/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
/**
 * A selection model that renders a column of checkboxes that can be toggled to
 * select or deselect rows. The default mode for this selection model is MULTI.
 *
 * The selection model will inject a header for the checkboxes in the first view
 * and according to the {@link #injectCheckbox} configuration.
 */
Ext.define('Ext.selection.CheckboxModel', {
    alias: 'selection.checkboxmodel',
    extend: 'Ext.selection.RowModel',

    /**
     * @cfg {"SINGLE"/"SIMPLE"/"MULTI"} mode
     * Modes of selection.
     * Valid values are `"SINGLE"`, `"SIMPLE"`, and `"MULTI"`.
     */
    mode: 'MULTI',

    /**
     * @cfg {Number/String} [injectCheckbox=0]
     * The index at which to insert the checkbox column.
     * Supported values are a numeric index, and the strings 'first' and 'last'.
     */
    injectCheckbox: 0,

    /**
     * @cfg {Boolean} checkOnly
     * True if rows can only be selected by clicking on the checkbox column.
     */
    checkOnly: false,
    
    /**
     * @cfg {Boolean} showHeaderCheckbox
     * Configure as `false` to not display the header checkbox at the top of the column.
     * When {@link Ext.data.Store#buffered} is set to `true`, this configuration will
     * not be available because the buffered data set does not always contain all data. 
     */
    showHeaderCheckbox: undefined,
    
    /**
     * @cfg {String} [checkSelector="x-grid-row-checker"]
     * The selector for determining whether the checkbox element is clicked. This may be changed to
     * allow for a wider area to be clicked, for example, the whole cell for the selector.
     */
    checkSelector: '.' + Ext.baseCSSPrefix + 'grid-row-checker',

    headerWidth: 24,

    // private
    checkerOnCls: Ext.baseCSSPrefix + 'grid-hd-checker-on',
    
    constructor: function(){
        var me = this;
        me.callParent(arguments);   
        
        // If mode is single and showHeaderCheck isn't explicity set to
        // true, hide it.
        if (me.mode === 'SINGLE' && me.showHeaderCheckbox !== true) {
            me.showHeaderCheckbox = false;
        } 
    },

    beforeViewRender: function(view) {
        var me = this,
            owner;
            
        me.callParent(arguments);

        // if we have a locked header, only hook up to the first
        if (!me.hasLockedHeader() || view.headerCt.lockedCt) {
            if (me.showHeaderCheckbox !== false) {
                view.headerCt.on('headerclick', me.onHeaderClick, me);
            }
            me.addCheckbox(view, true);
            owner = view.ownerCt;
            // Listen to the outermost reconfigure event
            if (view.headerCt.lockedCt) {
                owner = owner.ownerCt;
            }
            me.mon(owner, 'reconfigure', me.onReconfigure, me);
        }
    },

    bindComponent: function(view) {
        var me = this;
        me.sortable = false;
        me.callParent(arguments);
    },

    hasLockedHeader: function(){
        var views     = this.views,
            vLen      = views.length,
            v;

        for (v = 0; v < vLen; v++) {
            if (views[v].headerCt.lockedCt) {
                return true;
            }
        }
        return false;
    },

    /**
     * Add the header checkbox to the header row
     * @private
     * @param {Boolean} initial True if we're binding for the first time.
     */
    addCheckbox: function(view, initial){
        var me = this,
            checkbox = me.injectCheckbox,
            headerCt = view.headerCt;

        // Preserve behaviour of false, but not clear why that would ever be done.
        if (checkbox !== false) {
            if (checkbox == 'first') {
                checkbox = 0;
            } else if (checkbox == 'last') {
                checkbox = headerCt.getColumnCount();
            }
            Ext.suspendLayouts();
            if (view.getStore().buffered) {
                me.showHeaderCheckbox = false;
            }
            headerCt.add(checkbox,  me.getHeaderConfig());
            Ext.resumeLayouts();
        }

        if (initial !== true) {
            view.refresh();
        }
    },

    /**
     * Handles the grid's reconfigure event.  Adds the checkbox header if the columns have been reconfigured.
     * @private
     * @param {Ext.panel.Table} grid
     * @param {Ext.data.Store} store
     * @param {Object[]} columns
     */
    onReconfigure: function(grid, store, columns) {
        if(columns) {
            this.addCheckbox(this.views[0]);
        }
    },

    /**
     * Toggle the ui header between checked and unchecked state.
     * @param {Boolean} isChecked
     * @private
     */
    toggleUiHeader: function(isChecked) {
        var view     = this.views[0],
            headerCt = view.headerCt,
            checkHd  = headerCt.child('gridcolumn[isCheckerHd]'),
            cls = this.checkerOnCls;

        if (checkHd) {
            if (isChecked) {
                checkHd.addCls(cls);
            } else {
                checkHd.removeCls(cls);
            }
        }
    },

    /**
     * Toggle between selecting all and deselecting all when clicking on
     * a checkbox header.
     */
    onHeaderClick: function(headerCt, header, e) {
        if (header.isCheckerHd) {
            e.stopEvent();
            var me = this,
                isChecked = header.el.hasCls(Ext.baseCSSPrefix + 'grid-hd-checker-on');
                
            // Prevent focus changes on the view, since we're selecting/deselecting all records
            me.preventFocus = true;
            if (isChecked) {
                me.deselectAll();
            } else {
                me.selectAll();
            }
            delete me.preventFocus;
        }
    },

    /**
     * Retrieve a configuration to be used in a HeaderContainer.
     * This should be used when injectCheckbox is set to false.
     */
    getHeaderConfig: function() {
        var me = this,
            showCheck = me.showHeaderCheckbox !== false;     

        return {
            isCheckerHd: showCheck,
            text : '&#160;',
            clickTargetName: 'el',
            width: me.headerWidth,
            sortable: false,
            draggable: false,
            resizable: false,
            hideable: false,
            menuDisabled: true,
            dataIndex: '',
            cls: showCheck ? Ext.baseCSSPrefix + 'column-header-checkbox ' : '',
            renderer: Ext.Function.bind(me.renderer, me),
            editRenderer: me.editRenderer || me.renderEmpty,
            locked: me.hasLockedHeader()
        };
    },

    renderEmpty: function() {
        return '&#160;';
    },

    // After refresh, ensure that the header checkbox state matches
    refresh: function() {
        this.callParent(arguments);
        this.updateHeaderState();
    },

    /**
     * Generates the HTML to be rendered in the injected checkbox column for each row.
     * Creates the standard checkbox markup by default; can be overridden to provide custom rendering.
     * See {@link Ext.grid.column.Column#renderer} for description of allowed parameters.
     */
    renderer: function(value, metaData, record, rowIndex, colIndex, store, view) {
        var baseCSSPrefix = Ext.baseCSSPrefix;
        metaData.tdCls = baseCSSPrefix + 'grid-cell-special ' + baseCSSPrefix + 'grid-cell-row-checker';
        return '<div class="' + baseCSSPrefix + 'grid-row-checker">&#160;</div>';
    },
    
    processSelection: function(view, record, item, index, e){
        var me = this,
            checker = e.getTarget(me.checkSelector),
            mode;
            
        // checkOnly set, but we didn't click on a checker.
        if (me.checkOnly && !checker) {
            return;
        }

        if (checker) {
            mode = me.getSelectionMode();
            // dont change the mode if its single otherwise
            // we would get multiple selection
            if (mode !== 'SINGLE') {
                me.setSelectionMode('SIMPLE');
            }
            me.selectWithEvent(record, e);
            me.setSelectionMode(mode);
        } else {
            me.selectWithEvent(record, e);
        }
    },

    /**
     * Synchronize header checker value as selection changes.
     * @private
     */
    onSelectChange: function() {
        this.callParent(arguments);
        if (!this.suspendChange) {
            this.updateHeaderState();
        }
    },

    /**
     * @private
     */
    onStoreLoad: function() {
        this.callParent(arguments);
        this.updateHeaderState();
    },

    onStoreAdd: function() {
        this.callParent(arguments);
        this.updateHeaderState();
    },

    onStoreRemove: function() {
        this.callParent(arguments);
        this.updateHeaderState();
    },
    
    onStoreRefresh: function(){
        this.callParent(arguments);    
        this.updateHeaderState();
    },
    
    maybeFireSelectionChange: function(fireEvent) {
        if (fireEvent && !this.suspendChange) {
            this.updateHeaderState();
        }
        this.callParent(arguments);
    },
    
    resumeChanges: function(){
        this.callParent();
        if (!this.suspendChange) {
            this.updateHeaderState();
        }
    },

    /**
     * @private
     */
    updateHeaderState: function() {
        // check to see if all records are selected
        var me = this,
            store = me.store,
            storeCount = store.getCount(),
            views = me.views,
            hdSelectStatus = false,
            selectedCount = 0,
            selected, len, i;
            
        if (!store.buffered && storeCount > 0) {
            selected = me.selected;
            hdSelectStatus = true;
            for (i = 0, len = selected.getCount(); i < len; ++i) {
                if (!me.storeHasSelected(selected.getAt(i))) {
                    break;
                }
                ++selectedCount;
            }
            hdSelectStatus = storeCount === selectedCount;
        }
            
        if (views && views.length) {
            me.toggleUiHeader(hdSelectStatus);
        }
    }
});
