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 L5kParserTests
{
    [Fact]
    public void Controller_scope_TAG_block_parses_name_datatype_externalaccess()
    {
        const string body = """
            TAG
                Motor1_Speed : DINT (Description := "Motor 1 set point", ExternalAccess := Read/Write) := 0;
                Tank_Level : REAL (ExternalAccess := Read Only) := 0.0;
            END_TAG
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));

        doc.Tags.Count.ShouldBe(2);
        doc.Tags[0].Name.ShouldBe("Motor1_Speed");
        doc.Tags[0].DataType.ShouldBe("DINT");
        doc.Tags[0].ProgramScope.ShouldBeNull();
        doc.Tags[0].ExternalAccess.ShouldBe("Read/Write");
        doc.Tags[0].Description.ShouldBe("Motor 1 set point");
        doc.Tags[0].AliasFor.ShouldBeNull();

        doc.Tags[1].Name.ShouldBe("Tank_Level");
        doc.Tags[1].DataType.ShouldBe("REAL");
        doc.Tags[1].ExternalAccess.ShouldBe("Read Only");
    }

    [Fact]
    public void Program_scope_TAG_block_carries_program_name()
    {
        const string body = """
            PROGRAM MainProgram (Class := Standard)
                TAG
                    StepIndex : DINT := 0;
                    Running : BOOL := 0;
                END_TAG
            END_PROGRAM
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));

        doc.Tags.Count.ShouldBe(2);
        doc.Tags.ShouldAllBe(t => t.ProgramScope == "MainProgram");
        doc.Tags.Select(t => t.Name).ShouldBe(["StepIndex", "Running"]);
    }

    [Fact]
    public void Alias_tag_is_flagged()
    {
        const string body = """
            TAG
                Motor1 : DINT := 0;
                Motor1_Alias : DINT (AliasFor := "Motor1", ExternalAccess := Read/Write);
            END_TAG
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));

        var alias = doc.Tags.Single(t => t.Name == "Motor1_Alias");
        alias.AliasFor.ShouldBe("Motor1");
    }

    [Fact]
    public void DATATYPE_block_collects_member_lines()
    {
        const string body = """
            DATATYPE TankUDT (FamilyType := NoFamily)
                MEMBER Level : REAL (ExternalAccess := Read/Write) := 0.0;
                MEMBER Pressure : REAL := 0.0;
                MEMBER Active : BOOL := 0;
            END_DATATYPE
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));

        doc.DataTypes.Count.ShouldBe(1);
        var udt = doc.DataTypes[0];
        udt.Name.ShouldBe("TankUDT");
        udt.Members.Count.ShouldBe(3);
        udt.Members[0].Name.ShouldBe("Level");
        udt.Members[0].DataType.ShouldBe("REAL");
        udt.Members[0].ExternalAccess.ShouldBe("Read/Write");
        udt.Members[1].Name.ShouldBe("Pressure");
        udt.Members[2].Name.ShouldBe("Active");
        udt.Members[2].DataType.ShouldBe("BOOL");
    }

    [Fact]
    public void DATATYPE_member_with_array_dim_keeps_type_clean()
    {
        const string body = """
            DATATYPE BatchUDT
                MEMBER Recipe : DINT[16] := 0;
                MEMBER Name : STRING := "";
            END_DATATYPE
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));

        var udt = doc.DataTypes[0];
        var recipe = udt.Members.First(m => m.Name == "Recipe");
        recipe.DataType.ShouldBe("DINT");
        recipe.ArrayDim.ShouldBe(16);

        var nameMember = udt.Members.First(m => m.Name == "Name");
        nameMember.DataType.ShouldBe("STRING");
        nameMember.ArrayDim.ShouldBeNull();
    }

    [Fact]
    public void Block_comments_are_stripped_before_parsing()
    {
        const string body = """
            (* This is a long
               multi-line comment with TAG and END_TAG inside, parser must skip *)
            TAG
                Real_Tag : DINT := 0;
            END_TAG
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));
        doc.Tags.Count.ShouldBe(1);
        doc.Tags[0].Name.ShouldBe("Real_Tag");
    }

    [Fact]
    public void Unknown_sections_are_skipped_silently()
    {
        const string body = """
            CONFIG SomeConfig (Class := Standard)
                ConfigData := 0;
            END_CONFIG
            MOTION_GROUP Motion1
                Member := whatever;
            END_MOTION_GROUP
            TAG
                Real_Tag : DINT := 0;
            END_TAG
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));
        doc.Tags.Count.ShouldBe(1);
        doc.Tags[0].Name.ShouldBe("Real_Tag");
    }

    [Fact]
    public void Multi_line_TAG_entry_is_concatenated()
    {
        const string body = """
            TAG
                Motor1 : DINT (Description := "Long description spanning",
                               ExternalAccess := Read/Write) := 0;
            END_TAG
            """;

        var doc = L5kParser.Parse(new StringL5kSource(body));
        doc.Tags.Count.ShouldBe(1);
        doc.Tags[0].Description.ShouldBe("Long description spanning");
        doc.Tags[0].ExternalAccess.ShouldBe("Read/Write");
    }
}