Files
Swarm/DysonNetwork.Sphere/ActivityPub/ActivityPubObjectFactory.cs

126 lines
4.5 KiB
C#

using System.Text;
using DysonNetwork.Shared.Models;
using Markdig;
using Microsoft.EntityFrameworkCore;
namespace DysonNetwork.Sphere.ActivityPub;
public class ActivityPubObjectFactory(IConfiguration configuration, AppDatabase db)
{
public static readonly string PublicTo = "https://www.w3.org/ns/activitystreams#Public";
public async Task<SnFediverseActor?> GetLocalActorAsync(Guid publisherId)
{
return await db.FediverseActors
.Include(a => a.Instance)
.FirstOrDefaultAsync(a => a.PublisherId == publisherId);
}
public async Task<Dictionary<string, object>> CreatePostObject(
SnPost post,
string actorUrl
)
{
var baseDomain = configuration["ActivityPub:Domain"] ?? "localhost";
var assetsBaseUrl = configuration["ActivityPub:FileBaseUrl"] ?? $"https://{baseDomain}/files";
var postUrl = $"https://{baseDomain}/posts/{post.Id}";
// Build content by combining title, description, and main content
var contentBuilder = new StringBuilder();
if (!string.IsNullOrWhiteSpace(post.Title))
contentBuilder.Append($"# {post.Title}\n\n");
if (!string.IsNullOrWhiteSpace(post.Description))
contentBuilder.Append($"{post.Description}\n\n");
if (!string.IsNullOrWhiteSpace(post.Content))
contentBuilder.Append(post.Content);
// Ensure content is not empty for ActivityPub compatibility
if (contentBuilder.Length == 0)
contentBuilder.Append("Shared media");
if (post.Tags.Count > 0)
{
contentBuilder.Append("\n\n");
contentBuilder.Append(
string.Join(' ', post.Tags.Select(x => $"#{x.Slug}"))
);
}
var finalContent = contentBuilder.ToString();
var postReceivers = new List<string> { $"{actorUrl}/followers" };
if (post.RepliedPostId != null)
{
var repliedPost = await db.Posts
.Where(p => p.Id == post.RepliedPostId)
.Include(p => p.Publisher)
.Include(p => p.Actor)
.FirstOrDefaultAsync();
post.RepliedPost = repliedPost;
// Local post
if (repliedPost?.Publisher != null)
{
var actor = await GetLocalActorAsync(repliedPost.PublisherId!.Value);
if (actor?.FollowersUri != null)
postReceivers.Add(actor.FollowersUri);
}
// Fediverse post
if (repliedPost?.Actor?.FollowersUri != null)
postReceivers.Add(post.Actor!.FollowersUri!);
}
var postObject = new Dictionary<string, object>
{
["id"] = postUrl,
["type"] = post.Type == PostType.Article ? "Article" : "Note",
["published"] = (post.PublishedAt ?? post.CreatedAt).ToDateTimeOffset(),
["attributedTo"] = actorUrl,
["content"] = Markdown.ToHtml(finalContent),
["to"] = new[] { PublicTo },
["cc"] = postReceivers,
["attachment"] = post.Attachments.Select(a => new Dictionary<string, object>
{
["type"] = "Document",
["mediaType"] = a.MimeType ?? "media/jpeg",
["url"] = $"{assetsBaseUrl}/{a.Id}"
}).ToList<object>()
};
// The post's replied post is ensure loaded above, so we directly using it here
if (post.RepliedPost != null)
{
// Local post
if (post.RepliedPost.Publisher != null)
postObject["inReplyTo"] = $"https://{baseDomain}/posts/{post.RepliedPostId}";
// Fediverse post
if (post.RepliedPost.FediverseUri != null)
postObject["inReplyTo"] = post.RepliedPost.FediverseUri;
}
if (post.ForwardedPostId != null)
{
var forwardedPost = await db.Posts
.Where(p => p.Id == post.ForwardedPostId)
.Include(p => p.Publisher)
.FirstOrDefaultAsync();
// Local post
if (forwardedPost?.Publisher != null)
postObject["quoteUri"] = $"https://{baseDomain}/posts/{post.RepliedPostId}";
// Fediverse post
if (forwardedPost?.FediverseUri != null)
postObject["quoteUri"] = forwardedPost.FediverseUri;
}
if (post.EditedAt.HasValue)
postObject["updated"] = post.EditedAt.Value.ToDateTimeOffset();
return postObject;
}
}