rudeshark.net/packages/backend/src/remote/activitypub/resolver.ts
2022-04-17 13:26:31 +09:00

74 lines
2.0 KiB
TypeScript

import config from '@/config/index.js';
import { getJson } from '@/misc/fetch.js';
import { ILocalUser } from '@/models/entities/user.js';
import { getInstanceActor } from '@/services/instance-actor.js';
import { fetchMeta } from '@/misc/fetch-meta.js';
import { extractDbHost } from '@/misc/convert-host.js';
import { signedGet } from './request.js';
import { IObject, isCollectionOrOrderedCollection, ICollection, IOrderedCollection } from './type.js';
export default class Resolver {
private history: Set<string>;
private user?: ILocalUser;
constructor() {
this.history = new Set();
}
public getHistory(): string[] {
return Array.from(this.history);
}
public async resolveCollection(value: string | IObject): Promise<ICollection | IOrderedCollection> {
const collection = typeof value === 'string'
? await this.resolve(value)
: value;
if (isCollectionOrOrderedCollection(collection)) {
return collection;
} else {
throw new Error(`unrecognized collection type: ${collection.type}`);
}
}
public async resolve(value: string | IObject): Promise<IObject> {
if (value == null) {
throw new Error('resolvee is null (or undefined)');
}
if (typeof value !== 'string') {
return value;
}
if (this.history.has(value)) {
throw new Error('cannot resolve already resolved one');
}
this.history.add(value);
const meta = await fetchMeta();
const host = extractDbHost(value);
if (meta.blockedHosts.includes(host)) {
throw new Error('Instance is blocked');
}
if (config.signToActivityPubGet && !this.user) {
this.user = await getInstanceActor();
}
const object = (this.user
? await signedGet(value, this.user)
: await getJson(value, 'application/activity+json, application/ld+json')) as IObject;
if (object == null || (
Array.isArray(object['@context']) ?
!(object['@context'] as unknown[]).includes('https://www.w3.org/ns/activitystreams') :
object['@context'] !== 'https://www.w3.org/ns/activitystreams'
)) {
throw new Error('invalid response');
}
return object;
}
}