using MongoDB.Entities;

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

using System.Text.Json.Nodes;

namespace PrivaPub.Tests.Federation
{
	// Pleroma's and Akkoma's edited posts carry their earlier versions (formerRepresentations): a post first met after its
	// edits has its history, and an edit tells the ones missed in between
	[Trait("Category", "Integration")]
	public sealed class FormerRepresentationsTests : 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);
		static readonly DateTime Start = DateTime.UtcNow.AddHours(-1);

		static JsonObject Version(string text, int minutes) => new()
		{
			["type"] = "Note", ["content"] = $"<p>{text}</p>", ["published"] = Start.ToString("O"),
			["updated"] = minutes == 0 ? default : Start.AddMinutes(minutes).ToString("O")
		};

		async Task<(RemoteActor Carol, JsonObject Note)> Followed(string text, int minutes, params JsonObject[] former)
		{
			var token = TestContext.Current.CancellationToken;
			var (_, alice) = await _harness.Persona("alice");
			var carol = new RemoteActor(_harness.Peer, "carol");
			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = carol.Id, State = FollowState.Accepted }, token);
			var note = Version(text, minutes);
			note["id"] = $"{Origin(carol)}/objects/{Guid.NewGuid():N}";
			note["attributedTo"] = carol.Id;
			note["to"] = new JsonArray(Addressing.Public);
			note["cc"] = new JsonArray($"{carol.Id}/followers");
			if (former.Length > 0)
				note["formerRepresentations"] = new JsonObject { ["type"] = "OrderedCollection", ["totalItems"] = former.Length, ["orderedItems"] = new JsonArray(former) };
			return (carol, note);
		}

		Task Deliver(RemoteActor carol, string type, JsonObject note) => _harness.Deliver(carol, "/human-centipede", new JsonObject
		{
			["id"] = $"{Origin(carol)}/activities/{Guid.NewGuid():N}", ["type"] = type, ["actor"] = carol.Id,
			["to"] = new JsonArray(Addressing.Public), ["object"] = note.DeepClone()
		});

		Task<Post> Stored(JsonObject note) =>
			DB.Default.Find<Post>().Match(p => p.ObjectURI == note["id"]!.GetValue<string>()).ExecuteSingleAsync(TestContext.Current.CancellationToken);

		[Fact]
		public async Task A_post_first_met_after_its_edits_has_its_history()
		{
			var (carol, note) = await Followed("third", 40, Version("second", 20), Version("first", 0));

			await Deliver(carol, "Create", note);

			var post = await Stored(note);
			Assert.Equal(["<p>first</p>", "<p>second</p>"], post.Revisions.Select(r => r.ContentHtml));
			Assert.Equal("<p>third</p>", post.ContentHtml);
		}

		[Fact]
		public async Task An_edit_tells_the_versions_missed_in_between()
		{
			var (carol, note) = await Followed("first", 0);
			await Deliver(carol, "Create", note);

			var edited = (JsonObject)note.DeepClone();
			edited["content"] = "<p>third</p>";
			edited["updated"] = Start.AddMinutes(40).ToString("O");
			edited["formerRepresentations"] = new JsonObject
			{
				["type"] = "OrderedCollection", ["totalItems"] = 2, ["orderedItems"] = new JsonArray(Version("second", 20), Version("first", 0))
			};
			await Deliver(carol, "Update", edited);

			var post = await Stored(note);
			Assert.Equal(["<p>first</p>", "<p>second</p>"], post.Revisions.Select(r => r.ContentHtml));
			Assert.Equal("<p>third</p>", post.ContentHtml);
		}
	}
}