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

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

[Trait("Category", "Unit")]
public sealed class L5kIngestTests
{
    private const string DeviceHost = "ab://10.10.10.1/0,1";

    [Fact]
    public void Atomic_controller_scope_tag_becomes_AbCipTagDefinition()
    {
        const string body = """
            TAG
                Motor1_Speed : DINT (ExternalAccess := Read/Write) := 0;
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        result.Tags.Count.ShouldBe(1);
        var tag = result.Tags[0];
        tag.Name.ShouldBe("Motor1_Speed");
        tag.DeviceHostAddress.ShouldBe(DeviceHost);
        tag.TagPath.ShouldBe("Motor1_Speed");
        tag.DataType.ShouldBe(AbCipDataType.DInt);
        tag.Writable.ShouldBeTrue();
        tag.Members.ShouldBeNull();
    }

    [Fact]
    public void Program_scope_tag_uses_Program_prefix_and_compound_name()
    {
        const string body = """
            PROGRAM MainProgram
                TAG
                    StepIndex : DINT := 0;
                END_TAG
            END_PROGRAM
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        result.Tags.Count.ShouldBe(1);
        result.Tags[0].Name.ShouldBe("MainProgram.StepIndex");
        result.Tags[0].TagPath.ShouldBe("Program:MainProgram.StepIndex");
    }

    [Fact]
    public void Alias_tag_is_skipped()
    {
        const string body = """
            TAG
                Real : DINT := 0;
                Aliased : DINT (AliasFor := "Real");
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        result.SkippedAliasCount.ShouldBe(1);
        result.Tags.Count.ShouldBe(1);
        result.Tags.ShouldAllBe(t => t.Name != "Aliased");
    }

    [Fact]
    public void ExternalAccess_None_tag_is_skipped()
    {
        const string body = """
            TAG
                Hidden : DINT (ExternalAccess := None) := 0;
                Visible : DINT := 0;
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        result.SkippedNoAccessCount.ShouldBe(1);
        result.Tags.Single().Name.ShouldBe("Visible");
    }

    [Fact]
    public void ExternalAccess_ReadOnly_tag_becomes_non_writable()
    {
        const string body = """
            TAG
                Sensor : REAL (ExternalAccess := Read Only) := 0.0;
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        result.Tags.Single().Writable.ShouldBeFalse();
    }

    [Fact]
    public void UDT_typed_tag_picks_up_member_layout_from_DATATYPE_block()
    {
        const string body = """
            DATATYPE TankUDT
                MEMBER Level : REAL := 0.0;
                MEMBER Active : BOOL := 0;
            END_DATATYPE
            TAG
                Tank1 : TankUDT := [0.0, 0];
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        var tag = result.Tags.Single();
        tag.Name.ShouldBe("Tank1");
        tag.DataType.ShouldBe(AbCipDataType.Structure);
        tag.Members.ShouldNotBeNull();
        tag.Members!.Count.ShouldBe(2);
        tag.Members[0].Name.ShouldBe("Level");
        tag.Members[0].DataType.ShouldBe(AbCipDataType.Real);
        tag.Members[1].Name.ShouldBe("Active");
        tag.Members[1].DataType.ShouldBe(AbCipDataType.Bool);
    }

    [Fact]
    public void Unknown_datatype_falls_through_as_structure_with_no_members()
    {
        const string body = """
            TAG
                Mystery : SomeUnknownType := 0;
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

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

        var tag = result.Tags.Single();
        tag.DataType.ShouldBe(AbCipDataType.Structure);
        tag.Members.ShouldBeNull();
    }

    [Fact]
    public void Ingest_throws_when_DefaultDeviceHostAddress_missing()
    {
        var doc = new L5kDocument(new[] { new L5kTag("X", "DINT", null, null, null, null) }, Array.Empty<L5kDataType>());

        Should.Throw<InvalidOperationException>(() => new L5kIngest().Ingest(doc));
    }

    [Fact]
    public void NamePrefix_is_applied_to_imported_tags()
    {
        const string body = """
            TAG
                Speed : DINT := 0;
            END_TAG
            """;
        var doc = L5kParser.Parse(new StringL5kSource(body));

        var result = new L5kIngest
        {
            DefaultDeviceHostAddress = DeviceHost,
            NamePrefix = "PLC1_",
        }.Ingest(doc);

        result.Tags.Single().Name.ShouldBe("PLC1_Speed");
        result.Tags.Single().TagPath.ShouldBe("Speed"); // path on the PLC stays unchanged
    }
}