'use strict';

const nconf = require('nconf');

const winston = require('winston');
const _ = require('lodash');

const connection = module.exports;

connection.getConnectionString = function (mongo) {
	mongo = mongo || nconf.get('mongo');
	let usernamePassword = '';
	const uri = mongo.uri || '';
	if (mongo.username && mongo.password) {
		usernamePassword = `${nconf.get('mongo:username')}:${encodeURIComponent(nconf.get('mongo:password'))}@`;
	} else if (!uri.includes('@') || !uri.slice(uri.indexOf('://') + 3, uri.indexOf('@'))) {
		winston.warn('You have no mongo username/password setup!');
	}

	// Sensible defaults for Mongo, if not set
	if (!mongo.host) {
		mongo.host = '127.0.0.1';
	}
	if (!mongo.port) {
		mongo.port = 27017;
	}
	const dbName = mongo.database;
	if (dbName === undefined || dbName === '') {
		winston.warn('You have no database name, using "nodebb"');
		mongo.database = 'nodebb';
	}

	const hosts = mongo.host.split(',');
	const ports = mongo.port.toString().split(',');
	const servers = [];

	for (let i = 0; i < hosts.length; i += 1) {
		servers.push(`${hosts[i]}:${ports[i]}`);
	}

	return uri || `mongodb://${usernamePassword}${servers.join()}/${mongo.database}`;
};

connection.getConnectionOptions = function (mongo) {
	mongo = mongo || nconf.get('mongo');
	const connOptions = {
		poolSize: 10,
		connectTimeoutMS: 90000,
		useNewUrlParser: true,
		useUnifiedTopology: true,
	};

	return _.merge(connOptions, mongo.options || {});
};

connection.connect = async function (options) {
	const mongoClient = require('mongodb').MongoClient;

	const connString = connection.getConnectionString(options);
	const connOptions = connection.getConnectionOptions(options);

	return await mongoClient.connect(connString, connOptions);
};
