Refactor

1 files changed, 97 insertions, 0 deletions

diff --git a/src/remote/activitypub/resolver.ts b/src/remote/activitypub/resolver.ts
new file mode 100644
index 0000000000..ebfe25fe7e
--- /dev/null
+++ b/src/remote/activitypub/resolver.ts
@@ -0,0 +1,97 @@
+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<string>;
+
+	constructor(iterable?: Iterable<string>) {
+		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<Array<Promise<IResult>>> {
+		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);
+		});
+	}
+}