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

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

/// <summary>
///     Task #231 — verifies that tag/member descriptions parsed from L5K and L5X exports thread
///     through <see cref="AbCipTagDefinition.Description"/> /
///     <see cref="AbCipStructureMember.Description"/> + land on
///     <see cref="DriverAttributeInfo.Description"/> on the produced address-space variables, so
///     downstream OPC UA Variable nodes carry the source-project comment as their Description
///     attribute.
/// </summary>
[Trait("Category", "Unit")]
public sealed class AbCipDescriptionThreadingTests
{
    private const string DeviceHost = "ab://10.0.0.5/1,0";

    [Fact]
    public void L5kParser_captures_member_description_from_attribute_block()
    {
        const string body = """
            DATATYPE MyUdt
                MEMBER Speed : DINT (Description := "Belt speed in RPM");
            END_DATATYPE
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

        var member = doc.DataTypes.Single().Members.Single();
        member.Name.ShouldBe("Speed");
        member.Description.ShouldBe("Belt speed in RPM");
    }

    [Fact]
    public void L5xParser_captures_member_description_child_node()
    {
        const string xml = """
            <?xml version="1.0" encoding="UTF-8"?>
            <RSLogix5000Content>
              <Controller>
                <DataTypes>
                  <DataType Name="MyUdt">
                    <Members>
                      <Member Name="Speed" DataType="DINT" Dimension="0" ExternalAccess="Read/Write">
                        <Description><![CDATA[Belt speed in RPM]]></Description>
                      </Member>
                    </Members>
                  </DataType>
                </DataTypes>
              </Controller>
            </RSLogix5000Content>
            """;
        var doc = L5xParser.Parse(new StringL5kSource(xml));

        doc.DataTypes.Single().Members.Single().Description.ShouldBe("Belt speed in RPM");
    }

    [Fact]
    public void L5kIngest_threads_tag_and_member_descriptions_into_AbCipTagDefinition()
    {
        const string body = """
            DATATYPE MotorBlock
                MEMBER Speed : DINT (Description := "Setpoint RPM");
                MEMBER Status : DINT;
            END_DATATYPE
            TAG
                Motor1 : MotorBlock (Description := "Conveyor motor 1") := [];
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

        var result = new L5kIngest { DefaultDeviceHostAddress = DeviceHost }.Ingest(doc);

        var tag = result.Tags.Single();
        tag.Description.ShouldBe("Conveyor motor 1");
        tag.Members.ShouldNotBeNull();
        var members = tag.Members!.ToDictionary(m => m.Name);
        members["Speed"].Description.ShouldBe("Setpoint RPM");
        members["Status"].Description.ShouldBeNull();
    }

    [Fact]
    public async Task DiscoverAsync_sets_Description_on_DriverAttributeInfo_for_atomic_tag()
    {
        var builder = new RecordingBuilder();
        var drv = new AbCipDriver(new AbCipDriverOptions
        {
            Devices = [new AbCipDeviceOptions(DeviceHost)],
            Tags =
            [
                new AbCipTagDefinition(
                    Name: "Speed",
                    DeviceHostAddress: DeviceHost,
                    TagPath: "Motor1.Speed",
                    DataType: AbCipDataType.DInt,
                    Description: "Belt speed in RPM"),
                new AbCipTagDefinition(
                    Name: "NoDescription",
                    DeviceHostAddress: DeviceHost,
                    TagPath: "X",
                    DataType: AbCipDataType.DInt),
            ],
        }, "drv-1");
        await drv.InitializeAsync("{}", CancellationToken.None);

        await drv.DiscoverAsync(builder, CancellationToken.None);

        builder.Variables.Single(v => v.BrowseName == "Speed").Info.Description
            .ShouldBe("Belt speed in RPM");
        // Tags without descriptions leave Info.Description null (back-compat path).
        builder.Variables.Single(v => v.BrowseName == "NoDescription").Info.Description
            .ShouldBeNull();
    }

    [Fact]
    public async Task DiscoverAsync_sets_Description_on_DriverAttributeInfo_for_UDT_members()
    {
        var builder = new RecordingBuilder();
        var drv = new AbCipDriver(new AbCipDriverOptions
        {
            Devices = [new AbCipDeviceOptions(DeviceHost)],
            Tags =
            [
                new AbCipTagDefinition(
                    Name: "Motor1",
                    DeviceHostAddress: DeviceHost,
                    TagPath: "Motor1",
                    DataType: AbCipDataType.Structure,
                    Members:
                    [
                        new AbCipStructureMember(
                            Name: "Speed",
                            DataType: AbCipDataType.DInt,
                            Description: "Setpoint RPM"),
                        new AbCipStructureMember(
                            Name: "Status",
                            DataType: AbCipDataType.DInt),
                    ]),
            ],
        }, "drv-1");
        await drv.InitializeAsync("{}", CancellationToken.None);

        await drv.DiscoverAsync(builder, CancellationToken.None);

        builder.Variables.Single(v => v.BrowseName == "Speed").Info.Description
            .ShouldBe("Setpoint RPM");
        builder.Variables.Single(v => v.BrowseName == "Status").Info.Description
            .ShouldBeNull();
    }

    // ---- helpers ----

    private sealed class RecordingBuilder : IAddressSpaceBuilder
    {
        public List<(string BrowseName, string DisplayName)> Folders { get; } = new();
        public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = new();

        public IAddressSpaceBuilder Folder(string browseName, string displayName)
        { Folders.Add((browseName, displayName)); return this; }

        public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo info)
        { Variables.Add((browseName, info)); return new Handle(info.FullName); }

        public void AddProperty(string _, DriverDataType __, object? ___) { }

        private sealed class Handle(string fullRef) : IVariableHandle
        {
            public string FullReference => fullRef;
            public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
        }

        private sealed class NullSink : IAlarmConditionSink
        {
            public void OnTransition(AlarmEventArgs args) { }
        }
    }
}