProxySource([endpoint])],
            new FakeProxyProbe().Set(endpoint, alive: true),
            new ProxyOptions()
        );

        using var page = Build(pool);

        await pool.RefreshAsync(TestContext.Current.CancellationToken);
        await pool.SweepAsync(cancellationToken: TestContext.Current.CancellationToken);

        using (var lease = await pool.AcquireAsync(TestContext.Current.CancellationToken))
        {
            lease.ShouldNotBeNull().ReportSuccess(TimeSpan.FromMilliseconds(30));
        }

        page.RefreshProxyStats();

        page.ProxyRequests.ShouldNotBeNull().ShouldContain("1 of 1");
    }

    [Fact]
    public void Disposing_twice_is_safe()
    {
        // The container disposes each page once per registration — its own type and PageViewModel.
        var page = Build(new ProxyPool([], new FakeProxyProbe(), new ProxyOptions()));

        page.Dispose();

        Should.NotThrow(page.Dispose);
    }

    [Fact]
    public async Task The_summary_follows_the_pool_without_being_asked()
    {
        // The page has to react to a sweep it did not start; nobody presses refresh on a dashboard.
        var endpoint = Endpoint("1.2.3.4");
        var pool = new ProxyPool(
            [new FakeProxySource([endpoint])],
            new FakeProxyProbe().Set(endpoint, alive: true),
            new ProxyOptions()
        );

        using var page = Build(pool);
        page.ProxyTotal.ShouldBe(0);

        await pool.RefreshAsync(TestContext.Current.CancellationToken);

        page.ProxyTotal.ShouldBe(1);
    }
}