/**
 * @class Ext.ux.grid.menu.ListMenu
 * @extends Ext.menu.Menu
 * This is a supporting class for {@link Ext.ux.grid.filter.ListFilter}.
 * Although not listed as configuration options for this class, this class
 * also accepts all configuration options from {@link Ext.ux.grid.filter.ListFilter}.
 */
Ext.define('Ext.ux.grid.menu.ListMenu', {
    extend: 'Ext.menu.Menu',

    /**
     * @cfg {String} labelField
     * Defaults to 'text'.
     */
    labelField :  'text',
    /**
     * @cfg {String} paramPrefix
     * Defaults to 'Loading...'.
     */
    loadingText : 'Loading...',
    /**
     * @cfg {Boolean} loadOnShow
     * Defaults to true.
     */
    loadOnShow : true,
    /**
     * @cfg {Boolean} single
     * Specify true to group all items in this list into a single-select
     * radio button group. Defaults to false.
     */
    single : false,

    constructor : function (cfg) {
        this.selected = [];
        this.addEvents(
            /**
             * @event checkchange
             * Fires when there is a change in checked items from this list
             * @param {Object} item Ext.menu.CheckItem
             * @param {Object} checked The checked value that was set
             */
            'checkchange'
        );

        this.callParent([cfg = cfg || {}]);

        if(!cfg.store && cfg.options){
            var options = [];
            for(var i=0, len=cfg.options.length; i<len; i++){
                var value = cfg.options[i];
                switch(Ext.type(value)){
                    case 'array':  options.push(value); break;
                    case 'object': options.push([value.id, value[this.labelField]]); break;
                    case 'string': options.push([value, value]); break;
                }
            }

            this.store = Ext.create('Ext.data.ArrayStore', {
                fields: ['id', this.labelField],
                data:   options,
                listeners: {
                    'load': this.onLoad,
                    scope:  this
                }
            });
            this.loaded = true;
        } else {
            this.add({text: this.loadingText, iconCls: 'loading-indicator'});
            this.store.on('load', this.onLoad, this);
        }
    },

    destroy : function () {
        if (this.store) {
            this.store.destroy();
        }
        this.callParent();
    },

    /**
     * Lists will initially show a 'loading' item while the data is retrieved from the store.
     * In some cases the loaded data will result in a list that goes off the screen to the
     * right (as placement calculations were done with the loading item). This adapter will
     * allow show to be called with no arguments to show with the previous arguments and
     * thus recalculate the width and potentially hang the menu from the left.
     */
    show : function () {
        var lastArgs = null;
        return function(){
            if(arguments.length === 0){
                this.callParent(lastArgs);
            } else {
                lastArgs = arguments;
                if (this.loadOnShow && !this.loaded) {
                    this.store.load();
                }
                this.callParent(arguments);
            }
        };
    }(),

    /** @private */
    onLoad : function (store, records) {
        var me = this,
            visible = me.isVisible(),
            gid, item, itemValue, i, len;

        me.hide(false);

        me.removeAll(true);

        gid = me.single ? Ext.id() : null;
        for (i = 0, len = records.length; i < len; i++) {
            itemValue = records[i].get('id');
            item = Ext.create('Ext.menu.CheckItem', {
                text: records[i].get(me.labelField),
                group: gid,
                checked: Ext.Array.contains(me.selected, itemValue),
                hideOnClick: false,
                value: itemValue
            });

            item.on('checkchange', me.checkChange, me);

            me.add(item);
        }

        me.loaded = true;

        if (visible) {
            me.show();
        }
        me.fireEvent('load', me, records);
    },

    /**
     * Get the selected items.
     * @return {Array} selected
     */
    getSelected : function () {
        return this.selected;
    },

    /** @private */
    setSelected : function (value) {
        value = this.selected = [].concat(value);

        if (this.loaded) {
            this.items.each(function(item){
                item.setChecked(false, true);
                for (var i = 0, len = value.length; i < len; i++) {
                    if (item.value == value[i]) {
                        item.setChecked(true, true);
                    }
                }
            }, this);
        }
    },

    /**
     * Handler for the 'checkchange' event from an check item in this menu
     * @param {Object} item Ext.menu.CheckItem
     * @param {Object} checked The checked value that was set
     */
    checkChange : function (item, checked) {
        var value = [];
        this.items.each(function(item){
            if (item.checked) {
                value.push(item.value);
            }
        },this);
        this.selected = value;

        this.fireEvent('checkchange', item, checked);
    }
});