using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Runtime.Drivers;

namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.Drivers;

/// <summary>
///     lmxopcua#777: every write bound derives from the one write timeout, and each outer bound covers the worst case
///     of everything inside it — whatever the timeout. (The fixed 8 s Ask failed this from a 7 s timeout up.)
/// </summary>
public sealed class DriverWriteBoundsTests
{
    [Theory]
    [InlineData(0.5)]
    [InlineData(2)]
    [InlineData(5)]
    [InlineData(9)]
    [InlineData(10)]
    [InlineData(30)]
    [InlineData(300)]
    public void Each_outer_bound_covers_everything_inside_it(double timeoutSeconds)
    {
        var b = new DriverWriteBounds(TimeSpan.FromSeconds(timeoutSeconds));

        b.AbandonGrace.ShouldBeGreaterThan(TimeSpan.Zero);
        b.RunBound.ShouldBe(b.Timeout + b.AbandonGrace);
        // The child answers a write by queue budget + run bound after it was issued; the Asks sit strictly outside.
        b.ReplyBound.ShouldBe(b.QueueBudget + b.RunBound);
        b.HostAsk.ShouldBeGreaterThanOrEqualTo(b.ReplyBound + DriverWriteBounds.ReplyMargin);
        b.GatewayAsk.ShouldBeGreaterThanOrEqualTo(b.HostAsk + DriverWriteBounds.ReplyMargin);
    }

    [Fact]
    public void The_default_is_10s_and_the_grace_is_half_the_timeout_capped_at_2s()
    {
        DriverWriteBounds.Default.Timeout.ShouldBe(TimeSpan.FromSeconds(10));
        new DriverWriteBounds(TimeSpan.FromSeconds(3)).AbandonGrace.ShouldBe(TimeSpan.FromSeconds(1.5));
        new DriverWriteBounds(TimeSpan.FromSeconds(9)).AbandonGrace.ShouldBe(TimeSpan.FromSeconds(2));
        DriverInstanceActor.DefaultWriteTimeout.ShouldBe(DriverWriteBounds.Default.Timeout);
        DriverInstanceActor.DefaultQueuedWriteBudget.ShouldBe(DriverWriteBounds.Default.QueueBudget);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-1)]
    public void A_non_positive_timeout_is_rejected(double seconds) =>
        Should.Throw<ArgumentOutOfRangeException>(() => new DriverWriteBounds(TimeSpan.FromSeconds(seconds)));
}