/**
 * Displays a table of items and a pagination control.
 */
define(function(require) {
    'use strict';

    var _ = require('underscore'),
        Backgrid = require('backgrid'),
        Marionette = require('marionette'),

        BaseHeaderCell = require('./base-header-cell'),
        PagingFooter = require('./paging-footer'),
        listTableTemplate = require('text!components/generic-list/list/templates/table.underscore'),

        ListTableView;

    ListTableView = Marionette.LayoutView.extend({
        template: _.template(listTableTemplate),

        regions: {
            table: '.list-table',
            paginator: '.list-paging-footer'
        },

        initialize: function(options) {
            this.options = _.defaults({}, options, {
                tableName: gettext('Generic List'),
                trackSubject: 'list',
                appClass: ''
            });

            this.options = _.defaults(this.options, {
                trackSortEventName: ['edx', 'bi', this.options.trackSubject, 'sorted'].join('.'),
                trackPageEventName: ['edx', 'bi', this.options.trackSubject, 'paged'].join('.')
            });

            this.collection.on('backgrid:sort', this.onSort, this);
        },

        onSort: function(column, direction) {
            this.options.trackingModel.trigger('segment:track', this.options.trackSortEventName, {
                category: column.get('name') + '_' + direction.slice(0, -6)
            });
        },

        onBeforeShow: function() {
            this.showChildView('table', new Backgrid.Grid({
                className: 'table table-striped dataTable',  // Combine bootstrap and datatables styling
                collection: this.options.collection,
                columns: this.buildColumns()
            }));
            this.showChildView('paginator', new PagingFooter({
                collection: this.options.collection,
                trackingModel: this.options.trackingModel,
                appClass: this.options.appClass,
                trackPageEventName: this.options.trackPageEventName
            }));
            // Accessibility hacks
            this.$('table').prepend('<caption class="sr-only">' + this.options.tableName + '</caption>');
        },

        /**
         * Returns default column settings.
         */
        createDefaultColumn: function(label, name) {
            return {
                label: label,
                name: name,
                editable: false,
                sortable: true,
                sortType: 'toggle',
                sortValue: function(model, colName) {
                    var sortVal = model.get(colName);
                    if (sortVal === null || sortVal === undefined || sortVal === '') {
                        // Force null values to the end of the ascending sorted list
                        // NOTE: only works for sorting string value columns
                        return 'z';
                    } else {
                        return 'a ' + sortVal;
                    }
                },
                headerCell: BaseHeaderCell,
                cell: 'string'
            };
        },

        /**
         * Returns column formats for backgrid.  See course-list and roster tables
         * for examples of usage.
         *
         * Use createDefaultColumn for standard column settings.
         */
        buildColumns: function() {
            throw 'Not implemented'; // eslint-disable-line no-throw-literal
        }

    });

    return ListTableView;
});
