using MongoDB.Entities;

using PrivaPub.Models.Post;
using PrivaPub.Models.Social;
using PrivaPub.Tests.Support;

using System.Text.Json.Nodes;

namespace PrivaPub.Tests.Federation
{
	// pins across servers: an account elsewhere features its own posts (Add and Remove on its `featured` collection, and
	// the collection itself), a community features posts made in it, and a persona's pin is told to its followers
	[Trait("Category", "Integration")]
	public sealed class FeaturedTests : IAsyncLifetime
	{
		Harness _harness;

		public async ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			_harness = await Harness.Start();
		}

		public async ValueTask DisposeAsync()
		{
			if (_harness != default)
				await _harness.DisposeAsync();
		}

		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);

		// a public note of the actor's, served where its id points
		string Note(RemoteActor author, string text, string audience = default)
		{
			var path = $"/notes/{Guid.NewGuid():N}";
			var note = new JsonObject
			{
				["id"] = Origin(author) + path, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"), ["published"] = DateTime.UtcNow.ToString("O")
			};
			if (audience != default)
				note["audience"] = audience;
			_harness.Peer.Serve(path, note.ToJsonString());
			return Origin(author) + path;
		}

		JsonObject Featuring(RemoteActor actor, string type, string objectUri, string target = default) => new()
		{
			["id"] = $"{actor.Id}#{type}-{Guid.NewGuid():N}", ["type"] = type, ["actor"] = actor.Id, ["object"] = objectUri,
			["target"] = target ?? actor.Id + "/featured"
		};

		Task<List<RemoteFeatured>> FeaturedBy(RemoteActor actor) =>
			DB.Default.Find<RemoteFeatured>().Match(f => f.ActorURI == actor.Id).Sort(f => f.Position, Order.Ascending).ExecuteAsync(TestContext.Current.CancellationToken);

		[Fact]
		public async Task An_account_features_its_own_post_and_takes_it_back_but_nothing_else()
		{
			var bob = new RemoteActor(_harness.Peer, "bob");
			var carol = new RemoteActor(_harness.Peer, "carol", _harness.Peer.B);
			var mine = Note(bob, "pinned");
			var theirs = Note(carol, "not bob's");
			var older = Note(bob, "pinned before");

			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", older));
			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", mine));
			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", theirs));
			// Smithereen's wall is a collection of the actor's too, but no pin
			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", Note(bob, "on the wall"), bob.Id + "/wall"));

			Assert.Equal(new[] { mine, older }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == mine).ExecuteSingleAsync(TestContext.Current.CancellationToken);
			Assert.Equal(post.ID, (await FeaturedBy(bob))[0].PostId);

			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Remove", mine));

			Assert.Equal(new[] { older }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
		}

		[Fact]
		public async Task The_featured_collection_is_read_in_its_order_from_the_accounts_own_server()
		{
			var token = TestContext.Current.CancellationToken;
			var bob = new RemoteActor(_harness.Peer, "bob");
			var first = Note(bob, "first pin");
			var second = Note(bob, "second pin");
			_harness.Peer.Serve(new Uri(bob.Id).AbsolutePath + "/featured", new JsonObject
			{
				["id"] = bob.Id + "/featured", ["type"] = "OrderedCollection", ["totalItems"] = 2,
				["orderedItems"] = new JsonArray(new JsonObject { ["id"] = first, ["type"] = "Note" }, second)
			}.ToJsonString());
			var account = await _harness.Remote.GetActor(bob.Id, refresh: false, token);

			await _harness.Featured.Sync(account, token);

			Assert.Equal(new[] { first, second }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
		}

		[Fact]
		public async Task A_personas_pin_and_unpin_reach_its_followers_as_add_and_remove()
		{
			var token = TestContext.Current.CancellationToken;
			var (root, alice) = await _harness.Persona("alice");
			var follower = new RemoteActor(_harness.Peer, "fan");
			await _harness.FollowedBy(alice, follower);
			await _harness.Posts.InsertPost(root, new PrivaPub.ClientModels.Post.InsertPostForm { AvatarId = alice.Id, Text = "worth a pin" }, token);
			var post = await DB.Default.Find<Post>().Match(p => p.GroupUserId == alice.Id).ExecuteFirstAsync(token);

			await _harness.Outbox.PublishFeatured(alice.Id, post, featured: true, token);
			await _harness.Outbox.PublishFeatured(alice.Id, post, featured: false, token);

			var sent = (await _harness.Outgoing(follower.SharedInbox)).Concat(await _harness.Outgoing(follower.Id + "/inbox"))
				.Where(a => a["type"]!.GetValue<string>() is "Add" or "Remove").ToList();
			Assert.Equal(new[] { "Add", "Remove" }, sent.Select(a => a["type"]!.GetValue<string>()));
			Assert.All(sent, a => Assert.Equal((alice.PostUri(post.ID), alice.Featured), (a["object"]!.GetValue<string>(), a["target"]!.GetValue<string>())));
		}

		[Fact]
		public async Task A_community_features_a_post_made_in_it()
		{
			var token = TestContext.Current.CancellationToken;
			var (_, alice) = await _harness.Persona("alice");
			var community = new RemoteActor(_harness.Peer, "books", type: "Group");
			var member = new RemoteActor(_harness.Peer, "reader", _harness.Peer.B);
			var account = await _harness.Remote.GetActor(community.Id, refresh: false, token);
			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = community.Id, TargetAccountId = account.ID, State = FollowState.Accepted }, token);
			var post = Note(member, "a thread in the community", community.Id);

			await _harness.Deliver(community, "/human-centipede", new JsonObject
			{
				["id"] = $"{community.Id}#announce-{Guid.NewGuid():N}", ["type"] = "Announce", ["actor"] = community.Id,
				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
				["object"] = new JsonObject
				{
					["id"] = $"{Origin(member)}/activities/{Guid.NewGuid():N}", ["type"] = "Add", ["actor"] = member.Id, ["object"] = post,
					["target"] = community.Id + "/featured"
				}
			});

			Assert.Equal(new[] { post }, (await FeaturedBy(community)).Select(f => f.ObjectURI));
		}
	}
}