using Microsoft.Extensions.Caching.Memory;

using MongoDB.Entities;

using PrivaPub.Infrastructure.Jobs;
using PrivaPub.Models.Jobs;
using PrivaPub.Tests.Support;

namespace PrivaPub.Tests.Infrastructure
{
	[Trait("Category", "Integration")]
	public sealed class HostCircuitBreakerTests : IAsyncLifetime
	{
		readonly string _host = $"breaker{Guid.NewGuid():N}.example";

		public ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			return ValueTask.CompletedTask;
		}

		public async ValueTask DisposeAsync()
		{
			if (MongoFixture.Enabled)
				await DB.Default.DeleteAsync<RemoteInstance>(i => i.Host == _host);
		}

		[Fact]
		public async Task A_host_is_quarantined_only_past_the_threshold_and_freed_by_a_success()
		{
			var token = TestContext.Current.CancellationToken;
			var breaker = new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions()));

			for (var i = 1; i < HostCircuitBreaker.Threshold; i++)
				await breaker.Failed(_host, "503", token);
			Assert.Null(await breaker.UnavailableUntil(_host, token));

			await breaker.Failed(_host, "503", token);
			var until = await breaker.UnavailableUntil(_host, token);
			Assert.NotNull(until);
			Assert.InRange(until.Value, DateTime.UtcNow.AddMinutes(55), DateTime.UtcNow.AddMinutes(65));
			var instance = await DB.Default.Find<RemoteInstance>().Match(i => i.Host == _host).ExecuteFirstAsync(token);
			Assert.Equal(HostCircuitBreaker.Threshold, instance.ConsecutiveFailures);
			Assert.Equal("503", instance.LastError);

			await breaker.Succeeded(_host, token);
			Assert.Null(await breaker.UnavailableUntil(_host, token));
			instance = await DB.Default.Find<RemoteInstance>().Match(i => i.Host == _host).ExecuteFirstAsync(token);
			Assert.Equal(0, instance.ConsecutiveFailures);
			Assert.NotNull(instance.LastSuccessAt);
		}

		[Fact]
		public async Task A_healthy_host_is_written_at_most_once_an_hour()
		{
			var token = TestContext.Current.CancellationToken;
			var breaker = new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions()));

			await breaker.Succeeded(_host, token);
			var first = (await DB.Default.Find<RemoteInstance>().Match(i => i.Host == _host).ExecuteFirstAsync(token)).LastSuccessAt;
			await breaker.Succeeded(_host, token);
			var second = (await DB.Default.Find<RemoteInstance>().Match(i => i.Host == _host).ExecuteFirstAsync(token)).LastSuccessAt;

			Assert.Equal(first, second);
		}
	}
}