using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.DL205;

/// <summary>
///     Verifies DL205/DL260 binary-coded-decimal register handling against the
///     <c>dl205.json</c> pymodbus profile. HR[1072] = 0x1234 on the profile represents
///     decimal 1234 (BCD nibbles). Reading it as <see cref="ModbusDataType.Int16"/> would
///     return 0x1234 = 4660; the <see cref="ModbusDataType.Bcd16"/> path decodes 1234.
/// </summary>
[Collection(ModbusSimulatorCollection.Name)]
[Trait("Category", "Integration")]
[Trait("Device", "DL205")]
public sealed class DL205BcdQuirkTests(ModbusSimulatorFixture sim)
{
    /// <summary>Verifies DL205 binary-coded-decimal register decodes as decimal value 1234.</summary>
    [Fact]
    public async Task DL205_BCD16_decodes_HR1072_as_decimal_1234()
    {
        if (sim.SkipReason is not null) Assert.Skip(sim.SkipReason);
        if (!string.Equals(Environment.GetEnvironmentVariable("MODBUS_SIM_PROFILE"), "dl205",
                StringComparison.OrdinalIgnoreCase))
        {
            Assert.Skip("MODBUS_SIM_PROFILE != dl205 — skipping (standard profile does not seed HR[1072]).");
        }

        var options = new ModbusDriverOptions
        {
            Host = sim.Host,
            Port = sim.Port,
            UnitId = 1,
            Timeout = TimeSpan.FromSeconds(2),
            Tags =
            [
                new ModbusTagDefinition("DL205_Count_Bcd",
                    ModbusRegion.HoldingRegisters, Address: 1072,
                    DataType: ModbusDataType.Bcd16, Writable: false),
                new ModbusTagDefinition("DL205_Count_Int16",
                    ModbusRegion.HoldingRegisters, Address: 1072,
                    DataType: ModbusDataType.Int16, Writable: false),
            ],
            Probe = new ModbusProbeOptions { Enabled = false },
        };
        await using var driver = new ModbusDriver(options, driverInstanceId: "dl205-bcd");
        await driver.InitializeAsync("{}", TestContext.Current.CancellationToken);

        var results = await driver.ReadAsync(["DL205_Count_Bcd", "DL205_Count_Int16"],
            TestContext.Current.CancellationToken);

        results[0].StatusCode.ShouldBe(0u);
        results[0].Value.ShouldBe(1234, "DL205 BCD register 0x1234 represents decimal 1234 per the DirectLOGIC convention");

        results[1].StatusCode.ShouldBe(0u);
        results[1].Value.ShouldBe((short)0x1234, "same register read as Int16 returns the raw 0x1234 = 4660 value — proves BCD path is distinct");
    }
}