using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Wire;

namespace ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.Series;

/// <summary>
///     Live-wire coverage (focas-mock) for #257 (<c>cnc_statinfo</c> status flags) and #266 (PMC
///     range coalescing). Skips cleanly when <c>OTOPCUA_FOCAS_SIM_ENDPOINT</c> (default
///     <c>localhost:8193</c>) is unreachable. Read-only: no write path is exercised.
/// </summary>
[Collection(FocasSimCollection.Name)]
public sealed class WireBackendStatusAndPmcTests
{
    private readonly FocasSimFixture _fx;

    /// <summary>Initializes a new instance of the <see cref="WireBackendStatusAndPmcTests"/> class.</summary>
    /// <param name="fx">The FOCAS simulator fixture.</param>
    public WireBackendStatusAndPmcTests(FocasSimFixture fx) => _fx = fx;

    private string DeviceHost => _fx.DeviceUri;

    /// <summary>The mock's <c>cnc_statinfo</c> flags surface through the Status/ subtree and an authored FIXED: tag.</summary>
    [Fact]
    public async Task Status_flags_populate_via_wire_backend()
    {
        if (_fx.SkipReason is not null) Assert.Skip(_fx.SkipReason);
        var ct = TestContext.Current.CancellationToken;

        await _fx.LoadProfileAsync("FWLIB64", ct);
        await _fx.PatchStateAsync(new
        {
            sysinfo = new
            {
                addinfo = 0, max_axis = 8, cnc_type = "M ", mt_type = "M ",
                series = "30i ", version = "A1.0", axes = "1 ",
            },
            axis_names = new[] { "X" },
            statinfo = new { aut = 1, run = 3, motion = 1, mstb = 0, emergency = 0, alarm = 1, edit = 0 },
        }, ct);

        var driver = new FocasDriver(new FocasDriverOptions
        {
            Devices = [new FocasDeviceOptions(DeviceHost)],
            RawTags = FocasRawTags.Entries(
                new FocasTagDefinition("RunFlag", DeviceHost, "FIXED:Status/Run", FocasDataType.Int32, Writable: false)),
            Probe = new FocasProbeOptions { Enabled = false },
            FixedTree = new FocasFixedTreeOptions
            {
                Enabled = true,
                PollInterval = TimeSpan.FromMilliseconds(100),
                ProgramPollInterval = TimeSpan.FromMilliseconds(200),
            },
        }, driverInstanceId: "focas-wire-status", clientFactory: new WireFocasClientFactory());

        await using (driver)
        {
            await driver.InitializeAsync("{}", ct);
            await WaitFor(() => driver.GetDeviceState(DeviceHost) is { LastStatus: not null }, TimeSpan.FromSeconds(5));

            var state = driver.GetDeviceState(DeviceHost);
            state.ShouldNotBeNull();
            state.LastStatus.ShouldNotBeNull();
            state.LastStatus.Run.ShouldBe(3);
            state.LastStatus.Alarm.ShouldBe(1);

            var snaps = await driver.ReadAsync(["RunFlag", $"{DeviceHost}/Status/Alarm", $"{DeviceHost}/Status/RunText"], ct);
            snaps.ShouldAllBe(s => s.StatusCode == FocasStatusMapper.Good);
            snaps[0].Value.ShouldBe(3);
            snaps[1].Value.ShouldBe(1);
            snaps[2].Value.ShouldBe("START");

            // The flags follow the machine.
            await _fx.PatchStateAsync(new { statinfo = new { run = 1, emergency = 1 } }, ct);
            await WaitFor(() => driver.GetDeviceState(DeviceHost) is { LastStatus.Run: 1 }, TimeSpan.FromSeconds(5));
            driver.GetDeviceState(DeviceHost)!.LastStatus!.Emergency.ShouldBe(1);
        }
    }

    private static async Task WaitFor(Func<bool> pred, TimeSpan timeout)
    {
        var deadline = DateTime.UtcNow + timeout;
        while (DateTime.UtcNow < deadline)
        {
            if (pred()) return;
            await Task.Delay(50);
        }
    }
}