using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.ParityTests;

/// <summary>
///     PR 5.6 — History-read parity. Phase-1 routing lifted history off the
///     per-driver <see cref="IHistoryProvider"/> path onto the server-owned
///     <c>HistoryRouter</c> + <c>WonderwareHistorianBootstrap</c>; neither
///     Galaxy backend implements <see cref="IHistoryProvider"/> directly. So
///     the parity surface here is the *routing decision*: both backends must
///     identify the same set of historized attributes and produce the same
///     full-reference for each, so HistoryRouter routes reads identically.
/// </summary>
[Trait("Category", "ParityE2E")]
[Collection(nameof(ParityCollection))]
public sealed class HistoryReadParityTests
{
    private readonly ParityHarness _h;
    public HistoryReadParityTests(ParityHarness h) => _h = h;

    [Fact]
    public async Task Discover_emits_same_historized_attribute_set_for_both_backends()
    {
        _h.RequireBoth();

        var snapshots = await _h.RunOnAvailableAsync(async (driver, ct) =>
        {
            var b = new RecordingAddressSpaceBuilder();
            await ((ITagDiscovery)driver).DiscoverAsync(b, ct);
            return b.Variables
                .Where(v => v.AttributeInfo.IsHistorized)
                .Select(v => v.AttributeInfo.FullName)
                .ToHashSet(StringComparer.OrdinalIgnoreCase);
        }, CancellationToken.None);

        var legacy = snapshots[ParityHarness.Backend.LegacyHost];
        var mxgw = snapshots[ParityHarness.Backend.MxGateway];

        if (legacy.Count == 0)
        {
            Assert.Skip("dev Galaxy has no historized attributes — history routing parity unverified for this rig");
        }

        legacy.Except(mxgw, StringComparer.OrdinalIgnoreCase).ShouldBeEmpty(
            "every historized attribute discovered by the legacy backend must appear in the mxgw backend");
        mxgw.Except(legacy, StringComparer.OrdinalIgnoreCase).ShouldBeEmpty(
            "every historized attribute discovered by the mxgw backend must appear in the legacy backend");
    }

    [Fact]
    public async Task Neither_Galaxy_backend_implements_IHistoryProvider_directly()
    {
        // Pinning the architectural decision from Phase 1 (PR 1.3): per-driver
        // IHistoryProvider was retired in favor of the server-owned HistoryRouter.
        // If a regression brings IHistoryProvider back on either Galaxy driver,
        // this test fires.
        _h.RequireBoth();

        (_h.LegacyDriver as IHistoryProvider).ShouldBeNull(
            "legacy GalaxyProxyDriver must not surface IHistoryProvider — history routes through HistoryRouter");
        (_h.MxGatewayDriver as IHistoryProvider).ShouldBeNull(
            "in-process GalaxyDriver must not surface IHistoryProvider — history routes through HistoryRouter");
    }
}