text: "use strict";
  
  var EventEmitter = require('events').EventEmitter
    , inherits = require('util').inherits
    , f = require('util').format
    , ServerCapabilities = require('./topology_base').ServerCapabilities
    , MongoCR = require('mongodb-core').MongoCR
    , MongoError = require('mongodb-core').MongoError
    , CMongos = require('mongodb-core').Mongos
    , Cursor = require('./cursor')
    , AggregationCursor = require('./aggregation_cursor')
    , CommandCursor = require('./command_cursor')
    , Define = require('./metadata')
    , Server = require('./server')
    , Store = require('./topology_base').Store
    , shallowClone = require('./utils').shallowClone
    , MAX_JS_INT = require('./utils').MAX_JS_INT
    , translateOptions = require('./utils').translateOptions
    , filterOptions = require('./utils').filterOptions
    , mergeOptions = require('./utils').mergeOptions
    , os = require('os');
  
  // Get package.json variable
  var driverVersion = require(__dirname + '/../package.json').version;
  var nodejsversion = f('Node.js %s, %s', process.version, os.endianness());
  var type = os.type();
  var name = process.platform;
  var architecture = process.arch;
  var release = os.release();
  
  /**
   * @fileOverview The **Mongos** class is a class that represents a Mongos Proxy topology and is
   * used to construct connections.
   *
   * **Mongos Should not be used, use MongoClient.connect**
   * @example
   * var Db = require('mongodb').Db,
   *   Mongos = require('mongodb').Mongos,
   *   Server = require('mongodb').Server,
   *   test = require('assert');
   * // Connect using Mongos
   * var server = new Server('localhost', 27017);
   * var db = new Db('test', new Mongos([server]));
   * db.open(function(err, db) {
   *   // Get an additional db
   *   db.close();
   * });
   */
  
   // Allowed parameters
   var legalOptionNames = ['ha', 'haInterval', 'acceptableLatencyMS'
     , 'poolSize', 'ssl', 'checkServerIdentity', 'sslValidate'
     , 'sslCA', 'sslCert', 'sslKey', 'sslPass', 'socketOptions', 'bufferMaxEntries'
     , 'store', 'auto_reconnect', 'autoReconnect', 'emitError'
     , 'keepAlive', 'noDelay', 'connectTimeoutMS', 'socketTimeoutMS'
     , 'loggerLevel', 'logger', 'reconnectTries', 'appname', 'domainsEnabled'
     , 'servername', 'promoteLongs', 'promoteValues', 'promoteBuffers'];
  
  /**
   * Creates a new Mongos instance
   * @class
   * @deprecated
   * @param {Server[]} servers A seedlist of servers participating in the replicaset.
   * @param {object} [options=null] Optional settings.
   * @param {booelan} [options.ha=true] Turn on high availability monitoring.
   * @param {number} [options.haInterval=5000] Time between each replicaset status check.
   * @param {number} [options.poolSize=5] Number of connections in the connection pool for each server instance, set to 5 as default for legacy reasons.
   * @param {number} [options.acceptableLatencyMS=15] Cutoff latency point in MS for MongoS proxy selection
   * @param {boolean} [options.ssl=false] Use ssl connection (needs to have a mongod server with ssl support)
   * @param {boolean|function} [options.checkServerIdentity=true] Ensure we check server identify during SSL, set to false to disable checking. Only works for Node 0.12.x or higher. You can pass in a boolean or your own checkServerIdentity override function.
   * @param {object} [options.sslValidate=true] Validate mongod server certificate against ca (needs to have a mongod server with ssl support, 2.4 or higher)
   * @param {array} [options.sslCA=null] Array of valid certificates either as Buffers or Strings (needs to have a mongod server with ssl support, 2.4 or higher)
   * @param {(Buffer|string)} [options.sslCert=null] String or buffer containing the certificate we wish to present (needs to have a mongod server with ssl support, 2.4 or higher)
   * @param {(Buffer|string)} [options.sslKey=null] String or buffer containing the certificate private key we wish to present (needs to have a mongod server with ssl support, 2.4 or higher)
   * @param {(Buffer|string)} [options.sslPass=null] String or buffer containing the certificate password (needs to have a mongod server with ssl support, 2.4 or higher)
   * @param {string} [options.servername=null] String containing the server name requested via TLS SNI.
   * @param {object} [options.socketOptions=null] Socket options
   * @param {boolean} [options.socketOptions.noDelay=true] TCP Socket NoDelay option.
   * @param {number} [options.socketOptions.keepAlive=0] TCP KeepAlive on the socket with a X ms delay before start.
   * @param {number} [options.socketOptions.connectTimeoutMS=0] TCP Connection timeout setting
   * @param {number} [options.socketOptions.socketTimeoutMS=0] TCP Socket timeout setting
   * @param {boolean} [options.domainsEnabled=false] Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.
   * @fires Mongos#connect
   * @fires Mongos#ha
   * @fires Mongos#joined
   * @fires Mongos#left
   * @fires Mongos#fullsetup
   * @fires Mongos#open
   * @fires Mongos#close
   * @fires Mongos#error
   * @fires Mongos#timeout
   * @fires Mongos#parseError
   * @return {Mongos} a Mongos instance.
   */
  var Mongos = function(servers, options) {
    if(!(this instanceof Mongos)) return new Mongos(servers, options);
    options = options || {};
    var self = this;
  
    // Filter the options
    options = filterOptions(options, legalOptionNames);
  
    // Ensure all the instances are Server
    for(var i = 0; i < servers.length; i++) {
      if(!(servers[i] instanceof Server)) {
        throw MongoError.create({message: "all seed list instances must be of the Server type", driver:true});
      }
    }
  
    // Stored options
    var storeOptions = {
        force: false
      , bufferMaxEntries: typeof options.bufferMaxEntries == 'number' ? options.bufferMaxEntries : MAX_JS_INT
    }
  
    // Shared global store
    var store = options.store || new Store(self, storeOptions);
  
    // Set up event emitter
    EventEmitter.call(this);
  
    // Build seed list
    var seedlist = servers.map(function(x) {
      return {host: x.host, port: x.port}
    });
  
    // Get the reconnect option
    var reconnect = typeof options.auto_reconnect == 'boolean' ? options.auto_reconnect : true;
    reconnect = typeof options.autoReconnect == 'boolean' ? options.autoReconnect : reconnect;
  
    // Clone options
    var clonedOptions = mergeOptions({}, {
      disconnectHandler: store,
      cursorFactory: Cursor,
      reconnect: reconnect,
      emitError: typeof options.emitError == 'boolean' ? options.emitError : true,
      size: typeof options.poolSize == 'number' ? options.poolSize : 5
    });
  
    // Translate any SSL options and other connectivity options
    clonedOptions = translateOptions(clonedOptions, options);
  
    // Socket options
    var socketOptions = options.socketOptions && Object.keys(options.socketOptions).length > 0
      ? options.socketOptions : options;
  
    // Translate all the options to the mongodb-core ones
    clonedOptions = translateOptions(clonedOptions, socketOptions);
    if(typeof clonedOptions.keepAlive == 'number') {
      clonedOptions.keepAliveInitialDelay = clonedOptions.keepAlive;
      clonedOptions.keepAlive = clonedOptions.keepAlive > 0;
    }
  
    // Build default client information
    this.clientInfo = {
      driver: {
        name: "nodejs",
        version: driverVersion
      },
      os: {
        type: type,
        name: name,
        architecture: architecture,
        version: release
      },
      platform: nodejsversion
    }
  
    // Build default client information
    clonedOptions.clientInfo = this.clientInfo;
    // Do we have an application specific string
    if(options.appname) {
      clonedOptions.clientInfo.application = { name: options.appname };
    }
  
    // Create the Mongos
    var mongos = new CMongos(seedlist, clonedOptions)
    // Server capabilities
    var sCapabilities = null;
  
    // Internal state
    this.s = {
      // Create the Mongos
        mongos: mongos
      // Server capabilities
      , sCapabilities: sCapabilities
      // Debug turned on
      , debug: clonedOptions.debug
      // Store option defaults
      , storeOptions: storeOptions
      // Cloned options
      , clonedOptions: clonedOptions
      // Actual store of callbacks
      , store: store
      // Options
      , options: options
    }
  }
  
  var define = Mongos.define = new Define('Mongos', Mongos, false);
  
  /**
   * @ignore
   */
  inherits(Mongos, EventEmitter);
  
  // Last ismaster
  Object.defineProperty(Mongos.prototype, 'isMasterDoc', {
    enumerable:true, get: function() { return this.s.mongos.lastIsMaster(); }
  });
  
  // BSON property
  Object.defineProperty(Mongos.prototype, 'bson', {
    enumerable: true, get: function() {
      return this.s.mongos.s.bson;
    }
  });
  
  Object.defineProperty(Mongos.prototype, 'haInterval', {
    enumerable:true, get: function() { return this.s.mongos.s.haInterval; }
  });
  
  // Connect
  Mongos.prototype.connect = function(db, _options, callback) {
    var self = this;
    if('function' === typeof _options) callback = _options, _options = {};
    if(_options == null) _options = {};
    if(!('function' === typeof callback)) callback = null;
    self.s.options = _options;
  
    // Update bufferMaxEntries
    self.s.storeOptions.bufferMaxEntries = db.bufferMaxEntries;
  
    // Error handler
    var connectErrorHandler = function(event) {
      return function(err) {
        // Remove all event handlers
        var events = ['timeout', 'error', 'close'];
        events.forEach(function(e) {
          self.removeListener(e, connectErrorHandler);
        });
  
        self.s.mongos.removeListener('connect', connectErrorHandler);
  
        // Try to callback
        try {
          callback(err);
        } catch(err) {
          process.nextTick(function() { throw err; })
        }
      }
    }
  
    // Actual handler
    var errorHandler = function(event) {
      return function(err) {
        if(event != 'error') {
          self.emit(event, err);
        }
      }
    }
  
    // Error handler
    var reconnectHandler = function(err) {
      self.emit('reconnect');
      self.s.store.execute();
    }
  
    // relay the event
    var relay = function(event) {
      return function(t, server) {
        self.emit(event, t, server);
      }
    }
  
    // Connect handler
    var connectHandler = function() {
      // Clear out all the current handlers left over
      ["timeout", "error", "close", 'serverOpening', 'serverDescriptionChanged', 'serverHeartbeatStarted',
        'serverHeartbeatSucceeded', 'serverHeartbeatFailed', 'serverClosed', 'topologyOpening',
        'topologyClosed', 'topologyDescriptionChanged'].forEach(function(e) {
        self.s.mongos.removeAllListeners(e);
      });
  
      // Set up listeners
      self.s.mongos.once('timeout', errorHandler('timeout'));
      self.s.mongos.once('error', errorHandler('error'));
      self.s.mongos.once('close', errorHandler('close'));
  
      // Set up SDAM listeners
      self.s.mongos.on('serverDescriptionChanged', relay('serverDescriptionChanged'));
      self.s.mongos.on('serverHeartbeatStarted', relay('serverHeartbeatStarted'));
      self.s.mongos.on('serverHeartbeatSucceeded', relay('serverHeartbeatSucceeded'));
      self.s.mongos.on('serverHeartbeatFailed', relay('serverHeartbeatFailed'));
      self.s.mongos.on('serverOpening', relay('serverOpening'));
      self.s.mongos.on('serverClosed', relay('serverClosed'));
      self.s.mongos.on('topologyOpening', relay('topologyOpening'));
      self.s.mongos.on('topologyClosed', relay('topologyClosed'));
      self.s.mongos.on('topologyDescriptionChanged', relay('topologyDescriptionChanged'));
  
      // Set up serverConfig listeners
      self.s.mongos.on('fullsetup', relay('fullsetup'));
  
      // Emit open event
      self.emit('open', null, self);
  
      // Return correctly
      try {
        callback(null, self);
      } catch(err) {
        process.nextTick(function() { throw err; })
      }
    }
  
    // Set up listeners
    self.s.mongos.once('timeout', connectErrorHandler('timeout'));
    self.s.mongos.once('error', connectErrorHandler('error'));
    self.s.mongos.once('close', connectErrorHandler('close'));
    self.s.mongos.once('connect', connectHandler);
    // Join and leave events
    self.s.mongos.on('joined', relay('joined'));
    self.s.mongos.on('left', relay('left'));
  
    // Reconnect server
    self.s.mongos.on('reconnect', reconnectHandler);
  
    // Start connection
    self.s.mongos.connect(_options);
  }
  
  // Server capabilities
  Mongos.prototype.capabilities = function() {
    if(this.s.sCapabilities) return this.s.sCapabilities;
    if(this.s.mongos.lastIsMaster() == null) return null;
    this.s.sCapabilities = new ServerCapabilities(this.s.mongos.lastIsMaster());
    return this.s.sCapabilities;
  }
  
  define.classMethod('capabilities', {callback: false, promise:false, returns: [ServerCapabilities]});
  
  // Command
  Mongos.prototype.command = function(ns, cmd, options, callback) {
    this.s.mongos.command(ns, cmd, options, callback);
  }
  
  define.classMethod('command', {callback: true, promise:false});
  
  // Insert
  Mongos.prototype.insert = function(ns, ops, options, callback) {
    this.s.mongos.insert(ns, ops, options, function(e, m) {
      callback(e, m)
    });
  }
  
  define.classMethod('insert', {callback: true, promise:false});
  
  // Update
  Mongos.prototype.update = function(ns, ops, options, callback) {
    this.s.mongos.update(ns, ops, options, callback);
  }
  
  define.classMethod('update', {callback: true, promise:false});
  
  // Remove
  Mongos.prototype.remove = function(ns, ops, options, callback) {
    this.s.mongos.remove(ns, ops, options, callback);
  }
  
  define.classMethod('remove', {callback: true, promise:false});
  
  // Destroyed
  Mongos.prototype.isDestroyed = function() {
    return this.s.mongos.isDestroyed();
  }
  
  // IsConnected
  Mongos.prototype.isConnected = function() {
    return this.s.mongos.isConnected();
  }
  
  define.classMethod('isConnected', {callback: false, promise:false, returns: [Boolean]});
  
  // Insert
  Mongos.prototype.cursor = function(ns, cmd, options) {
    options.disconnectHandler = this.s.store;
    return this.s.mongos.cursor(ns, cmd, options);
  }
  
  define.classMethod('cursor', {callback: false, promise:false, returns: [Cursor, AggregationCursor, CommandCursor]});
  
  Mongos.prototype.lastIsMaster = function() {
    return this.s.mongos.lastIsMaster();
  }
  
  Mongos.prototype.close = function(forceClosed) {
    this.s.mongos.destroy();
    // We need to wash out all stored processes
    if(forceClosed == true) {
      this.s.storeOptions.force = forceClosed;
      this.s.store.flush();
    }
  }
  
  define.classMethod('close', {callback: false, promise:false});
  
  Mongos.prototype.auth = function() {
    var args = Array.prototype.slice.call(arguments, 0);
    this.s.mongos.auth.apply(this.s.mongos, args);
  }
  
  define.classMethod('auth', {callback: true, promise:false});
  
  Mongos.prototype.logout = function() {
    var args = Array.prototype.slice.call(arguments, 0);
    this.s.mongos.logout.apply(this.s.mongos, args);
  }
  
  define.classMethod('logout', {callback: true, promise:false});
  
  /**
   * All raw connections
   * @method
   * @return {array}
   */
  Mongos.prototype.connections = function() {
    return this.s.mongos.connections();
  }
  
  define.classMethod('connections', {callback: false, promise:false, returns:[Array]});
  
  /**
   * A mongos connect event, used to verify that the connection is up and running
   *
   * @event Mongos#connect
   * @type {Mongos}
   */
  
  /**
   * The mongos high availability event
   *
   * @event Mongos#ha
   * @type {function}
   * @param {string} type The stage in the high availability event (start|end)
   * @param {boolean} data.norepeat This is a repeating high availability process or a single execution only
   * @param {number} data.id The id for this high availability request
   * @param {object} data.state An object containing the information about the current replicaset
   */
  
  /**
   * A server member left the mongos set
   *
   * @event Mongos#left
   * @type {function}
   * @param {string} type The type of member that left (primary|secondary|arbiter)
   * @param {Server} server The server object that left
   */
  
  /**
   * A server member joined the mongos set
   *
   * @event Mongos#joined
   * @type {function}
   * @param {string} type The type of member that joined (primary|secondary|arbiter)
   * @param {Server} server The server object that joined
   */
  
  /**
   * Mongos fullsetup event, emitted when all proxies in the topology have been connected to.
   *
   * @event Mongos#fullsetup
   * @type {Mongos}
   */
  
  /**
   * Mongos open event, emitted when mongos can start processing commands.
   *
   * @event Mongos#open
   * @type {Mongos}
   */
  
  /**
   * Mongos close event
   *
   * @event Mongos#close
   * @type {object}
   */
  
  /**
   * Mongos error event, emitted if there is an error listener.
   *
   * @event Mongos#error
   * @type {MongoError}
   */
  
  /**
   * Mongos timeout event
   *
   * @event Mongos#timeout
   * @type {object}
   */
  
  /**
   * Mongos parseError event
   *
   * @event Mongos#parseError
   * @type {object}
   */
  
  module.exports = Mongos;
  