/**
 * http://github.com/valums/file-uploader
 *
 * Multiple file upload component with progress-bar, drag-and-drop.
 * © 2010 Andrew Valums ( andrew(at)valums.com)
 *
 * Licensed under GNU GPL 2 or later, see license.txt.
 */

//
// Helper functions
//

var qq = qq || {};

/**
 * Adds all missing properties from second obj to first obj
 */
qq.extend = function(first, second){
  for (var prop in second){
    first[prop] = second[prop];
  }
};

/**
 * Searches for a given element in the array, returns -1 if it is not present.
 * @param {Number}[from] The index at which to begin the search
 */
qq.indexOf = function(arr, elt, from){
  if(arr.indexOf) return arr.indexOf(elt, from);

  from = from || 0;
  var len = arr.length;

  if(from < 0) from += len;

  for (; from < len; from++){
    if(from in arr && arr[from] === elt){
      return from;
    }
  }
  return -1;
};

qq.getUniqueId = (function(){
  var id = 0;
  return function(){ return id++; };
})();

//
// Events

qq.attach = function(element, type, fn){
  if(element.addEventListener){
    element.addEventListener(type, fn, false);
  }else if(element.attachEvent){
    element.attachEvent('on' + type, fn);
  }
};
qq.detach = function(element, type, fn){
  if(element.removeEventListener){
    element.removeEventListener(type, fn, false);
  }else if(element.attachEvent){
    element.detachEvent('on' + type, fn);
  }
};

qq.preventDefault = function(e){
  if(e.preventDefault){
    e.preventDefault();
  }else{
    e.returnValue = false;
  }
};

//
// Node manipulations

/**
 * Insert node a before node b.
 */
qq.insertBefore = function(a, b){
  b.parentNode.insertBefore(a, b);
};
qq.remove = function(element){
  element.parentNode.removeChild(element);
};

qq.contains = function(parent, descendant){
  // compareposition returns false in this case
  if(parent == descendant) return true;

  if(parent.contains){
    return parent.contains(descendant);
  }else{
    return !!(descendant.compareDocumentPosition(parent) & 8);
  }
};

/**
 * Creates and returns element from html string
 * Uses innerHTML to create an element
 */
qq.toElement = (function(){
  var div = document.createElement('div');
  return function(html){
    div.innerHTML = html;
    var element = div.firstChild;
    div.removeChild(element);
    return element;
  };
})();

//
// Node properties and attributes

/**
 * Sets styles for an element.
 * Fixes opacity in IE6-8.
 */
qq.css = function(element, styles){
  if(styles.opacity != null){
    if(typeof element.style.opacity != 'string' && typeof(element.filters) != 'undefined'){
      styles.filter = 'alpha(opacity=' + Math.round(100 * styles.opacity) + ')';
    }
  }
  qq.extend(element.style, styles);
};
qq.hasClass = function(element, name){
  var re = new RegExp('(^|)' + name + '( |$)');
  return re.test(element.className);
};
qq.addClass = function(element, name){
  if(!qq.hasClass(element, name)){
    element.className += ' ' + name;
  }
};
qq.removeClass = function(element, name){
  var re = new RegExp('(^|)' + name + '( |$)');
  element.className = element.className.replace(re, ' ').replace(/^\s+|\s+$/g, "");
};
qq.setText = function(element, text){
  element.innerText = text;
  element.textContent = text;
};

//
// Selecting elements

qq.children = function(element){
  var children = [],
  child = element.firstChild;

  while (child){
    if(child.nodeType == 1){
      children.push(child);
    }
    child = child.nextSibling;
  }

  return children;
};

qq.getByClass = function(element, className){
  if(element.querySelectorAll){
    return element.querySelectorAll('.' + className);
  }

  var result = [];
  var candidates = element.getElementsByTagName("*");
  var len = candidates.length;

  for (var i = 0; i < len; i++){
    if(qq.hasClass(candidates[i], className)){
      result.push(candidates[i]);
    }
  }
  return result;
};

/**
 * obj2url() takes a json-object as argument and generates
 * a querystring. pretty much like jQuery.param()
 *
 * how to use:
 *
 *    `qq.obj2url({a:'b',c:'d'},'http://any.url/upload?otherParam=value');`
 *
 * will result in:
 *
 *    `http://any.url/upload?otherParam=value&a=b&c=d`
 *
 * @param  Object JSON-Object
 * @param  String current querystring-part
 * @return String encoded querystring
 */
qq.obj2url = function(obj, temp, prefixDone){
  var uristrings = [],
    prefix = '&',
    add = function(nextObj, i){
      var nextTemp = temp
        ? (/\[\]$/.test(temp)) // prevent double-encoding
          ? temp
          : temp+'['+i+']'
        : i;
      if((nextTemp != 'undefined') && (i != 'undefined')) {
        uristrings.push(
          (typeof nextObj === 'object')
            ? qq.obj2url(nextObj, nextTemp, true)
            : (Object.prototype.toString.call(nextObj) === '[object Function]')
              ? encodeURIComponent(nextTemp) + '=' + encodeURIComponent(nextObj())
              : encodeURIComponent(nextTemp) + '=' + encodeURIComponent(nextObj)
       );
      }
    };

  if(!prefixDone && temp) {
    prefix = (/\?/.test(temp)) ? (/\?$/.test(temp)) ? '' : '&' : '?';
    uristrings.push(temp);
    uristrings.push(qq.obj2url(obj));
  }else if((Object.prototype.toString.call(obj) === '[object Array]') && (typeof obj != 'undefined')) {
    // we wont use a for-in-loop on an array (performance)
    for (var i = 0, len = obj.length; i < len; ++i){
      add(obj[i], i);
    }
  }else if((typeof obj != 'undefined') && (obj !== null) && (typeof obj === "object")){
    // for anything else but a scalar, we will use for-in-loop
    for (var i in obj){
      add(obj[i], i);
    }
  }else{
    uristrings.push(encodeURIComponent(temp) + '=' + encodeURIComponent(obj));
  }

  return uristrings.join(prefix).replace(/^&/, '').replace(/%20/g, '+');
};

//
//
// Uploader Classes
//
//

var qq = qq || {};

/**
 * Creates upload button, validates upload, but doesn't create file list or dd.
 */
qq.FileUploaderBasic = function(o){
  this._options = {
    // set to true to see the server response
    debug: false,
    action: '/server/upload',
    params: {},
    button: null,
    multiple: true,
    maxConnections: 3,
    // validation
    allowedExtensions: [],
    sizeLimit: 0,
    minSizeLimit: 0,
    // events
    // return false to cancel submit
    onSubmit: function(id, fileName){},
    onProgress: function(id, fileName, loaded, total){},
    onComplete: function(id, fileName, responseJSON){},
    onCancel: function(id, fileName){},
    // messages
    messages: {
      typeError: "{file}has invalid extension. Only {extensions}are allowed.",
      sizeError: "{file}is too large, maximum file size is {sizeLimit}.",
      minSizeError: "{file}is too small, minimum file size is {minSizeLimit}.",
      emptyError: "{file}is empty, please select files again without it.",
      onLeave: "The files are being uploaded, if you leave now the upload will be cancelled."
    },
    showMessage: function(message){
        alert(message);
    }
  };
  qq.extend(this._options, o);

  // number of files being uploaded
  this._filesInProgress = 0;
  this._handler = this._createUploadHandler();

  if(this._options.button){
    this._button = this._createUploadButton(this._options.button);
  }

  this._preventLeaveInProgress();
};

qq.FileUploaderBasic.prototype = {
  setParams: function(params){
    this._options.params = params;
  },
  getInProgress: function(){
    return this._filesInProgress;
  },
  _createUploadButton: function(element){
    var self = this;

    return new qq.UploadButton({
      element: element,
      multiple: this._options.multiple && qq.UploadHandlerXhr.isSupported(),
      onChange: function(input){
        self._onInputChange(input);
      }
    });
  },
  _createUploadHandler: function(){
    var self = this, handlerClass;

    if(qq.UploadHandlerXhr.isSupported()){
      handlerClass = 'UploadHandlerXhr';
    }else{
      handlerClass = 'UploadHandlerForm';
    }

    var handler = new qq[handlerClass]({
      debug: this._options.debug,
      action: this._options.action,
      maxConnections: this._options.maxConnections,
      onProgress: function(id, fileName, loaded, total){
        self._onProgress(id, fileName, loaded, total);
        self._options.onProgress(id, fileName, loaded, total);
      },
      onComplete: function(id, fileName, result){
        self._onComplete(id, fileName, result);
        self._options.onComplete(id, fileName, result);
      },
      onCancel: function(id, fileName){
        self._onCancel(id, fileName);
        self._options.onCancel(id, fileName);
      }
    });

    return handler;
  },
  _preventLeaveInProgress: function(){
    var self = this;

    qq.attach(window, 'beforeunload', function(e){
      if(!self._filesInProgress){return;}

      var e = e || window.event;
      // for ie, ff
      e.returnValue = self._options.messages.onLeave;
      // for webkit
      return self._options.messages.onLeave;
    });
  },
  _onSubmit: function(id, fileName){
    this._filesInProgress++;
  },
  _onProgress: function(id, fileName, loaded, total){
  },
  _onComplete: function(id, fileName, result){
    this._filesInProgress--;
    if(result.error){
      this._options.showMessage(result.error);
    }
  },
  _onCancel: function(id, fileName){
    this._filesInProgress--;
  },
  _onInputChange: function(input){
    if(this._handler instanceof qq.UploadHandlerXhr){
      this._uploadFileList(input.files);
    }else{
      if(this._validateFile(input)){
        this._uploadFile(input);
      }
    }
    this._button.reset();
  },
  _uploadFileList: function(files){
    for (var i=0; i<files.length; i++){
      if( !this._validateFile(files[i])){
        return;
      }
    }

    for (var i=0; i<files.length; i++){
      this._uploadFile(files[i]);
    }
  },
  _uploadFile: function(fileContainer){
    var id = this._handler.add(fileContainer);
    var fileName = this._handler.getName(id);

    if(this._options.onSubmit(id, fileName) !== false){
      this._onSubmit(id, fileName);
      this._handler.upload(id, this._options.params);
    }
  },
  _validateFile: function(file){
    var name, size;

    if(file.value){
      // it is a file input
      // get input value and remove path to normalize
      name = file.value.replace(/.*(\/|\\)/, "");
    }else{
      // fix missing properties in Safari
      name = file.fileName != null ? file.fileName : file.name;
      size = file.fileSize != null ? file.fileSize : file.size;
    }

    if(! this._isAllowedExtension(name)){
      this._error('typeError', name);
      return false;
    }else if(size === 0){
      this._error('emptyError', name);
      return false;
    }else if(size && this._options.sizeLimit && size > this._options.sizeLimit){
      this._error('sizeError', name);
      return false;
    }else if(size && size < this._options.minSizeLimit){
      this._error('minSizeError', name);
      return false;
    }

    return true;
  },
  _error: function(code, fileName){
    var message = this._options.messages[code];
    function r(name, replacement){ message = message.replace(name, replacement); }

    r('{file}', this._formatFileName(fileName));
    r('{extensions}', this._options.allowedExtensions.join(', '));
    r('{sizeLimit}', this._formatSize(this._options.sizeLimit));
    r('{minSizeLimit}', this._formatSize(this._options.minSizeLimit));

    this._options.showMessage(message);
  },
  _formatFileName: function(name){
    if(name.length > 33){
      name = name.slice(0, 19) + '...' + name.slice(-13);
    }
    return name;
  },
  _isAllowedExtension: function(fileName){
    var ext = (-1 !== fileName.indexOf('.')) ? fileName.replace(/.*[.]/, '').toLowerCase() : '';
    var allowed = this._options.allowedExtensions;

    if(!allowed.length){return true;}

    for (var i=0; i<allowed.length; i++){
      if(allowed[i].toLowerCase() == ext){ return true;}
    }

    return false;
  },
  _formatSize: function(bytes){
    var i = -1;
    do {
      bytes = bytes / 1024;
      i++;
    }while (bytes > 99);

    return Math.max(bytes, 0.1).toFixed(1) + ['kB', 'MB', 'GB', 'TB', 'PB', 'EB'][i];
  }
};


/**
 * Class that creates upload widget with drag-and-drop and file list
 * @inherits qq.FileUploaderBasic
 */
qq.FileUploader = function(o){
  // call parent constructor
  qq.FileUploaderBasic.apply(this, arguments);

  // additional options
  qq.extend(this._options, {
    element: null,
    // if set, will be used instead of qq-upload-list in template
    listElement: null,

    template: '<div class="qq-uploader">' +
              '<div class="qq-upload-drop-area"><span>Drop files here to upload</span></div>' +
              '<div class="qq-upload-button">Upload a file</div>' +
              '<ul class="qq-upload-list"></ul>' +
            '</div>',

    // template for one item in file list
    fileTemplate: '<li>' +
                  '<span class="qq-upload-file"></span>' +
                  '<span class="qq-upload-spinner"></span>' +
                  '<span class="qq-upload-size"></span>' +
                  '<a class="qq-upload-cancel" href="#">Cancel</a>' +
                  '<span class="qq-upload-failed-text">Failed</span>' +
              '</li>',

    classes: {
      // used to get elements from templates
      button: 'qq-upload-button',
      drop: 'qq-upload-drop-area',
      dropActive: 'qq-upload-drop-area-active',
      list: 'qq-upload-list',

      file: 'qq-upload-file',
      spinner: 'qq-upload-spinner',
      size: 'qq-upload-size',
      cancel: 'qq-upload-cancel',

      // added to list item when upload completes
      // used in css to hide progress spinner
      success: 'qq-upload-success',
      fail: 'qq-upload-fail'
    }
  });
  // overwrite options with user supplied
  qq.extend(this._options, o);

  this._element = this._options.element;
  this._element.innerHTML = this._options.template;
  this._listElement = this._options.listElement || this._find(this._element, 'list');

  this._classes = this._options.classes;

  this._button = this._createUploadButton(this._find(this._element, 'button'));

  this._bindCancelEvent();
  this._setupDragDrop();
};

// inherit from Basic Uploader
qq.extend(qq.FileUploader.prototype, qq.FileUploaderBasic.prototype);

qq.extend(qq.FileUploader.prototype, {
  /**
    * Gets one of the elements listed in this._options.classes
    **/
  _find: function(parent, type){
    var element = qq.getByClass(parent, this._options.classes[type])[0];
    if(!element){
      throw new Error('element not found ' + type);
    }

    return element;
  },
  _setupDragDrop: function(){
    var self = this, dropArea = this._find(this._element, 'drop');

    var dz = new qq.UploadDropZone({
      element: dropArea,
      onEnter: function(e){
        qq.addClass(dropArea, self._classes.dropActive);
        e.stopPropagation();
      },
      onLeave: function(e){
        e.stopPropagation();
      },
      onLeaveNotDescendants: function(e){
        qq.removeClass(dropArea, self._classes.dropActive);
      },
      onDrop: function(e){
        dropArea.style.display = 'none';
        qq.removeClass(dropArea, self._classes.dropActive);
        self._uploadFileList(e.dataTransfer.files);
      }
    });

    dropArea.style.display = 'none';

    qq.attach(document, 'dragenter', function(e){
      if(!dz._isValidFileDrag(e)) return;
      dropArea.style.display = 'block';
    });
    qq.attach(document, 'dragleave', function(e){
      if(!dz._isValidFileDrag(e)) return;
      var relatedTarget = document.elementFromPoint(e.clientX, e.clientY);
      // only fire when leaving document out
      if( ! relatedTarget || relatedTarget.nodeName == "HTML"){
        dropArea.style.display = 'none';
      }
    });
  },
  _onSubmit: function(id, fileName){
    qq.FileUploaderBasic.prototype._onSubmit.apply(this, arguments);
    this._addToList(id, fileName);
  },
  _onProgress: function(id, fileName, loaded, total){
    qq.FileUploaderBasic.prototype._onProgress.apply(this, arguments);

    var item = this._getItemByFileId(id);
    var size = this._find(item, 'size');
    size.style.display = 'inline';

    var text;
    if(loaded != total){
      text = Math.round(loaded / total * 100) + '% from ' + this._formatSize(total);
    }else{
      text = this._formatSize(total);
    }

    qq.setText(size, text);
  },
  _onComplete: function(id, fileName, result){
    qq.FileUploaderBasic.prototype._onComplete.apply(this, arguments);

    // mark completed
    var item = this._getItemByFileId(id);
    qq.remove(this._find(item, 'cancel'));
    qq.remove(this._find(item, 'spinner'));

    if(result.success){
      qq.addClass(item, this._classes.success);
    }else{
      qq.addClass(item, this._classes.fail);
    }
  },
  _addToList: function(id, fileName){
    var item = qq.toElement(this._options.fileTemplate);
    item.qqFileId = id;

    var fileElement = this._find(item, 'file');
    qq.setText(fileElement, this._formatFileName(fileName));
    this._find(item, 'size').style.display = 'none';

    this._listElement.appendChild(item);
  },
  _getItemByFileId: function(id){
    var item = this._listElement.firstChild;

    // there can't be txt nodes in dynamically created list
    // and we can  use nextSibling
    while (item){
      if(item.qqFileId == id) return item;
      item = item.nextSibling;
    }
  },
  /**
    * delegate click event for cancel link
    **/
  _bindCancelEvent: function(){
    var self = this, list = this._listElement;

    qq.attach(list, 'click', function(e){
      e = e || window.event;
      var target = e.target || e.srcElement;

      if(qq.hasClass(target, self._classes.cancel)){
        qq.preventDefault(e);

        var item = target.parentNode;
        self._handler.cancel(item.qqFileId);
        qq.remove(item);
      }
    });
  }
});

qq.UploadDropZone = function(o){
  this._options = {
    element: null,
    onEnter: function(e){},
    onLeave: function(e){},
    // is not fired when leaving element by hovering descendants
    onLeaveNotDescendants: function(e){},
    onDrop: function(e){}
  };
  qq.extend(this._options, o);

  this._element = this._options.element;

  this._disableDropOutside();
  this._attachEvents();
};

qq.UploadDropZone.prototype = {
  _disableDropOutside: function(e){
    // run only once for all instances
    if(!qq.UploadDropZone.dropOutsideDisabled){
      qq.attach(document, 'dragover', function(e){
        if(e.dataTransfer){
          e.dataTransfer.dropEffect = 'none';
          e.preventDefault();
        }
      });

      qq.UploadDropZone.dropOutsideDisabled = true;
    }
  },
  _attachEvents: function(){
    var self = this;

    qq.attach(self._element, 'dragover', function(e){
      if(!self._isValidFileDrag(e)) return;

      var effect = e.dataTransfer.effectAllowed;
      if(effect == 'move' || effect == 'linkMove'){
        e.dataTransfer.dropEffect = 'move'; // for FF (only move allowed)
      }else{
        e.dataTransfer.dropEffect = 'copy'; // for Chrome
      }

      e.stopPropagation();
      e.preventDefault();
    });

    qq.attach(self._element, 'dragenter', function(e){
      if(!self._isValidFileDrag(e)) return;

      self._options.onEnter(e);
    });

    qq.attach(self._element, 'dragleave', function(e){
      if(!self._isValidFileDrag(e)) return;

      self._options.onLeave(e);

      var relatedTarget = document.elementFromPoint(e.clientX, e.clientY);
      // do not fire when moving a mouse over a descendant
      if(qq.contains(this, relatedTarget)) return;

      self._options.onLeaveNotDescendants(e);
    });

    qq.attach(self._element, 'drop', function(e){
      if(!self._isValidFileDrag(e)) return;

      e.preventDefault();
      self._options.onDrop(e);
    });
  },
  _isValidFileDrag: function(e){
    var dt = e.dataTransfer,
      // do not check dt.types.contains in webkit, because it crashes safari 4
      isWebkit = navigator.userAgent.indexOf("AppleWebKit") > -1;

    // dt.effectAllowed is none in Safari 5
    // dt.types.contains check is for firefox
    return dt && dt.effectAllowed != 'none' &&
      (dt.files || (!isWebkit && dt.types.contains && dt.types.contains('Files')));

  }
};

qq.UploadButton = function(o){
  this._options = {
    element: null,
    // if set to true adds multiple attribute to file input
    multiple: false,
    // name attribute of file input
    name: 'file',
    onChange: function(input){},
    hoverClass: 'qq-upload-button-hover',
    focusClass: 'qq-upload-button-focus'
  };

  qq.extend(this._options, o);

  this._element = this._options.element;

  // make button suitable container for input
  qq.css(this._element, {
    position: 'relative',
    overflow: 'hidden',
    // Make sure browse button is in the right side
    // in Internet Explorer
    direction: 'ltr'
  });

  this._input = this._createInput();
};

qq.UploadButton.prototype = {
  /* returns file input element */
  getInput: function(){
    return this._input;
  },
  /* cleans/recreates the file input */
  reset: function(){
    if(this._input.parentNode){
      qq.remove(this._input);
    }

    qq.removeClass(this._element, this._options.focusClass);
    this._input = this._createInput();
  },
  _createInput: function(){
    var input = document.createElement("input");

    if(this._options.multiple){
      input.setAttribute("multiple", "multiple");
    }

    input.setAttribute("type", "file");
    input.setAttribute("name", this._options.name);

    qq.css(input, {
      position: 'absolute',
      // in Opera only 'browse' button
      // is clickable and it is located at
      // the right side of the input
      right: 0,
      top: 0,
      fontFamily: 'Arial',
      // 4 persons reported this, the max values that worked for them were 243, 236, 236, 118
      fontSize: '118px',
      margin: 0,
      padding: 0,
      cursor: 'pointer',
      opacity: 0
    });

    this._element.appendChild(input);

    var self = this;
    qq.attach(input, 'change', function(){
      self._options.onChange(input);
    });

    qq.attach(input, 'mouseover', function(){
      qq.addClass(self._element, self._options.hoverClass);
    });
    qq.attach(input, 'mouseout', function(){
      qq.removeClass(self._element, self._options.hoverClass);
    });
    qq.attach(input, 'focus', function(){
      qq.addClass(self._element, self._options.focusClass);
    });
    qq.attach(input, 'blur', function(){
      qq.removeClass(self._element, self._options.focusClass);
    });

    // IE and Opera, unfortunately have 2 tab stops on file input
    // which is unacceptable in our case, disable keyboard access
    if(window.attachEvent){
      // it is IE or Opera
      input.setAttribute('tabIndex', "-1");
    }

    return input;
  }
};

/**
 * Class for uploading files, uploading itself is handled by child classes
 */
qq.UploadHandlerAbstract = function(o){
  this._options = {
    debug: false,
    action: '/upload.php',
    // maximum number of concurrent uploads
    maxConnections: 999,
    onProgress: function(id, fileName, loaded, total){},
    onComplete: function(id, fileName, response){},
    onCancel: function(id, fileName){}
  };
  qq.extend(this._options, o);

  this._queue = [];
  // params for files in queue
  this._params = [];
};
qq.UploadHandlerAbstract.prototype = {
  log: function(str){
    if(this._options.debug && window.console) console.log('[uploader] ' + str);
  },
  /**
    * Adds file or file input to the queue
    * @returns id
    **/
  add: function(file){},
  /**
    * Sends the file identified by id and additional query params to the server
    */
  upload: function(id, params){
    var len = this._queue.push(id);

    var copy = {};
    qq.extend(copy, params);
    this._params[id] = copy;

    // if too many active uploads, wait...
    if(len <= this._options.maxConnections){
      this._upload(id, this._params[id]);
    }
  },
  /**
    * Cancels file upload by id
    */
  cancel: function(id){
    this._cancel(id);
    this._dequeue(id);
  },
  /**
    * Cancells all uploads
    */
  cancelAll: function(){
    for (var i=0; i<this._queue.length; i++){
      this._cancel(this._queue[i]);
    }
    this._queue = [];
  },
  /**
    * Returns name of the file identified by id
    */
  getName: function(id){},
  /**
    * Returns size of the file identified by id
    */
  getSize: function(id){},
  /**
    * Returns id of files being uploaded or
    * waiting for their turn
    */
  getQueue: function(){
    return this._queue;
  },
  /**
    * Actual upload method
    */
  _upload: function(id){},
  /**
    * Actual cancel method
    */
  _cancel: function(id){},
  /**
    * Removes element from queue, starts upload of next
    */
  _dequeue: function(id){
    var i = qq.indexOf(this._queue, id);
    this._queue.splice(i, 1);

    var max = this._options.maxConnections;

    if(this._queue.length >= max){
      var nextId = this._queue[max-1];
      this._upload(nextId, this._params[nextId]);
    }
  }
};

/**
 * Class for uploading files using form and iframe
 * @inherits qq.UploadHandlerAbstract
 */
qq.UploadHandlerForm = function(o){
  qq.UploadHandlerAbstract.apply(this, arguments);

  this._inputs = {};
};
// @inherits qq.UploadHandlerAbstract
qq.extend(qq.UploadHandlerForm.prototype, qq.UploadHandlerAbstract.prototype);

qq.extend(qq.UploadHandlerForm.prototype, {
  add: function(fileInput){
    fileInput.setAttribute('name', 'qqfile');
    var id = 'qq-upload-handler-iframe' + qq.getUniqueId();

    this._inputs[id] = fileInput;

    // remove file input from DOM
    if(fileInput.parentNode){
      qq.remove(fileInput);
    }

    return id;
  },
  getName: function(id){
    // get input value and remove path to normalize
    return this._inputs[id].value.replace(/.*(\/|\\)/, "");
  },
  _cancel: function(id){
    this._options.onCancel(id, this.getName(id));

    delete this._inputs[id];

    var iframe = document.getElementById(id);
    if(iframe){
      // to cancel request set src to something else
      // we use src="javascript:false;" because it doesn't
      // trigger ie6 prompt on https
      iframe.setAttribute('src', 'javascript:false;');

      qq.remove(iframe);
    }
  },
  _upload: function(id, params){
    var input = this._inputs[id];

    if(!input){
      throw new Error('file with passed id was not added, or already uploaded or cancelled');
    }

    var fileName = this.getName(id);

    var iframe = this._createIframe(id);
    var form = this._createForm(iframe, params);
    form.appendChild(input);

    var self = this;
    this._attachLoadEvent(iframe, function(){
      self.log('iframe loaded');

      var response = self._getIframeContentJSON(iframe);

      self._options.onComplete(id, fileName, response);
      self._dequeue(id);

      delete self._inputs[id];
      // timeout added to fix busy state in FF3.6
      setTimeout(function(){
        qq.remove(iframe);
      }, 1);
    });

    form.submit();
    qq.remove(form);

    return id;
  },
  _attachLoadEvent: function(iframe, callback){
    qq.attach(iframe, 'load', function(){
      // when we remove iframe from dom
      // the request stops, but in IE load
      // event fires
      if(!iframe.parentNode){
        return;
      }

      // fixing Opera 10.53
      if(iframe.contentDocument &&
          iframe.contentDocument.body &&
          iframe.contentDocument.body.innerHTML == "false"){
        // In Opera event is fired second time
        // when body.innerHTML changed from false
        // to server response approx. after 1 sec
        // when we upload file with iframe
        return;
      }

      callback();
    });
  },
  /**
    * Returns json object received by iframe from server.
    */
  _getIframeContentJSON: function(iframe){
    // iframe.contentWindow.document - for IE<7
    var doc = iframe.contentDocument ? iframe.contentDocument: iframe.contentWindow.document, response;

    this.log("converting iframe's innerHTML to JSON");
    this.log("innerHTML = " + doc.body.innerHTML);

    try{
      response = eval("(" + doc.body.innerHTML + ")");
    }catch(err){
      response = {};
    }

    return response;
  },
  /**
    * Creates iframe with unique name
    */
  _createIframe: function(id){
    // We can't use following code as the name attribute
    // won't be properly registered in IE6, and new window
    // on form submit will open
    // var iframe = document.createElement('iframe');
    // iframe.setAttribute('name', id);

    var iframe = qq.toElement('<iframe src="javascript:false;" name="' + id + '" />');
    // src="javascript:false;" removes ie6 prompt on https

    iframe.setAttribute('id', id);

    iframe.style.display = 'none';
    document.body.appendChild(iframe);

    return iframe;
  },
  /**
    * Creates form, that will be submitted to iframe
    */
  _createForm: function(iframe, params){
    // We can't use the following code in IE6
    // var form = document.createElement('form');
    // form.setAttribute('method', 'post');
    // form.setAttribute('enctype', 'multipart/form-data');
    // Because in this case file won't be attached to request
    var form = qq.toElement('<form method="post" enctype="multipart/form-data"></form>');

    var queryString = qq.obj2url(params, this._options.action);

    form.setAttribute('action', queryString);
    form.setAttribute('target', iframe.name);
    form.style.display = 'none';
    document.body.appendChild(form);

    return form;
  }
});

/**
 * Class for uploading files using xhr
 * @inherits qq.UploadHandlerAbstract
 */
qq.UploadHandlerXhr = function(o){
  qq.UploadHandlerAbstract.apply(this, arguments);

  this._files = [];
  this._xhrs = [];

  // current loaded size in bytes for each file
  this._loaded = [];
};

// static method
qq.UploadHandlerXhr.isSupported = function(){
  var input = document.createElement('input');
  input.type = 'file';

  return(
    'multiple' in input &&
    typeof File != "undefined" &&
    typeof (new XMLHttpRequest()).upload != "undefined");
};

// @inherits qq.UploadHandlerAbstract
qq.extend(qq.UploadHandlerXhr.prototype, qq.UploadHandlerAbstract.prototype)

qq.extend(qq.UploadHandlerXhr.prototype, {
  /**
    * Adds file to the queue
    * Returns id to use with upload, cancel
    **/
  add: function(file){
    if(!(file instanceof File)){
      throw new Error('Passed obj in not a File (in qq.UploadHandlerXhr)');
    }

    return this._files.push(file) - 1;
  },
  getName: function(id){
    var file = this._files[id];
    // fix missing name in Safari 4
    return file.fileName != null ? file.fileName : file.name;
  },
  getSize: function(id){
    var file = this._files[id];
    return file.fileSize != null ? file.fileSize : file.size;
  },
  /**
    * Returns uploaded bytes for file identified by id
    */
  getLoaded: function(id){
    return this._loaded[id] || 0;
  },
  /**
    * Sends the file identified by id and additional query params to the server
    * @param {Object} params name-value string pairs
    */
  _upload: function(id, params){
    var file = this._files[id],
        name = this.getName(id),
        size = this.getSize(id);

    this._loaded[id] = 0;

    var xhr = this._xhrs[id] = new XMLHttpRequest();
    var self = this;

    xhr.upload.onprogress = function(e){
      if(e.lengthComputable){
        self._loaded[id] = e.loaded;
        self._options.onProgress(id, name, e.loaded, e.total);
      }
    };

    xhr.onreadystatechange = function(){
      if(xhr.readyState == 4){
        self._onComplete(id, xhr);
      }
    };

    // build query string
    params = params || {};
    params['qqfile'] = name;
    var queryString = qq.obj2url(params, this._options.action);

    xhr.open("POST", queryString, true);
    xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
    xhr.setRequestHeader("X-File-Name", encodeURIComponent(name));
    xhr.setRequestHeader("Content-Type", "application/octet-stream");
    xhr.send(file);
  },
  _onComplete: function(id, xhr){
    // the request was aborted/cancelled
    if(!this._files[id]) return;

    var name = this.getName(id);
    var size = this.getSize(id);

    this._options.onProgress(id, name, size, size);

    if(xhr.status == 200){
      this.log("xhr - server response received");
      this.log("responseText = " + xhr.responseText);

      var response;

      try{
          response = eval("(" + xhr.responseText + ")");
      }catch(err){
          response = {};
      }

      this._options.onComplete(id, name, response);

    }else{
      this._options.onComplete(id, name, {});
    }

    this._files[id] = null;
    this._xhrs[id] = null;
    this._dequeue(id);
  },
  _cancel: function(id){
    this._options.onCancel(id, this.getName(id));

    this._files[id] = null;

    if(this._xhrs[id]){
      this._xhrs[id].abort();
      this._xhrs[id] = null;
    }
  }
});