Iceshrimp.NET/Iceshrimp.Backend/Core/Federation/ActivityStreams/LDHelpers.cs
2023-12-24 00:57:07 +01:00

78 lines
No EOL
3.1 KiB
C#

using System.Collections;
using System.Globalization;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using VDS.RDF;
using VDS.RDF.JsonLd;
using VDS.RDF.Parsing;
using VDS.RDF.Writing.Formatting;
namespace Iceshrimp.Backend.Core.Federation.ActivityStreams;
public static class LDHelpers {
private static readonly JsonLdProcessorOptions Options = new() { DocumentLoader = CustomLoader };
public static readonly Dictionary<string, RemoteDocument> ContextCache = new() {
{
"https://www.w3.org/ns/activitystreams", new RemoteDocument {
ContextUrl = new Uri("https://www.w3.org/ns/activitystreams"),
DocumentUrl = new Uri("https://www.w3.org/ns/activitystreams"),
Document = JToken.Parse(File.ReadAllText(Path.Combine("Core", "Federation", "ActivityStreams",
"Contexts", "as.json")))
}
}, {
"https://w3id.org/security/v1", new RemoteDocument {
ContextUrl = new Uri("https://w3id.org/security/v1"),
DocumentUrl = new Uri("https://w3c-ccg.github.io/security-vocab/contexts/security-v1.jsonld"),
Document = JToken.Parse(File.ReadAllText(Path.Combine("Core", "Federation", "ActivityStreams",
"Contexts", "security.json")))
}
}
};
public static readonly JToken DefaultContext =
JToken.Parse(File.ReadAllText(Path.Combine("Core", "Federation", "ActivityStreams", "Contexts",
"default.json")));
private static RemoteDocument CustomLoader(Uri uri, JsonLdLoaderOptions jsonLdLoaderOptions) {
//TODO: cache in redis
RemoteDocument? result;
ContextCache.TryGetValue(uri.ToString(), out result);
if (result != null) return result;
result = DefaultDocumentLoader.LoadJson(uri, jsonLdLoaderOptions);
ContextCache.Add(uri.ToString(), result);
return result;
}
private static string NormalizeForSignature(IEnumerable input) {
//TODO: Find a way to convert JSON-LD to RDF directly
//TODO: Fix XMLSchema#string thingy /properly/
var store = new TripleStore();
new JsonLdParser(new JsonLdProcessorOptions { DocumentLoader = CustomLoader, PruneBlankNodeIdentifiers = true })
.Load(store, new StringReader(JsonConvert.SerializeObject(input)));
//Console.WriteLine(store.Triples.SkipLast(1).Last().Object);
var formatter = new NQuadsFormatter(NQuadsSyntax.Rdf11);
Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
var ordered = store.Triples
.Select(p => formatter.Format(p).Replace("^^<http://www.w3.org/2001/XMLSchema#string>", ""))
.Order().ToList();
var processedP1 = ordered.Where(p => p.StartsWith('_')).ToList();
var processedP2 = ordered.Except(processedP1);
return string.Join('\n', processedP2.Union(processedP1));
}
public static JArray? Expand(JToken? json) {
return JsonLdProcessor.Expand(json, Options);
}
public static JObject? Compact(JToken? json) {
return JsonLdProcessor.Compact(json, DefaultContext, Options);
}
public static JObject? Compact(object obj) {
return Compact(JToken.FromObject(obj));
}
}