/**
 * @license Highcharts JS v3.0.6 (2013-10-04)
 * Prototype adapter
 *
 * @author Michael Nelson, Torstein Hønsi.
 *
 * Feel free to use and modify this script.
 * Highcharts license: www.highcharts.com/license.
 */

// JSLint options:
/*global Effect, Class, Event, Element, $, $$, $A */

// Adapter interface between prototype and the Highcharts charting library
var HighchartsAdapter = (function () {

    var hasEffect = typeof Effect !== 'undefined';

    return {

        /**
         * Initialize the adapter. This is run once as Highcharts is first run.
         * @param {Object} pathAnim The helper object to do animations across adapters.
         */
        init: function (pathAnim) {
            if (hasEffect) {
                /**
                 * Animation for Highcharts SVG element wrappers only
                 * @param {Object} element
                 * @param {Object} attribute
                 * @param {Object} to
                 * @param {Object} options
                 */
                Effect.HighchartsTransition = Class.create(Effect.Base, {
                    initialize: function (element, attr, to, options) {
                        var from,
                            opts;

                        this.element = element;
                        this.key = attr;
                        from = element.attr ? element.attr(attr) : $(element).getStyle(attr);

                        // special treatment for paths
                        if (attr === 'd') {
                            this.paths = pathAnim.init(
                                element,
                                element.d,
                                to
                            );
                            this.toD = to;


                            // fake values in order to read relative position as a float in update
                            from = 0;
                            to = 1;
                        }

                        opts = Object.extend((options || {}), {
                            from: from,
                            to: to,
                            attribute: attr
                        });
                        this.start(opts);
                    },
                    setup: function () {
                        HighchartsAdapter._extend(this.element);
                        // If this is the first animation on this object, create the _highcharts_animation helper that
                        // contain pointers to the animation objects.
                        if (!this.element._highchart_animation) {
                            this.element._highchart_animation = {};
                        }

                        // Store a reference to this animation instance.
                        this.element._highchart_animation[this.key] = this;
                    },
                    update: function (position) {
                        var paths = this.paths,
                            element = this.element,
                            obj;

                        if (paths) {
                            position = pathAnim.step(paths[0], paths[1], position, this.toD);
                        }

                        if (element.attr) { // SVGElement

                            if (element.element) { // If not, it has been destroyed (#1405)
                                element.attr(this.options.attribute, position);
                            }

                        } else { // HTML, #409
                            obj = {};
                            obj[this.options.attribute] = position;
                            $(element).setStyle(obj);
                        }

                    },
                    finish: function () {
                        // Delete the property that holds this animation now that it is finished.
                        // Both canceled animations and complete ones gets a 'finish' call.
                        if (this.element && this.element._highchart_animation) { // #1405
                            delete this.element._highchart_animation[this.key];
                        }
                    }
                });
            }
        },

        /**
         * Run a general method on the framework, following jQuery syntax
         * @param {Object} el The HTML element
         * @param {String} method Which method to run on the wrapped element
         */
        adapterRun: function (el, method) {

            // This currently works for getting inner width and height. If adding
            // more methods later, we need a conditional implementation for each.
            return parseInt($(el).getStyle(method), 10);

        },

        /**
         * Downloads a script and executes a callback when done.
         * @param {String} scriptLocation
         * @param {Function} callback
         */
        getScript: function (scriptLocation, callback) {
            var head = $$('head')[0]; // Returns an array, so pick the first element.
            if (head) {
                // Append a new 'script' element, set its type and src attributes, add a 'load' handler that calls the callback
                head.appendChild(new Element('script', { type: 'text/javascript', src: scriptLocation}).observe('load', callback));
            }
        },

        /**
         * Custom events in prototype needs to be namespaced. This method adds a namespace 'h:' in front of
         * events that are not recognized as native.
         */
        addNS: function (eventName) {
            var HTMLEvents = /^(?:load|unload|abort|error|select|change|submit|reset|focus|blur|resize|scroll)$/,
                MouseEvents = /^(?:click|mouse(?:down|up|over|move|out))$/;
            return (HTMLEvents.test(eventName) || MouseEvents.test(eventName)) ?
                eventName :
            'h:' + eventName;
        },

        // el needs an event to be attached. el is not necessarily a dom element
        addEvent: function (el, event, fn) {
            if (el.addEventListener || el.attachEvent) {
                Event.observe($(el), HighchartsAdapter.addNS(event), fn);

            } else {
                HighchartsAdapter._extend(el);
                el._highcharts_observe(event, fn);
            }
        },

        // motion makes things pretty. use it if effects is loaded, if not... still get to the end result.
        animate: function (el, params, options) {
            var key,
                fx;

            // default options
            options = options || {};
            options.delay = 0;
            options.duration = (options.duration || 500) / 1000;
            options.afterFinish = options.complete;

            // animate wrappers and DOM elements
            if (hasEffect) {
                for (key in params) {
                    // The fx variable is seemingly thrown away here, but the Effect.setup will add itself to the _highcharts_animation object
                    // on the element itself so its not really lost.
                    fx = new Effect.HighchartsTransition($(el), key, params[key], options);
                }
            } else {
                if (el.attr) { // #409 without effects
                    for (key in params) {
                        el.attr(key, params[key]);
                    }
                }
                if (options.complete) {
                    options.complete();
                }
            }

            if (!el.attr) { // HTML element, #409
                $(el).setStyle(params);
            }
        },

        // this only occurs in higcharts 2.0+
        stop: function (el) {
            var key;
            if (el._highcharts_extended && el._highchart_animation) {
                for (key in el._highchart_animation) {
                    // Cancel the animation
                    // The 'finish' function in the Effect object will remove the reference
                    el._highchart_animation[key].cancel();
                }
            }
        },

        // um.. each
        each: function (arr, fn) {
            $A(arr).each(fn);
        },

        inArray: function (item, arr, from) {
            return arr ? arr.indexOf(item, from) : -1;
        },

        /**
         * Get the cumulative offset relative to the top left of the page. This method, unlike its
         * jQuery and MooTools counterpart, still suffers from issue #208 regarding the position
         * of a chart within a fixed container.
         */
        offset: function (el) {
            return $(el).cumulativeOffset();
        },

        // fire an event based on an event name (event) and an object (el).
        // again, el may not be a dom element
        fireEvent: function (el, event, eventArguments, defaultFunction) {
            if (el.fire) {
                el.fire(HighchartsAdapter.addNS(event), eventArguments);
            } else if (el._highcharts_extended) {
                eventArguments = eventArguments || {};
                el._highcharts_fire(event, eventArguments);
            }

            if (eventArguments && eventArguments.defaultPrevented) {
                defaultFunction = null;
            }

            if (defaultFunction) {
                defaultFunction(eventArguments);
            }
        },

        removeEvent: function (el, event, handler) {
            if ($(el).stopObserving) {
                if (event) {
                    event = HighchartsAdapter.addNS(event);
                }
                $(el).stopObserving(event, handler);
            } if (window === el) {
                Event.stopObserving(el, event, handler);
            } else {
                HighchartsAdapter._extend(el);
                el._highcharts_stop_observing(event, handler);
            }
        },

        washMouseEvent: function (e) {
            return e;
        },

        // um, grep
        grep: function (arr, fn) {
            return arr.findAll(fn);
        },

        // um, map
        map: function (arr, fn) {
            return arr.map(fn);
        },

        // extend an object to handle highchart events (highchart objects, not svg elements).
        // this is a very simple way of handling events but whatever, it works (i think)
        _extend: function (object) {
            if (!object._highcharts_extended) {
                Object.extend(object, {
                    _highchart_events: {},
                    _highchart_animation: null,
                    _highcharts_extended: true,
                    _highcharts_observe: function (name, fn) {
                        this._highchart_events[name] = [this._highchart_events[name], fn].compact().flatten();
                    },
                    _highcharts_stop_observing: function (name, fn) {
                        if (name) {
                            if (fn) {
                                this._highchart_events[name] = [this._highchart_events[name]].compact().flatten().without(fn);
                            } else {
                                delete this._highchart_events[name];
                            }
                        } else {
                            this._highchart_events = {};
                        }
                    },
                    _highcharts_fire: function (name, args) {
                        var target = this;
                        (this._highchart_events[name] || []).each(function (fn) {
                            // args is never null here
                            if (args.stopped) {
                                return; // "throw $break" wasn't working. i think because of the scope of 'this'.
                            }

                            // Attach a simple preventDefault function to skip default handler if called
                            args.preventDefault = function () {
                                args.defaultPrevented = true;
                            };
                            args.target = target;

                            // If the event handler return false, prevent the default handler from executing
                            if (fn.bind(this)(args) === false) {
                                args.preventDefault();
                            }
                        }
                            .bind(this));
                    }
                });
            }
        }
    };
}());
