import RemoteUserObject from '../../models/remote-user-object'; import { IObject } from './type'; const request = require('request-promise-native'); type IResult = { resolver: Resolver; object: IObject; }; export default class Resolver { private requesting: Set; constructor(iterable?: Iterable) { this.requesting = new Set(iterable); } private async resolveUnrequestedOne(value) { if (typeof value !== 'string') { return { resolver: this, object: value }; } const resolver = new Resolver(this.requesting); resolver.requesting.add(value); const object = await request({ url: value, headers: { Accept: 'application/activity+json, application/ld+json' }, json: true }); if (object === null || ( Array.isArray(object['@context']) ? !object['@context'].includes('https://www.w3.org/ns/activitystreams') : object['@context'] !== 'https://www.w3.org/ns/activitystreams' )) { throw new Error(); } return { resolver, object }; } private async resolveCollection(value) { if (Array.isArray(value)) { return value; } const resolved = typeof value === 'string' ? await this.resolveUnrequestedOne(value) : value; switch (resolved.type) { case 'Collection': return resolved.items; case 'OrderedCollection': return resolved.orderedItems; default: return [resolved]; } } public async resolve(value): Promise>> { const collection = await this.resolveCollection(value); return collection .filter(element => !this.requesting.has(element)) .map(this.resolveUnrequestedOne.bind(this)); } public resolveOne(value) { if (this.requesting.has(value)) { throw new Error(); } return this.resolveUnrequestedOne(value); } public async resolveRemoteUserObjects(value) { const collection = await this.resolveCollection(value); return collection.filter(element => !this.requesting.has(element)).map(element => { if (typeof element === 'string') { const object = RemoteUserObject.findOne({ uri: element }); if (object !== null) { return object; } } return this.resolveUnrequestedOne(element); }); } }