using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Admin.Components.Pages.Modbus;
using ZB.MOM.WW.OtOpcUa.Driver.Modbus;

namespace ZB.MOM.WW.OtOpcUa.Admin.Tests;

/// <summary>
///     #145 Admin UI: smoke coverage for the ModbusOptionsEditor view model. The Blazor
///     component itself is exercised in browser-runtime tests; this fixture pins the default
///     values the form initialises to so a regression that flips an unedited row to a
///     non-default value gets caught.
/// </summary>
[Trait("Category", "Unit")]
public sealed class ModbusOptionsViewModelTests
{
    [Fact]
    public void DriversTab_Serialized_Defaults_RoundTrip_Through_Factory()
    {
        // #147 — the form's SaveAsync serialises ModbusOptionsViewModel to the JSON DTO
        // shape ModbusDriverFactoryExtensions consumes. This test pins the round-trip:
        // unedited form → JSON → driver instance → options match defaults.
        var vm = new ModbusOptionsEditor.ModbusOptionsViewModel();
        var json = SerializeForRoundTrip(vm);

        var driver = ModbusDriverFactoryExtensions.CreateInstance("modbus-roundtrip", json);
        var opts = (ModbusDriverOptions)typeof(ModbusDriver)
            .GetField("_options", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)!
            .GetValue(driver)!;

        opts.Host.ShouldBe(vm.Host);
        opts.Port.ShouldBe(vm.Port);
        opts.UnitId.ShouldBe(vm.UnitId);
        opts.Family.ShouldBe(vm.Family);
        opts.MelsecSubFamily.ShouldBe(vm.MelsecSubFamily);
        opts.KeepAlive.Enabled.ShouldBe(vm.KeepAliveEnabled);
        opts.MaxRegistersPerRead.ShouldBe((ushort)vm.MaxRegistersPerRead);
        opts.MaxCoilsPerRead.ShouldBe((ushort)vm.MaxCoilsPerRead);
        opts.MaxReadGap.ShouldBe((ushort)vm.MaxReadGap);
        opts.WriteOnChangeOnly.ShouldBe(vm.WriteOnChangeOnly);
    }

    [Fact]
    public void DriversTab_Serializes_Edited_Values_Correctly()
    {
        // Sanity: changing a few fields in the view model produces a JSON the factory
        // accepts and the resulting driver carries the edited values.
        var vm = new ModbusOptionsEditor.ModbusOptionsViewModel
        {
            Host = "10.5.5.5",
            Port = 1502,
            UnitId = 7,
            Family = ModbusFamily.DL205,
            MaxReadGap = 12,
            WriteOnChangeOnly = true,
        };
        var json = SerializeForRoundTrip(vm);
        var driver = ModbusDriverFactoryExtensions.CreateInstance("modbus-edited", json);
        var opts = (ModbusDriverOptions)typeof(ModbusDriver)
            .GetField("_options", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)!
            .GetValue(driver)!;

        opts.Host.ShouldBe("10.5.5.5");
        opts.Port.ShouldBe(1502);
        opts.UnitId.ShouldBe((byte)7);
        opts.Family.ShouldBe(ModbusFamily.DL205);
        opts.MaxReadGap.ShouldBe((ushort)12);
        opts.WriteOnChangeOnly.ShouldBeTrue();
    }

    /// <summary>
    ///     Mirror of DriversTab.razor's SerializeModbusOptions — kept here so the test
    ///     doesn't have to reach through Blazor component plumbing to invoke it. If the
    ///     component method signature drifts, update both.
    /// </summary>
    private static string SerializeForRoundTrip(ModbusOptionsEditor.ModbusOptionsViewModel m) =>
        System.Text.Json.JsonSerializer.Serialize(new
        {
            host = m.Host,
            port = m.Port,
            unitId = m.UnitId,
            family = m.Family.ToString(),
            melsecSubFamily = m.MelsecSubFamily.ToString(),
            keepAlive = new
            {
                enabled = m.KeepAliveEnabled,
                timeMs = m.KeepAliveTimeSec * 1000,
                intervalMs = m.KeepAliveIntervalSec * 1000,
                retryCount = m.KeepAliveRetryCount,
            },
            reconnect = new
            {
                initialDelayMs = m.ReconnectInitialDelayMs,
                maxDelayMs = m.ReconnectMaxDelayMs,
                backoffMultiplier = m.ReconnectBackoffMultiplier,
            },
            maxRegistersPerRead = m.MaxRegistersPerRead,
            maxRegistersPerWrite = m.MaxRegistersPerWrite,
            maxCoilsPerRead = m.MaxCoilsPerRead,
            maxReadGap = m.MaxReadGap,
            useFC15ForSingleCoilWrites = m.UseFC15ForSingleCoilWrites,
            useFC16ForSingleRegisterWrites = m.UseFC16ForSingleRegisterWrites,
            writeOnChangeOnly = m.WriteOnChangeOnly,
            tags = Array.Empty<object>(),
        });

    [Fact]
    public void Defaults_Match_DriverOption_Defaults()
    {
        var vm = new ModbusOptionsEditor.ModbusOptionsViewModel();
        var driverDefault = new ModbusDriverOptions();

        vm.Host.ShouldBe(driverDefault.Host);
        vm.Port.ShouldBe(driverDefault.Port);
        vm.UnitId.ShouldBe(driverDefault.UnitId);
        vm.Family.ShouldBe(driverDefault.Family);
        vm.MelsecSubFamily.ShouldBe(driverDefault.MelsecSubFamily);

        vm.KeepAliveEnabled.ShouldBe(driverDefault.KeepAlive.Enabled);
        vm.KeepAliveTimeSec.ShouldBe((int)driverDefault.KeepAlive.Time.TotalSeconds);
        vm.KeepAliveIntervalSec.ShouldBe((int)driverDefault.KeepAlive.Interval.TotalSeconds);
        vm.KeepAliveRetryCount.ShouldBe(driverDefault.KeepAlive.RetryCount);

        vm.ReconnectInitialDelayMs.ShouldBe((int)driverDefault.Reconnect.InitialDelay.TotalMilliseconds);
        vm.ReconnectMaxDelayMs.ShouldBe((int)driverDefault.Reconnect.MaxDelay.TotalMilliseconds);
        vm.ReconnectBackoffMultiplier.ShouldBe(driverDefault.Reconnect.BackoffMultiplier);

        vm.MaxRegistersPerRead.ShouldBe(driverDefault.MaxRegistersPerRead);
        vm.MaxRegistersPerWrite.ShouldBe(driverDefault.MaxRegistersPerWrite);
        vm.MaxCoilsPerRead.ShouldBe(driverDefault.MaxCoilsPerRead);
        vm.MaxReadGap.ShouldBe(driverDefault.MaxReadGap);
        vm.UseFC15ForSingleCoilWrites.ShouldBe(driverDefault.UseFC15ForSingleCoilWrites);
        vm.UseFC16ForSingleRegisterWrites.ShouldBe(driverDefault.UseFC16ForSingleRegisterWrites);
        vm.WriteOnChangeOnly.ShouldBe(driverDefault.WriteOnChangeOnly);
    }
}