(function(root) {

    "use strict";

    var DataLoader = root.Rkns.DataLoader = {

        converters: {

            from1to2: function(data) {

                var i, len;

                if(typeof data.nodes !== 'undefined') {

                    for(i=0, len=data.nodes.length; i<len; i++) {

                        var node = data.nodes[i];

                        if(node.color) {

                            console.log("node color : ", node.color);

                            node.style = {

                                color: node.color,

                            };

                        }

                        else {

                            node.style = {};

                        }

                    }

                }

                if(typeof data.edges !== 'undefined') {

                    for(i=0, len=data.edges.length; i<len; i++) {

                        var edge = data.edges[i];

                        if(edge.color) {

                            edge.style = {

                                color: edge.color,

                            };

                        }

                        else {

                            edge.style = {};

                        }

                    }

                }

                data.schema_version = "2";

                return data;

            },

        }

    };

    DataLoader.Loader = function(project, options) {

        this.project = project;

        this.dataConverters = _.defaults(options.converters || {}, DataLoader.converters);

    };

    DataLoader.Loader.prototype.convert = function(data) {

        var schemaVersionFrom = this.project.getSchemaVersion(data);

        var schemaVersionTo = this.project.getSchemaVersion();

        if (schemaVersionFrom !== schemaVersionTo) {

            var converterName = "from" + schemaVersionFrom + "to" + schemaVersionTo;

            if (typeof this.dataConverters[converterName] === 'function') {

                console.log("Apply conversion function :", converterName);

                data = this.dataConverters[converterName](data);

            }

        }

        return data;

    };

    DataLoader.Loader.prototype.load = function(data) {

        this.project.set(this.convert(data), {

            validate: true

        });

        Backbone.history.start();

    };

})(window);