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;

[Trait("Category", "Unit")]
public sealed class TwinCATDriverTests
{
    [Fact]
    public void DriverType_is_TwinCAT()
    {
        var drv = new TwinCATDriver(new TwinCATDriverOptions(), "drv-1");
        drv.DriverType.ShouldBe("TwinCAT");
        drv.DriverInstanceId.ShouldBe("drv-1");
    }

    [Fact]
    public async Task InitializeAsync_parses_device_addresses()
    {
        var drv = new TwinCATDriver(new TwinCATDriverOptions
        {
            Devices =
            [
                new TwinCATDeviceOptions("ads://5.23.91.23.1.1:851"),
                new TwinCATDeviceOptions("ads://10.0.0.1.1.1:852", DeviceName: "Machine2"),
            ],
        }, "drv-1");

        await drv.InitializeAsync("{}", CancellationToken.None);

        drv.DeviceCount.ShouldBe(2);
        drv.GetDeviceState("ads://5.23.91.23.1.1:851")!.ParsedAddress.Port.ShouldBe(851);
        drv.GetDeviceState("ads://10.0.0.1.1.1:852")!.Options.DeviceName.ShouldBe("Machine2");
    }

    [Fact]
    public async Task InitializeAsync_malformed_address_faults()
    {
        var drv = new TwinCATDriver(new TwinCATDriverOptions
        {
            Devices = [new TwinCATDeviceOptions("not-an-address")],
        }, "drv-1");

        await Should.ThrowAsync<InvalidOperationException>(
            () => drv.InitializeAsync("{}", CancellationToken.None));
        drv.GetHealth().State.ShouldBe(DriverState.Faulted);
    }

    [Fact]
    public async Task ShutdownAsync_clears_devices()
    {
        var drv = new TwinCATDriver(new TwinCATDriverOptions
        {
            Devices = [new TwinCATDeviceOptions("ads://5.23.91.23.1.1:851")],
            Probe = new TwinCATProbeOptions { Enabled = false },
        }, "drv-1");
        await drv.InitializeAsync("{}", CancellationToken.None);

        await drv.ShutdownAsync(CancellationToken.None);
        drv.DeviceCount.ShouldBe(0);
        drv.GetHealth().State.ShouldBe(DriverState.Unknown);
    }

    [Fact]
    public async Task ReinitializeAsync_cycles_devices()
    {
        var drv = new TwinCATDriver(new TwinCATDriverOptions
        {
            Devices = [new TwinCATDeviceOptions("ads://5.23.91.23.1.1:851")],
            Probe = new TwinCATProbeOptions { Enabled = false },
        }, "drv-1");
        await drv.InitializeAsync("{}", CancellationToken.None);
        await drv.ReinitializeAsync("{}", CancellationToken.None);

        drv.DeviceCount.ShouldBe(1);
        drv.GetHealth().State.ShouldBe(DriverState.Healthy);
    }

    [Fact]
    public void DataType_mapping_covers_atomic_iec_types()
    {
        TwinCATDataType.Bool.ToDriverDataType().ShouldBe(DriverDataType.Boolean);
        TwinCATDataType.DInt.ToDriverDataType().ShouldBe(DriverDataType.Int32);
        TwinCATDataType.LInt.ToDriverDataType().ShouldBe(DriverDataType.Int64);
        TwinCATDataType.ULInt.ToDriverDataType().ShouldBe(DriverDataType.UInt64);
        TwinCATDataType.Real.ToDriverDataType().ShouldBe(DriverDataType.Float32);
        TwinCATDataType.LReal.ToDriverDataType().ShouldBe(DriverDataType.Float64);
        TwinCATDataType.String.ToDriverDataType().ShouldBe(DriverDataType.String);
        TwinCATDataType.WString.ToDriverDataType().ShouldBe(DriverDataType.String);
        // IEC durations map to UA Duration; absolute timestamps map to UA DateTime.
        TwinCATDataType.Time.ToDriverDataType().ShouldBe(DriverDataType.Duration);
        TwinCATDataType.TimeOfDay.ToDriverDataType().ShouldBe(DriverDataType.Duration);
        TwinCATDataType.Date.ToDriverDataType().ShouldBe(DriverDataType.DateTime);
        TwinCATDataType.DateTime.ToDriverDataType().ShouldBe(DriverDataType.DateTime);
    }

    [Fact]
    public void IecTime_post_process_converts_TIME_to_TimeSpan_ms()
    {
        var ts = (TimeSpan)AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.Time, 12_345u)!;
        ts.ShouldBe(TimeSpan.FromMilliseconds(12_345));
    }

    [Fact]
    public void IecTime_post_process_converts_TOD_to_TimeSpan_ms()
    {
        var ts = (TimeSpan)AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.TimeOfDay, 3_600_000u)!;
        ts.ShouldBe(TimeSpan.FromHours(1));
    }

    [Fact]
    public void IecTime_post_process_converts_DT_to_DateTime_utc()
    {
        // 1970-01-01 + 1 hour = 1970-01-01 01:00:00 UTC
        var dt = (DateTime)AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.DateTime, 3600u)!;
        dt.ShouldBe(new DateTime(1970, 1, 1, 1, 0, 0, DateTimeKind.Utc));
        dt.Kind.ShouldBe(DateTimeKind.Utc);
    }

    [Fact]
    public void IecTime_post_process_converts_DATE_to_midnight_utc()
    {
        // 86400 seconds = exactly 1970-01-02 00:00 UTC
        var dt = (DateTime)AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.Date, 86_400u)!;
        dt.ShouldBe(new DateTime(1970, 1, 2, 0, 0, 0, DateTimeKind.Utc));
    }

    [Fact]
    public void IecTime_post_process_passthrough_for_non_time_types()
    {
        AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.DInt, 42).ShouldBe(42);
        AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.LReal, 3.14).ShouldBe(3.14);
    }

    [Fact]
    public void ConvertForWrite_TIME_accepts_TimeSpan_and_returns_UDINT_ms()
    {
        var raw = AdsTwinCATClient.ConvertForWrite(TwinCATDataType.Time, TimeSpan.FromMilliseconds(2_500));
        raw.ShouldBeOfType<uint>();
        ((uint)raw).ShouldBe(2_500u);
    }

    [Fact]
    public void ConvertForWrite_TOD_accepts_double_ms()
    {
        var raw = AdsTwinCATClient.ConvertForWrite(TwinCATDataType.TimeOfDay, 60_000.0);
        ((uint)raw).ShouldBe(60_000u);
    }

    [Fact]
    public void ConvertForWrite_DT_accepts_DateTime_and_returns_UDINT_seconds()
    {
        var raw = AdsTwinCATClient.ConvertForWrite(
            TwinCATDataType.DateTime,
            new DateTime(1970, 1, 1, 1, 0, 0, DateTimeKind.Utc));
        ((uint)raw).ShouldBe(3600u);
    }

    [Fact]
    public void ConvertForWrite_DT_round_trips_via_post_process()
    {
        var original = new DateTime(2024, 6, 15, 12, 30, 45, DateTimeKind.Utc);
        var raw = (uint)AdsTwinCATClient.ConvertForWrite(TwinCATDataType.DateTime, original);
        var roundTrip = (DateTime)AdsTwinCATClient.PostProcessIecTime(TwinCATDataType.DateTime, raw)!;
        roundTrip.ShouldBe(original);
    }

    [Fact]
    public void ConvertForWrite_DT_rejects_pre_epoch_values()
    {
        Should.Throw<ArgumentOutOfRangeException>(() =>
            AdsTwinCATClient.ConvertForWrite(
                TwinCATDataType.DateTime,
                new DateTime(1969, 12, 31, 23, 59, 59, DateTimeKind.Utc)));
    }

    [Theory]
    [InlineData(0u, TwinCATStatusMapper.Good)]
    [InlineData(1798u, TwinCATStatusMapper.BadNodeIdUnknown)]   // symbol not found
    [InlineData(1808u, TwinCATStatusMapper.BadNotWritable)]     // access denied
    [InlineData(1861u, TwinCATStatusMapper.BadTimeout)]         // sync timeout
    [InlineData(1793u, TwinCATStatusMapper.BadOutOfRange)]      // invalid index group
    [InlineData(1794u, TwinCATStatusMapper.BadOutOfRange)]      // invalid index offset
    [InlineData(1792u, TwinCATStatusMapper.BadNotSupported)]    // service not supported
    [InlineData(7u, TwinCATStatusMapper.BadCommunicationError)] // port unreachable
    [InlineData(99999u, TwinCATStatusMapper.BadCommunicationError)] // unknown → generic comm fail
    public void StatusMapper_covers_known_ads_error_codes(uint adsError, uint expected)
    {
        TwinCATStatusMapper.MapAdsError(adsError).ShouldBe(expected);
    }
}