var summaryModule = (function(postal, $) {
    var summaryTemplate = "#summary-tmpl",
        summaryItemTemplate = "#summary-item-tmpl",
        qtySummarySelector = "#summary-list",
        orderTotalSummarySelector = "#summary-list",
        wireUpSummary = function(summary) {
            postal.subscribe("summary", "init", _.bind(summary.init, summary));
        },
        wireUpQuantitySummary = function(qtySummary) {
            postal.subscribe("summary", "qtychange", function(msg) {
                qtySummary.qty++;
                qtySummary.notifyOfChange();
            });

            postal.subscribe("summary", "init", function() {
                qtySummary.qty = 0;
                qtySummary.notifyOfChange();
            });
        },
        wireUpOrderTotalSummary = function(ordTtlSummary) {
            postal.subscribe("summary", "ordertotalchange", function(msg) {
                ordTtlSummary.total += msg.price;
                ordTtlSummary.notifyOfChange();
            });

            postal.subscribe("summary", "init", function() {
                ordTtlSummary.total = 0;
                ordTtlSummary.notifyOfChange();
            });
        },
        SummaryPrototype = {
            init: function() {
                this.items = [
                    new QuantitySummary(new SummaryItemDomProxy(qtySummarySelector), "summary-qty"),
                    new OrderTotalSummary(new SummaryItemDomProxy(orderTotalSummarySelector), "summary-total")
                ];
                this.proxy.render(this);
            }
        },
        Summary = function(domProxy) {
            this.items = [];
            this.proxy = domProxy;
            wireUpSummary(this);
        },
        SummaryDomProxyPrototype = {
            render: function(model) {
                $(this.selector).html(_.template($(summaryTemplate).html(), model));
                $.each(model.items, function(idx, item){
                    item.notifyOfChange();
                });
            }
        },
        SummaryDomProxy = function(selector) {
            this.selector = selector;
        },
        QuantitySummaryPrototype = {
            notifyOfChange: function() {
                this.proxy.render({ msg: this.qty + " item(s) selected.", id: this.id });
            }
        },
        QuantitySummary = function(domProxy, id) {
            this.qty = 0;
            this.id = id;
            this.proxy = domProxy;
            wireUpQuantitySummary(this);
        },
        OrderTotalSummaryPrototype = {
            notifyOfChange: function() {
                this.proxy.render({ msg: "Current Order Total: $" + this.total.toFixed(2), id: this.id });
            }
        },
        OrderTotalSummary = function(domProxy, id) {
            this.total = 0;
            this.id = id;
            this.proxy = domProxy;
            wireUpOrderTotalSummary(this);
        },
        SummaryItemDomProxyPrototype = {
            render: function(model) {
                var target = $("#" + model.id),
                    rendered = _.template($(summaryItemTemplate).html(), model);
                if(target.length === 0) {
                    $(this.selector).append(rendered);
                }
                else {
                    target.replaceWith(rendered);
                }
            }
        },
        SummaryItemDomProxy = function(selector) {
            this.selector = selector;
        };

    Summary.prototype = SummaryPrototype;
    SummaryDomProxy.prototype = SummaryDomProxyPrototype;
    QuantitySummary.prototype = QuantitySummaryPrototype;
    OrderTotalSummary.prototype = OrderTotalSummaryPrototype;
    SummaryItemDomProxy.prototype = SummaryItemDomProxyPrototype;

    return {
        start: function(selector) {
            return new Summary(new SummaryDomProxy(selector));
        }
    }
})(postal, jQuery);