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

/**
 * @class Ext.ux.grid.GridFilters
 * @extends Ext.util.Observable
 * <p>GridFilter is a plugin (<code>ptype='gridfilters'</code>) for grids that
 * allow for a slightly more robust representation of filtering than what is
 * provided by the default store.</p>
 * <p>Filtering is adjusted by the user using the grid's column header menu
 * (this menu can be disabled through configuration). Through this menu users
 * can configure, enable, and disable filters for each column.</p>
 * <p><b><u>Features:</u></b></p>
 * <div class="mdetail-params"><ul>
 * <li><b>Filtering implementations</b> :
 * <div class="sub-desc">
 * Default filtering for Strings, Numeric Ranges, Date Ranges, Lists (which can
 * be backed by a Ext.data.Store), and Boolean. Additional custom filter types
 * and menus are easily created by extending Ext.ux.grid.filter.Filter.
 * </div></li>
 * <li><b>Graphical indicators</b> :
 * <div class="sub-desc">
 * Columns that are filtered have {@link #filterCls a configurable css class}
 * applied to the column headers.
 * </div></li>
 * <li><b>Paging</b> :
 * <div class="sub-desc">
 * If specified as a plugin to the grid's configured PagingToolbar, the current page
 * will be reset to page 1 whenever you update the filters.
 * </div></li>
 * <li><b>Automatic Reconfiguration</b> :
 * <div class="sub-desc">
 * Filters automatically reconfigure when the grid 'reconfigure' event fires.
 * </div></li>
 * <li><b>Stateful</b> :
 * Filter information will be persisted across page loads by specifying a
 * <code>stateId</code> in the Grid configuration.
 * <div class="sub-desc">
 * The filter collection binds to the
 * <code>{@link Ext.grid.GridPanel#beforestaterestore beforestaterestore}</code>
 * and <code>{@link Ext.grid.GridPanel#beforestatesave beforestatesave}</code>
 * events in order to be stateful. 
 * </div></li>
 * <li><b>Grid Changes</b> :
 * <div class="sub-desc"><ul>
 * <li>A <code>filters</code> <i>property</i> is added to the grid pointing to
 * this plugin.</li>
 * <li>A <code>filterupdate</code> <i>event</i> is added to the grid and is
 * fired upon onStateChange completion.</li>
 * </ul></div></li>
 * <li><b>Server side code examples</b> :
 * <div class="sub-desc"><ul>
 * <li><a href="http://www.vinylfox.com/extjs/grid-filter-php-backend-code.php">PHP</a> - (Thanks VinylFox)</li>
 * <li><a href="http://extjs.com/forum/showthread.php?p=77326#post77326">Ruby on Rails</a> - (Thanks Zyclops)</li>
 * <li><a href="http://extjs.com/forum/showthread.php?p=176596#post176596">Ruby on Rails</a> - (Thanks Rotomaul)</li>
 * <li><a href="http://www.debatablybeta.com/posts/using-extjss-grid-filtering-with-django/">Python</a> - (Thanks Matt)</li>
 * <li><a href="http://mcantrell.wordpress.com/2008/08/22/extjs-grids-and-grails/">Grails</a> - (Thanks Mike)</li>
 * </ul></div></li>
 * </ul></div>
 * <p><b><u>Example usage:</u></b></p>
 * <pre><code>    
var store = new Ext.data.GroupingStore({
    ...
});
 
var filters = new Ext.ux.grid.GridFilters({
    autoReload: false, //don&#39;t reload automatically
    local: true, //only filter locally
    // filters may be configured through the plugin,
    // or in the column definition within the column model configuration
    filters: [{
        type: 'numeric',
        dataIndex: 'id'
    }, {
        type: 'string',
        dataIndex: 'name'
    }, {
        type: 'numeric',
        dataIndex: 'price'
    }, {
        type: 'date',
        dataIndex: 'dateAdded'
    }, {
        type: 'list',
        dataIndex: 'size',
        options: ['extra small', 'small', 'medium', 'large', 'extra large'],
        phpMode: true
    }, {
        type: 'boolean',
        dataIndex: 'visible'
    }]
});
var cm = new Ext.grid.ColumnModel([{
    ...
}]);
 
var grid = new Ext.grid.GridPanel({
     ds: store,
     cm: cm,
     view: new Ext.grid.GroupingView(),
     plugins: [filters],
     height: 400,
     width: 700,
     bbar: new Ext.PagingToolbar({
         store: store,
         pageSize: 15,
         plugins: [filters] //reset page to page 1 if filters change
     })
 });

store.load({params: {start: 0, limit: 15}});

// a filters property is added to the grid
grid.filters
 * </code></pre>
 */
Ext.ux.grid.GridFilters = Ext.extend(Ext.util.Observable, {
    /**
     * @cfg {Boolean} autoReload
     * Defaults to true, reloading the datasource when a filter change happens.
     * Set this to false to prevent the datastore from being reloaded if there
     * are changes to the filters.  See <code>{@link updateBuffer}</code>.
     */
    autoReload : true,
    /**
     * @cfg {Boolean} encode
     * Specify true for {@link #buildQuery} to use Ext.util.JSON.encode to
     * encode the filter query parameter sent with a remote request.
     * Defaults to false.
     */
    /**
     * @cfg {Array} filters
     * An Array of filters config objects. Refer to each filter type class for
     * configuration details specific to each filter type. Filters for Strings,
     * Numeric Ranges, Date Ranges, Lists, and Boolean are the standard filters
     * available.
     */
    /**
     * @cfg {String} filterCls
     * The css class to be applied to column headers with active filters.
     * Defaults to <tt>'ux-filterd-column'</tt>.
     */
    filterCls : 'ux-filtered-column',
    /**
     * @cfg {Boolean} local
     * <tt>true</tt> to use Ext.data.Store filter functions (local filtering)
     * instead of the default (<tt>false</tt>) server side filtering.
     */
    local : false,
    /**
     * @cfg {String} menuFilterText
     * defaults to <tt>'Filters'</tt>.
     */
    menuFilterText : 'Filters',
    /**
     * @cfg {String} paramPrefix
     * The url parameter prefix for the filters.
     * Defaults to <tt>'filter'</tt>.
     */
    paramPrefix : 'filter',
    /**
     * @cfg {Boolean} showMenu
     * Defaults to true, including a filter submenu in the default header menu.
     */
    showMenu : true,
    /**
     * @cfg {String} stateId
     * Name of the value to be used to store state information.
     */
    stateId : undefined,
    /**
     * @cfg {Integer} updateBuffer
     * Number of milliseconds to defer store updates since the last filter change.
     */
    updateBuffer : 500,

    /** @private */
    constructor : function (config) {
        config = config || {};
        this.deferredUpdate = new Ext.util.DelayedTask(this.reload, this);
        this.filters = new Ext.util.MixedCollection();
        this.filters.getKey = function (o) {
            return o ? o.dataIndex : null;
        };
        this.addFilters(config.filters);
        delete config.filters;
        Ext.apply(this, config);
    },

    /** @private */
    init : function (grid) {
        if (grid instanceof Ext.grid.GridPanel) {
            this.grid = grid;
            
            this.bindStore(this.grid.getStore(), true);
            // assumes no filters were passed in the constructor, so try and use ones from the colModel
            if(this.filters.getCount() == 0){
                this.addFilters(this.grid.getColumnModel());
            }
          
            this.grid.filters = this;
             
            this.grid.addEvents({'filterupdate': true});
              
            grid.on({
                scope: this,
                beforestaterestore: this.applyState,
                beforestatesave: this.saveState,
                beforedestroy: this.destroy,
                reconfigure: this.onReconfigure
            });
            
            if (grid.rendered){
                this.onRender();
            } else {
                grid.on({
                    scope: this,
                    single: true,
                    render: this.onRender
                });
            }
                      
        } else if (grid instanceof Ext.PagingToolbar) {
            this.toolbar = grid;
        }
    },
        
    /**
     * @private
     * Handler for the grid's beforestaterestore event (fires before the state of the
     * grid is restored).
     * @param {Object} grid The grid object
     * @param {Object} state The hash of state values returned from the StateProvider.
     */   
    applyState : function (grid, state) {
        var key, filter;
        this.applyingState = true;
        this.clearFilters();
        if (state.filters) {
            for (key in state.filters) {
                filter = this.filters.get(key);
                if (filter) {
                    filter.setValue(state.filters[key]);
                    filter.setActive(true);
                }
            }
        }
        this.deferredUpdate.cancel();
        if (this.local) {
            this.reload();
        }
        delete this.applyingState;
    },
    
    /**
     * Saves the state of all active filters
     * @param {Object} grid
     * @param {Object} state
     * @return {Boolean}
     */
    saveState : function (grid, state) {
        var filters = {};
        this.filters.each(function (filter) {
            if (filter.active) {
                filters[filter.dataIndex] = filter.getValue();
            }
        });
        return (state.filters = filters);
    },
    
    /**
     * @private
     * Handler called when the grid is rendered
     */    
    onRender : function () {
        this.grid.getView().on('refresh', this.onRefresh, this);
        this.createMenu();
    },

    /**
     * @private
     * Handler called by the grid 'beforedestroy' event
     */    
    destroy : function () {
        this.removeAll();
        this.purgeListeners();

        if(this.filterMenu){
            Ext.menu.MenuMgr.unregister(this.filterMenu);
            this.filterMenu.destroy();
             this.filterMenu = this.menu.menu = null;            
        }
    },

    /**
     * Remove all filters, permanently destroying them.
     */    
    removeAll : function () {
        if(this.filters){
            Ext.destroy.apply(Ext, this.filters.items);
            // remove all items from the collection 
            this.filters.clear();
        }
    },


    /**
     * Changes the data store bound to this view and refreshes it.
     * @param {Store} store The store to bind to this view
     */
    bindStore : function(store, initial){
        if(!initial && this.store){
            if (this.local) {
                store.un('load', this.onLoad, this);
            } else {
                store.un('beforeload', this.onBeforeLoad, this);
            }
        }
        if(store){
            if (this.local) {
                store.on('load', this.onLoad, this);
            } else {
                store.on('beforeload', this.onBeforeLoad, this);
            }
        }
        this.store = store;
    },

    /**
     * @private
     * Handler called when the grid reconfigure event fires
     */    
    onReconfigure : function () {
        this.bindStore(this.grid.getStore());
        this.store.clearFilter();
        this.removeAll();
        this.addFilters(this.grid.getColumnModel());
        this.updateColumnHeadings();
    },

    createMenu : function () {
        var view = this.grid.getView(),
            hmenu = view.hmenu;

        if (this.showMenu && hmenu) {
            
            this.sep  = hmenu.addSeparator();
            this.filterMenu = new Ext.menu.Menu({
                id: this.grid.id + '-filters-menu'
            }); 
            this.menu = hmenu.add({
                checked: false,
                itemId: 'filters',
                text: this.menuFilterText,
                menu: this.filterMenu
            });

            this.menu.on({
                scope: this,
                checkchange: this.onCheckChange,
                beforecheckchange: this.onBeforeCheck
            });
            hmenu.on('beforeshow', this.onMenu, this);
        }
        this.updateColumnHeadings();
    },

    /**
     * @private
     * Get the filter menu from the filters MixedCollection based on the clicked header
     */
    getMenuFilter : function () {
        var view = this.grid.getView();
        if (!view || view.hdCtxIndex === undefined) {
            return null;
        }
        return this.filters.get(
            view.cm.config[view.hdCtxIndex].dataIndex
        );
    },

    /**
     * @private
     * Handler called by the grid's hmenu beforeshow event
     */    
    onMenu : function (filterMenu) {
        var filter = this.getMenuFilter();

        if (filter) {
/*            
TODO: lazy rendering
            if (!filter.menu) {
                filter.menu = filter.createMenu();
            }
*/
            this.menu.menu = filter.menu;
            this.menu.setChecked(filter.active, false);
            // disable the menu if filter.disabled explicitly set to true
            this.menu.setDisabled(filter.disabled === true);
        }
        
        this.menu.setVisible(filter !== undefined);
        this.sep.setVisible(filter !== undefined);
    },
    
    /** @private */
    onCheckChange : function (item, value) {
        this.getMenuFilter().setActive(value);
    },
    
    /** @private */
    onBeforeCheck : function (check, value) {
        return !value || this.getMenuFilter().isActivatable();
    },

    /**
     * @private
     * Handler for all events on filters.
     * @param {String} event Event name
     * @param {Object} filter Standard signature of the event before the event is fired
     */   
    onStateChange : function (event, filter) {
        if (event === 'serialize') {
            return;
        }

        if (filter == this.getMenuFilter()) {
            this.menu.setChecked(filter.active, false);
        }

        if ((this.autoReload || this.local) && !this.applyingState) {
            this.deferredUpdate.delay(this.updateBuffer);
        }
        this.updateColumnHeadings();
            
        if (!this.applyingState) {
            this.grid.saveState();
        }    
        this.grid.fireEvent('filterupdate', this, filter);
    },
    
    /**
     * @private
     * Handler for store's beforeload event when configured for remote filtering
     * @param {Object} store
     * @param {Object} options
     */
    onBeforeLoad : function (store, options) {
        options.params = options.params || {};
        this.cleanParams(options.params);       
        var params = this.buildQuery(this.getFilterData());
        Ext.apply(options.params, params);
    },
    
    /**
     * @private
     * Handler for store's load event when configured for local filtering
     * @param {Object} store
     * @param {Object} options
     */
    onLoad : function (store, options) {
        store.filterBy(this.getRecordFilter());
    },

    /**
     * @private
     * Handler called when the grid's view is refreshed
     */    
    onRefresh : function () {
        this.updateColumnHeadings();
    },

    /**
     * Update the styles for the header row based on the active filters
     */    
    updateColumnHeadings : function () {
        var view = this.grid.getView(),
            hds, i, len, filter;
        if (view.mainHd) {
            hds = view.mainHd.select('td').removeClass(this.filterCls);
            for (i = 0, len = view.cm.config.length; i < len; i++) {
                filter = this.getFilter(view.cm.config[i].dataIndex);
                if (filter && filter.active) {
                    hds.item(i).addClass(this.filterCls);
                }
            }
        }
    },
    
    /** @private */
    reload : function () {
        if (this.local) {
            this.grid.store.clearFilter(true);
            this.grid.store.filterBy(this.getRecordFilter());
        } else {
            var start,
                store = this.grid.store;
            this.deferredUpdate.cancel();
            if (this.toolbar) {
                start = store.paramNames.start;
                if (store.lastOptions && store.lastOptions.params && store.lastOptions.params[start]) {
                    store.lastOptions.params[start] = 0;
                }
            }
            store.reload();
        }
    },
    
    /**
     * Method factory that generates a record validator for the filters active at the time
     * of invokation.
     * @private
     */
    getRecordFilter : function () {
        var f = [], len, i;
        this.filters.each(function (filter) {
            if (filter.active) {
                f.push(filter);
            }
        });
        
        len = f.length;
        return function (record) {
            for (i = 0; i < len; i++) {
                if (!f[i].validateRecord(record)) {
                    return false;
                }
            }
            return true;
        };
    },
    
    /**
     * Adds a filter to the collection and observes it for state change.
     * @param {Object/Ext.ux.grid.filter.Filter} config A filter configuration or a filter object.
     * @return {Ext.ux.grid.filter.Filter} The existing or newly created filter object.
     */
    addFilter : function (config) {
        var Cls = this.getFilterClass(config.type),
            filter = config.menu ? config : (new Cls(config));
        this.filters.add(filter);
        
        Ext.util.Observable.capture(filter, this.onStateChange, this);
        return filter;
    },

    /**
     * Adds filters to the collection.
     * @param {Array/Ext.grid.ColumnModel} filters Either an Array of
     * filter configuration objects or an Ext.grid.ColumnModel.  The columns
     * of a passed Ext.grid.ColumnModel will be examined for a <code>filter</code>
     * property and, if present, will be used as the filter configuration object.   
     */
    addFilters : function (filters) {
        if (filters) {
            var i, len, filter, cm = false, dI;
            if (filters instanceof Ext.grid.ColumnModel) {
                filters = filters.config;
                cm = true;
            }
            for (i = 0, len = filters.length; i < len; i++) {
                filter = false;
                if (cm) {
                    dI = filters[i].dataIndex;
                    filter = filters[i].filter || filters[i].filterable;
                    if (filter){
                        filter = (filter === true) ? {} : filter;
                        Ext.apply(filter, {dataIndex:dI});
                        // filter type is specified in order of preference:
                        //     filter type specified in config
                        //     type specified in store's field's type config
                        filter.type = filter.type || this.store.fields.get(dI).type;  
                    }
                } else {
                    filter = filters[i];
                }
                // if filter config found add filter for the column 
                if (filter) {
                    this.addFilter(filter);
                }
            }
        }
    },
    
    /**
     * Returns a filter for the given dataIndex, if one exists.
     * @param {String} dataIndex The dataIndex of the desired filter object.
     * @return {Ext.ux.grid.filter.Filter}
     */
    getFilter : function (dataIndex) {
        return this.filters.get(dataIndex);
    },

    /**
     * Turns all filters off. This does not clear the configuration information
     * (see {@link #removeAll}).
     */
    clearFilters : function () {
        this.filters.each(function (filter) {
            filter.setActive(false);
        });
    },

    /**
     * Returns an Array of the currently active filters.
     * @return {Array} filters Array of the currently active filters.
     */
    getFilterData : function () {
        var filters = [], i, len;

        this.filters.each(function (f) {
            if (f.active) {
                var d = [].concat(f.serialize());
                for (i = 0, len = d.length; i < len; i++) {
                    filters.push({
                        field: f.dataIndex,
                        data: d[i]
                    });
                }
            }
        });
        return filters;
    },
    
    /**
     * Function to take the active filters data and build it into a query.
     * The format of the query depends on the <code>{@link #encode}</code>
     * configuration:
     * <div class="mdetail-params"><ul>
     * 
     * <li><b><tt>false</tt></b> : <i>Default</i>
     * <div class="sub-desc">
     * Flatten into query string of the form (assuming <code>{@link #paramPrefix}='filters'</code>:
     * <pre><code>
filters[0][field]="someDataIndex"&
filters[0][data][comparison]="someValue1"&
filters[0][data][type]="someValue2"&
filters[0][data][value]="someValue3"&
     * </code></pre>
     * </div></li>
     * <li><b><tt>true</tt></b> : 
     * <div class="sub-desc">
     * JSON encode the filter data
     * <pre><code>
filters[0][field]="someDataIndex"&
filters[0][data][comparison]="someValue1"&
filters[0][data][type]="someValue2"&
filters[0][data][value]="someValue3"&
     * </code></pre>
     * </div></li>
     * </ul></div>
     * Override this method to customize the format of the filter query for remote requests.
     * @param {Array} filters A collection of objects representing active filters and their configuration.
     *    Each element will take the form of {field: dataIndex, data: filterConf}. dataIndex is not assured
     *    to be unique as any one filter may be a composite of more basic filters for the same dataIndex.
     * @return {Object} Query keys and values
     */
    buildQuery : function (filters) {
        var p = {}, i, f, root, dataPrefix, key, tmp,
            len = filters.length;

        if (!this.encode){
            for (i = 0; i < len; i++) {
                f = filters[i];
                root = [this.paramPrefix, '[', i, ']'].join('');
                p[root + '[field]'] = f.field;
                
                dataPrefix = root + '[data]';
                for (key in f.data) {
                    p[[dataPrefix, '[', key, ']'].join('')] = f.data[key];
                }
            }
        } else {
            tmp = [];
            for (i = 0; i < len; i++) {
                f = filters[i];
                tmp.push(Ext.apply(
                    {},
                    {field: f.field},
                    f.data
                ));
            }
            // only build if there is active filter 
            if (tmp.length > 0){
                p[this.paramPrefix] = Ext.util.JSON.encode(tmp);
            }
        }
        return p;
    },
    
    /**
     * Removes filter related query parameters from the provided object.
     * @param {Object} p Query parameters that may contain filter related fields.
     */
    cleanParams : function (p) {
        // if encoding just delete the property
        if (this.encode) {
            delete p[this.paramPrefix];
        // otherwise scrub the object of filter data
        } else {
            var regex, key;
            regex = new RegExp('^' + this.paramPrefix + '\[[0-9]+\]');
            for (key in p) {
                if (regex.test(key)) {
                    delete p[key];
                }
            }
        }
    },
    
    /**
     * Function for locating filter classes, overwrite this with your favorite
     * loader to provide dynamic filter loading.
     * @param {String} type The type of filter to load ('Filter' is automatically
     * appended to the passed type; eg, 'string' becomes 'StringFilter').
     * @return {Class} The Ext.ux.grid.filter.Class 
     */
    getFilterClass : function (type) {
        // map the supported Ext.data.Field type values into a supported filter
        switch(type) {
            case 'auto':
              type = 'string';
              break;
            case 'int':
            case 'float':
              type = 'numeric';
              break;
        }
        return Ext.ux.grid.filter[type.substr(0, 1).toUpperCase() + type.substr(1) + 'Filter'];
    }
});

// register ptype
Ext.preg('gridfilters', Ext.ux.grid.GridFilters);
