using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.FOCAS;

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

/// <summary>
///     CONV-4 — <see cref="FocasDriver.ResolveHost"/> must resolve an equipment-tag reference (raw
///     TagConfig JSON) to its OWN device host so per-host breaker keys are correct for equipment
///     tags. An address-less equipment ref (FOCAS coalesces a missing <c>deviceHostAddress</c> to
///     <c>""</c>) must fall back rather than key an empty host.
/// </summary>
[Trait("Category", "Unit")]
public sealed class FocasResolveHostTests
{
    private const string DeviceA = "focas://10.0.0.5:8193";
    private const string DeviceB = "focas://10.0.0.6:8193";

    // FOCAS's equipment-ref resolver validates against the initialized Devices map, so — unlike
    // the other drivers — the driver must be initialized (as it always is when ResolveHost runs at
    // runtime) before an equipment ref resolves. Probe off / no connect: init just parses devices.
    private static async Task<FocasDriver> NewDriverAsync()
    {
        var drv = new FocasDriver(
            new FocasDriverOptions
            {
                Devices = [new FocasDeviceOptions(DeviceA), new FocasDeviceOptions(DeviceB)],
                Probe = new FocasProbeOptions { Enabled = false },
            },
            "focas-1", new FakeFocasClientFactory());
        await drv.InitializeAsync("{}", CancellationToken.None);
        return drv;
    }

    /// <summary>An equipment-tag ref naming device B resolves to device B's host, not the first device.</summary>
    [Fact]
    public async Task ResolveHost_EquipmentTagRef_ReturnsItsOwnDeviceHost()
    {
        var drv = await NewDriverAsync();
        var json = $$"""{"deviceHostAddress":"{{DeviceB}}","address":"R100","dataType":"Byte"}""";
        drv.ResolveHost(json).ShouldBe(DeviceB);
    }

    /// <summary>An equipment ref with no deviceHostAddress falls back to the first device, not an empty host.</summary>
    [Fact]
    public async Task ResolveHost_EquipmentTagRef_WithoutDeviceHost_FallsBack()
    {
        var drv = await NewDriverAsync();
        var json = """{"address":"R100","dataType":"Byte"}""";
        drv.ResolveHost(json).ShouldBe(DeviceA);
    }

    /// <summary>An unresolvable ref keeps the current first-device fallback.</summary>
    [Fact]
    public async Task ResolveHost_UnknownRef_KeepsCurrentFallback()
    {
        var drv = await NewDriverAsync();
        drv.ResolveHost("totally-unknown").ShouldBe(DeviceA);
    }
}