using libplctag;
using ZB.MOM.WW.OtOpcUa.Driver.Ab.Transport;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.AbCip;

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

[Trait("Category", "Unit")]
public sealed class AbCipStatusMapperTests
{
    /// <summary>Verifies that transport status values are mapped to OPC UA status codes.</summary>
    /// <param name="status">The transport status to map.</param>
    /// <param name="expected">The expected OPC UA status code.</param>
    [Theory]
    [InlineData(AbStatus.Ok, AbCipStatusMapper.Good)]
    [InlineData(AbStatus.Pending, AbCipStatusMapper.GoodMoreData)]
    [InlineData(AbStatus.Timeout, AbCipStatusMapper.BadTimeout)]
    [InlineData(AbStatus.NotFound, AbCipStatusMapper.BadNodeIdUnknown)]
    [InlineData(AbStatus.NotAllowed, AbCipStatusMapper.BadNotWritable)]
    [InlineData(AbStatus.OutOfBounds, AbCipStatusMapper.BadOutOfRange)]
    [InlineData(AbStatus.TooLarge, AbCipStatusMapper.BadOutOfRange)]
    [InlineData(AbStatus.TooSmall, AbCipStatusMapper.BadOutOfRange)]
    [InlineData(AbStatus.Unsupported, AbCipStatusMapper.BadNotSupported)]
    [InlineData(AbStatus.TypeMismatch, AbCipStatusMapper.BadTypeMismatch)]
    [InlineData(AbStatus.DeviceStateConflict, AbCipStatusMapper.BadDeviceFailure)]
    [InlineData(AbStatus.BadConnection, AbCipStatusMapper.BadCommunicationError)]
    [InlineData(AbStatus.BadReply, AbCipStatusMapper.BadCommunicationError)]
    [InlineData(AbStatus.Partial, AbCipStatusMapper.BadCommunicationError)]
    [InlineData(AbStatus.Abort, AbCipStatusMapper.BadCommunicationError)]
    public void MapStatus_maps_every_AbStatus(AbStatus status, uint expected)
    {
        AbCipStatusMapper.MapStatus(status).ShouldBe(expected);
        // The int overload must agree - it is the seam IAbCipTagRuntime.GetStatus() drives.
        AbCipStatusMapper.MapStatus((int)status).ShouldBe(expected);
    }

    /// <summary>Verifies that timeout is distinguished from generic communication error.</summary>
    [Fact]
    public void MapStatus_distinguishes_timeout_from_generic_comms_error()
    {
        AbCipStatusMapper.MapStatus((int)AbStatus.Timeout).ShouldBe(AbCipStatusMapper.BadTimeout);
        AbCipStatusMapper.MapStatus((int)AbStatus.NotFound).ShouldBe(AbCipStatusMapper.BadNodeIdUnknown);
        AbCipStatusMapper.MapStatus((int)AbStatus.NotFound).ShouldNotBe(AbCipStatusMapper.BadCommunicationError);
    }

    /// <summary>Verifies MapException maps transport exceptions by status and everything else to comms error.</summary>
    [Fact]
    public void MapException_uses_the_transport_status()
    {
        AbCipStatusMapper.MapException(new AbTransportException(AbStatus.NotFound, "x"))
            .ShouldBe(AbCipStatusMapper.BadNodeIdUnknown);
        AbCipStatusMapper.MapException(new InvalidOperationException("x"))
            .ShouldBe(AbCipStatusMapper.BadCommunicationError);
    }

    /// <summary>
    ///     Regression oracle: the OPC UA code the pre-AbStatus <c>MapLibplctagStatus</c> returned for every
    ///     libplctag member (table copied from the deleted switch) must equal
    ///     <c>MapStatus(ToAbStatus(member))</c>.
    /// </summary>
    /// <param name="status">A libplctag status.</param>
    [Theory]
    [MemberData(nameof(AllLibplctagStatuses))]
    public void Translation_plus_MapStatus_matches_the_old_libplctag_mapping(Status status)
    {
        AbCipStatusMapper.MapStatus(LibplctagStatusTranslation.ToAbStatus(status)).ShouldBe(OldMapLibplctagStatus(status));
    }

    /// <summary>Every defined libplctag <see cref="Status"/> member.</summary>
    /// <returns>One row per member.</returns>
    public static IEnumerable<object[]> AllLibplctagStatuses() =>
        Enum.GetValues<Status>().Select(s => new object[] { s });

    private static uint OldMapLibplctagStatus(Status status) => status switch
    {
        Status.Ok => AbCipStatusMapper.Good,
        Status.Pending => AbCipStatusMapper.GoodMoreData,
        Status.ErrorTimeout => AbCipStatusMapper.BadTimeout,
        Status.ErrorNotFound or Status.ErrorNoMatch or Status.ErrorBadDevice => AbCipStatusMapper.BadNodeIdUnknown,
        Status.ErrorNotAllowed => AbCipStatusMapper.BadNotWritable,
        Status.ErrorOutOfBounds or Status.ErrorTooLarge or Status.ErrorTooSmall => AbCipStatusMapper.BadOutOfRange,
        Status.ErrorUnsupported or Status.ErrorNotImplemented => AbCipStatusMapper.BadNotSupported,
        _ => AbCipStatusMapper.BadCommunicationError, // incl. BadConnection/BadGateway/BadReply/Partial/Abort/...
    };

    /// <summary>A decode past the buffer end surfaces as BadOutOfRange once the adapter wraps it.</summary>
    [Fact]
    public void Wrapped_decode_OutOfBounds_maps_to_BadOutOfRange()
    {
        var ex = Should.Throw<AbTransportException>(() =>
            LibplctagStatusTranslation.WrapSync<int>(() => throw new LibPlcTagException("ErrorOutOfBounds")));

        AbCipStatusMapper.MapException(ex).ShouldBe(AbCipStatusMapper.BadOutOfRange);
    }
}