Ext.namespace('Ext.ux.grid.filter');

/** 
 * @class Ext.ux.grid.filter.Filter
 * @extends Ext.util.Observable
 * Abstract base class for filter implementations.
 */
Ext.ux.grid.filter.Filter = Ext.extend(Ext.util.Observable, {
    
/**
     * @cfg {Boolean} active
     * Indicates the initial status of the filter (defaults to false).
     */
    active : false,
    
/**
     * True if this filter is active.  Use setActive() to alter after configuration.
     * @type Boolean
     * @property active
     */
    
/**
     * @cfg {String} dataIndex 
     * The {@link Ext.data.Store} dataIndex of the field this filter represents.
     * The dataIndex does not actually have to exist in the store.
     */
    dataIndex : null,
    
/**
     * The filter configuration menu that will be installed into the filter submenu of a column menu.
     * @type Ext.menu.Menu
     * @property
     */
    menu : null,
    
/**
     * @cfg {Number} updateBuffer
     * Number of milliseconds to wait after user interaction to fire an update. Only supported 
     * by filters: 'list', 'numeric', and 'string'. Defaults to 500.
     */
    updateBuffer : 500,

    constructor : function (config) {
        Ext.apply(this, config);
            
        this.addEvents(
            
/**
             * @event activate
             * Fires when an inactive filter becomes active
             * @param {Ext.ux.grid.filter.Filter} this
             */
            'activate',
            
/**
             * @event deactivate
             * Fires when an active filter becomes inactive
             * @param {Ext.ux.grid.filter.Filter} this
             */
            'deactivate',
            
/**
             * @event serialize
             * Fires after the serialization process. Use this to attach additional parameters to serialization
             * data before it is encoded and sent to the server.
             * @param {Array/Object} data A map or collection of maps representing the current filter configuration.
             * @param {Ext.ux.grid.filter.Filter} filter The filter being serialized.
             */
            'serialize',
            
/**
             * @event update
             * Fires when a filter configuration has changed
             * @param {Ext.ux.grid.filter.Filter} this The filter object.
             */
            'update'
        );
        Ext.ux.grid.filter.Filter.superclass.constructor.call(this);

        this.menu = new Ext.menu.Menu();
        this.init(config);
        if(config && config.value){
            this.setValue(config.value);
            this.setActive(config.active !== false, true);
            delete config.value;
        }
    },

    
/**
     * Destroys this filter by purging any event listeners, and removing any menus.
     */
    destroy : function(){
        if (this.menu){
            this.menu.destroy();
        }
        this.purgeListeners();
    },

    
/**
     * Template method to be implemented by all subclasses that is to
     * initialize the filter and install required menu items.
     * Defaults to Ext.emptyFn.
     */
    init : Ext.emptyFn,
    
    
/**
     * Template method to be implemented by all subclasses that is to
     * get and return the value of the filter.
     * Defaults to Ext.emptyFn.
     * @return {Object} The 'serialized' form of this filter
     * @methodOf Ext.ux.grid.filter.Filter
     */
    getValue : Ext.emptyFn,
    
    
/**
     * Template method to be implemented by all subclasses that is to
     * set the value of the filter and fire the 'update' event.
     * Defaults to Ext.emptyFn.
     * @param {Object} data The value to set the filter
     * @methodOf Ext.ux.grid.filter.Filter
     */	
    setValue : Ext.emptyFn,
    
    
/**
     * Template method to be implemented by all subclasses that is to
     * return true if the filter has enough configuration information to be activated.
     * Defaults to return true.
     * @return {Boolean}
     */
    isActivatable : function(){
        return true;
    },
    
    
/**
     * Template method to be implemented by all subclasses that is to
     * get and return serialized filter data for transmission to the server.
     * Defaults to Ext.emptyFn.
     */
    getSerialArgs : Ext.emptyFn,

    
/**
     * Template method to be implemented by all subclasses that is to
     * validates the provided Ext.data.Record against the filters configuration.
     * Defaults to return true.
     * @param {Ext.data.Record} record The record to validate
     * @return {Boolean} true if the record is valid within the bounds
     * of the filter, false otherwise.
     */
    validateRecord : function(){
        return true;
    },

    
/**
     * Returns the serialized filter data for transmission to the server
     * and fires the 'serialize' event.
     * @return {Object/Array} An object or collection of objects containing
     * key value pairs representing the current configuration of the filter.
     * @methodOf Ext.ux.grid.filter.Filter
     */
    serialize : function(){
        var args = this.getSerialArgs();
        this.fireEvent('serialize', args, this);
        return args;
    },

    /** @private */
    fireUpdate : function(){
        if (this.active) {
            this.fireEvent('update', this);
        }
        this.setActive(this.isActivatable());
    },
    
    
/**
     * Sets the status of the filter and fires the appropriate events.
     * @param {Boolean} active        The new filter state.
     * @param {Boolean} suppressEvent True to prevent events from being fired.
     * @methodOf Ext.ux.grid.filter.Filter
     */
    setActive : function(active, suppressEvent){
        if(this.active != active){
            this.active = active;
            if (suppressEvent !== true) {
                this.fireEvent(active ? 'activate' : 'deactivate', this);
            }
        }
    }    
});