lmxopcua/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/TwinCATDiagnosticsTests.cs

using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Driver.TwinCAT;

namespace ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests;

/// <summary>Gitea #645 / #314 — PLC state / task-cycle facts on the optional IDriverDiagnostics bag.</summary>
[Trait("Category", "Unit")]
public sealed class TwinCATDiagnosticsTests
{
    private const string Host1 = "ads://5.23.91.23.1.1:851";
    private const string Host2 = "ads://5.23.91.24.1.1:851";

    private static TwinCATDriver NewDriver(FakeTwinCATClientFactory factory, bool probe, params (string host, string? name)[] devices) =>
        new(new TwinCATDriverOptions
        {
            Devices = [.. devices.Select(d => new TwinCATDeviceOptions(d.host, d.name))],
            Probe = new TwinCATProbeOptions { Enabled = probe, Interval = TimeSpan.FromMilliseconds(20) },
        }, "drv-diag", factory);

    private static FakeTwinCATClient PlcClient() => new()
    {
        AdsStateText = "Run",
        Values =
        {
            [TwinCATDriver.SymAppName] = "Plc30 App",
            [TwinCATDriver.SymOnlineChangeCnt] = 7u,
            [TwinCATDriver.SymCycleTime] = 100_000u,   // 10.0 ms
            [TwinCATDriver.SymLastExecTime] = 25_000u, // 2.5 ms
        },
    };

    private static async Task Sample(TwinCATDriver drv, FakeTwinCATClient client, string host)
    {
        var state = drv.GetDeviceState(host)!;
        await drv.SampleDeviceDiagnosticsAsync(state, client, CancellationToken.None);
    }

    /// <summary>Verifies the driver advertises the optional capability and is empty before any sample.</summary>
    [Fact]
    public async Task Bag_is_empty_before_the_first_sample()
    {
        var drv = NewDriver(new FakeTwinCATClientFactory(), false, (Host1, null));
        await drv.InitializeAsync("{}", CancellationToken.None);

        var diag = drv.ShouldBeAssignableTo<IDriverDiagnostics>()!;
        diag.GetDiagnostics().ShouldBeEmpty();
    }

    /// <summary>Verifies a single-device driver publishes flat keys with state, app, cycle, exec and jitter.</summary>
    [Fact]
    public async Task Single_device_publishes_flat_keys()
    {
        var drv = NewDriver(new FakeTwinCATClientFactory(), false, (Host1, null));
        await drv.InitializeAsync("{}", CancellationToken.None);
        await Sample(drv, PlcClient(), Host1);

        var bag = ((IDriverDiagnostics)drv).GetDiagnostics();

        bag["TwinCAT.AdsState"].ShouldBe("Run");
        bag["TwinCAT.AppName"].ShouldBe("Plc30 App");
        bag["TwinCAT.OnlineChangeCnt"].ShouldBe("7");
        bag["TwinCAT.CycleTimeMs"].ShouldBe("10.0");
        bag["TwinCAT.LastExecTimeMs"].ShouldBe("2.5");
        bag["TwinCAT.JitterMs"].ShouldBe("-7.5");
        DriverDiagnostics.Bound(bag).Count.ShouldBe(bag.Count); // within the host's 16-entry cap
    }

    /// <summary>Verifies several devices are told apart by device name, falling back to host address.</summary>
    [Fact]
    public async Task Multiple_devices_are_prefixed()
    {
        var drv = NewDriver(new FakeTwinCATClientFactory(), false, (Host1, "Elma01"), (Host2, null));
        await drv.InitializeAsync("{}", CancellationToken.None);
        await Sample(drv, PlcClient(), Host1);
        await Sample(drv, PlcClient(), Host2);

        var bag = ((IDriverDiagnostics)drv).GetDiagnostics();

        bag["TwinCAT.Elma01.AdsState"].ShouldBe("Run");
        bag[$"TwinCAT.{Host2}.CycleTimeMs"].ShouldBe("10.0");
        bag.ContainsKey("TwinCAT.AdsState").ShouldBeFalse();
    }

    /// <summary>Verifies a runtime without _TaskInfo (older TwinCAT 2) still yields the facts it has, and
    /// the missing symbols are asked for once, not on every probe tick.</summary>
    [Fact]
    public async Task Missing_task_info_gives_a_partial_bag_and_is_not_re_asked()
    {
        var drv = NewDriver(new FakeTwinCATClientFactory(), false, (Host1, null));
        await drv.InitializeAsync("{}", CancellationToken.None);
        var client = new FakeTwinCATClient { AdsStateText = "Run" };
        client.Values[TwinCATDriver.SymAppName] = "Plc1";
        client.ReadStatuses[TwinCATDriver.SymCycleTime] = TwinCATStatusMapper.BadNodeIdUnknown;
        client.ReadStatuses[TwinCATDriver.SymLastExecTime] = TwinCATStatusMapper.BadNodeIdUnknown;
        client.ReadStatuses[TwinCATDriver.SymOnlineChangeCnt] = TwinCATStatusMapper.BadNodeIdUnknown;

        await Sample(drv, client, Host1);
        var readsAfterFirst = client.SingleReadCount;
        await Sample(drv, client, Host1);

        var bag = ((IDriverDiagnostics)drv).GetDiagnostics();
        bag["TwinCAT.AdsState"].ShouldBe("Run");
        bag["TwinCAT.AppName"].ShouldBe("Plc1");
        bag.Keys.ShouldNotContain("TwinCAT.CycleTimeMs");
        bag.Keys.ShouldNotContain("TwinCAT.JitterMs");
        client.SingleReadCount.ShouldBe(readsAfterFirst + 1); // only AppName is read again
    }

    /// <summary>Verifies a failed sample keeps the previous snapshot rather than blanking the bag.</summary>
    [Fact]
    public async Task Failed_sample_keeps_the_last_values()
    {
        var drv = NewDriver(new FakeTwinCATClientFactory(), false, (Host1, null));
        await drv.InitializeAsync("{}", CancellationToken.None);
        var client = PlcClient();
        await Sample(drv, client, Host1);

        client.ThrowOnRead = true;
        client.AdsStateText = null;
        await Sample(drv, client, Host1);

        var bag = ((IDriverDiagnostics)drv).GetDiagnostics();
        bag["TwinCAT.CycleTimeMs"].ShouldBe("10.0");
        bag["TwinCAT.AdsState"].ShouldBe("Run");
    }

    /// <summary>Verifies the probe loop itself fills the bag — no manual sampling.</summary>
    [Fact]
    public async Task Probe_loop_populates_the_bag()
    {
        var factory = new FakeTwinCATClientFactory { Customise = PlcClient };
        var drv = NewDriver(factory, true, (Host1, null));
        await drv.InitializeAsync("{}", CancellationToken.None);
        try
        {
            IReadOnlyDictionary<string, string> bag = new Dictionary<string, string>();
            for (var i = 0; i < 100 && bag.Count == 0; i++)
            {
                await Task.Delay(50);
                bag = ((IDriverDiagnostics)drv).GetDiagnostics();
            }
            bag["TwinCAT.OnlineChangeCnt"].ShouldBe("7");
        }
        finally { await drv.ShutdownAsync(CancellationToken.None); }
    }
}