/* global define */
define(['jquery', 'underscore', 'backbone', 'models/DataONEObject'],
    function($, _, Backbone, DataONEObject) {

	var EMLDistribution = Backbone.Model.extend({

		defaults: {
			objectXML: null,
			objectDOM: null,
			mediumName: null,
			mediumVolume: null,
			mediumFormat: null,
			mediumNote: null,
			onlineDescription: null,
			parentModel: null
		},

		initialize: function(attributes){
			if(attributes.objectDOM) this.parse(attributes.objectDOM);

			this.on("change:mediumName change:mediumVolume change:mediumFormat " +
					"change:mediumNote change:onlineDescription", this.trickleUpChange);
		},

		/*
         * Maps the lower-case EML node names (valid in HTML DOM) to the camel-cased EML node names (valid in EML).
         * Used during parse() and serialize()
         */
		nodeNameMap: function(){
			return{
				"authsystem" : "authSystem",
        "connectiondefinition" : "connectionDefinition",
        "mediumdensity" : "mediumDensity",
        "mediumdensityunits" : "mediumDensityUnits",
				"mediumformat" : "mediumFormat",
				"mediumname" : "mediumName",
				"mediumnote" : "mediumNote",
				"mediumvolume" : "mediumVolume",
				"onlinedescription" : "onlineDescription"
			}
		},

		parse: function(objectDOM){
			if(!objectDOM)
				var xml = this.get("objectDOM");

			var offline = $(xml).find("offline"),
				online = $(xml).find("online");

			if(offline.length){
				if($(offline).children("mediumname").length) this.parseNode($(offline).children("mediumname"));
				if($(offline).children("mediumvolume").length) this.parseNode($(offline).children("mediumvolume"));
				if($(offline).children("mediumformat").length) this.parseNode($(offline).children("mediumformat"));
				if($(offline).children("mediumnote").length) this.parseNode($(offline).children("mediumnote"));
			}

			if(online.length){
				if($(online).children("onlinedescription").length) this.parseNode($(online).children("onlinedescription"));
			}
		},

		parseNode: function(node){
			if(!node || (Array.isArray(node) && !node.length))
				return;

			this.set($(node)[0].localName, $(node).text());
		},

		serialize: function(){
			var objectDOM = this.updateDOM(),
				xmlString = objectDOM.outerHTML;

			//Camel-case the XML
	    	xmlString = this.formatXML(xmlString);

	    	return xmlString;
		},

		/*
		 * Makes a copy of the original XML DOM and updates it with the new values from the model.
		 */
		updateDOM: function(){
			 var objectDOM = this.get("objectDOM").cloneNode(true);

			 // Remove empty (zero-length or whitespace-only) nodes
			$(objectDOM).find("*").filter(function() { return $.trim(this.innerHTML) === ""; } ).remove();

			 return objectDOM;
		},

    /*
    * Climbs up the model heirarchy until it finds the EML model
    *
    * @return {EML211 or false} - Returns the EML 211 Model or false if not found
    */
    getParentEML: function(){
      var emlModel = this.get("parentModel"),
          tries = 0;

      while (emlModel.type !== "EML" && tries < 6){
        emlModel = emlModel.get("parentModel");
        tries++;
      }

      if( emlModel && emlModel.type == "EML")
        return emlModel;
      else
        return false;

    },

		trickleUpChange: function(){
			MetacatUI.rootDataPackage.packageModel.set("changed", true);
		},

		formatXML: function(xmlString){
			return DataONEObject.prototype.formatXML.call(this, xmlString);
		}
	});

	return EMLDistribution;
});