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 authored raw tag (by its RawPath)
///     to its OWN device host so per-host breaker keys are correct for multi-device drivers. A reference
///     that resolves to no authored tag falls back to the first device rather than keying 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";

    // The driver builds its RawPath → definition table (with each tag's resolved device host) at
    // InitializeAsync, so the driver must be initialized before ResolveHost can resolve a tag — as it
    // always is when ResolveHost runs at runtime. Probe off / no connect: init just parses devices + tags.
    private static async Task<FocasDriver> NewDriverAsync(params FocasTagDefinition[] tags)
    {
        var drv = new FocasDriver(
            new FocasDriverOptions
            {
                Devices = [new FocasDeviceOptions(DeviceA), new FocasDeviceOptions(DeviceB)],
                RawTags = FocasRawTags.Entries(tags),
                Probe = new FocasProbeOptions { Enabled = false },
            },
            "focas-1", new FakeFocasClientFactory());
        await drv.InitializeAsync("{}", CancellationToken.None);
        return drv;
    }

    /// <summary>An authored tag routed to device B resolves to device B's host, not the first device.</summary>
    [Fact]
    public async Task ResolveHost_AuthoredTag_ReturnsItsOwnDeviceHost()
    {
        var drv = await NewDriverAsync(new FocasTagDefinition("eq/onB", DeviceB, "R100", FocasDataType.Byte));
        drv.ResolveHost("eq/onB").ShouldBe(DeviceB);
    }

    /// <summary>A reference that resolves to no authored tag falls back to the first device, not an empty host.</summary>
    [Fact]
    public async Task ResolveHost_UnresolvedRef_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);
    }
}
