import type { IUser } from '@rocket.chat/core-typings';
import { Users, Subscriptions } from '@rocket.chat/models';
import { escapeRegExp } from '@rocket.chat/string-helpers';
import type { Mongo } from 'meteor/mongo';
import type { Filter, FindOptions, RootFilterOperators } from 'mongodb';

import { hasPermissionAsync } from '../../../authorization/server/functions/hasPermission';
import { settings } from '../../../settings/server';

type UserAutoComplete = Required<Pick<IUser, '_id' | 'name' | 'username' | 'nickname' | 'status' | 'avatarETag'>>;

export async function findUsersToAutocomplete({
	uid,
	selector,
}: {
	uid: string;
	selector: { exceptions: Required<IUser>['username'][]; conditions: Filter<IUser>; term: string };
}): Promise<{
	items: UserAutoComplete[];
}> {
	const searchFields = settings.get<string>('Accounts_SearchFields').trim().split(',');
	const exceptions = selector.exceptions || [];
	const conditions = selector.conditions || {};
	const options: FindOptions<IUser> & { limit: number } = {
		projection: {
			name: 1,
			username: 1,
			nickname: 1,
			status: 1,
			avatarETag: 1,
			freeSwitchExtension: 1,
		},
		sort: {
			username: 1,
		},
		limit: 10,
	};

	// Search on DMs first, to list known users before others.
	const contacts = await Subscriptions.findConnectedUsersExcept(uid, selector.term, exceptions, searchFields, conditions, 10, 'd');
	if (contacts.length >= options.limit) {
		return { items: contacts as UserAutoComplete[] };
	}

	options.limit -= contacts.length;
	contacts.forEach(({ username }) => exceptions.push(username));

	if (!(await hasPermissionAsync(uid, 'view-outside-room'))) {
		const users = await Subscriptions.findConnectedUsersExcept(uid, selector.term, exceptions, searchFields, conditions, 10);
		return { items: contacts.concat(users) as UserAutoComplete[] };
	}

	const users = await Users.findActiveByUsernameOrNameRegexWithExceptionsAndConditions<UserAutoComplete>(
		new RegExp(escapeRegExp(selector.term), 'i'),
		exceptions,
		conditions,
		options,
	).toArray();

	return {
		items: (contacts as UserAutoComplete[]).concat(users),
	};
}

/**
 * Returns a new query object with the inclusive fields only
 */
export function getInclusiveFields(query: Record<string, 1 | 0>): Record<string, 1> {
	const newQuery = Object.create(null);

	for (const [key, value] of Object.entries(query)) {
		if (value === 1) {
			newQuery[key] = value;
		}
	}

	return newQuery;
}

/**
 * get the default fields if **fields** are empty (`{}`) or `undefined`/`null`
 * @param fields the fields from parsed jsonQuery
 */
export function getNonEmptyFields(fields: Record<string, 1 | 0>): Record<string, 1 | 0> {
	const defaultFields = {
		name: 1,
		username: 1,
		emails: 1,
		roles: 1,
		status: 1,
		active: 1,
		avatarETag: 1,
		lastLogin: 1,
		type: 1,
	} as const;

	if (!fields || Object.keys(fields).length === 0) {
		return defaultFields;
	}

	return { ...defaultFields, ...fields };
}

/**
 * get the default query if **query** is empty (`{}`) or `undefined`/`null`
 * @param query the query from parsed jsonQuery
 */
export function getNonEmptyQuery<T extends IUser>(query: Mongo.Query<T> | undefined | null, canSeeAllUserInfo?: boolean): Mongo.Query<T> {
	const defaultQuery: Mongo.Query<IUser> = {
		$or: [{ username: { $regex: '', $options: 'i' } }, { name: { $regex: '', $options: 'i' } }],
	};

	if (canSeeAllUserInfo) {
		defaultQuery.$or?.push({ 'emails.address': { $regex: '', $options: 'i' } });
	}

	if (!query || Object.keys(query).length === 0) {
		return defaultQuery;
	}

	return { ...defaultQuery, ...query };
}

type FindPaginatedUsersByStatusProps = {
	uid: string;
	offset: number;
	count: number;
	sort: Record<string, 1 | -1>;
	status: 'active' | 'deactivated';
	roles: string[] | null;
	searchTerm: string;
	hasLoggedIn: boolean;
	type: string;
	inactiveReason?: ('deactivated' | 'pending_approval' | 'idle_too_long')[];
};

export async function findPaginatedUsersByStatus({
	uid,
	offset,
	count,
	sort,
	status,
	roles,
	searchTerm,
	hasLoggedIn,
	type,
	inactiveReason,
}: FindPaginatedUsersByStatusProps) {
	const actualSort: Record<string, 1 | -1> = sort || { username: 1 };
	if (sort?.status) {
		actualSort.active = sort.status;
	}
	const match: Filter<IUser & RootFilterOperators<IUser>> = {};
	switch (status) {
		case 'active':
			match.active = true;
			break;
		case 'deactivated':
			match.active = false;
			break;
	}

	if (hasLoggedIn !== undefined) {
		match.lastLogin = { $exists: hasLoggedIn };
	}

	if (type) {
		match.type = type;
	}

	const canSeeAllUserInfo = await hasPermissionAsync(uid, 'view-full-other-user-info');

	const projection = {
		name: 1,
		username: 1,
		emails: 1,
		roles: 1,
		status: 1,
		active: 1,
		avatarETag: 1,
		lastLogin: 1,
		type: 1,
		reason: 1,
		federated: 1,
		freeSwitchExtension: 1,
	};

	if (searchTerm?.trim()) {
		match.$or = [
			...(canSeeAllUserInfo ? [{ 'emails.address': { $regex: escapeRegExp(searchTerm || ''), $options: 'i' } }] : []),
			{
				username: { $regex: escapeRegExp(searchTerm || ''), $options: 'i' },
			},
			{
				name: { $regex: escapeRegExp(searchTerm || ''), $options: 'i' },
			},
		];
	}
	if (roles?.length && !roles.includes('all')) {
		match.roles = { $in: roles };
	}

	if (inactiveReason) {
		const inactiveReasonCondition = {
			$or: [
				{ inactiveReason: { $in: inactiveReason } },
				// This condition is to make it backward compatible with the old behavior
				// The deactivated users not having the inactiveReason field should be returned as well
				...(inactiveReason.includes('deactivated') || inactiveReason.includes('idle_too_long')
					? [{ inactiveReason: { $exists: false } }]
					: []),
			],
		};

		if (match.$or) {
			match.$and = [{ $or: match.$or }, inactiveReasonCondition];
			delete match.$or;
		} else {
			Object.assign(match, inactiveReasonCondition);
		}
	}

	const { cursor, totalCount } = Users.findPaginated(
		{
			...match,
		},
		{
			sort: actualSort,
			skip: offset,
			limit: count,
			projection,
			allowDiskUse: true,
		},
	);
	const [users, total] = await Promise.all([cursor.toArray(), totalCount]);
	return {
		users,
		count: users.length,
		offset,
		total,
	};
}