using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Logging.Abstractions;

using MongoDB.Entities;

using PrivaPub.Federation.Actors;
using PrivaPub.Federation.Outbox;
using PrivaPub.Infrastructure.Jobs;
using PrivaPub.Models;
using PrivaPub.Models.Jobs;
using PrivaPub.Models.User;
using PrivaPub.StaticServices;
using PrivaPub.Tests.Support;

using System.Text.Json.Nodes;

namespace PrivaPub.Tests.Infrastructure
{
	[Xunit.Collection(nameof(Exclusive))]
	[Trait("Category", "Integration")]
	public sealed class DeliveryWorkerTests : IAsyncLifetime
	{
		static readonly string[] PeerHosts = { "localhost", "127.0.0.1" };

		Peer _peer;

		public async ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			_peer = await Peer.Start();
			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
		}

		public async ValueTask DisposeAsync()
		{
			if (_peer == default)
				return;
			await _peer.DisposeAsync();
			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
		}

		[Fact]
		public async Task A_dead_host_does_not_hold_up_deliveries_to_live_ones()
		{
			var token = TestContext.Current.CancellationToken;
			var (privateKey, publicKey) = Keys.NewKeyPair();
			var avatar = new Avatar { UserName = $"sender{Guid.NewGuid():N}"[..20], PrivateKey = privateKey, PublicKey = publicKey };
			await DB.Default.SaveAsync(avatar, token);
			var local = new LocalActorService(new DbEntities(), new StaticOptions<AppConfiguration>(new AppConfiguration { BackendBaseAddress = "https://privapub.test" }));
			var sender = local.FromAvatar(avatar);
			var run = $"https://privapub.test/a/{Guid.NewGuid():N}/";
			var queue = new JobQueue(j => j.DedupeKey.StartsWith(run));
			var delivery = new DeliveryService(new DbEntities(), queue);
			_peer.Answer("/dead/inbox", 503, TimeSpan.FromMilliseconds(300));
			_peer.Answer("/live/inbox", 202);

			var deadInboxes = Enumerable.Range(0, 60).Select(i => $"{_peer.B}/dead/inbox?{i}");
			await delivery.Enqueue(sender, deadInboxes, new JsonObject { ["id"] = run + "dead", ["type"] = "Create" }, token);
			await delivery.Enqueue(sender, new[] { $"{_peer.A}/live/inbox" }, new JsonObject { ["id"] = run + "live", ["type"] = "Create" }, token);

			var handler = new DeliveryJobHandler(local, Peer.Http(), new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions())), NullLogger<DeliveryJobHandler>.Instance);
			using var worker = new JobWorker(queue, new IJobHandler[] { handler }, NullLogger<JobWorker>.Instance);
			await worker.StartAsync(token);
			try
			{
				await Until(() => Task.FromResult(_peer.Requests.Any(r => r.Path == "/live/inbox")), token);
				var deadSoFar = _peer.Requests.Count(r => r.Path == "/dead/inbox");
				var live = Assert.Single(_peer.Requests, r => r.Path == "/live/inbox");
				Assert.Contains($"keyId=\"{sender.KeyId}\"", live.Signature);
				Assert.True(deadSoFar < 30, $"{deadSoFar} dead deliveries were tried before the live one");

				await Until(() => DB.Default.Find<Job>().Match(j => j.DedupeKey.StartsWith(run + "dead") && j.State == JobState.Pending && j.Attempts > 0).ExecuteAnyAsync(token), token);
			}
			finally
			{
				await worker.StopAsync(CancellationToken.None);
			}

			var retried = await DB.Default.Find<Job>().Match(j => j.DedupeKey.StartsWith(run + "dead") && j.Attempts > 0 && j.State == JobState.Pending).ExecuteFirstAsync(token);
			Assert.Equal("503", retried.LastError?.Split(' ')[0]);
			Assert.True(retried.RunAt > DateTime.UtcNow);
			Assert.True((await DB.Default.Find<RemoteInstance>().Match(i => i.Host == "localhost").ExecuteFirstAsync(token))?.ConsecutiveFailures > 0);
		}

		static async Task Until(Func<Task<bool>> condition, CancellationToken token)
		{
			var deadline = DateTime.UtcNow.AddSeconds(30);
			while (!await condition())
			{
				Assert.True(DateTime.UtcNow < deadline, "timed out");
				await Task.Delay(50, token);
			}
		}
	}
}