'use strict';

var utils = require('./utils');
var URL = require('url');

module.exports = function createClient (port_arg, host_arg, options) {

    if (typeof port_arg === 'number' || typeof port_arg === 'string' && /^\d+$/.test(port_arg)) {

        var host;
        if (typeof host_arg === 'string') {
            host = host_arg;
        } else {
            options = options || host_arg;
        }
        options = utils.clone(options);
        options.host = host || options.host;
        options.port = port_arg;

    } else if (typeof port_arg === 'string' || port_arg && port_arg.url) {

        options = utils.clone(port_arg.url ? port_arg : host_arg || options);
        var parsed = URL.parse(port_arg.url || port_arg, true, true);

        // [redis:]//[[user][:password]@][host][:port][/db-number][?db=db-number[&password=bar[&option=value]]]
        if (parsed.hostname || parsed.slashes) { // The host might be an empty string
            if (parsed.auth) {
                options.password = parsed.auth.split(':')[1];
            }
            if (!/^([a-z]+:)?\/\//i.test(parsed.href)) {
                throw new Error('Connection string must use the "redis:" protocol or begin with slashes //');
            }
            if (parsed.pathname && parsed.pathname !== '/') {
                options.db = parsed.pathname.substr(1);
            }
            options.host = parsed.hostname;
            options.port = parsed.port;

            if (parsed.search !== '') {
                var elem;
                for (elem in parsed.query) { // jshint ignore: line
                    // If options are passed twice, only the parsed options will be used
                    if (elem in options) {
                        if (options[elem] === parsed.query[elem]) {
                            console.warn('node_redis: WARNING: You passed the ' + elem + ' option twice!');
                        } else {
                            throw new Error('The ' + elem + ' option is added twice and does not match');
                        }
                    }
                    options[elem] = parsed.query[elem];
                }
            }
        } else {
            options.path = port_arg;
        }

    } else if (typeof port_arg === 'object' || port_arg === undefined) {
        options = utils.clone(port_arg || options);
        options.host = options.host || host_arg;
    }

    if (!options) {
        throw new Error('Unknown type of connection in createClient()');
    }

    return options;
};