/**
 * Module dependencies.
 */

var url = require('./url');
var parser = require('socket.io-parser');
var Manager = require('./manager');
var debug = require('debug')('socket.io-client');

/**
 * Module exports.
 */

module.exports = exports = lookup;

/**
 * Managers cache.
 */

var cache = exports.managers = {};

/**
 * Looks up an existing `Manager` for multiplexing.
 * If the user summons:
 *
 *   `io('http://localhost/a');`
 *   `io('http://localhost/b');`
 *
 * We reuse the existing instance based on same scheme/port/host,
 * and we initialize sockets for each namespace.
 *
 * @api public
 */

function lookup (uri, opts) {
  if (typeof uri === 'object') {
    opts = uri;
    uri = undefined;
  }

  opts = opts || {};

  var parsed = url(uri);
  var source = parsed.source;
  var id = parsed.id;
  var path = parsed.path;
  var sameNamespace = cache[id] && path in cache[id].nsps;
  var newConnection = opts.forceNew || opts['force new connection'] ||
                      false === opts.multiplex || sameNamespace;

  var io;

  if (newConnection) {
    debug('ignoring socket cache for %s', source);
    io = Manager(source, opts);
  } else {
    if (!cache[id]) {
      debug('new io instance for %s', source);
      cache[id] = Manager(source, opts);
    }
    io = cache[id];
  }
  if (parsed.query && !opts.query) {
    opts.query = parsed.query;
  } else if (opts && 'object' === typeof opts.query) {
    opts.query = encodeQueryString(opts.query);
  }
  return io.socket(parsed.path, opts);
}
/**
 *  Helper method to parse query objects to string.
 * @param {object} query
 * @returns {string}
 */
function encodeQueryString (obj) {
  var str = [];
  for (var p in obj) {
    if (obj.hasOwnProperty(p)) {
      str.push(encodeURIComponent(p) + '=' + encodeURIComponent(obj[p]));
    }
  }
  return str.join('&');
}
/**
 * Protocol version.
 *
 * @api public
 */

exports.protocol = parser.protocol;

/**
 * `connect`.
 *
 * @param {String} uri
 * @api public
 */

exports.connect = lookup;

/**
 * Expose constructors for standalone build.
 *
 * @api public
 */

exports.Manager = require('./manager');
exports.Socket = require('./socket');