import config from '../../config';
import * as mongo from 'mongodb';
import User, { isLocalUser, isRemoteUser, ILocalUser, IUser } from '../../models/user';
import Note, { packMany } from '../../models/note';
import Following from '../../models/following';
import renderAdd from '../../remote/activitypub/renderer/add';
import renderRemove from '../../remote/activitypub/renderer/remove';
import { renderActivity } from '../../remote/activitypub/renderer';
import { deliver } from '../../queue';

/**
 * 指定した投稿をピン留めします
 * @param user
 * @param noteId
 */
export async function addPinned(user: IUser, noteId: mongo.ObjectID) {
	// Fetch pinee
	const note = await Note.findOne({
		_id: noteId,
		userId: user._id
	});

	if (note === null) {
		throw new Error('note not found');
	}

	let pinnedNoteIds = user.pinnedNoteIds || [];

	//#region 現在ピン留め投稿している投稿が実際にデータベースに存在しているのかチェック
	// データベースの欠損などで存在していない(または破損している)場合があるので。
	// 存在していなかったらピン留め投稿から外す
	const pinnedNotes = await packMany(pinnedNoteIds, null, { detail: true });

	pinnedNoteIds = pinnedNoteIds.filter(id => pinnedNotes.some(n => n.id.toString() === id.toHexString()));
	//#endregion

	if (pinnedNoteIds.length >= 5) {
		throw new Error('cannot pin more notes');
	}

	if (pinnedNoteIds.some(id => id.equals(note._id))) {
		throw new Error('already exists');
	}

	pinnedNoteIds.unshift(note._id);

	await User.update(user._id, {
		$set: {
			pinnedNoteIds: pinnedNoteIds
		}
	});

	// Deliver to remote followers
	if (isLocalUser(user)) {
		deliverPinnedChange(user._id, note._id, true);
	}
}

/**
 * 指定した投稿のピン留めを解除します
 * @param user
 * @param noteId
 */
export async function removePinned(user: IUser, noteId: mongo.ObjectID) {
	// Fetch unpinee
	const note = await Note.findOne({
		_id: noteId,
		userId: user._id
	});

	if (note === null) {
		throw new Error('note not found');
	}

	const pinnedNoteIds = (user.pinnedNoteIds || []).filter(id => !id.equals(note._id));

	await User.update(user._id, {
		$set: {
			pinnedNoteIds: pinnedNoteIds
		}
	});

	// Deliver to remote followers
	if (isLocalUser(user)) {
		deliverPinnedChange(user._id, noteId, false);
	}
}

export async function deliverPinnedChange(userId: mongo.ObjectID, noteId: mongo.ObjectID, isAddition: boolean) {
	const user = await User.findOne({
		_id: userId
	});

	if (!isLocalUser(user)) return;

	const queue = await CreateRemoteInboxes(user);

	if (queue.length < 1) return;

	const target = `${config.url}/users/${user._id}/collections/featured`;

	const item = `${config.url}/notes/${noteId}`;
	const content = renderActivity(isAddition ? renderAdd(user, target, item) : renderRemove(user, target, item));
	for (const inbox of queue) {
		deliver(user, content, inbox);
	}
}

/**
 * ローカルユーザーのリモートフォロワーのinboxリストを作成する
 * @param user ローカルユーザー
 */
async function CreateRemoteInboxes(user: ILocalUser): Promise<string[]> {
	const followers = await Following.find({
		followeeId: user._id
	});

	const queue: string[] = [];

	for (const following of followers) {
		const follower = following._follower;

		if (isRemoteUser(follower)) {
			const inbox = follower.sharedInbox || follower.inbox;
			if (!queue.includes(inbox)) queue.push(inbox);
		}
	}

	return queue;
}