SocialPub/PrivaPub/Federation/Inbox/Handlers/DeleteHandler.cs

using MongoDB.Entities;

using PrivaPub.Federation.Actors;
using PrivaPub.Federation.Objects;
using PrivaPub.Federation.Outbox;
using PrivaPub.Federation.Rendering;
using PrivaPub.Models.Federation;
using PrivaPub.Models.Group;
using PrivaPub.Models.Post;
using PrivaPub.Models.Social;
using PrivaPub.Models.User;
using PrivaPub.StaticServices;

using System.Text.Json.Nodes;

using static PrivaPub.Federation.Inbox.ForeignMembers;
using static PrivaPub.Federation.Objects.ActivityJson;

using PostEntity = PrivaPub.Models.Post.Post;

namespace PrivaPub.Federation.Inbox.Handlers
{
	public class DeleteHandler : IActivityHandler
	{
		readonly DbEntities _dbEntities;
		readonly ILocalActorService _localActors;
		readonly IRemoteActorService _remoteActors;
		readonly IDeliveryService _delivery;

		public DeleteHandler(DbEntities dbEntities, ILocalActorService localActors, IRemoteActorService remoteActors, IDeliveryService delivery)
		{
			_dbEntities = dbEntities;
			_localActors = localActors;
			_remoteActors = remoteActors;
			_delivery = delivery;
		}

		public string Type => "Delete";

		public async Task Handle(JsonNode activity, ForeignAvatar actor, CancellationToken token)
		{
			var delete = activity;

			var objectUri = Id(delete["object"]);
			if (!Origin.Same(objectUri, actor.ActorURI))
				return;

			if (objectUri == actor.ActorURI)
			{
				actor.DeletionAt = DateTime.UtcNow;
				actor.AccountState = AvatarAccountState.Deleted;
				await DB.Default.SaveAsync(actor, token);
				var followers = await _dbEntities.Followers.Match(f => f.ActorURI == actor.ActorURI).ExecuteAsync(token);
				foreach (var follower in followers)
				{
					await DB.Default.DeleteAsync<Follower>(follower.ID);
					if (follower.LocalActorKind == LocalActorKind.Group)
						await RemoveForeignMember(follower.LocalActorId, actor.ActorURI, token);
				}
				await DB.Default.DeleteAsync<Following>(f => f.TargetActorURI == actor.ActorURI);
				await DB.Default.DeleteAsync<TimelineEntry>(e => e.AuthorAccountId == actor.ID);
				return;
			}

			var post = await _dbEntities.Posts.Match(p => p.ObjectURI == objectUri && p.ActorURI == actor.ActorURI).ExecuteFirstAsync(token);
			if (post == default)
				return;
			await DB.Default.DeleteAsync<PostEntity>(post.ID);
			await DB.Default.DeleteAsync<TimelineEntry>(e => e.PostId == post.ID || e.ReblogOfPostId == post.ID);
			await DB.Default.DeleteAsync<PostEntity>(p => p.ReblogOfPostId == post.ID);
			if (!string.IsNullOrEmpty(post.AnsweringToPostId))
				await DB.Default.Update<PostEntity>().MatchID(post.AnsweringToPostId).Modify(b => b.Inc(p => p.RepliesCount, -1)).ExecuteAsync(token);
		}
	}
}