'use strict';
  
  var packageData = require('../package.json');
  var EventEmitter = require('events').EventEmitter;
  var util = require('util');
  
  module.exports = function (options) {
      return new StubTransport(options);
  };
  
  function StubTransport(options) {
      EventEmitter.call(this);
      this.options = options || {};
      this.name = 'Stub';
      this.version = packageData.version;
  }
  util.inherits(StubTransport, EventEmitter);
  
  StubTransport.prototype.isIdle = function () {
      return true;
  };
  
  StubTransport.prototype.verify = function (callback) {
      setImmediate(function () {
          if (this.options.error) {
              return callback(new Error(this.options.error));
          }
          return callback(null, true);
      }.bind(this));
  };
  
  StubTransport.prototype.send = function (mail, callback) {
  
      if (this.options.error) {
          setImmediate(function () {
              callback(new Error(this.options.error));
          }.bind(this));
          return;
      }
  
      if (this.options.keepBcc) {
          mail.message.keepBcc = true;
      }
  
      var message = mail.message.createReadStream();
      var chunks = [];
      var chunklen = 0;
      var envelope = mail.data.envelope || mail.message.getEnvelope();
  
      this._log('info', 'envelope', JSON.stringify(envelope));
      this.emit('envelope', envelope);
  
      message.on('error', function (err) {
          setImmediate(function () {
              callback(err);
          });
      });
  
      message.on('data', function (chunk) {
          chunks.push(chunk);
          chunklen += chunk.length;
  
          this._log('verbose', 'message', chunk.toString());
          this.emit('data', chunk.toString());
      }.bind(this));
  
      message.on('end', function () {
          setImmediate(function () {
              var messageId = (mail.message.getHeader('message-id') || '').replace(/[<>\s]/g, '');
              var response = Buffer.concat(chunks, chunklen);
              var info = {
                  envelope: mail.data.envelope || mail.message.getEnvelope(),
                  messageId: messageId,
                  response: response
              };
              this._log('info', 'end', 'Processed <%s> (%sB)', messageId, response.length);
              this.emit('end', info);
              callback(null, info);
          }.bind(this));
      }.bind(this));
  };
  
  /**
   * Log emitter
   * @param {String} level Log level
   * @param {String} type Optional type of the log message
   * @param {String} message Message to log
   */
  StubTransport.prototype._log = function ( /* level, type, message */ ) {
      var args = Array.prototype.slice.call(arguments);
      var level = (args.shift() || 'INFO').toUpperCase();
      var type = (args.shift() || '');
      var message = util.format.apply(util, args);
  
      this.emit('log', {
          name: packageData.name,
          version: packageData.version,
          level: level,
          type: type,
          message: message
      });
  };