8 files changed, 372 insertions, 0 deletions
diff --git a/src/common/remote/activitypub/act/create.ts b/src/common/remote/activitypub/act/create.ts
new file mode 100644
index 0000000000..6c62f7ab9e
--- /dev/null
+++ b/src/common/remote/activitypub/act/create.ts
@@ -0,0 +1,9 @@
+import create from '../create';
+
+export default (resolver, actor, activity) => {
+	if ('actor' in activity && actor.account.uri !== activity.actor) {
+		throw new Error;
+	}
+
+	return create(resolver, actor, activity.object);
+};
diff --git a/src/common/remote/activitypub/act/index.ts b/src/common/remote/activitypub/act/index.ts
new file mode 100644
index 0000000000..0f4084a61e
--- /dev/null
+++ b/src/common/remote/activitypub/act/index.ts
@@ -0,0 +1,22 @@
+import create from './create';
+import createObject from '../create';
+import Resolver from '../resolver';
+
+export default (actor, value) => {
+	return (new Resolver).resolve(value).then(resolved => Promise.all(resolved.map(async asyncResult => {
+		const { resolver, object } = await asyncResult;
+		const created = await (await createObject(resolver, actor, [object]))[0];
+
+		if (created !== null) {
+			return created;
+		}
+
+		switch (object.type) {
+		case 'Create':
+			return create(resolver, actor, object);
+
+		default:
+			return null;
+		}
+	})));
+}
diff --git a/src/common/remote/activitypub/create.ts b/src/common/remote/activitypub/create.ts
new file mode 100644
index 0000000000..4aaaeb3060
--- /dev/null
+++ b/src/common/remote/activitypub/create.ts
@@ -0,0 +1,86 @@
+import { JSDOM } from 'jsdom';
+import config from '../../../conf';
+import Post from '../../../models/post';
+import RemoteUserObject, { IRemoteUserObject } from '../../../models/remote-user-object';
+import uploadFromUrl from '../../drive/upload_from_url';
+const createDOMPurify = require('dompurify');
+
+function createRemoteUserObject($ref, $id, { id }) {
+	const object = { $ref, $id };
+
+	if (!id) {
+		return { object };
+	}
+
+	return RemoteUserObject.insert({ uri: id, object });
+}
+
+async function createImage(actor, object) {
+	if ('attributedTo' in object && actor.account.uri !== object.attributedTo) {
+		throw new Error;
+	}
+
+	const { _id } = await uploadFromUrl(object.url, actor);
+	return createRemoteUserObject('driveFiles.files', _id, object);
+}
+
+async function createNote(resolver, actor, object) {
+	if ('attributedTo' in object && actor.account.uri !== object.attributedTo) {
+		throw new Error;
+	}
+
+	const mediaIds = 'attachment' in object &&
+		(await Promise.all(await create(resolver, actor, object.attachment)))
+			.filter(media => media !== null && media.object.$ref === 'driveFiles.files')
+			.map(({ object }) => object.$id);
+
+	const { window } = new JSDOM(object.content);
+
+	const { _id } = await Post.insert({
+		channelId: undefined,
+		index: undefined,
+		createdAt: new Date(object.published),
+		mediaIds,
+		replyId: undefined,
+		repostId: undefined,
+		poll: undefined,
+		text: window.document.body.textContent,
+		textHtml: object.content && createDOMPurify(window).sanitize(object.content),
+		userId: actor._id,
+		appId: null,
+		viaMobile: false,
+		geo: undefined
+	});
+
+	// Register to search database
+	if (object.content && config.elasticsearch.enable) {
+		const es = require('../../db/elasticsearch');
+
+		es.index({
+			index: 'misskey',
+			type: 'post',
+			id: _id.toString(),
+			body: {
+				text: window.document.body.textContent
+			}
+		});
+	}
+
+	return createRemoteUserObject('posts', _id, object);
+}
+
+export default async function create(parentResolver, actor, value): Promise<Promise<IRemoteUserObject>[]> {
+	const results = await parentResolver.resolveRemoteUserObjects(value);
+
+	return results.map(asyncResult => asyncResult.then(({ resolver, object }) => {
+		switch (object.type) {
+		case 'Image':
+			return createImage(actor, object);
+
+		case 'Note':
+			return createNote(resolver, actor, object);
+		}
+
+		return null;
+	}));
+};
diff --git a/src/common/remote/activitypub/resolve-person.ts b/src/common/remote/activitypub/resolve-person.ts
new file mode 100644
index 0000000000..c7c131b0ea
--- /dev/null
+++ b/src/common/remote/activitypub/resolve-person.ts
@@ -0,0 +1,104 @@
+import { JSDOM } from 'jsdom';
+import { toUnicode } from 'punycode';
+import User, { validateUsername, isValidName, isValidDescription } from '../../../models/user';
+import queue from '../../../queue';
+import webFinger from '../webfinger';
+import create from './create';
+import Resolver from './resolver';
+
+async function isCollection(collection) {
+	return ['Collection', 'OrderedCollection'].includes(collection.type);
+}
+
+export default async (value, usernameLower, hostLower, acctLower) => {
+	if (!validateUsername(usernameLower)) {
+		throw new Error;
+	}
+
+	const { resolver, object } = await (new Resolver).resolveOne(value);
+
+	if (
+		object === null ||
+		object.type !== 'Person' ||
+		typeof object.preferredUsername !== 'string' ||
+		object.preferredUsername.toLowerCase() !== usernameLower ||
+		!isValidName(object.name) ||
+		!isValidDescription(object.summary)
+	) {
+		throw new Error;
+	}
+
+	const [followers, following, outbox, finger] = await Promise.all([
+		resolver.resolveOne(object.followers).then(
+			resolved => isCollection(resolved.object) ? resolved.object : null,
+			() => null
+		),
+		resolver.resolveOne(object.following).then(
+			resolved => isCollection(resolved.object) ? resolved.object : null,
+			() => null
+		),
+		resolver.resolveOne(object.outbox).then(
+			resolved => isCollection(resolved.object) ? resolved.object : null,
+			() => null
+		),
+		webFinger(object.id, acctLower),
+	]);
+
+	const summaryDOM = JSDOM.fragment(object.summary);
+
+	// Create user
+	const user = await User.insert({
+		avatarId: null,
+		bannerId: null,
+		createdAt: Date.parse(object.published),
+		description: summaryDOM.textContent,
+		followersCount: followers.totalItem,
+		followingCount: following.totalItem,
+		name: object.name,
+		postsCount: outbox.totalItem,
+		driveCapacity: 1024 * 1024 * 8, // 8MiB
+		username: object.preferredUsername,
+		usernameLower,
+		host: toUnicode(finger.subject.replace(/^.*?@/, '')),
+		hostLower,
+		account: {
+			uri: object.id,
+		},
+	});
+
+	queue.create('http', {
+		type: 'performActivityPub',
+		actor: user._id,
+		outbox
+	}).save();
+
+	const [avatarId, bannerId] = await Promise.all([
+		object.icon,
+		object.image
+	].map(async value => {
+		if (value === undefined) {
+			return null;
+		}
+
+		try {
+			const created = await create(resolver, user, value);
+
+			await Promise.all(created.map(asyncCreated => asyncCreated.then(created => {
+				if (created !== null && created.object.$ref === 'driveFiles.files') {
+					throw created.object.$id;
+				}
+			}, () => {})));
+
+			return null;
+		} catch (id) {
+			return id;
+		}
+	}));
+
+	User.update({ _id: user._id }, { $set: { avatarId, bannerId } });
+
+	user.avatarId = avatarId;
+	user.bannerId = bannerId;
+
+	return user;
+};
diff --git a/src/common/remote/activitypub/resolver.ts b/src/common/remote/activitypub/resolver.ts
new file mode 100644
index 0000000000..50ac1b0b19
--- /dev/null
+++ b/src/common/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;
+};
+
+async function resolveUnrequestedOne(this: Resolver, 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 };
+}
+
+async function resolveCollection(this: Resolver, value) {
+	if (Array.isArray(value)) {
+		return value;
+	}
+
+	const resolved = typeof value === 'string' ?
+		await resolveUnrequestedOne.call(this, value) :
+		value;
+
+	switch (resolved.type) {
+	case 'Collection':
+		return resolved.items;
+
+	case 'OrderedCollection':
+		return resolved.orderedItems;
+
+	default:
+		return [resolved];
+	}
+}
+
+export default class Resolver {
+	requesting: Set<string>;
+
+	constructor(iterable?: Iterable<string>) {
+		this.requesting = new Set(iterable);
+	}
+
+	async resolve(value): Promise<Promise<IResult>[]> {
+		const collection = await resolveCollection.call(this, value);
+
+		return collection
+			.filter(element => !this.requesting.has(element))
+			.map(resolveUnrequestedOne.bind(this));
+	}
+
+	resolveOne(value) {
+		if (this.requesting.has(value)) {
+			throw new Error;
+		}
+
+		return resolveUnrequestedOne.call(this, value);
+	}
+
+	async resolveRemoteUserObjects(value) {
+		const collection = await resolveCollection.call(this, 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 resolveUnrequestedOne.call(this, element);
+		});
+	}
+}
diff --git a/src/common/remote/activitypub/type.ts b/src/common/remote/activitypub/type.ts
new file mode 100644
index 0000000000..5c4750e140
--- /dev/null
+++ b/src/common/remote/activitypub/type.ts
@@ -0,0 +1,3 @@
+export type IObject = {
+	type: string;
+}
diff --git a/src/common/remote/resolve-user.ts b/src/common/remote/resolve-user.ts
new file mode 100644
index 0000000000..13d155830e
--- /dev/null
+++ b/src/common/remote/resolve-user.ts
@@ -0,0 +1,26 @@
+import { toUnicode, toASCII } from 'punycode';
+import User from '../../models/user';
+import resolvePerson from './activitypub/resolve-person';
+import webFinger from './webfinger';
+
+export default async (username, host, option) => {
+	const usernameLower = username.toLowerCase();
+	const hostLowerAscii = toASCII(host).toLowerCase();
+	const hostLower = toUnicode(hostLowerAscii);
+
+	let user = await User.findOne({ usernameLower, hostLower }, option);
+
+	if (user === null) {
+		const acctLower = `${usernameLower}@${hostLowerAscii}`;
+
+		const finger = await webFinger(acctLower, acctLower);
+		const self = finger.links.find(link => link.rel && link.rel.toLowerCase() === 'self');
+		if (!self) {
+			throw new Error;
+		}
+
+		user = await resolvePerson(self.href, usernameLower, hostLower, acctLower);
+	}
+
+	return user;
+};
diff --git a/src/common/remote/webfinger.ts b/src/common/remote/webfinger.ts
new file mode 100644
index 0000000000..23f0aaa55f
--- /dev/null
+++ b/src/common/remote/webfinger.ts
@@ -0,0 +1,25 @@
+const WebFinger = require('webfinger.js');
+
+const webFinger = new WebFinger({});
+
+type ILink = {
+  href: string;
+  rel: string;
+}
+
+type IWebFinger = {
+  links: Array<ILink>;
+  subject: string;
+}
+
+export default (query, verifier): Promise<IWebFinger> => new Promise((res, rej) => webFinger.lookup(query, (error, result) => {
+	if (error) {
+		return rej(error);
+	}
+
+	if (result.object.subject.toLowerCase().replace(/^acct:/, '') !== verifier) {
+		return rej('WebFinger verfification failed');
+	}
+
+	res(result.object);
+}));