(function () {
    var STORAGE_KEY = 'weather.cities';
    var server = {
        getWeather: function (zip) {
            return $.getJSON('/Weather/GetWeather?zip=' + zip);
        }
    };

    var WeatherApp = Backbone.Model.extend({
        defaults: {
            'unit': 'F'
        },
        initialize: function () {
            this.cities = new CityCollection();

            if(Modernizr.localstorage && localStorage[STORAGE_KEY]) {
                _.each(localStorage[STORAGE_KEY].split(','), function(z) {
                    this.addCity(z);
                }, this);
            } 
            else {
                this.addCity(98052);
                this.addCity(10001);
                this.addCity(75201);
                this.addCity(94121);
            }
            
            // bind to collection changes after adding the starting cities
            this.cities.bind('add remove', this.saveCities, this);
        },
        saveCities: function () {
            var data = this.cities.map(function(c) {
                 return c.get('zip')
            }).join();

            localStorage[STORAGE_KEY] = data;
        },
        addCity: function (zip) {
            var city = new City({ 'app': this, 'zip': zip });
            this.cities.add(city);
            city.refresh();
        },
        getCities: function () {
            return this.cities;
        },
        refresh: function () {
            this.cities.each(function (c) {
                c.refresh();
            });
        },
        changeUnit: function () {
            var u = this.get('unit');
            if (u === 'F')
                u = 'C';
            else
                u = 'F';

            this.set({ 'unit': u });
        },
        getUnit: function () {
            return this.get('unit');
        }
    });

    var WeatherView = Backbone.View.extend({
        events: {
            'click #unitCheckbox': 'changeUnit',
            'click #refreshLink': 'refreshAll',
            'submit form': 'addCity'
        },
        initialize: function () {
            this.template = _.template($('#weatherTemplate').html());
            this.model.bind('change', this.render, this);
            this.model.getCities().bind('all', this.focus, this);
        },
        focus: function () {
            $(this.el).find('#zipTextbox').focus();
        },
        changeUnit: function () {
            this.model.changeUnit();
        },
        refreshAll: function (evt) {
            evt.preventDefault();
            this.model.refresh();
        },
        addCity: function (evt) {
            evt.preventDefault();
            var $text = $('#zipTextbox');

            var zip = $text.val();
            if (zip) {
                this.model.addCity($text.val());
                $text.val('');
            }

            $text.focus();
        },
        render: function () {
            var self = this;

            //load the main UI
            $(this.el).html(this.template(this.model.toJSON()));
            $('#unitCheckbox').lightSwitch({
                switchImg: '/Content/lib/lightswitch/switch-unit.png',
                switchImgCover: '/Content/lib/lightswitch/switchplate.png',
            });

            // load the cities list
            var citiesView = new CityCollectionView({ collection: this.model.getCities() });
            $('#citiesDiv').html(citiesView.render().el);

            this.focus();

            return this;
        }
    });

    var City = Backbone.Model.extend({
        defaults: {
            'name': '???',
            'temperature': '???',
            'state': '???',
            'url': '???'
        },
        initialize: function () {
            this.app = this.get('app');
            this.state = 'init';
            this.farenheit = '???';
            this.celsius = '???';
        },
        invoke: function (event) {
            this.state = event;
            this.trigger(event);
        },
        getState: function () {
            return this.state;
        },
        getViewData: function () {
            var json = this.toJSON();
            json.unit = this.app.getUnit();
            json.temperature = this.app.getUnit() === 'F' ? this.farenheit : this.celsius;

            return json;
        },
        refresh: function () {
            this.invoke('loading');

            var self = this;
            var promise = server.getWeather(this.get('zip'));
            promise.done(function (data) {
                if (data.success) {
                    self.farenheit = data.temperature;
                    self.celsius = Math.round((data.temperature - 32) / 1.8);
                    self.set({
                        'name': data.city,
                        'state': data.state,
                        'url': data.url
                    });
                    self.invoke('update');
                }
                else {
                    self.invoke('error');
                }
            });
            promise.fail(function (data) {
                self.invoke('error');
            });
        }
    });

    var CityView = Backbone.View.extend({
        className: 'city',
        events: {
            'click .city-refresh': 'refresh',
            'click .city-remove': 'remove'
        },
        initialize: function () {
            this.template = _.template($('#cityTemplate').html());
            this.loadingTemplate = _.template($('#cityLoadingTemplate').html());
            this.errorTemplate = _.template($('#cityErrorTemplate').html());
            this.model.bind('update loading error', this.render, this);
        },
        render: function () {
            var viewData = this.model.getViewData();
            switch (this.model.getState()) {
                case 'loading':
                    this.$el.removeClass('city-error');
                    this.$el.html(this.loadingTemplate(viewData));
                    break;
                case 'error':
                    this.$el.html(this.errorTemplate(viewData));
                    this.$el.addClass('city-error');
                    break;
                default:
                    this.$el.removeClass('city-error');
                    this.$el.html(this.template(viewData));
                    break;

            }
            this.$el.data('zip', viewData.zip);
            
            return this;
        },
        remove: function () {
            this.model.destroy();
        },
        refresh: function () {
            this.model.refresh();
        }
    });

    var CityCollection = Backbone.Collection.extend({
        model: City
    });

    var CityCollectionView = Backbone.View.extend({
        tagName: 'ul',
        events: {
            'sortupdate': 'updateOrder'
        },
        initialize: function () {
            this.collection.bind('add destroy', this.render, this);
        },
        updateOrder: function () {
            var self = this;
            var sortedModels = [];
            this.$el.find('.city').each(function(index, city) {
                var cityModel = self.collection.where({ 'zip': $(city).data('zip') })[0];
                sortedModels.push(cityModel);
            });

            self.collection.reset(sortedModels);
        },
        render: function () {
            var self = this;
            self.$el.empty();
            this.collection.forEach(function (c) {
                var cityView = new CityView({ model: c });
                var $li = $('<li>').html(cityView.render().el);
                self.$el.append($li);
            });
            if(this.collection.length > 0) {
                self.$el.sortable();    
            }
            
            return this;
        }
    });

    $(function () {
        var appView = new WeatherView({ model: new WeatherApp() });
        appView.setElement($('#appDiv'));
        appView.render();

    });
})();