export default async (username: string, _host: string, option?: any): Promise<IUser> => {
	const usernameLower = username.toLowerCase();

	if (_host == null) {
		return await User.findOne({ usernameLower });
	}

	const hostAscii = toASCII(_host).toLowerCase();
	const host = toUnicode(hostAscii);

	if (config.host == host) {
		return await User.findOne({ usernameLower });
	}

	let user = await User.findOne({ usernameLower, host }, option);

	if (user === null) {
		const acctLower = `${usernameLower}@${hostAscii}`;

		const finger = await webFinger(acctLower);
		const self = finger.links.find(link => link.rel && link.rel.toLowerCase() === 'self');
		if (!self) {
			throw new Error('self link not found');
		}

		user = await createPerson(self.href);
	}

	return user;
};

	serialize : function (components:MailtoComponents, options:URIOptions):URIComponents {
		const to = toArray(components.to);
		if (to) {
			for (let x = 0, xl = to.length; x < xl; ++x) {
				const toAddr = String(to[x]);
				const atIdx = toAddr.lastIndexOf("@");
				const localPart = (toAddr.slice(0, atIdx)).replace(PCT_ENCODED, decodeUnreserved).replace(PCT_ENCODED, toUpperCase).replace(NOT_LOCAL_PART, pctEncChar);
				let domain = toAddr.slice(atIdx + 1);

				//convert IDN via punycode
				try {
					domain = (!options.iri ? punycode.toASCII(unescapeComponent(domain, options).toLowerCase()) : punycode.toUnicode(domain));
				} catch (e) {
					components.error = components.error || "Email address's domain name can not be converted to " + (!options.iri ? "ASCII" : "Unicode") + " via punycode: " + e;
				}

				to[x] = localPart + "@" + domain;
			}

			components.path = to.join(",");
		}

		const headers = components.headers = components.headers || {};

		if (components.subject) headers["subject"] = components.subject;
		if (components.body) headers["body"] = components.body;

		const fields = [];
		for (const name in headers) {
			if (headers[name] !== O[name]) {
				fields.push(
					name.replace(PCT_ENCODED, decodeUnreserved).replace(PCT_ENCODED, toUpperCase).replace(NOT_HFNAME, pctEncChar) +
					"=" +
					headers[name].replace(PCT_ENCODED, decodeUnreserved).replace(PCT_ENCODED, toUpperCase).replace(NOT_HFVALUE, pctEncChar)
				);
			}
		}
		if (fields.length) {
			components.query = fields.join("&");
		}

		return components;
	}

export async function createPerson(value: any, resolver?: Resolver): Promise<IUser> {
	if (resolver == null) resolver = new Resolver();

	const object = await resolver.resolve(value) as any;

	const err = validatePerson(object);

	if (err) {
		throw err;
	}

	const person: IPerson = object;

	log(`Creating the Person: ${person.id}`);

	const [followersCount = 0, followingCount = 0, notesCount = 0, finger] = await Promise.all([
		resolver.resolve(person.followers).then(
			resolved => isCollectionOrOrderedCollection(resolved) ? resolved.totalItems : undefined,
			() => undefined
		),
		resolver.resolve(person.following).then(
			resolved => isCollectionOrOrderedCollection(resolved) ? resolved.totalItems : undefined,
			() => undefined
		),
		resolver.resolve(person.outbox).then(
			resolved => isCollectionOrOrderedCollection(resolved) ? resolved.totalItems : undefined,
			() => undefined
		),
		webFinger(person.id)
	]);

	const host = toUnicode(finger.subject.replace(/^.*?@/, '')).toLowerCase();

	const isBot = object.type == 'Service';

	// Create user
	let user: IRemoteUser;
	try {
		user = await User.insert({
			avatarId: null,
			bannerId: null,
			createdAt: Date.parse(person.published) || null,
			description: htmlToMFM(person.summary),
			followersCount,
			followingCount,
			notesCount,
			name: person.name,
			isLocked: person.manuallyApprovesFollowers,
			username: person.preferredUsername,
			usernameLower: person.preferredUsername.toLowerCase(),
			host,
			publicKey: {
				id: person.publicKey.id,
				publicKeyPem: person.publicKey.publicKeyPem
			},
			inbox: person.inbox,
			sharedInbox: person.sharedInbox,
			endpoints: person.endpoints,
			uri: person.id,
			url: person.url,
			isBot
		}) as IRemoteUser;
	} catch (e) {
		// duplicate key error
		if (e.code === 11000) {
			throw new Error('already registered');
		}

		console.error(e);
		throw e;
	}

	//#region Increment users count
	Meta.update({}, {
		$inc: {
			'stats.usersCount': 1
		}
	}, { upsert: true });
	//#endregion

	//#region アイコンとヘッダー画像をフェッチ
	const [avatar, banner] = (await Promise.all<IDriveFile>([
		person.icon,
		person.image
	].map(img =>
		img == null
			? Promise.resolve(null)
			: resolveImage(user, img)
	)));

	const avatarId = avatar ? avatar._id : null;
	const bannerId = banner ? banner._id : null;
	const avatarUrl = avatar && avatar.metadata.url ? avatar.metadata.url : null;
	const bannerUrl = banner && banner.metadata.url ? banner.metadata.url : null;

	await User.update({ _id: user._id }, {
		$set: {
			avatarId,
			bannerId,
			avatarUrl,
//.........这里部分代码省略.........

export default (host: string) => {
	return toUnicode(host).toLowerCase();
};