using Opc.Ua;
using Opc.Ua.Server;
using Shouldly;
using Xunit;

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

/// <summary>
///     R08:1.1 (#736): the server raw cap (<c>ServerHistorian:MaxRawValuesPerRead</c>) is advertised as
///     <c>HistoryServerCapabilities/MaxReturnDataValues</c> (i=11273) through <see cref="HistoryPaging.AdvertiseMaxReturnDataValues"/>,
///     read back the way a client would — through the SDK master node manager — over a real server.
/// </summary>
public sealed class HistoryServerCapabilitiesAdvertisementTests(BoundsServerFixture fx) : IClassFixture<BoundsServerFixture>
{
    private async Task<uint> ReadAdvertisedAsync()
    {
        var context = new OperationContext(new RequestHeader(), secureChannelContext: null, RequestType.Read, identity: null);
        var nodesToRead = new ReadValueIdCollection
        {
            new ReadValueId { NodeId = VariableIds.HistoryServerCapabilities_MaxReturnDataValues, AttributeId = Attributes.Value },
        };
        var (values, _) = await fx.Nm.Server.NodeManager.ReadAsync(context, 0, TimestampsToReturn.Neither, nodesToRead, TestContext.Current.CancellationToken);
        values.Count.ShouldBe(1);
        StatusCode.IsGood(values[0].StatusCode).ShouldBeTrue(values[0].StatusCode.ToString());
        return (uint)values[0].Value;
    }

    [Fact]
    public async Task The_cap_is_advertised_as_MaxReturnDataValues_and_a_re_sync_overwrites_it()
    {
        await fx.Gate.WaitAsync(TestContext.Current.CancellationToken);
        try
        {
            HistoryPaging.AdvertiseMaxReturnDataValues(fx.Nm.Server, 10_000).ShouldBeTrue();
            (await ReadAdvertisedAsync()).ShouldBe(10_000u);

            HistoryPaging.AdvertiseMaxReturnDataValues(fx.Nm.Server, 2_500).ShouldBeTrue();
            (await ReadAdvertisedAsync()).ShouldBe(2_500u);

            // Unbounded (the opt-out) advertises Part 11's "no limit".
            HistoryPaging.AdvertiseMaxReturnDataValues(fx.Nm.Server, 0).ShouldBeTrue();
            (await ReadAdvertisedAsync()).ShouldBe(0u);
            HistoryPaging.AdvertiseMaxReturnDataValues(fx.Nm.Server, -5).ShouldBeTrue();
            (await ReadAdvertisedAsync()).ShouldBe(0u);
        }
        finally
        {
            HistoryPaging.AdvertiseMaxReturnDataValues(fx.Nm.Server, 0);
            fx.Gate.Release();
        }
    }

    [Fact]
    public void No_server_is_a_quiet_false()
    {
        HistoryPaging.AdvertiseMaxReturnDataValues(null, 10_000).ShouldBeFalse();
    }
}