NodeBB/src/controllers/activitypub/index.js

'use strict';

const nconf = require('nconf');

const db = require('../../database');
const user = require('../../user');
const activitypub = require('../../activitypub');
const helpers = require('../helpers');

const Controller = module.exports;

Controller.profiles = require('./profiles');

Controller.getActor = async (req, res) => {
	// todo: view:users priv gate
	const { userslug } = req.params;
	const { uid } = res.locals;
	const { username, aboutme, picture, 'cover:url': cover } = await user.getUserData(uid);
	const publicKey = await activitypub.getPublicKey(uid);

	res.status(200).json({
		'@context': [
			'https://www.w3.org/ns/activitystreams',
			'https://w3id.org/security/v1',
		],
		id: `${nconf.get('url')}/user/${userslug}`,
		url: `${nconf.get('url')}/user/${userslug}`,
		followers: `${nconf.get('url')}/user/${userslug}/followers`,
		following: `${nconf.get('url')}/user/${userslug}/following`,
		inbox: `${nconf.get('url')}/user/${userslug}/inbox`,
		outbox: `${nconf.get('url')}/user/${userslug}/outbox`,

		type: 'Person',
		preferredUsername: username,
		summary: aboutme,
		icon: picture ? `${nconf.get('url')}${picture}` : null,
		image: cover ? `${nconf.get('url')}${cover}` : null,

		publicKey: {
			id: `${nconf.get('url')}/user/${userslug}#key`,
			owner: `${nconf.get('url')}/user/${userslug}`,
			publicKeyPem: publicKey,
		},
	});
};

Controller.getFollowing = async (req, res) => {
	const { followingCount: totalItems } = await user.getUserFields(res.locals.uid, ['followingCount']);

	const page = parseInt(req.query.page, 10) || 1;
	const resultsPerPage = 50;
	const start = Math.max(0, page - 1) * resultsPerPage;
	const stop = start + resultsPerPage - 1;

	let orderedItems = await user.getFollowing(res.locals.uid, start, stop);
	orderedItems = orderedItems.map(({ userslug }) => `${nconf.get('url')}/user/${userslug}`);
	res.status(200).json({
		'@context': 'https://www.w3.org/ns/activitystreams',
		type: 'OrderedCollection',
		totalItems,
		orderedItems,
	});
};

Controller.getFollowers = async (req, res) => {
	const { followerCount: totalItems } = await user.getUserFields(res.locals.uid, ['followerCount']);

	const page = parseInt(req.query.page, 10) || 1;
	const resultsPerPage = 50;
	const start = Math.max(0, page - 1) * resultsPerPage;
	const stop = start + resultsPerPage - 1;

	let orderedItems = await user.getFollowers(res.locals.uid, start, stop);
	orderedItems = orderedItems.map(({ userslug }) => `${nconf.get('url')}/user/${userslug}`);
	res.status(200).json({
		'@context': 'https://www.w3.org/ns/activitystreams',
		type: 'OrderedCollection',
		totalItems,
		orderedItems,
	});
};

Controller.getOutbox = async (req, res) => {
	// stub
	res.status(200).json({
		'@context': 'https://www.w3.org/ns/activitystreams',
		type: 'OrderedCollection',
		totalItems: 0,
		orderedItems: [],
	});
};

Controller.postOutbox = async (req, res) => {
	// This is a client-to-server feature so it is deliberately not implemented at this time.
	res.sendStatus(405);
};

Controller.getInbox = async (req, res) => {
	// This is a client-to-server feature so it is deliberately not implemented at this time.
	res.sendStatus(405);
};

Controller.postInbox = async (req, res) => {
	switch (req.body.type) {
		case 'Follow': {
			await activitypub.inbox.follow(req.body.actor.name, req.body.object.name);
			break;
		}

		case 'Unfollow': {
			await activitypub.inbox.unfollow(req.body.actor.name, req.body.object.name);
			break;
		}
	}

	res.sendStatus(201);
};

/**
 * Main ActivityPub verbs
 */

Controller.follow = async (req, res) => {
	try {
		const { uid: objectId } = req.params;
		await activitypub.send(req.uid, objectId, {
			type: 'Follow',
			object: {
				type: 'Person',
				name: objectId,
			},
		});

		const now = Date.now();
		await db.sortedSetAdd(`followingRemote:${req.uid}`, now, objectId);
		await recountFollowing(req.uid);

		helpers.formatApiResponse(200, res);
	} catch (e) {
		helpers.formatApiResponse(400, res, e);
	}
};

Controller.unfollow = async (req, res) => {
	try {
		const { uid: objectId } = req.params;
		await activitypub.send(req.uid, objectId, {
			type: 'Unfollow',
			object: {
				type: 'Person',
				name: objectId,
			},
		});

		await db.sortedSetRemove(`followingRemote:${req.uid}`, objectId);
		await recountFollowing(req.uid);

		helpers.formatApiResponse(200, res);
	} catch (e) {
		helpers.formatApiResponse(400, res, e);
	}
};

async function recountFollowing(uid) {
	const [followingCount, followingRemoteCount] = await Promise.all([
		db.sortedSetCard(`following:${uid}`),
		db.sortedSetCard(`followingRemote:${uid}`),
	]);
	await user.setUserField(uid, 'followingCount', followingCount + followingRemoteCount);
}