/* */ 
(function(Buffer) {
  var util = require("util");
  var Stream = require("stream").Stream;
  var DelayedStream = require("delayed-stream");
  module.exports = CombinedStream;
  function CombinedStream() {
    this.writable = false;
    this.readable = true;
    this.dataSize = 0;
    this.maxDataSize = 2 * 1024 * 1024;
    this.pauseStreams = true;
    this._released = false;
    this._streams = [];
    this._currentStream = null;
  }
  util.inherits(CombinedStream, Stream);
  CombinedStream.create = function(options) {
    var combinedStream = new this();
    options = options || {};
    for (var option in options) {
      combinedStream[option] = options[option];
    }
    return combinedStream;
  };
  CombinedStream.isStreamLike = function(stream) {
    return (typeof stream !== 'function') && (typeof stream !== 'string') && (typeof stream !== 'boolean') && (typeof stream !== 'number') && (!Buffer.isBuffer(stream));
  };
  CombinedStream.prototype.append = function(stream) {
    var isStreamLike = CombinedStream.isStreamLike(stream);
    if (isStreamLike) {
      if (!(stream instanceof DelayedStream)) {
        var newStream = DelayedStream.create(stream, {
          maxDataSize: Infinity,
          pauseStream: this.pauseStreams
        });
        stream.on('data', this._checkDataSize.bind(this));
        stream = newStream;
      }
      this._handleErrors(stream);
      if (this.pauseStreams) {
        stream.pause();
      }
    }
    this._streams.push(stream);
    return this;
  };
  CombinedStream.prototype.pipe = function(dest, options) {
    Stream.prototype.pipe.call(this, dest, options);
    this.resume();
    return dest;
  };
  CombinedStream.prototype._getNext = function() {
    this._currentStream = null;
    var stream = this._streams.shift();
    if (typeof stream == 'undefined') {
      this.end();
      return ;
    }
    if (typeof stream !== 'function') {
      this._pipeNext(stream);
      return ;
    }
    var getStream = stream;
    getStream(function(stream) {
      var isStreamLike = CombinedStream.isStreamLike(stream);
      if (isStreamLike) {
        stream.on('data', this._checkDataSize.bind(this));
        this._handleErrors(stream);
      }
      this._pipeNext(stream);
    }.bind(this));
  };
  CombinedStream.prototype._pipeNext = function(stream) {
    this._currentStream = stream;
    var isStreamLike = CombinedStream.isStreamLike(stream);
    if (isStreamLike) {
      stream.on('end', this._getNext.bind(this));
      stream.pipe(this, {end: false});
      return ;
    }
    var value = stream;
    this.write(value);
    this._getNext();
  };
  CombinedStream.prototype._handleErrors = function(stream) {
    var self = this;
    stream.on('error', function(err) {
      self._emitError(err);
    });
  };
  CombinedStream.prototype.write = function(data) {
    this.emit('data', data);
  };
  CombinedStream.prototype.pause = function() {
    if (!this.pauseStreams) {
      return ;
    }
    if (this.pauseStreams && this._currentStream && typeof(this._currentStream.pause) == 'function')
      this._currentStream.pause();
    this.emit('pause');
  };
  CombinedStream.prototype.resume = function() {
    if (!this._released) {
      this._released = true;
      this.writable = true;
      this._getNext();
    }
    if (this.pauseStreams && this._currentStream && typeof(this._currentStream.resume) == 'function')
      this._currentStream.resume();
    this.emit('resume');
  };
  CombinedStream.prototype.end = function() {
    this._reset();
    this.emit('end');
  };
  CombinedStream.prototype.destroy = function() {
    this._reset();
    this.emit('close');
  };
  CombinedStream.prototype._reset = function() {
    this.writable = false;
    this._streams = [];
    this._currentStream = null;
  };
  CombinedStream.prototype._checkDataSize = function() {
    this._updateDataSize();
    if (this.dataSize <= this.maxDataSize) {
      return ;
    }
    var message = 'DelayedStream#maxDataSize of ' + this.maxDataSize + ' bytes exceeded.';
    this._emitError(new Error(message));
  };
  CombinedStream.prototype._updateDataSize = function() {
    this.dataSize = 0;
    var self = this;
    this._streams.forEach(function(stream) {
      if (!stream.dataSize) {
        return ;
      }
      self.dataSize += stream.dataSize;
    });
    if (this._currentStream && this._currentStream.dataSize) {
      this.dataSize += this._currentStream.dataSize;
    }
  };
  CombinedStream.prototype._emitError = function(err) {
    this._reset();
    this.emit('error', err);
  };
})(require("buffer").Buffer);
