using FluentAssertions;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Slim.Tests.Models;
using System;
using System.Threading.Tasks;

namespace Slim.Tests;

[TestClass]
public sealed class MemoryLeakTests
{
    private const int ScopesCount = 10000;

    [TestMethod]
    public async Task CreateAndReleaseScopesDisposeManagerGCCollects()
    {
        var di = new ServiceManager();
        di.RegisterSingleton<IIndependentService, IndependentService>();
        di.RegisterScoped<IDependentService, DependentService>();
        var independentService = di.GetService<IIndependentService>();
        var dependentService = di.GetService<IDependentService>();

        var weakRefs = new WeakReference[ScopesCount];
        for (int i = 0; i < ScopesCount; i++)
        {
            var scopedDi = di.CreateScope();
            weakRefs[i] = new WeakReference(scopedDi);
            var scopedDependentService = scopedDi.GetService<IDependentService>();
            scopedDependentService.Should().NotBeNull();
            scopedDependentService.Should().NotBe(dependentService);
            scopedDependentService.IndependentService.Should().NotBeNull();
            scopedDependentService.IndependentService.Should().Be(independentService);
        }

        await Task.Delay(1500);
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
        foreach (var weakRef in weakRefs)
        {
            weakRef.IsAlive.Should().BeFalse();
        }
    }
}