import { Meteor } from 'meteor/meteor';
import { DDPRateLimiter } from 'meteor/ddp-rate-limiter';
import s from 'underscore.string';

const sortChannels = function(field, direction) {
	switch (field) {
		case 'createdAt':
			return {
				ts: direction === 'asc' ? 1 : -1,
			};
		default:
			return {
				[field]: direction === 'asc' ? 1 : -1,
			};
	}
};

const sortUsers = function(field, direction) {
	switch (field) {
		default:
			return {
				[field]: direction === 'asc' ? 1 : -1,
			};
	}
};

Meteor.methods({
	browseChannels({ text = '', type = 'channels', sortBy = 'name', sortDirection = 'asc', page, offset, limit = 10 }) {
		const regex = new RegExp(s.trim(s.escapeRegExp(text)), 'i');

		if (!['channels', 'users'].includes(type)) {
			return;
		}

		if (!['asc', 'desc'].includes(sortDirection)) {
			return;
		}

		if ((!page && page !== 0) && (!offset && offset !== 0)) {
			return;
		}

		if (!['name', 'createdAt', 'usersCount', ...type === 'channels' ? ['usernames'] : [], ...type === 'users' ? ['username'] : []].includes(sortBy)) {
			return;
		}

		const skip = Math.max(0, offset || (page > -1 ? limit * page : 0));

		limit = limit > 0 ? limit : 10;

		const options = {
			skip,
			limit,
		};

		const user = Meteor.user();
		if (type === 'channels') {

			const sort = sortChannels(sortBy, sortDirection);
			if (!RocketChat.authz.hasPermission(user._id, 'view-c-room')) {
				return;
			}
			return {
				results: RocketChat.models.Rooms.findByNameAndType(regex, 'c', {
					...options,
					sort,
					fields: {
						description: 1,
						topic: 1,
						name: 1,
						lastMessage: 1,
						ts: 1,
						archived: 1,
						usersCount: 1,
					},
				}).fetch(),
				total: RocketChat.models.Rooms.findByNameAndType(regex, 'c').count(),
			};
		}

		// type === users
		if (!RocketChat.authz.hasPermission(user._id, 'view-outside-room') || !RocketChat.authz.hasPermission(user._id, 'view-d-room')) {
			return;
		}
		const sort = sortUsers(sortBy, sortDirection);
		return {
			results: RocketChat.models.Users.findByActiveUsersExcept(text, [user.username], {
				...options,
				sort,
				fields: {
					username: 1,
					name: 1,
					createdAt: 1,
					emails: 1,
				},
			}).fetch(),
			total: RocketChat.models.Users.findByActiveUsersExcept(text, [user.username]).count(),
		};
	},
});

DDPRateLimiter.addRule({
	type: 'method',
	name: 'browseChannels',
	userId(/* userId*/) {
		return true;
	},
}, 100, 100000);