using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

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

/// <summary>
///     Gitea #610 — pins <see cref="DriverArrayWriteSupport"/>'s Modbus row against the REAL write path. For every
///     region × element type, the server advertises an array node writable exactly when the driver accepts a
///     whole-array write for it. A driver change that gains or loses an array encoder fails here until the table
///     follows — so the server can never advertise a write this driver refuses (nor hide one it accepts).
/// </summary>
[Trait("Category", "Unit")]
public sealed class ModbusArrayWriteSupportParityTests
{
    private static IEnumerable<(ModbusRegion Region, ModbusDataType DataType)> Shapes() =>
        from region in Enum.GetValues<ModbusRegion>()
        from dt in Enum.GetValues<ModbusDataType>()
        select (region, dt);

    public static TheoryData<ModbusRegion, ModbusDataType> AllShapes()
    {
        var data = new TheoryData<ModbusRegion, ModbusDataType>();
        foreach (var (region, dt) in Shapes()) data.Add(region, dt);
        return data;
    }

    [Theory]
    [MemberData(nameof(AllShapes))]
    public async Task Table_agrees_with_the_driver_write_path(ModbusRegion region, ModbusDataType dataType)
    {
        var json = $$"""{"region":"{{region}}","address":10,"dataType":"{{dataType}}","stringLength":4,"isArray":true,"arrayLength":2}""";
        var fake = new ModbusDriverTests.FakeTransport();
        var drv = new ModbusDriver(
            new ModbusDriverOptions { Host = "fake", RawTags = [new RawTagEntry("cell/modbus/arr", json, false)] },
            "modbus-array-parity", _ => fake);
        await drv.InitializeAsync("{}", CancellationToken.None);

        // A two-element value every element type can convert (Convert.ToBoolean / ToInt16 / ToSingle … of 1).
        var result = await drv.WriteAsync([new WriteRequest("cell/modbus/arr", new object[] { 1, 1 })], CancellationToken.None);
        var driverAccepts = result.Single().StatusCode == 0u;

        DriverArrayWriteSupport.Supports(DriverTypeNames.Modbus, "Int16", json).ShouldBe(
            driverAccepts, $"region={region} dataType={dataType}: driver status 0x{result.Single().StatusCode:X8}");
    }

    /// <summary>Positive control: the theory above is not vacuously "everything refused".</summary>
    [Fact]
    public void The_matrix_contains_both_answers()
    {
        var answers = Shapes()
            .Select(s => DriverArrayWriteSupport.Supports(
                DriverTypeNames.Modbus, "Int16",
                $$"""{"region":"{{s.Region}}","address":10,"dataType":"{{s.DataType}}"}"""))
            .ToHashSet();
        answers.ShouldBe(new[] { true, false }, ignoreOrder: true);
    }
}