using ZB.MOM.WW.ScadaBridge.CentralUI.Services;
using Xunit;

namespace ZB.MOM.WW.ScadaBridge.CentralUI.Tests;

public class PollGateTests
{
    /// <summary>Verifies that a rejected renderer dispatch releases the gate and reports the fault.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task RejectedRendererDispatch_ReleasesGateAndObservesFault()
    {
        var gate = new PollGate();
        Exception? observed = null;
        await gate.RunAsync(() => Task.FromException(new ObjectDisposedException("renderer")), ex => observed = ex);
        Assert.IsType<ObjectDisposedException>(observed);
        Assert.True(gate.TryEnter());
    }

    /// <summary>Verifies that a second entry attempt while the gate is held returns false.</summary>
    [Fact]
    public void TryEnter_SecondCallWhileHeld_ReturnsFalse()
    {
        var gate = new PollGate();
        Assert.True(gate.TryEnter());
        Assert.False(gate.TryEnter());
        gate.Exit();
        Assert.True(gate.TryEnter());
    }
}