import * as mfm from 'mfm-js';
import { toHtml } from '@/mfm/to-html.js';
import config from '@/config/index.js';
import { fetchMeta } from '@/misc/fetch-meta.js';
import { Users, Notes, Instances, UserProfiles, Emojis, DriveFiles } from '@/models/index.js';
import { Emoji } from '@/models/entities/emoji.js';
import { User } from '@/models/entities/user.js';
import { IsNull, In } from 'typeorm';
import { MAX_NOTE_TEXT_LENGTH, FILE_TYPE_BROWSERSAFE } from '@/const.js';
import define from '../../define.js';

export const meta = {
	requireCredential: false,
	requireCredentialPrivateMode: true,
	allowGet: true,

	tags: ['meta'],
} as const;

export const paramDef = {
	type: 'object',
	properties: {},
	required: [],
} as const;

// eslint-disable-next-line import/no-default-export
export default define(meta, paramDef, async () => {
	const now = Date.now();
	const [
		meta,
		total,
		localPosts,
		instanceCount,
		firstAdmin,
		emojis,
	] = await Promise.all([
		fetchMeta(true),
		Users.count({ where: { host: IsNull() } }),
		Notes.count({ where: { userHost: IsNull(), replyId: IsNull() } }),
		Instances.count(),
		Users.findOne({
			where: { host: IsNull(), isAdmin: true, isDeleted: false, isBot: false },
			order: { id: 'ASC' },
		}),
		Emojis.find({
			where: { host: IsNull(), type: In(FILE_TYPE_BROWSERSAFE) },
			select: ['id', 'name', 'originalUrl', 'publicUrl'],
		}).then(l =>
			l.reduce((a, e) =>
				{
					a[e.name] = e
					return a
				},
				{} as Record<string, Emoji>
			)
		),
	]);

	let descSplit = splitN(meta.description, '\n', 2);
	let shortDesc = markup(descSplit.length > 0 ? descSplit[0]: '');
	let longDesc = markup(meta.description ?? '');

	return {
			"uri": config.hostname,
			"title": meta.name,
			"short_description": shortDesc,
			"description": longDesc,
			"email": meta.maintainerEmail,
			"version": config.version,
			"urls": {
				"streaming_api": `wss://${config.host}`
			},
			"stats": {
				"user_count": total,
				"status_count": localPosts,
				"domain_count": instanceCount
			},
			"thumbnail": meta.logoImageUrl,
			"languages": meta.langs,
			"registrations": !meta.disableRegistration,
			"approval_required": false,
			"invites_enabled": false,
			"configuration": {
				"accounts": {
					"max_featured_tags": 16
				},
				"statuses": {
					"max_characters": MAX_NOTE_TEXT_LENGTH,
					"max_media_attachments": 16,
					"characters_reserved_per_url": 0
				},
				"media_attachments": {
					"supported_mime_types": FILE_TYPE_BROWSERSAFE,
					"image_size_limit": 10485760,
					"image_matrix_limit": 16777216,
					"video_size_limit": 41943040,
					"video_frame_rate_limit": 60,
					"video_matrix_limit": 2304000
				},
				"polls": {
					"max_options": 10,
					"max_characters_per_option": 50,
					"min_expiration": 15,
					"max_expiration": -1
				}
			},
			"contact_account": await getContact(firstAdmin, emojis),
			"rules": []
	};
});

const splitN = (
	s: string | null,
	split: string,
	n: number
): string[] => {
	const ret: string[] = [];
	if (s == null) return ret;
	if (s === '') {
		ret.push(s);
		return ret;
	}

	let start = 0;
	let pos = s.indexOf(split);
	if (pos === -1) {
		ret.push(s);
		return ret;
	}

	for (let i = 0; i < n - 1; i++) {
		ret.push(s.substring(start, pos));
		start = pos + split.length;
		pos = s.indexOf(split, start);
		if (pos === -1) break;
	}
	ret.push(s.substring(start));

	return ret;
};

type ContactType = {
	id: string;
	username: string;
	acct: string;
	display_name: string;
	note?: string;
	noindex?: boolean;
	fields?: {
		name: string;
		value: string;
		verified_at:string | null;
	}[];
	locked: boolean;
	bot: boolean;
	created_at: string;
	url: string;
	followers_count: number;
	following_count: number;
	statuses_count: number;
	last_status_at?: string;
	emojis: any;
} | null;

const getContact = async (
	user: User | null,
	emojis: Record<string, Emoji>
): Promise<ContactType> => {
	if (!user) return null;

	let contact: ContactType = {
		id: user.id,
		username: user.username,
		acct: user.username,
		display_name: user.name ?? user.username,
		locked: user.isLocked,
		bot: user.isBot,
		created_at: user.createdAt.toISOString(),
		url: `${config.url}/@${user.username}`,
		followers_count: user.followersCount,
		following_count: user.followingCount,
		statuses_count: user.notesCount,
		last_status_at: user.lastActiveDate?.toISOString(),
		emojis: emojis ? user.emojis.filter(e => e in emojis).map(e => ({
			shortcode: e,
			static_url: emojis[e].publicUrl,
			url: emojis[e].publicUrl,
			visible_in_picker: true,
		})) : [],
	};

	const [profile] = await Promise.all([
		UserProfiles.findOne({ where: { userId: user.id }}),
		loadDriveFiles(contact, 'avatar', user.avatarId),
		loadDriveFiles(contact, 'header', user.bannerId),
	]);

	if (!profile) {
		return contact;
	}

	contact = {
		...contact,
		note: markup(profile.description ?? ''),
		noindex: profile.noCrawle,
		fields: profile.fields.map(f => ({
			name: f.name,
			value: f.value,
			verified_at: null,
		}))
	};

	return contact;
}

const loadDriveFiles = async (contact: any, key: string, fileId: string | null) => {
	if (fileId) {
		const file = await DriveFiles.findOneBy({ id: fileId });
		if (file) {
			contact[key] = file.webpublicUrl ?? file.url;
			contact[`${key}_static`] = contact[key];
		}
	}
}

const markup = (text: string): string => toHtml(mfm.parse(text)) ?? '';