/* @private
 * Internal drag zone implementation for the calendar components. This provides base functionality
 * and is primarily for the month view -- DayViewDD adds day/week view-specific functionality.
 */
Ext.ensible.cal.DragZone = Ext.extend(Ext.dd.DragZone, {
    ddGroup : 'CalendarDD',
    eventSelector : '.ext-cal-evt',
    
    constructor : function(el, config){
        if(!Ext.ensible.cal._statusProxyInstance){
            Ext.ensible.cal._statusProxyInstance = new Ext.ensible.cal.StatusProxy();
        }
        this.proxy = Ext.ensible.cal._statusProxyInstance;
        Ext.ensible.cal.DragZone.superclass.constructor.call(this, el, config);
    },
    
    getDragData : function(e){
        // Check whether we are dragging on an event first
        var t = e.getTarget(this.eventSelector, 3);
        if(t){
            var rec = this.view.getEventRecordFromEl(t);
            if(!rec){
                // if rec is null here it usually means there was a timing issue between drag 
                // start and the browser reporting it properly. Simply ignore and it will 
                // resolve correctly once the browser catches up.
                return;
            }
            return {
                type: 'eventdrag',
                ddel: t,
                eventStart: rec.data[Ext.ensible.cal.EventMappings.StartDate.name],
                eventEnd: rec.data[Ext.ensible.cal.EventMappings.EndDate.name],
                proxy: this.proxy
            };
        }
        
        // If not dragging an event then we are dragging on 
        // the calendar to add a new event
        t = this.view.getDayAt(e.xy[0], e.xy[1]);
        if(t.el){
            return {
                type: 'caldrag',
                start: t.date,
                proxy: this.proxy
            };
        }
        return null;
    },
    
    onInitDrag : function(x, y){
        if(this.dragData.ddel){
            var ghost = this.dragData.ddel.cloneNode(true),
                child = Ext.fly(ghost).child('dl');
            
            Ext.fly(ghost).setWidth('auto');
            
            if(child){
                // for IE/Opera
                child.setHeight('auto');
            }
            this.proxy.update(ghost);
            this.onStartDrag(x, y);
        }
        else if(this.dragData.start){
            this.onStartDrag(x, y);
        }
        this.view.onInitDrag();
        return true;
    },
    
    afterRepair : function(){
        if(Ext.enableFx && this.dragData.ddel){
            Ext.Element.fly(this.dragData.ddel).highlight(this.hlColor || 'c3daf9');
        }
        this.dragging = false;
    },
    
    getRepairXY : function(e){
        if(this.dragData.ddel){
            return Ext.Element.fly(this.dragData.ddel).getXY();
        }
    },
    
    afterInvalidDrop : function(e, id){
        Ext.select('.ext-dd-shim').hide();
    },
    
    destroy : function(){
        Ext.ensible.cal.DragZone.superclass.destroy.call(this);
        delete Ext.ensible.cal._statusProxyInstance;
    }    
});

/* @private
 * Internal drop zone implementation for the calendar components. This provides base functionality
 * and is primarily for the month view -- DayViewDD adds day/week view-specific functionality.
 */
Ext.ensible.cal.DropZone = Ext.extend(Ext.dd.DropZone, {
    ddGroup : 'CalendarDD',
    eventSelector : '.ext-cal-evt',
    dateRangeFormat : '{0}-{1}',
    dateFormat : 'n/j',
    
    // private
    shims : [],
    
    getTargetFromEvent : function(e){
        var dragOffset = this.dragOffset || 0,
            y = e.getPageY() - dragOffset,
            d = this.view.getDayAt(e.getPageX(), y);
        
        return d.el ? d : null;
    },
    
    onNodeOver : function(n, dd, e, data){
        var D = Ext.ensible.Date,
            start = data.type == 'eventdrag' ? n.date : D.min(data.start, n.date),
            end = data.type == 'eventdrag' ? n.date.add(Date.DAY, D.diffDays(data.eventStart, data.eventEnd)) : 
                D.max(data.start, n.date);
        
        if(!this.dragStartDate || !this.dragEndDate || (D.diffDays(start, this.dragStartDate) != 0) || (D.diffDays(end, this.dragEndDate) != 0)){
            this.dragStartDate = start;
            this.dragEndDate = end.clearTime().add(Date.DAY, 1).add(Date.MINUTE, -30);
            this.shim(start, end);
            
            var range = start.format(this.dateFormat);
                
            if(D.diffDays(start, end) > 0){
                end = end.format(this.dateFormat);
                range = String.format(this.dateRangeFormat, range, end);
            }
            var msg = String.format(data.type == 'eventdrag' ? this.moveText : this.createText, range);
            data.proxy.updateMsg(msg);
        }
        return this.dropAllowed;
    },
    
    shim : function(start, end){
        this.currWeek = -1;
        var dt = start.clone(),
            i = 0, shim, box,
            cnt = Ext.ensible.Date.diffDays(dt, end)+1
        
        Ext.each(this.shims, function(shim){
            if(shim){
                shim.isActive = false;
            }
        });
        
        while(i++ < cnt){
            var dayEl = this.view.getDayEl(dt);
            
            // if the date is not in the current view ignore it (this
            // can happen when an event is dragged to the end of the
            // month so that it ends outside the view)
            if(dayEl){
                var wk = this.view.getWeekIndex(dt),
                    shim = this.shims[wk];
            
                if(!shim){
                    shim = this.createShim();
                    this.shims[wk] = shim;
                }
                if(wk != this.currWeek){
                    shim.boxInfo = dayEl.getBox();
                    this.currWeek = wk;
                }
                else{
                    box = dayEl.getBox();
                    shim.boxInfo.right = box.right;
                    shim.boxInfo.width = box.right - shim.boxInfo.x;
                }
                shim.isActive = true;
            }
            dt = dt.add(Date.DAY, 1);
        }
        
        Ext.each(this.shims, function(shim){
            if(shim){
                if(shim.isActive){
                    shim.show();
                    shim.setBox(shim.boxInfo);
                }
                else if(shim.isVisible()){
                    shim.hide();
                }
            }
        });
    },
    
    createShim : function(){
        var owner = this.view.ownerCalendarPanel ? this.view.ownerCalendarPanel : this.view;
        if(!this.shimCt){
            this.shimCt = Ext.get('ext-dd-shim-ct-'+owner.id);
            if(!this.shimCt){
                this.shimCt = document.createElement('div');
                this.shimCt.id = 'ext-dd-shim-ct-'+owner.id;
                owner.getEl().parent().appendChild(this.shimCt);
            }
        }
        var el = document.createElement('div');
        el.className = 'ext-dd-shim';
        this.shimCt.appendChild(el);
        
        return new Ext.Layer({
            shadow:false, 
            useDisplay:true, 
            constrain:false
        }, el);
    },
    
    clearShims : function(){
        Ext.each(this.shims, function(shim){
            if(shim){
                shim.hide();
            }
        });
    },
    
    onContainerOver : function(dd, e, data){
        return this.dropAllowed;
    },
    
    onCalendarDragComplete : function(){
        delete this.dragStartDate;
        delete this.dragEndDate;
        this.clearShims();
    },
    
    onNodeDrop : function(n, dd, e, data){
        if(n && data){
            if(data.type == 'eventdrag'){
                var rec = this.view.getEventRecordFromEl(data.ddel),
                    dt = Ext.ensible.Date.copyTime(rec.data[Ext.ensible.cal.EventMappings.StartDate.name], n.date);
                    
                this.view.onEventDrop(rec, dt);
                this.onCalendarDragComplete();
                return true;
            }
            if(data.type == 'caldrag'){
                this.view.onCalendarEndDrag(this.dragStartDate, this.dragEndDate, 
                    this.onCalendarDragComplete.createDelegate(this));
                //shims are NOT cleared here -- they stay visible until the handling
                //code calls the onCalendarDragComplete callback which hides them.
                return true;
            }
        }
        this.onCalendarDragComplete();
        return false;
    },
    
    onContainerDrop : function(dd, e, data){
        this.onCalendarDragComplete();
        return false;
    }
});