using System.Text.Json;
using System.Text.Json.Serialization;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers.Forms;
using ZB.MOM.WW.OtOpcUa.Driver.AbCip;

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

public sealed class AbCipDriverPageFormSerializationTests
{
    private static readonly JsonSerializerOptions _opts = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        WriteIndented = false,
    };

    private static readonly JsonSerializerOptions TestJsonOpts = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
    };

    [Fact]
    public void RoundTrip_PreservesKnownFields()
    {
        var original = new AbCipDriverOptions
        {
            Timeout = TimeSpan.FromSeconds(5),
            EnableControllerBrowse = true,
            EnableAlarmProjection = true,
            AlarmPollInterval = TimeSpan.FromSeconds(2),
            EnableDeclarationOnlyUdtGrouping = true,
            Probe = new AbCipProbeOptions
            {
                Enabled = true,
                Interval = TimeSpan.FromSeconds(10),
                Timeout = TimeSpan.FromSeconds(3),
                ProbeTagPath = "Program:Main.HealthBit",
            },
            ProbeTimeoutSeconds = 10,
            Devices =
            [
                new AbCipDeviceOptions("ab://10.0.0.1/1,0", AbCipPlcFamily.ControlLogix, "PLC-1"),
            ],
        };

        var json = JsonSerializer.Serialize(original, _opts);
        var back = JsonSerializer.Deserialize<AbCipDriverOptions>(json, _opts);

        back.ShouldNotBeNull();
        back.Timeout.ShouldBe(TimeSpan.FromSeconds(5));
        back.EnableControllerBrowse.ShouldBeTrue();
        back.EnableAlarmProjection.ShouldBeTrue();
        back.AlarmPollInterval.ShouldBe(TimeSpan.FromSeconds(2));
        back.EnableDeclarationOnlyUdtGrouping.ShouldBeTrue();
        back.Probe.Enabled.ShouldBeTrue();
        back.Probe.Interval.ShouldBe(TimeSpan.FromSeconds(10));
        back.Probe.Timeout.ShouldBe(TimeSpan.FromSeconds(3));
        back.Probe.ProbeTagPath.ShouldBe("Program:Main.HealthBit");
        back.ProbeTimeoutSeconds.ShouldBe(10);
        back.Devices.Count.ShouldBe(1);
        back.Devices[0].HostAddress.ShouldBe("ab://10.0.0.1/1,0");
        back.Devices[0].PlcFamily.ShouldBe(AbCipPlcFamily.ControlLogix);
    }

    [Fact]
    public void Deserialize_DropsUnknownFields()
    {
        var jsonWithExtra = """{"unknownField":"old-value","probeTimeoutSeconds":10}""";

        var optsWithSkip = new JsonSerializerOptions(_opts)
        {
            UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
        };

        var back = JsonSerializer.Deserialize<AbCipDriverOptions>(jsonWithExtra, optsWithSkip);
        back.ShouldNotBeNull();
        back.ProbeTimeoutSeconds.ShouldBe(10);
    }

    // v3 Batch-2 (WP3): the embedded-Devices CollectionEditor + AbCipDeviceRow retired — devices are now
    // separate Device entities authored via the raw-tree DeviceModal (AbCipDeviceModel, HostAddress/PlcFamily
    // into DeviceConfig). The former DeviceRow_* / ValidateDeviceRow_* tests were removed. The channel-config
    // FormModel now lives in AbCipDriverForm; the multi-device Devices array it preserves is covered below.

    [Fact]
    public void Device_list_survives_form_serialize_round_trip()
    {
        var devices = new List<AbCipDeviceOptions>
        {
            new("ab://10.0.0.1/1,0", AbCipPlcFamily.ControlLogix, "PLC-1"),
            new("ab://10.0.0.2/1,0", AbCipPlcFamily.CompactLogix, "PLC-2"),
        };
        var opts = new AbCipDriverForm.FormModel().ToOptions(devices);
        var json = JsonSerializer.Serialize(opts, TestJsonOpts);
        var back = JsonSerializer.Deserialize<AbCipDriverOptions>(json, TestJsonOpts)!;
        back.Devices.Count.ShouldBe(2);
        back.Devices[0].HostAddress.ShouldBe("ab://10.0.0.1/1,0");
        back.Devices[0].PlcFamily.ShouldBe(AbCipPlcFamily.ControlLogix);
        back.Devices[1].PlcFamily.ShouldBe(AbCipPlcFamily.CompactLogix);
    }

    // ---- Task 19: Transport (native AB transport switch) ----
    // These drive the form's OWN load/save path (TryDeserialize -> FromOptions -> ToOptions -> Serialize),
    // which uses the production JsonSerializerOptions, so a numeric enum or a dropped field shows up here.

    [Theory]
    [InlineData(AbCipTransport.Libplctag)]
    [InlineData(AbCipTransport.Native)]
    [InlineData(null)]
    public void Transport_survives_FromOptions_ToOptions(AbCipTransport? transport)
    {
        var original = new AbCipDriverOptions { Transport = transport };
        var back = AbCipDriverForm.FormModel.FromOptions(original).ToOptions([]);
        back.Transport.ShouldBe(transport);
    }

    [Fact]
    public void Native_transport_serializes_as_a_string()
    {
        var form = new AbCipDriverForm.FormModel { Transport = AbCipTransport.Native };
        var json = AbCipDriverForm.Serialize(form.ToOptions([]));
        json.ShouldContain("\"transport\":\"Native\"");
    }

    [Theory]
    [InlineData("Native", AbCipTransport.Native)]
    [InlineData("Libplctag", AbCipTransport.Libplctag)]
    public void Editing_an_unrelated_field_preserves_an_explicit_transport(string savedValue, AbCipTransport expected)
    {
        // The regression the review found: FromOptions/ToOptions dropped Transport, so an operator who set
        // a transport was silently reverted the next time they saved ANY other edit.
        var saved = $$"""{"transport":"{{savedValue}}","timeout":"00:00:02","devices":[]}""";
        var loaded = AbCipDriverForm.TryDeserialize(saved);
        loaded.ShouldNotBeNull();
        loaded.Transport.ShouldBe(expected);

        var form = AbCipDriverForm.FormModel.FromOptions(loaded);
        form.TimeoutSeconds = 7;
        var json = AbCipDriverForm.Serialize(form.ToOptions(loaded.Devices));

        json.ShouldContain($"\"transport\":\"{savedValue}\"");
        json.ShouldContain("\"timeout\":\"00:00:07\"");
    }

    [Fact]
    public void A_config_without_transport_loads_as_Default_and_an_unrelated_edit_keeps_the_key_absent()
    {
        // Task 22 reverses Task 19's "re-emit an explicit Libplctag": that would pin every edited driver to
        // a concrete transport and bypass the driver-side default (and AbLegacy's PLC-5 / LogixPccc
        // exclusion). Absent loads as Default (null) and a save that edits something else still omits it.
        var loaded = AbCipDriverForm.TryDeserialize("""{"probeTimeoutSeconds":5}""");
        loaded.ShouldNotBeNull();
        var form = AbCipDriverForm.FormModel.FromOptions(loaded);
        form.Transport.ShouldBeNull();

        form.TimeoutSeconds = 7;
        var json = AbCipDriverForm.Serialize(form.ToOptions(loaded.Devices));
        json.ShouldNotContain("transport", Case.Insensitive);
        json.ShouldContain("\"timeout\":\"00:00:07\"");
    }

    [Fact]
    public void Choosing_Default_over_an_explicit_transport_drops_the_key()
    {
        var loaded = AbCipDriverForm.TryDeserialize("""{"transport":"Libplctag"}""");
        loaded.ShouldNotBeNull();
        var form = AbCipDriverForm.FormModel.FromOptions(loaded);
        form.Transport.ShouldBe(AbCipTransport.Libplctag);

        form.Transport = null; // the "Default (...)" dropdown option
        AbCipDriverForm.Serialize(form.ToOptions(loaded.Devices)).ShouldNotContain("transport", Case.Insensitive);
    }
}