// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.AspNetCore.InternalTesting;
 
namespace Microsoft.AspNetCore.ConcurrencyLimiter.Tests.PolicyTests;
 
public class QueuePolicyTests
{
    [Fact]
    public void DoesNotWaitIfSpaceAvailable()
    {
        using var s = TestUtils.CreateQueuePolicy(2);
 
        var t1 = s.TryEnterAsync();
        Assert.True(t1.IsCompleted);
 
        var t2 = s.TryEnterAsync();
        Assert.True(t2.IsCompleted);
 
        var t3 = s.TryEnterAsync();
        Assert.False(t3.IsCompleted);
    }
 
    [Fact]
    public async Task WaitsIfNoSpaceAvailable()
    {
        using var s = TestUtils.CreateQueuePolicy(1);
        Assert.True(await s.TryEnterAsync().DefaultTimeout());
 
        var waitingTask = s.TryEnterAsync();
        Assert.False(waitingTask.IsCompleted);
 
        s.OnExit();
        Assert.True(await waitingTask.DefaultTimeout());
    }
 
    [Fact]
    public void DoesNotWaitIfQueueFull()
    {
        using var s = TestUtils.CreateQueuePolicy(2, 1);
 
        var t1 = s.TryEnterAsync();
        Assert.True(t1.IsCompleted);
        Assert.True(t1.Result);
 
        var t2 = s.TryEnterAsync();
        Assert.True(t2.IsCompleted);
        Assert.True(t2.Result);
 
        var t3 = s.TryEnterAsync();
        Assert.False(t3.IsCompleted);
 
        var t4 = s.TryEnterAsync();
        Assert.True(t4.IsCompleted);
        Assert.False(t4.Result);
    }
 
    [Fact]
    public async Task IsEncapsulated()
    {
        using var s1 = TestUtils.CreateQueuePolicy(1);
        using var s2 = TestUtils.CreateQueuePolicy(1);
 
        Assert.True(await s1.TryEnterAsync().DefaultTimeout());
        Assert.True(await s2.TryEnterAsync().DefaultTimeout());
    }
}