// A basic view implementation that expects an `URL` to be passed as one of the parameters
// to the view; it will format that `URL` using any other parameters, and use it to retrieve
// an `HTML` fragment from the server. This is only one of many strategies that could be
// followed to create views, of course. It also assumes that the parameters object will
// get a title property.
var BaseView = View.extend({
    // Subclasses must ensure there is an url property to the parameter object passed
    // into this superconstructor, i.e.:
    //
    //     this._super(params)
    //
    // Any parameters passed in to the view constructor will be substituted
    // into the URL string using the String format method (see utilities.js).
    //
    //     @param {Object} params
    initialize: function(params) {
        this.url    = this.getUrl(params);
        this.params = params;
        this.buffer = Application.params.BUFFER_EL;
    },
    getUrl: function(params) {
        if (params.url) {
            return params.url.format(params);
        } else {
            return "/" + Application.params.APP_NAME + "/" + params.view;
        }
    },
    getTitle: function() {
        // The title varies on the Team View between Android and iOS.
        // cstuart 2011-08-29
        if ($.client.ios) {
            this.params.title = this.params.ios_title || this.params.title;
        }
        return this.params.title || this.params.view.capitalize();
    },
    getMetric: function() {
        return this.params.metric || "/" + this.params.view.capitalize();
    },
    getButtons: function() {
        return this.params.buttons || "Back:";
    },
    getAction: function() {
        return this.params.action || "<None>";
    },
    getFilter: function() {
        return this.params.filter || "<None>";
    },
    getSection: function() {
        return this.params.view;
    },
    // Loads the content of the view from the server (the content should be wrapped by a `div`).
    // The content is inserted into the page.
    create: function() {
        var view = this;

        // This is a hack. The TSN keys include periods that confuse the Rails page caching system. Convert
        // here to underscores, and back to periods again on the server using a filter.
        view.url = view.url.replace(/\./g,"_");

        function onError() {
            var params = {};
            // The old currentView won't exist in the case of a 404 or
            // other server error.
            if (Application.currentView && Application.currentView.params) {
                params = Application.currentView.params;
            }
            $.hideLoader();
            $.flash("A network error occurred.", params, true);
            throw new Error('An error occurred.');
        }
        $.showLoader();
        $.ajax({
            url: view.url,
            success: function(response) {
                // If the server is unreachable, zepto calls `success`
                // and then the `response` is empty. Catch it here and throw an error.
                if (response === "") onError();

                var response = $.highResifyLogosForRetinaAndAndroid(response);

                view.buffer.html(response);
                view.element = view.buffer.find('div').get(0);
                view._evaluateDataAttribute();
                Application.appendView(view);
                $.hideLoader();
                $.delayedLoad();
            },
            error: function() {
                onError();
            }
        });
    },
    onClientCallback: function(name, value) {
        console.log('BaseView.onClientCallback({' + name + ': ' + value + '})');
    },
    // If HTML returned from the server includes a `<data id="view_data" data=""></data>` element,
    // this should contain an object literal (JSON string) with values that will be merged into
    // the parameters for this view instance. This is used to pass back additional information
    // from the server via the HTML. For example, when loading a player it might be useful to
    // return the key for the player's team so that can be used when communicating with the client:
    //
    //     <data id="view_data" data="{'title': '<%= @team.city_name %> <%= @team.team_name %>'}"></data>
    //
    // This will add the integer 1588 (correctly typed) under the property "team_key" to the
    // parameters (`this.params`) for this view.
    _evaluateDataAttribute: function() {
        var view_data_el = Application.params.BUFFER_EL.find("#view_data");
        if (view_data_el.size() === 0) return;
        if (!view_data_el.attr('data')) return;

        var data = eval.call(window, "(" + view_data_el.attr("data") + ")");
        for (var key in data) {
            // If you escape a non-string value, it is first converted to a string, which we don't want
            this.params[key] = (typeof data[key] == "string") ? unescape(data[key]) : data[key];
        }
    }
});