/**
 * @class Ext.selection.RowModel
 * @extends Ext.selection.Model
 * 
 * Implement row based navigation via keyboard.
 *
 * Must synchronize across grid sections
 */
Ext.define('Ext.selection.RowModel', {
    extend: 'Ext.selection.Model',
    alias: 'selection.rowmodel',
    requires: ['Ext.util.KeyNav'],
    
    /**
     * @private
     * Number of pixels to scroll to the left/right when pressing
     * left/right keys.
     */
    deltaScroll: 5,
    
    /**
     * @cfg {Boolean} enableKeyNav
     * 
     * Turns on/off keyboard navigation within the grid. Defaults to true.
     */
    enableKeyNav: true,
    
    constructor: function(){
        this.addEvents(
            /**
             * @event deselect
             * Fired after a record is deselected
             * @param {Ext.selection.RowSelectionModel} this
             * @param {Ext.data.Model} record The deselected record
             * @param {Number} index The row index deselected
             */
            'deselect',
            
            /**
             * @event select
             * Fired after a record is selected
             * @param {Ext.selection.RowSelectionModel} this
             * @param {Ext.data.Model} record The selected record
             * @param {Number} index The row index selected
             */
            'select'
        );
        this.callParent(arguments);    
    },

    bindComponent: function(view) {
        var me = this;
        
        me.views = me.views || [];
        me.views.push(view);
        me.bind(view.getStore(), true);

        view.on({
            itemmousedown: me.onRowMouseDown,
            scope: me
        });

        if (me.enableKeyNav) {
            me.initKeyNav(view);
        }
    },

    initKeyNav: function(view) {
        var me = this;
        
        if (!view.rendered) {
            view.on('render', Ext.Function.bind(me.initKeyNav, me, [view], 0), me, {single: true});
            return;
        }

        view.el.set({
            tabIndex: -1
        });

        // view.el has tabIndex -1 to allow for
        // keyboard events to be passed to it.
        me.keyNav = new Ext.util.KeyNav(view.el, {
            up: me.onKeyUp,
            down: me.onKeyDown,
            right: me.onKeyRight,
            left: me.onKeyLeft,
            pageDown: me.onKeyPageDown,
            pageUp: me.onKeyPageUp,
            home: me.onKeyHome,
            end: me.onKeyEnd,
            scope: me
        });
        view.el.on(Ext.EventManager.getKeyEvent(), me.onKeyPress, me);
    },

    // Returns the number of rows currently visible on the screen or
    // false if there were no rows. This assumes that all rows are
    // of the same height and the first view is accurate.
    getRowsVisible: function() {
        var rowsVisible = false,
            view = this.views[0],
            row = view.getNode(0),
            rowHeight, gridViewHeight;

        if (row) {
            rowHeight = Ext.fly(row).getHeight();
            gridViewHeight = view.el.getHeight();
            rowsVisible = Math.floor(gridViewHeight / rowHeight);
        }

        return rowsVisible;
    },

    // go to last visible record in grid.
    onKeyEnd: function(e, t) {
        var me = this,
            last = me.store.getAt(me.store.getCount() - 1);
            
        if (last) {
            if (e.shiftKey) {
                me.selectRange(last, me.lastFocused || 0);
                me.setLastFocused(last);
            } else if (e.ctrlKey) {
                me.setLastFocused(last);
            } else {
                me.doSelect(last);
            }
        }
    },

    // go to first visible record in grid.
    onKeyHome: function(e, t) {
        var me = this,
            first = me.store.getAt(0);
            
        if (first) {
            if (e.shiftKey) {
                me.selectRange(first, me.lastFocused || 0);
                me.setLastFocused(first);
            } else if (e.ctrlKey) {
                me.setLastFocused(first);
            } else {
                me.doSelect(first, false);
            }
        }
    },

    // Go one page up from the lastFocused record in the grid.
    onKeyPageUp: function(e, t) {
        var me = this,
            rowsVisible = me.getRowsVisible(),
            selIdx,
            prevIdx,
            prevRecord,
            currRec;
            
        if (rowsVisible) {
            selIdx = me.lastFocused ? me.store.indexOf(me.lastFocused) : 0;
            prevIdx = selIdx - rowsVisible;
            if (prevIdx < 0) {
                prevIdx = 0;
            }
            prevRecord = me.store.getAt(prevIdx);
            if (e.shiftKey) {
                currRec = me.store.getAt(selIdx);
                me.selectRange(prevRecord, currRec, e.ctrlKey, 'up');
                me.setLastFocused(prevRecord);
            } else if (e.ctrlKey) {
                e.preventDefault();
                me.setLastFocused(prevRecord);
            } else {
                me.doSelect(prevRecord);
            }

        }
    },

    // Go one page down from the lastFocused record in the grid.
    onKeyPageDown: function(e, t) {
        var me = this,
            rowsVisible = me.getRowsVisible(),
            selIdx,
            nextIdx,
            nextRecord,
            currRec;
            
        if (rowsVisible) {
            selIdx = me.lastFocused ? me.store.indexOf(me.lastFocused) : 0;
            nextIdx = selIdx + rowsVisible;
            if (nextIdx >= me.store.getCount()) {
                nextIdx = me.store.getCount() - 1;
            }
            nextRecord = me.store.getAt(nextIdx);
            if (e.shiftKey) {
                currRec = me.store.getAt(selIdx);
                me.selectRange(nextRecord, currRec, e.ctrlKey, 'down');
                me.setLastFocused(nextRecord);
            } else if (e.ctrlKey) {
                // some browsers, this means go thru browser tabs
                // attempt to stop.
                e.preventDefault();
                me.setLastFocused(nextRecord);
            } else {
                me.doSelect(nextRecord);
            }
        }
    },

    // Select/Deselect based on pressing Spacebar.
    // Assumes a SIMPLE selectionmode style
    onKeyPress: function(e, t) {
        if (e.getKey() === e.SPACE) {
            e.stopEvent();
            var me = this,
                record = me.lastFocused;
                
            if (record) {
                if (me.isSelected(record)) {
                    me.doDeselect(record, false);
                } else {
                    me.doSelect(record, true);
                }
            }
        }
    },

    // Navigate one record up. This could be a selection or
    // could be simply focusing a record for discontiguous
    // selection. Provides bounds checking.
    onKeyUp: function(e, t) {
        var me = this,
            view = me.views[0],
            idx  = me.store.indexOf(me.lastFocused),
            record;
            
        if (idx > 0) {
            // needs to be the filtered count as thats what
            // will be visible.
            record = me.store.getAt(idx - 1);
            if (e.shiftKey && me.lastFocused) {
                if (me.isSelected(me.lastFocused) && me.isSelected(record)) {
                    me.doDeselect(me.lastFocused, true);
                    me.setLastFocused(record);
                } else if (!me.isSelected(me.lastFocused)) {
                    me.doSelect(me.lastFocused, true);
                    me.doSelect(record, true);
                } else {
                    me.doSelect(record, true);
                }
            } else if (e.ctrlKey) {
                me.setLastFocused(record);
            } else {
                me.doSelect(record);
                //view.focusRow(idx - 1);
            }
        }
        // There was no lastFocused record, and the user has pressed up
        // Ignore??
        //else if (this.selected.getCount() == 0) {
        //    
        //    this.doSelect(record);
        //    //view.focusRow(idx - 1);
        //}
    },

    // Navigate one record down. This could be a selection or
    // could be simply focusing a record for discontiguous
    // selection. Provides bounds checking.
    onKeyDown: function(e, t) {
        var me = this,
            view = me.views[0],
            idx  = me.store.indexOf(me.lastFocused),
            record;
            
        // needs to be the filtered count as thats what
        // will be visible.
        if (idx + 1 < me.store.getCount()) {
            record = me.store.getAt(idx + 1);
            if (me.selected.getCount() === 0) {
                me.doSelect(record);
                //view.focusRow(idx + 1);
            } else if (e.shiftKey && me.lastFocused) {
                if (me.isSelected(me.lastFocused) && me.isSelected(record)) {
                    me.doDeselect(me.lastFocused, true);
                    me.setLastFocused(record);
                } else if (!me.isSelected(me.lastFocused)) {
                    me.doSelect(me.lastFocused, true);
                    me.doSelect(record, true);
                } else {
                    me.doSelect(record, true);
                }
            } else if (e.ctrlKey) {
                me.setLastFocused(record);
            } else {
                me.doSelect(record);
                //view.focusRow(idx + 1);
            }
        }
    },
    
    scrollByDeltaX: function(delta) {
        var view    = this.views[0],
            section = view.up(),
            hScroll = section.horizontalScroller;
            
        if (hScroll) {
            hScroll.scrollByDeltaX(delta);
        }
    },
    
    onKeyLeft: function(e, t) {
        this.scrollByDeltaX(-this.deltaScroll);
    },
    
    onKeyRight: function(e, t) {
        this.scrollByDeltaX(this.deltaScroll);
    },

    // Select the record with the event included so that
    // we can take into account ctrlKey, shiftKey, etc
    onRowMouseDown: function(view, record, item, index, e) {
        view.el.focus();
        this.selectWithEvent(record, e);
    },

    // Allow the GridView to update the UI by
    // adding/removing a CSS class from the row.
    onSelectChange: function(record, isSelected, suppressEvent) {
        var me      = this,
            views   = me.views,
            viewsLn = views.length,
            store   = me.store,
            rowIdx  = store.indexOf(record),
            i = 0;
            
        for (; i < viewsLn; i++) {
            if (isSelected) {
                views[i].onRowSelect(rowIdx, suppressEvent);
                if (!suppressEvent) {
                    me.fireEvent('select', me, record, rowIdx);
                }
            } else {
                views[i].onRowDeselect(rowIdx, suppressEvent);
                if (!suppressEvent) {
                    me.fireEvent('deselect', me, record, rowIdx);
                }
            }
        }
    },

    // Provide indication of what row was last focused via
    // the gridview.
    onLastFocusChanged: function(oldFocused, newFocused, supressFocus) {
        var views   = this.views,
            viewsLn = views.length,
            store   = this.store,
            rowIdx,
            i = 0;
            
        if (oldFocused) {
            rowIdx = store.indexOf(oldFocused);
            if (rowIdx != -1) {
                for (; i < viewsLn; i++) {
                    views[i].onRowFocus(rowIdx, false);
                }
            }
        }

        if (newFocused) {
            rowIdx = store.indexOf(newFocused);
            if (rowIdx != -1) {
                for (i = 0; i < viewsLn; i++) {
                    views[i].onRowFocus(rowIdx, true, supressFocus);
                }
            }
        }
    },
    
    onEditorTab: function(editingPlugin, e) {
        var me = this,
            view = me.views[0],
            record = editingPlugin.getActiveRecord(),
            header = editingPlugin.getActiveColumn(),
            position = view.getPosition(record, header),
            direction = e.shiftKey ? 'left' : 'right',
            newPosition  = view.walkCells(position, direction, e, this.preventWrap);
            
        if (newPosition) {
            editingPlugin.startEditByPosition(newPosition);
        }
    },
    
    selectByPosition: function(position) {
        var record = this.store.getAt(position.row);
        this.select(record);
    }
});