/* 
 * Egroupware Calendar timegrid
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package etemplate
 * @subpackage api
 * @link http://www.egroupware.org
 * @author Nathan Gray
 * @version $Id$
 */


"use strict";

/*egw:uses
	/etemplate/js/et2_core_valueWidget;
	/calendar/js/et2_widget_planner_row.js;
	/calendar/js/et2_widget_event.js;
*/

/**
 * Class which implements the "calendar-planner" XET-Tag for displaying a longer
 * ( > 10 days) span of time
 *
 * @augments et2_valueWidget
 * @class
 */
var et2_calendar_planner = et2_valueWidget.extend([et2_IDetachedDOM, et2_IResizeable],
{
	createNamespace: true,
	
	attributes: {
		start_date: {
			name: "Start date",
			type: "any"
		},
		end_date: {
			name: "End date",
			type: "any"
		},
		group_by: {
			name: "Group by",
			type: "string", // or category ID
			default: "0",
			description: "Display planner by 'user', 'month', or the given category"
		},
		owner: {
			name: "Owner",
			type: "any", // Integer, or array of integers
			default: 0,
			description: "Account ID number of the calendar owner, if not the current user"
		},
		filter: {
			name: "Filter",
			type: "string",
			default: '',
			description: 'A filter that is used to select events.  It is passed along when events are queried.'
		},
		value: {
			type: "any",
			description: "A list of events, optionally you can set start_date, end_date and group_by as keys and events will be fetched"
		},
		"onchange": {
			"name": "onchange",
			"type": "js",
			"default": et2_no_init,
			"description": "JS code which is executed when the date range changes."
		},
		"onevent_change": {
			"name": "onevent_change",
			"type": "js",
			"default": et2_no_init,
			"description": "JS code which is executed when an event changes."
		}
	},

	/**
	 * Constructor
	 *
	 * @memberOf et2_calendar_planner
	 * @constructor
	 */
	init: function() {
		this._super.apply(this, arguments);

		// Main container
		this.div = $j(document.createElement("div"))
			.addClass("calendar_plannerWidget");

		// Header
		this.gridHeader = $j(document.createElement("div"))
			.addClass("calendar_plannerHeader")
			.appendTo(this.div);
		this.headerTitle = $j(document.createElement("div"))
			.addClass("calendar_plannerHeaderTitle")
			.appendTo(this.gridHeader);
		this.headers = $j(document.createElement("div"))
			.addClass("calendar_plannerHeaderRows")
			.appendTo(this.gridHeader);

		this.rows = $j(document.createElement("div"))
			.appendTo(this.div);

		this.vertical_bar = $j(document.createElement("div"))
			.addClass('verticalBar')
			.appendTo(this.div);
		
		// Used for its date calculations
		this.date_helper = et2_createWidget('date-time',{},null);
		this.date_helper.loadingFinished();

		this.value = [];

		// Update timer, to avoid redrawing twice when changing start & end date
		this.update_timer = null;
		this.doInvalidate = true;

		this.setDOMNode(this.div[0]);

		this.registeredCallbacks = [];
	},

	destroy: function() {
		this._super.apply(this, arguments);
		this.div.off();

		for(var i = 0; i < this.registeredCallbacks.length; i++)
		{
			egw.dataUnregisterUID(this.registeredCallbacks[i],false,this);
		}

		// date_helper has no parent, so we must explicitly remove it
		this.date_helper.destroy();
		this.date_helper = null;
		
		// Stop the invalidate timer
		if(this.update_timer)
		{
			window.clearTimeout(this.update_timer);
		}
	},

	doLoadingFinished: function() {
		this._super.apply(this, arguments);
		
		// Don't bother to draw anything if there's no date yet
		if(this.options.start_date)
		{
			this._drawGrid();
		}

		// Actions may be set on a parent, so we need to explicitly get in here
		// and get ours
		this._link_actions(this.options.actions || this._parent.options.actions || []);

		// Automatically bind drag and resize for every event using jQuery directly
		// - no action system -
		var planner = this;

		/**
		 * If user puts the mouse over an event, then we'll set up resizing so
		 * they can adjust the length.  Should be a little better on resources
		 * than binding it for every calendar event.
		 */
		this.div.on('mouseover', '.calendar_calEvent:not(.ui-resizable):not(.rowNoEdit)', function() {
				// Load the event
				planner._get_event_info(this);
				var that = this;

				//Resizable event handler
				$j(this).resizable
				({
					distance: 10,
					grid: [5, 10000],
					autoHide: false,
					handles: 'e',
					containment:'parent',

					/**
					 *  Triggered when the resizable is created.
					 *
					 * @param {event} event
					 * @param {Object} ui
					 */
					create:function(event, ui)
					{
						var resizeHelper = event.target.getAttribute('data-resize');
						if (resizeHelper == 'WD' || resizeHelper == 'WDS')
						{
							jQuery(this).resizable('destroy');
						}
					},

					/**
					 * Triggered at the end of resizing the calEvent.
					 *
					 * @param {event} event
					 * @param {Object} ui
					 */
					stop:function(event, ui)
					{
						var e = new jQuery.Event('change');
						e.originalEvent = event;
						e.data = {duration: 0};
						var event_data = planner._get_event_info(this);
						var event_widget = planner.getWidgetById('event_'+event_data.id);
						var sT = event_widget.options.value.start_m;
						if (typeof this.dropEnd != 'undefined')
						{
							var eT = parseInt(this.dropEnd.getUTCHours() * 60) + parseInt(this.dropEnd.getUTCMinutes());
							e.data.duration = ((eT - sT)/60) * 3600;

							if(event_widget)
							{
								event_widget.options.value.end_m = eT;
								event_widget.options.value.duration = e.data.duration;
							}

							// Leave the helper there until the update is done
							var loading = ui.helper.clone().appendTo(ui.helper.parent());

							// and add a loading icon so user knows something is happening
							$j('.calendar_timeDemo',loading).after('<div class="loading"></div>');

							$j(this).trigger(e);

							// That cleared the resize handles, so remove for re-creation...
							$j(this).resizable('destroy');

							// Remove loading, done or not
							loading.remove();
						}
						// Clear the helper, re-draw
						if(event_widget)
						{
							event_widget._parent.position_event(event_widget);
						}
					},

					/**
					 * Triggered during the resize, on the drag of the resize handler
					 *
					 * @param {event} event
					 * @param {Object} ui
					 */
					resize:function(event, ui)
					{
						planner._drag_helper(this,{
							top:ui.position.top,
							left: ui.position.left + ui.helper.width()
						},ui.helper.outerHeight());
					}
				});
			})
			.on('mousemove', function(event) {
				// Not when over header
				if($j(event.target).closest('.calendar_eventRows').length == 0)
				{
					planner.vertical_bar.hide();
					return;
				}
				// Position bar by mouse
				planner.vertical_bar.position({
					my: 'right-1',
					of: event,
					collision: 'fit'
				});
				planner.vertical_bar.css('top','0px');

				// Get time at mouse
				if(planner.options.group_by == 'month')
				{
					var time = planner._get_time_from_position(event.clientX, event.clientY);
				}
				else
				{
					var time = planner._get_time_from_position(event.offsetX, event.offsetY);
				}
				// Passing to formatter, cancel out timezone
				if(time)
				{
					var formatDate = new Date(time.valueOf() + time.getTimezoneOffset() * 60 * 1000);
					planner.vertical_bar
						.html('<span>'+date(egw.preference('timeformat','calendar') == 12 ? 'h:ia' : 'H:i',formatDate)+'</span>')
						.show();
				}
				else
				{
					// No (valid) time, just hide
					planner.vertical_bar.hide();
				}
			});

		// Customize and override some draggable settings
		this.div.on('dragcreate','.calendar_calEvent', function(event, ui) {
				$j(this).draggable('option','cancel','.rowNoEdit');
				// Act like you clicked the header, makes it easier to position
				$j(this).draggable('option','cursorAt', {top: 5, left: 5});
			})
			.on('dragstart', '.calendar_calEvent', function(event,ui) {
				$j('.calendar_calEvent',ui.helper).width($j(this).width())
					.height($j(this).outerHeight())
					.css('top', '').css('left','')
					.appendTo(ui.helper);
				ui.helper.width($j(this).width());
			});
		return true;
	},
	
	/**
	 * These handle the differences between the different group types.
	 * They provide the different titles, labels and grouping
	 */
	groupers: {
		// Group by user has one row for each user
		user:
		{
			// Title in top left corner
			title: function() { return this.egw().lang('User');},
			// Column headers
			headers: function() {
				var start = new Date(this.options.start_date);
				var end = new Date(this.options.end_date);
				var start_date = new Date(start.getUTCFullYear(), start.getUTCMonth(),start.getUTCDate());
				var end_date = new Date(end.getUTCFullYear(), end.getUTCMonth(),end.getUTCDate());
				var day_count = Math.round((end_date - start_date) /(1000*3600*24))+1;
				if(day_count >= 28)
				{
					this.headers.append(this._header_months(start, day_count));
				}
				if(day_count >= 5 && day_count < 120)
				{
					this.headers.append(this._header_weeks(start, day_count));
				}
				if(day_count < 60)
				{
					this.headers.append(this._header_days(start, day_count));
				}
				if(day_count <= 7)
				{
					this.headers.append(this._header_hours(start, day_count));
				}
			},
			// Labels for the rows
			row_labels: function() {
				var labels = [];
				var accounts = egw.accounts();
				var already_added = [];
				for(var i = 0; i < this.options.owner.length; i++)
				{
					var user = this.options.owner[i];
					if(parseInt(user) === 0)
					{
						// 0 means current user
						user = egw.user('account_id');
					}
					if (isNaN(user))		// resources
					{
						var planner = this;
						var label = egw.link_title('resources',user.match(/\d+/)[0],function(name) {
							for(var j = 0; j < labels.length; j++)
							{
								if(labels[j].id == this)
								{
									labels[j].label = name;
									break;
								}
							}
							var row = planner.getWidgetById(this);
							if(row && row.set_label)
							{
								row.set_label(name);
							}
						},user);
						if(already_added.indexOf(user) < 0)
						{
							labels.push({id: user, label: label, data: {participants:user,owner:''}});
							already_added.push(''+user);
						}
					}
					else if (user < 0)	// groups
					{
						egw.accountData(user,'account_fullname',true,function(result) {
							for(var id in result)
							{
								if(already_added.indexOf(''+id) < 0)
								{
									this.push({id: id, label: result[id], data: {participants:id,owner:id}});
									already_added.push(''+id);
								}
							}
						},labels);
					}
					else	// users
					{
						user = parseInt(user)
						for(var j = 0; j < accounts.length && already_added.indexOf(''+user) < 0; j++)
						{
							if(accounts[j].value === user)
							{
								labels.push({id: user, label: accounts[j].label, data: {participants:user,owner:user}});
								already_added.push(''+user);
								break;
							}
						}
					}
				}

				return labels;
			},
			// Group the events into the rows
			group: function(labels, rows, event) {
				// convert filter to allowed status
				var status_to_show = ['U','A','T','D','G'];
				switch(this.options.filter)
				{
					case 'unknown':
						status_to_show = ['U','G']; break;
					case 'accepted':
						status_to_show = ['A']; break;
					case 'tentative':
						status_to_show = ['T']; break;
					case 'rejected':
						status_to_show = ['R']; break;
					case 'delegated':
						status_to_show = ['D']; break;
					case 'all':
						status_to_show = ['U','A','T','D','G','R']; break;
					default:
						status_to_show = ['U','A','T','D','G']; break;
				}
				var participants = event.participants;
				var add_row = function(user, participant) {
					var label_index = false;
					for(var i = 0; i < labels.length; i++)
					{
						if(labels[i].id == user)
						{
							label_index = i;
							break;
						}
					}
					if(participant && label_index !== false && status_to_show.indexOf(participant.substr(0,1)) >= 0 ||
						this.options.filter === 'owner' && event.owner === user)
					{
						if(typeof rows[label_index] === 'undefined')
						{
							rows[label_index] = [];
						}
						rows[label_index].push(event);
					}
				}
				for(var user in participants)
				{
					var participant = participants[user];
					if (parseInt(user) < 0)	// groups
					{
						var planner = this;
						egw.accountData(user,'account_fullname',true,function(result) {
							for(var id in result)
							{
								if(!participants[id]) add_row.call(planner,id,participant);
							}
						},labels);
						continue;
					}
					add_row.call(this, user, participant);
				}
			},
			// Draw a single row
			draw_row: function(sort_key, label, events) {
				return this._drawRow(sort_key, label,events,this.options.start_date, this.options.end_date);
			}
		},

		// Group by month has one row for each month
		month:
		{
			title: function() { return this.egw().lang('Month');},
			headers: function() {
				this.headers.append(this._header_day_of_month());
			},
			row_labels: function() {
				var labels = [];
				var d = new Date(this.options.start_date);
				d = new Date(d.valueOf() + d.getTimezoneOffset() * 60 * 1000);
				for(var i = 0; i < 12; i++)
				{
					// Not using UTC because we corrected for timezone offset
					labels.push({id: d.getFullYear() +'-'+d.getMonth(), label:app.calendar.egw.lang(date('F',d))+' '+d.getFullYear()});
					d.setMonth(d.getMonth()+1);
				}
				return labels;
			},
			group: function(labels, rows,event) {
				// Yearly planner does not show infologs
				if(event && event.app && event.app == 'infolog') return;

				var start = new Date(event.start);
				start = new Date(start.valueOf() + start.getTimezoneOffset() * 60 * 1000);
				var key = start.getFullYear() +'-'+start.getMonth();
				var label_index = false;
				for(var i = 0; i < labels.length; i++)
				{
					if(labels[i].id == key)
					{
						label_index = i;
						break;
					}
				}
				if(typeof rows[label_index] === 'undefined')
				{
					rows[label_index] = [];
				}
				rows[label_index].push(event);

				// end in a different month?
				var end = new Date(event.end);
				end = new Date(end.valueOf() + end.getTimezoneOffset() * 60 * 1000);
				var end_key = end.getFullYear() +'-'+end.getMonth();
				var year = start.getFullYear();
				var month = start.getMonth();
				while(key !== end_key)
				{
					if (++month > 11)
					{
						++year;
						month = 0;
					}
					key = sprintf('%04d-%d',year,month);
					for(var i = 0; i < labels.length; i++)
					{
						if(labels[i].id == key)
						{
							label_index = i;
							if(typeof rows[label_index] === 'undefined')
							{
								rows[label_index] = [];
							}
							break;
						}
					}
					rows[label_index].push(event);
				}
			},
			// Draw a single row, but split up the dates
			draw_row: function(sort_key, label, events)
			{
				var key = sort_key.split('-');
				this._drawRow(
					sort_key, label, events,
					new Date(key[0]+"-"+sprintf("%02d",parseInt(key[1])+1)+"-01T00:00:00Z"),
					new Date(key[0],parseInt(key[1])+1,0)
				);
			}
		},
		// Group by category has one row for each [sub]category
		category:
		{
			title: function() { return this.egw().lang('Category');},
			headers: function() {
				var start = new Date(this.options.start_date);
				var end = new Date(this.options.end_date);
				var start_date = new Date(start.getUTCFullYear(), start.getUTCMonth(),start.getUTCDate());
				var end_date = new Date(end.getUTCFullYear(), end.getUTCMonth(),end.getUTCDate());
				var day_count = Math.round((end_date - start_date) /(1000*3600*24))+1;

				if(day_count >= 28)
				{
					this.headers.append(this._header_months(start, day_count));
				}
				
				if(day_count >= 5 && day_count < 120)
				{
					this.headers.append(this._header_weeks(start, day_count));
				}
				if(day_count < 60)
				{
					this.headers.append(this._header_days(start, day_count));
				}
				if(day_count <= 7)
				{
					this.headers.append(this._header_hours(start, day_count));
				}
			},
			row_labels: function() {
				return [{id:'',label: egw.lang('none'), data: {}}];
			},
			group: function(labels, rows, event) {
				var cats = event.category;
				if(typeof event.category === 'string')
				{
					cats = cats.split(',');
				}
				for(var cat = 0; cat < cats.length; cat++)
				{
					var label_index = false;
					var category = cats[cat];
					if(category == '0' || !category) category = '';
					for(var i = 0; i < labels.length; i++)
					{
						if(labels[i].id == category)
						{
							label_index = i;
							break;
						}
					}
					if(label_index === false)
					{
						label_index = labels.length;
						labels.push({id: category, label: '', data: {cat_id:category}});
						var im = this.getInstanceManager();
						// Fake it to use the cache / call
						var categories = et2_selectbox.cat_options({
							_type:'select-cat',
							getInstanceManager: function() {return im;}
						}, {application:event.app||'calendar'});
						if(categories && !categories.length)
						{
							// Categories not loaded.  They've started, but it's too late now
							// Try again once they're all loaded
							this.invalidate();
							return;
						}
						for(var i in categories )
						{
							if(parseInt(categories[i].value) === parseInt(category))
							{
								labels[labels.length-1].label = categories[i].label;
								break;
							}
						}
					}
					if(typeof rows[label_index] === 'undefined')
					{
						rows[label_index] = [];
					}
					rows[label_index].push(event);
				}
			},
			draw_row: function(sort_key, label, events) {
				return this._drawRow(sort_key, label,events,this.options.start_date, this.options.end_date);
			}
		}
	},

	/**
	 * Something changed, and the planner needs to be re-drawn.  We wait a bit to
	 * avoid re-drawing twice if start and end date both changed, then recreate.
	 *
	 * @param {boolean} trigger=false Trigger an event once things are done.
	 *	Waiting until invalidate completes prevents 2 updates when changing the date range.
	 * @returns {undefined}
	 */
	invalidate: function(trigger) {

		// Busy
		if(!this.doInvalidate || this.update_timer) return;

		// Wait a bit to see if anything else changes, then re-draw the days
		if(this.update_timer !== null)
		{
			window.clearTimeout(this.update_timer);
		}
		this.update_timer = window.setTimeout(jQuery.proxy(function() {
			this.doInvalidate = false;

			this.widget.value = this.widget._fetch_data();

			// Show AJAX loader
			framework.applications.calendar.sidemenuEntry.showAjaxLoader();

			this.widget._drawGrid();

			// Update actions
			if(this._actionManager)
			{
				this._link_actions(this._actionManager.children);
			}

			// Hide AJAX loader
			framework.applications.calendar.sidemenuEntry.hideAjaxLoader();

			if(this.trigger)
			{
				this.widget.change();
			}
			this.widget.update_timer = null;
			this.doInvalidate = true;
		},{widget:this,"trigger":trigger}),ET2_GRID_INVALIDATE_TIMEOUT);
	},

	detachFromDOM: function() {
		// Remove the binding to the change handler
		$j(this.div).off("change.et2_calendar_timegrid");

		this._super.apply(this, arguments);
	},

	attachToDOM: function() {
		this._super.apply(this, arguments);

		// Add the binding for the event change handler
		$j(this.div).on("change.et2_calendar_timegrid", '.calendar_calEvent', this, function(e) {
			// Make sure function gets a reference to the widget
			var args = Array.prototype.slice.call(arguments);
			if(args.indexOf(this) == -1) args.push(this);

			return e.data.event_change.apply(e.data, args);
		});

		// Add the binding for the change handler
		$j(this.div).on("change.et2_calendar_timegrid", '*:not(.calendar_calEvent)', this, function(e) {
				return e.data.change.call(e.data, e, this);
			});

	},

	getDOMNode: function(_sender)
	{
		if(_sender === this || !_sender)
		{
			return this.div[0];
		}
		if(_sender._parent === this)
		{
			return this.rows[0];
		}
	},

	/**
	 * Creates all the DOM nodes for the planner grid
	 *
	 * Any existing nodes (& children) are removed, the headers & labels are
	 * determined according to the current group_by value, and then the rows
	 * are created.
	 *
	 * @method
	 * @private
	 *
	 */
	_drawGrid: function()
	{

		this.div.css('height', this.options.height);

		// Clear old events
		var delete_index = this._children.length - 1;
		while(this._children.length > 0 && delete_index >= 0)
		{
			this._children[delete_index].free();
			this.removeChild(this._children[delete_index--]);
		}
		
		// Clear old rows
		this.rows.empty();

		var grouper = this.groupers[isNaN(this.options.group_by) ? this.options.group_by : 'category'];
		if(!grouper) return;

		// Headers
		this.headers.empty();
		this.headerTitle.text(grouper.title.apply(this));
		grouper.headers.apply(this);

		// Get the rows / labels
		var labels = grouper.row_labels.call(this);
		
		// Group the events
		var events = {};
		for(var i = 0; i < this.value.length; i++)
		{
			grouper.group.call(this, labels, events, this.value[i]);
		}

		// Set height for rows
		this.rows.height(this.div.parent().height() - this.headers.outerHeight());

		// Draw the rows
		for(var key in labels)
		{
			var row = grouper.draw_row.call(this,labels[key].id, labels[key].label, events[key] || []);

			// Add extra data for clicking on row
			for(var extra in labels[key].data)
			{
				row.getDOMNode().dataset[extra] = labels[key].data[extra];
			}
		}

		// Adjust header if there's a scrollbar
		this.gridHeader.css('margin-right', (this.rows.width() - this.rows.children().first().width()) + 'px')
		this.value = [];
	},

	/**
	 * Draw a single row of the planner
	 *
	 * @param {string} key Index into the grouped labels & events
	 * @param {string} label
	 * @param {Array} events
	 * @param {Date} start
	 * @param {Date} end
	 */
	_drawRow: function(key, label, events, start, end)
	{
		var row = et2_createWidget('calendar-planner_row',{
				id: key,
				label: label,
				start_date: start,
				end_date: end,
				value: events
			},this);


		if(this.isInTree())
		{
			row.doLoadingFinished();
		}
		
		// Add actual events
		row._update_events(events);

		return row;
	},


	_header_day_of_month: function()
	{
		var day_width = 3.23; // 100.0 / 31;

		// month scale with navigation
		var content = '<div class="calendar_plannerScale">';
		var start = new Date(this.options.start_date);
		start = new Date(start.valueOf() + start.getTimezoneOffset() * 60 * 1000);
		var end = new Date(this.options.end_date);
		end = new Date(end.valueOf() + end.getTimezoneOffset() * 60 * 1000);

		var title = app.calendar.egw.lang(date('F',start))+' '+date('Y',start)+' - '+
			app.calendar.egw.lang(date('F',end))+' '+date('Y',end);

		// calculate date for navigation links
		var time = new Date(start);
		time.setUTCFullYear(time.getUTCFullYear()-1);
		var last_year = time.toJSON();
		time.setUTCMonth(time.getUTCMonth()+11);
		var last_month = time.toJSON();
		time.setUTCMonth(time.getUTCMonth()+2);
		var next_month = time.toJSON();
		time.setUTCMonth(time.getUTCMonth()+11);
		var next_year = time.toJSON();

		title = this._scroll_button('first',last_year) +
			this._scroll_button('left', last_month) +
			title +
			this._scroll_button('right', next_month) +
			this._scroll_button('last', next_year);

		content += '<div class="calendar_plannerMonthScale th et2_link" style="left: 0; width: 100%;">'+
				title+"</div>";
		content += "</div>";		// end of plannerScale

		// day of month scale
		content +='<div class="calendar_plannerScale">';

		for(var left = 0, i = 0; i < 31; left += day_width,++i)
		{
			content += '<div class="calendar_plannerDayOfMonthScale " style="left: '+left+'%; width: '+day_width+'%;">'+
				(1+i)+"</div>\n";
		}
		content += "</div>\n";

		return content;
	},

	/**
	 * Make a header showing the months
	 * @param {Date} start
	 * @param {number} days
	 * @returns {string} HTML snippet
	 */
	_header_months: function(start, days)
	{
		var content = '<div class="calendar_plannerScale" data-planner_days="0" data-last="">';
		var days_in_month = 0;
		var day_width = 100 / days;
		var t = new Date(start.valueOf());
		for(var left = 0,i = 0; i < days;t.setUTCDate(1),t.setUTCMonth(t.getUTCMonth()+1),left += days_in_month*day_width,i += days_in_month)
		{
			var u = new Date(t.getUTCFullYear(),t.getUTCMonth()+1,0,-t.getTimezoneOffset()/60);
			this.date_helper.set_year(t.getUTCFullYear());
			this.date_helper.set_month(t.getUTCMonth()+2);
			this.date_helper.set_date(0);
			days_in_month = this.date_helper.get_date() - (t.getUTCDate()-1);

			if(days_in_month <= 0) break;
			
			if (i + days_in_month > days)
			{
				days_in_month = days - i;
			}
			if (days_in_month > 5)
			{
				var title = app.calendar.egw.lang(date('F',new Date(t.valueOf() + t.getTimezoneOffset() * 60 * 1000)))
			}
			if (days_in_month > 10)
			{
				title += ' '+t.getUTCFullYear();
			
				// previous links
				var prev = new Date(t);
				prev.setUTCMonth(prev.getUTCMonth()-1);
				if(prev.valueOf() < start.valueOf() - (20 * 1000*3600*24))
				{
					var full = prev.toJSON();
					prev.setUTCDate(prev.getUTCDate() + 15);
					prev.setUTCDate(start.getUTCDate() < 15 ? 1 : 15);
					var half = prev.toJSON();
					title = this._scroll_button('first',full) + this._scroll_button('left',half) + title;
				}
			
				// show next scales, if there are more then 10 days in the next month or there is no next month
				var end = new Date(start);
				end.setUTCDate(end.getUTCDate()+days);
				var days_in_next_month = end.getUTCDate();
				if (days_in_next_month <= 10 || end.getUTCMonth() == t.getUTCMonth())
				{
					// next links
					var next = new Date(t);
					next.setUTCMonth(next.getUTCMonth()+1);
					full = next.toJSON();
					next.setUTCDate(next.getUTCDate() - 15);
					next.setUTCDate(next.getUTCDate() < 15 ? 1 : 15);
					half = next.toJSON();

					title += this._scroll_button('right',half) + this._scroll_button('last',full);
				}
			}
			else
			{
				title = '&nbsp;';
			}
			content += '<div class="calendar_plannerMonthScale et2_clickable et2_link" data-date="'+t.toJSON()+ '"'+// data-planner_days='+days_in_month+
				' style="left: '+left+'%; width: '+(day_width*days_in_month)+'%;">'+
				title+"</div>";
		}
		content += "</div>";		// end of plannerScale

		return content;
	},

	/**
	 * Make a header showing the week numbers
	 * 
	 * @param {Date} start
	 * @param {number} days
	 * @returns {string} HTML snippet
	 */
	_header_weeks: function(start, days)
	{
		var week_width = 100 / days * (days <= 7 ? days : 7);

		var content = '<div class="calendar_plannerScale" data-planner_days=7>';
		var state = ''

		// we're not using UTC so date() formatting function works
		//var t = new Date(start.valueOf() + start.getTimezoneOffset() * 60 * 1000);
		var t = new Date(start);
		for(var left = 0,i = 0; i < days; t.setUTCDate(t.getUTCDate() + 7),left += week_width,i += 7)
		{
			var title = app.calendar.egw.lang('Week')+' '+app.calendar.date.week_number(t);

			state = new Date(t.valueOf() - start.getTimezoneOffset() * 60 * 1000).toJSON();
			if (days  <= 7)
			{
				// prev. week
				var left = new Date(t);
				left.setUTCHours(0);
				left.setUTCMinutes(0);
				left.setUTCDate(left.getUTCDate() - 7);

				// next week
				var right = new Date(t);
				right.setUTCHours(0);
				right.setUTCMinutes(0);
				right.setUTCDate(right.getUTCDate() + 7);

				title = this._scroll_button('left',left.toJSON()) + title + this._scroll_button('right',right.toJSON());
			}
			
			content += '<div class="calendar_plannerWeekScale et2_clickable et2_link" data-date=\'' + state + '\' style="left: '+left+'%; width: '+week_width+'%;">'+title+"</div>";
		}
		content += "</div>";		// end of plannerScale

		return content;
	},

	/**
	 * Make a header for some days
	 *
	 * @param {Date} start
	 * @param {number} days
	 * @returns {string} HTML snippet
	 */
	_header_days: function(start, days)
	{
		var day_width = 100 / days;
		var content = '<div class="calendar_plannerScale'+(days > 3 ? 'Day' : '')+'" data-planner_days="1" >';

		// we're not using UTC so date() formatting function works
		var t = new Date(start.valueOf() + start.getTimezoneOffset() * 60 * 1000);
		for(var left = 0,i = 0; i < days; t.setDate(t.getDate()+1),left += day_width,++i)
		{
			var holidays = [];
			var day_class = this.day_class_holiday(t,holidays);
			var title = '';
			var state = '';

			if (days <= 3)
			{
				title = app.calendar.egw.lang(date('l',t))+', '+date('j',t)+'. '+app.calendar.egw.lang(date('F',t));
			}
			else if (days <= 7)
			{
				title = app.calendar.egw.lang(date('l',t))+' '+date('j',t);
			}
			else
			{
				title = app.calendar.egw.lang(date('D',t)).substr(0,2)+'<br />'+date('j',t);
			}
			state = new Date(t.valueOf() - start.getTimezoneOffset() * 60 * 1000).toJSON();
			if (days < 5)
			{
				if (!i)	// prev. day only for the first day
				{
					var prev = new Date(t);
					prev.setUTCDate(prev.getUTCDate() - 1);
					prev.setUTCHours(0);
					prev.setUTCMinutes(0);
					title = this._scroll_button('left',prev.toJSON()) + title;
				}
				if (i == days-1)	// next day only for the last day
				{
					var next = new Date(t);
					next.setUTCDate(next.getUTCDate() + 1);
					next.setUTCHours(0);
					next.setUTCMinutes(0);
					title += this._scroll_button('right',next.toJSON());
				}
			}
			content += '<div class="calendar_plannerDayScale et2_clickable et2_link '+ day_class+
				'" data-date=\'' + state +'\' style="left: '+left+'%; width: '+day_width+'%;"'+
				(holidays ? ' title="'+holidays.join(',')+'"' : '')+'>'+title+"</div>\n";
		}
		content += "</div>";		// end of plannerScale

		return content;
	},

	/**
	 * Create a header with hours
	 * 
	 * @param {Date} start
	 * @param {number} days
	 * @returns {string} HTML snippet for the header
	 */
	_header_hours: function(start,days)
	{
		var divisors = [1,2,3,4,6,8,12];
		var decr = 1;
		for(var i = 0; i < divisors.length; i++)	// numbers dividing 24 without rest
		{
			if (divisors[i] > days) break;
			decr = divisors[i];
		}
		var hours = days * 24;
		if (days === 1)			// for a single day we calculate the hours of a days, to take into account daylight saving changes (23 or 25 hours)
		{
			var t = new Date(start.getUTCFullYear(),start.getUTCMonth(),start.getUTCDate(),-start.getTimezoneOffset()/60);
			var s = new Date(start);
			s.setUTCHours(23);
			s.setUTCMinutes(59);
			s.setUTCSeconds(59);
			hours = Math.ceil((s.getTime() - t.getTime()) / 3600000);
		}
		var cell_width = 100 / hours * decr;

		var content = '<div class="calendar_plannerScale">';
		
		// we're not using UTC so date() formatting function works
		var t = new Date(start.valueOf() + start.getTimezoneOffset() * 60 * 1000);
		for(var left = 0,i = 0; i < hours; left += cell_width,i += decr)
		{
			var title = date(egw.preference('timeformat','calendar') == 12 ? 'ha' : 'H',t);

			content += '<div class="calendar_plannerHourScale et2_link" data-date="' + t.toJSON() +'" style="left: '+left+'%; width: '+(cell_width)+'%;">'+title+"</div>";
			t.setHours(t.getHours()+decr);
		}
		content += "</div>";		// end of plannerScale

		return content;
	},

	/**
	 * Create a pagination button, and inserts it
	 * 
	 */
	_scroll_button: function(image, date)
	{
		return '<img class="et2_clickable" src="' + egw.image(image)+ '" data-date="' + (date.toJSON ? date.toJSON():date) + '"/>';
	},

	/**
	 * Applies class for today, and any holidays for current day
	 *
	 * @param {Date} date
	 * @param {string[]} holiday_list Filled with a list of holidays for that day
	 *
	 * @return {string} CSS Classes for the day.  calendar_calBirthday, calendar_calHoliday, calendar_calToday and calendar_weekend as appropriate
	 */
	day_class_holiday: function(date,holiday_list) {

		if(!date) return '';

		var day_class = '';
		
		// Holidays and birthdays
		var holidays = et2_calendar_daycol.get_holidays(this,date.getUTCFullYear());

		// Pass a string rather than the date object, to make sure it doesn't get changed
		this.date_helper.set_value(date.toJSON());
		var date_key = ''+this.date_helper.get_year() + sprintf('%02d',this.date_helper.get_month()) + sprintf('%02d',this.date_helper.get_date());
		if(holidays && holidays[date_key])
		{
			holidays = holidays[date_key];
			for(var i = 0; i < holidays.length; i++)
			{
				if (typeof holidays[i]['birthyear'] !== 'undefined')
				{
					day_class += ' calendar_calBirthday ';

					holiday_list.push(holidays[i]['name']);
				}
				else
				{
					day_class += 'calendar_calHoliday ';

					holiday_list.push(holidays[i]['name']);
				}
			}
		}
		holidays = holiday_list.join(',');
		var today = new Date();
		if(date_key === ''+today.getFullYear()+
			sprintf("%02d",today.getMonth()+1)+
			sprintf("%02d",today.getDate())
		)
		{
			day_class += "calendar_calToday ";
		}
		if(date.getUTCDay() == 0 || date.getUTCDay() == 6)
		{
			day_class += "calendar_weekend ";
		}
		return day_class;
	},

	/**
	 * Link the actions to the DOM nodes / widget bits.
	 *
	 * @todo This currently does nothing
	 * @param {object} actions {ID: {attributes..}+} map of egw action information
	 */
	_link_actions: function(actions)
	{
		if(!this._actionObject)
		{
			// Get the parent?  Might be a grid row, might not.  Either way, it is
			// just a container with no valid actions
			var objectManager = egw_getObjectManager(this.getInstanceManager().app,true,1);
			objectManager = objectManager.getObjectById(this.getInstanceManager().uniqueId,2) || objectManager;
			var parent = objectManager.getObjectById(this.id,3) || objectManager.getObjectById(this._parent.id,3) || objectManager;
			if(!parent)
			{
				debugger;
				egw.debug('error','No parent objectManager found')
				return;
			}

			for(var i = 0; i < parent.children.length; i++)
			{
				var parent_finder = jQuery('#'+this.div.id, parent.children[i].iface.doGetDOMNode());
				if(parent_finder.length > 0)
				{
					parent = parent.children[i];
					break;
				}
			}
		}

		// This binds into the egw action system.  Most user interactions (drag to move, resize)
		// are handled internally using jQuery directly.
		var widget_object = this._actionObject || parent.getObjectById(this.id);

		var aoi = new et2_action_object_impl(this,this.getDOMNode());

		aoi.doTriggerEvent = function(_event, _data) {
			
			// Determine target node
			var event = _data.event || false;
			if(!event) return;
			if(_data.ui.draggable.hasClass('rowNoEdit')) return;

			/*
			We have to handle the drop in the normal event stream instead of waiting
			for the egwAction system so we can get the helper, and destination
			*/
			if(event.type === 'drop')
			{
				this.getWidget()._event_drop.call($j('.calendar_d-n-d_timeCounter',_data.ui.helper)[0],this.getWidget(),event, _data.ui);
			}
			var drag_listener = function(event, ui) {
				aoi.getWidget()._drag_helper($j('.calendar_d-n-d_timeCounter',ui.helper)[0],{
						top:ui.position.top,
						left: ui.position.left - $j(this).parent().offset().left
					},0);
			};
			var time = $j('.calendar_d-n-d_timeCounter',_data.ui.helper);
			switch(_event)
			{
				// Triggered once, when something is dragged into the timegrid's div
				case EGW_AI_DRAG_OVER:
					// Listen to the drag and update the helper with the time
					// This part lets us drag between different timegrids
					_data.ui.draggable.on('drag.et2_timegrid'+widget_object.id, drag_listener);
					_data.ui.draggable.on('dragend.et2_timegrid'+widget_object.id, function() {
						_data.ui.draggable.off('drag.et2_timegrid' + widget_object.id);
					});
					if(time.length)
					{
						// The out will trigger after the over, so we count
						time.data('count',time.data('count')+1);
					}
					else
					{
						_data.ui.helper.prepend('<div class="calendar_d-n-d_timeCounter" data-count="1"><span></span></div>');
					}

					break;

				// Triggered once, when something is dragged out of the timegrid
				case EGW_AI_DRAG_OUT:
					// Stop listening
					_data.ui.draggable.off('drag.et2_timegrid'+widget_object.id);
					// Remove any highlighted time squares
					$j('[data-date]',this.doGetDOMNode()).removeClass("ui-state-active");

					// Out triggers after the over, count to not accidentally remove
					time.data('count',time.data('count')-1);
					if(time.length && time.data('count') <= 0)
					{
						time.remove();
					}
					break;
			}
		};

		if (widget_object == null) {
			// Add a new container to the object manager which will hold the widget
			// objects
			widget_object = parent.insertObject(false, new egwActionObject(
				this.id, parent, aoi,
				this._actionManager || parent.manager.getActionById(this.id) || parent.manager
			),EGW_AO_FLAG_IS_CONTAINER);
		}
		else
		{
			widget_object.setAOI(aoi);
		}
		// Go over the widget & add links - this is where we decide which actions are
		// 'allowed' for this widget at this time
		var action_links = this._get_action_links(actions);

		this._init_links_dnd(widget_object.manager, action_links);

		widget_object.updateActionLinks(action_links);
		this._actionObject = widget_object;
	},

	/**
	 * Automatically add dnd support for linking
	 */
	_init_links_dnd: function(mgr,actionLinks) {
		var self = this;

		var drop_action = mgr.getActionById('egw_link_drop');
		var drag_action = mgr.getActionById('egw_link_drag');

		// Check if this app supports linking
		if(!egw.link_get_registry(this.dataStorePrefix || 'calendar', 'query') ||
			egw.link_get_registry(this.dataStorePrefix || 'calendar', 'title'))
		{
			if(drop_action)
			{
				drop_action.remove();
				if(actionLinks.indexOf(drop_action.id) >= 0)
				{
					actionLinks.splice(actionLinks.indexOf(drop_action.id),1);
				}
			}
			if(drag_action)
			{
				drag_action.remove();
				if(actionLinks.indexOf(drag_action.id) >= 0)
				{
					actionLinks.splice(actionLinks.indexOf(drag_action.id),1);
				}
			}
			return;
		}

		// Don't re-add
		if(drop_action == null)
		{
			// Create the drop action that links entries
			drop_action = mgr.addAction('drop', 'egw_link_drop', egw.lang('Create link'), egw.image('link'), function(action, source, dropped) {
				// Extract link IDs
				var links = [];
				var id = '';
				for(var i = 0; i < source.length; i++)
				{
					if(!source[i].id) continue;
					id = source[i].id.split('::');
					links.push({app: id[0] == 'filemanager' ? 'link' : id[0], id: id[1]});
				}
				if(!links.length)
				{
					return;
				}
				if(links.length && dropped && dropped.iface.getWidget() && dropped.iface.getWidget().instanceOf(et2_calendar_event))
				{
					// Link the entries
					egw.json(self.egw().getAppName()+".etemplate_widget_link.ajax_link.etemplate",
						dropped.id.split('::').concat([links]),
						function(result) {
							if(result)
							{
								this.egw().message('Linked');
							}
						},
						self,
						true,
						self
					).sendRequest();
				}
			},true);
		}
		if(actionLinks.indexOf(drop_action.id) < 0)
		{
			actionLinks.push(drop_action.id);
		}
		// Accept other links, and files dragged from the filemanager
		// This does not handle files dragged from the desktop.  They are
		// handled by et2_nextmatch, since it needs DOM stuff
		if(drop_action.acceptedTypes.indexOf('link') == -1)
		{
			drop_action.acceptedTypes.push('link');
		}

		// Don't re-add
		if(drag_action == null)
		{
			// Create drag action that allows linking
			drag_action = mgr.addAction('drag', 'egw_link_drag', egw.lang('link'), 'link', function(action, selected) {
				// As we wanted to have a general defaul helper interface, we return null here and not using customize helper for links
				// TODO: Need to decide if we need to create a customized helper interface for links anyway
				//return helper;
				return null;
			},true);
		}
		// The planner itself is not draggable, the action is there for the children
		if(false && actionLinks.indexOf(drag_action.id) < 0)
		{
			actionLinks.push(drag_action.id);
		}
		drag_action.set_dragType('link');
	},

	/**
	 * Get all action-links / id's of 1.-level actions from a given action object
	 *
	 * Here we are only interested in drop events.
	 *
	 * @param actions
	 * @returns {Array}
	 */
	_get_action_links: function(actions)
	{
		var action_links = [];
		// TODO: determine which actions are allowed without an action (empty actions)
		for(var i in actions)
		{
			var action = actions[i];
			if(action.type === 'drop')
			{
				action_links.push(typeof action.id !== 'undefined' ? action.id : i);
			}
		}
		return action_links;
	},

	/**
	 * Show the current time while dragging
	 * Used for resizing as well as drag & drop
	 */
	_drag_helper: function(element, position ,height)
	{
		var time = this._get_time_from_position(position.left, position.top);
		element.dropEnd = time;
		var formatted_time = jQuery.datepicker.formatTime(
			egw.preference("timeformat") === "12" ? "h:mmtt" : "HH:mm",
			{
				hour: time.getUTCHours(),
				minute: time.getUTCMinutes(),
				seconds: 0,
				timezone: 0
			},
			{"ampm": (egw.preference("timeformat") === "12")}
		);

		element.innerHTML = '<div class="calendar_d-n-d_timeCounter"><span class="calendar_timeDemo" >'+formatted_time+'</span></div>';

		//$j(element).width($j(helper).width());
	},
	
	/**
	 * Handler for dropping an event on the timegrid
	 */
	_event_drop: function(planner, event,ui) {
		var e = new jQuery.Event('change');
		e.originalEvent = event;
		e.data = {start: 0};
		if (typeof this.dropEnd != 'undefined')
		{
			var drop_date = this.dropEnd.toJSON() ||false;

			var event_data = planner._get_event_info(ui.draggable);
			var event_widget = planner.getWidgetById('event_'+event_data.id);
			if(event_widget)
			{
				event_widget._parent.date_helper.set_value(drop_date);
				event_widget.options.value.start = new Date(event_widget._parent.date_helper.getValue());

				// Leave the helper there until the update is done
				var loading = ui.helper.clone().appendTo(ui.helper.parent());
				// and add a loading icon so user knows something is happening
				$j('.calendar_timeDemo',loading).after('<div class="loading"></div>');

				event_widget.recur_prompt(function(button_id) {
					if(button_id === 'cancel' || !button_id) return;
					//Get infologID if in case if it's an integrated infolog event
					if (event_data.app === 'infolog')
					{
						// If it is an integrated infolog event we need to edit infolog entry
						egw().json('stylite_infolog_calendar_integration::ajax_moveInfologEvent',
							[event_data.id, event_widget.options.value.start||false],
							function() {loading.remove();}
						).sendRequest(true);
					}
					else
					{
						//Edit calendar event
						egw().json('calendar.calendar_uiforms.ajax_moveEvent', [
								button_id==='series' ? event_data.id : event_data.app_id,event_data.owner,
								event_widget.options.value.start,
								planner.options.owner||egw.user('account_id')
							],
							function() { loading.remove();}
						).sendRequest(true);
					}
				});
			}
		}
	},

	/**
	 * Use the egw.data system to get data from the calendar list for the
	 * selected time span.
	 * 
	 */
	_fetch_data: function()
	{
		var value = [];
		var fetch = false;
		this.doInvalidate = false;

		for(var i = 0; i < this.registeredCallbacks.length; i++)
		{
			egw.dataUnregisterUID(this.registeredCallbacks[i],false,this);
		}
		this.registeredCallbacks.splice(0,this.registeredCallbacks.length);

		// Remember previous day to avoid multi-days duplicating
		var last_data = [];

		var t = new Date(this.options.start_date);
		var end = new Date(this.options.end_date);
		do
		{
			// Cache is by date (and owner, if seperate)
			var date = t.getUTCFullYear() + sprintf('%02d',t.getUTCMonth()+1) + sprintf('%02d',t.getUTCDate());
			var cache_id = app.classes.calendar._daywise_cache_id(date, this.options.owner);

			if(egw.dataHasUID(cache_id))
			{
				var c = egw.dataGetUIDdata(cache_id);
				if(c.data && c.data !== null)
				{
					// There is data, pass it along now
					for(var j = 0; j < c.data.length; j++)
					{
						if(last_data.indexOf(c.data[j]) === -1 && egw.dataHasUID('calendar::'+c.data[j]))
						{
							value.push(egw.dataGetUIDdata('calendar::'+c.data[j]).data);
						}
					}
					last_data = c.data;
				}
			}
			else
			{
				fetch = true;
				// Assume it's empty, if there is data it will be filled later
				egw.dataStoreUID(cache_id, []);
			}
			this.registeredCallbacks.push(cache_id);
			egw.dataRegisterUID(cache_id, function(data) {
				if(data && data.length)
				{
					// If displaying by category, we need the infolog (or other app) categories too
					var im = this.getInstanceManager();
					for(var i = 0; i < data.length && this.options.group_by == 'category'; i++)
					{
						var event = egw.dataGetUIDdata('calendar::'+data[i]);
						if(event && event.data && event.data.app)
						{
							// Fake it to use the cache / call
							et2_selectbox.cat_options({
								_type:'select-cat',
								getInstanceManager: function() {return im;}
							}, {application:event.data.app||'calendar'});

							// Get CSS too
							egw.includeCSS('/phpgwapi/categories.php?app='+event.data.app);
						}
					}
					
					this.invalidate(false);
				}
			}, this, this.getInstanceManager().execId,this.id);
			
			t.setUTCDate(t.getUTCDate() + 1);
		}
		while(t < end);
		// Need to get some more from the server
		if(fetch && app.calendar)
		{
			app.calendar._fetch_data({
				first: this.options.start_date,
				last: this.options.end_date,
				owner: this.options.owner,
				filter: this.options.filter
			}, this.getInstanceManager());
		}

		this.doInvalidate = true;
		return value;
	},

	/**
	 * Provide specific data to be displayed.
	 * This is a way to set start and end dates, owner and event data in once call.
	 *
	 * @param {Object[]} events Array of events, indexed by date in Ymd format:
	 *	{
	 *		20150501: [...],
	 *		20150502: [...]
	 *	}
	 *	Days should be in order.
	 *
	 */
	set_value: function(events)
	{
		if(typeof events !== 'object') return false;

		if(events.owner)
		{
			this.set_owner(events.owner);
			delete events.owner;
		}
		if(events.start_date)
		{
			this.set_start_date(events.start_date);
			delete events.start_date;
		}
		if(events.end_date)
		{
			this.set_end_date(events.end_date);
			delete events.end_date;
		}

		if(typeof events.length === "undefined" && events)
		{
			for(var key in events)
			{
				if(typeof events[key] === 'object' && events[key] !== null)
				{
					this.value.push(events[key]);
				}
			}
		}
		else
		{
			this.value = events || [];
		}
	},

	/**
	 * Change the start date
	 * 
	 * @param {string|number|Date} new_date New starting date
	 * @returns {undefined}
	 */
	set_start_date: function(new_date)
	{
		if(!new_date || new_date === null)
		{
			throw new Error('Invalid start date. ' + new_date.toString());
		}

		// Use date widget's existing functions to deal
		if(typeof new_date === "object" || typeof new_date === "string" && new_date.length > 8)
		{
			this.date_helper.set_value(new_date);
		}
		else if(typeof new_date === "string")
		{
			this.date_helper.set_year(new_date.substring(0,4));
			this.date_helper.set_month(new_date.substring(4,6));
			this.date_helper.set_date(new_date.substring(6,8));
		}

		var old_date = this.options.start_date;
		this.options.start_date = new Date(this.date_helper.getValue());

		if(old_date !== this.options.start_date && this.isAttached())
		{
			this.invalidate(true);
		}
	},

	/**
	 * Change the end date
	 *
	 * @param {string|number|Date} new_date New end date
	 * @returns {undefined}
	 */
	set_end_date: function(new_date)
	{
		if(!new_date || new_date === null)
		{
			throw new Error('Invalid end date. ' + new_date.toString());
		}
		// Use date widget's existing functions to deal
		if(typeof new_date === "object" || typeof new_date === "string" && new_date.length > 8)
		{
			this.date_helper.set_value(new_date);
		}
		else if(typeof new_date === "string")
		{
			this.date_helper.set_year(new_date.substring(0,4));
			this.date_helper.set_month(new_date.substring(4,6));
			this.date_helper.set_date(new_date.substring(6,8));
		}

		this.date_helper.set_hours(23);
		this.date_helper.set_minutes(59);
		this.date_helper.date.setSeconds(59);
		var old_date = this.options.end_date;
		this.options.end_date = new Date(this.date_helper.getValue());

		if(old_date !== this.options.end_date && this.isAttached())
		{
			this.invalidate(true);
		}
	},

	/**
	 * Change how the planner is grouped
	 * 
	 * @param {string|number} group_by 'user', 'month', or an integer category ID
	 * @returns {undefined}
	 */
	set_group_by: function(group_by)
	{
		if(isNaN(group_by) && typeof this.groupers[group_by] === 'undefined')
		{
			throw new Error('Invalid group_by "'+group_by+'"');
		}
		var old = this.options.group_by;
		this.options.group_by = ''+group_by;

		if(old !== this.options.group_by && this.isAttached())
		{
			this.invalidate(true);
		}
	},

	/**
	 * Set which users to display when filtering, and for rows when grouping by user.
	 *
	 * @param {number|number[]} _owner Account ID
	 */
	set_owner: function(_owner)
	{
		var old = this.options.owner;
		if(!jQuery.isArray(_owner))
		{
			if(typeof _owner === "string")
			{
				_owner = _owner.split(',');
			}
			else
			{
				_owner = [_owner];
			}
		}
		else
		{
			_owner = jQuery.extend([],_owner);
		}
		this.options.owner = _owner;
		if(old !== this.options.owner && this.isAttached())
		{
			this.invalidate(true);
		}
	},


	/**
	 * Call change handler, if set
	 */
	change: function(event) {
		if (this.onchange)
		{
			if(typeof this.onchange == 'function')
			{
				// Make sure function gets a reference to the widget
				var args = Array.prototype.slice.call(arguments);
				if(args.indexOf(this) == -1) args.push(this);

				return this.onchange.apply(this, args);
			} else {
				return (et2_compileLegacyJS(this.options.onchange, this, _node))();
			}
		}
	},

	/**
	 * Call event change handler, if set
	 */
	event_change: function(event, dom_node) {
		if (this.onevent_change)
		{
			var event_data = this._get_event_info(dom_node);
			var event_widget = this.getWidgetById('event_'+event_data.id);
			et2_calendar_event.recur_prompt(event_data, jQuery.proxy(function(button_id, event_data) {
				// No need to continue
				if(button_id === 'cancel') return false;

				if(typeof this.onevent_change == 'function')
				{
					// Make sure function gets a reference to the widget
					var args = Array.prototype.slice.call(arguments);

					if(args.indexOf(event_widget) == -1) args.push(event_widget);

					// Put button ID in event
					event.button_id = button_id;

					return this.onevent_change.apply(this, [event, event_widget, button_id]);
				} else {
					return (et2_compileLegacyJS(this.options.onevent_change, event_widget, dom_node))();
				}
			},this));
		}
		return false;
	},

	/**
	 * Click handler calling custom handler set via onclick attribute to this.onclick
	 *
	 * This also handles all its own actions, including navigation.  If there is
	 * an event associated with the click, it will be found and passed to the
	 * onclick function.
	 *
	 * @param {Event} _ev
	 * @returns {boolean}
	 */
	click: function(_ev)
	{
		var result = true;
		
		// Is this click in the event stuff, or in the header?
		if(this.gridHeader.has(_ev.target).length === 0 && !$j(_ev.target).hasClass('calendar_plannerRowHeader'))
		{
			// Event came from inside, maybe a calendar event
			var event = this._get_event_info(_ev.originalEvent.target);
			if(typeof this.onclick == 'function')
			{
				// Make sure function gets a reference to the widget, splice it in as 2. argument if not
				var args = Array.prototype.slice.call(arguments);
				if(args.indexOf(this) == -1) args.splice(1, 0, this);

				result = this.onclick.apply(this, args);
			}

			if(event.id && result && !this.options.disabled && !this.options.readonly)
			{
				et2_calendar_event.recur_prompt(event);

				return false;
			}
			else if (!event.id)
			{
				// Clicked in row, but not on an event
				// Default handler to open a new event at the selected time
				if(this.options.group_by == 'month')
				{
					var date = this._get_time_from_position(_ev.clientX, _ev.clientY);
				}
				else
				{
					var date = this._get_time_from_position(_ev.offsetX, _ev.offsetY);
				}
				var row = $j(_ev.target).closest('.calendar_plannerRowWidget');
				var data = row.length ? row[0].dataset : {};
				this.egw().open(null, 'calendar', 'add', jQuery.extend({
					start: date.toJSON(),
					hour: date.getUTCHours(),
					minute: date.getUTCMinutes()
				},data) , '_blank');
				return false;
			}
			return result;
		}
		else if (!jQuery.isEmptyObject(_ev.target.dataset))
		{
			// Click on a header, we can go there
			_ev.data = jQuery.extend({},_ev.target.parentNode.dataset, _ev.target.dataset);
			for(var key in _ev.data)
			{
				if(!_ev.data[key])
				{
					delete _ev.data[key];
				}
			}

			// Handle it locally
			var old_start = this.options.start_date;
			if(_ev.data.date)
			{
				this.set_start_date(_ev.data.date);
			}
			if(_ev.data.planner_days)
			{
				_ev.data.planner_days = parseInt(_ev.data.planner_days);
				if(_ev.data.planner_days)
				{
					var d = new Date(this.options.start_date);
					d.setUTCDate(d.getUTCDate() +_ev.data.planner_days-1);
					this.set_end_date(d);
				}
			}
			else if (old_start !== this.options.start_date)
			{
				var diff = Math.round((new Date(this.options.start_date) - new Date(old_start)) / (1000 * 3600 * 24));
				var end = new Date(this.options.end_date);
				end.setUTCDate(end.getUTCDate() + diff)
				this.set_end_date(end);
			}

			// Notify anyone who's interested
			this.change(_ev);
		}
		else
		{
			// Default handler to open a new event at the selected time
			// TODO: Determine date / time more accurately from position
			this.egw().open(null, 'calendar', 'add', {
				date: _ev.target.dataset.date || this.options.start_date.toJSON(),
				hour: _ev.target.dataset.hour || this.options.day_start,
				minute: _ev.target.dataset.minute || 0
			} , '_blank');
			return false;
		}
	},

	_get_event_info: function(dom_node)
	{
		// Determine as much relevant info as can be found
		var event_node = $j(dom_node).closest('[data-id]',this.div)[0];
		var day_node = $j(event_node).closest('[data-date]',this.div)[0];
		
		return jQuery.extend({
				event_node: event_node,
				day_node: day_node,
			},
			event_node ? event_node.dataset : {},
			day_node ? day_node.dataset : {}
		);
	},

	
	/**
	 * Get time from position
	 * 
	 * @param {number} x
	 * @param {number} y
	 * @returns {DOMNode[]} time node(s) for the given position
	 */
	_get_time_from_position: function(x,y) {
		
		x = Math.round(x);
		y = Math.round(y);

		var rel_x = Math.min(x / $j('.calendar_eventRows',this.div).width(),1);
		var rel_time = 0;

		// Simple math, the x is offset from start date
		if(this.options.group_by !== 'month')
		{
			rel_time = (new Date(this.options.end_date) - new Date(this.options.start_date))*rel_x/1000;
			this.date_helper.set_value(this.options.start_date.toJSON());
		}
		else
		{
			// Find the correct row so we know which month, then get the offset
			var row = $j(document.elementFromPoint(x, y)).closest('.calendar_plannerRowWidget');
			var row_widget = null;
			for(var i = 0; i < this._children.length && row.length > 0; i++)
			{
				if(this._children[i].div[0] == row[0])
				{
					row_widget = this._children[i];
					break;
				}
			}
			if(row_widget)
			{
				rel_x = Math.min((x-row_widget.rows.offset().left)/row_widget.rows.width(),1);
				rel_time = (new Date(row_widget.options.end_date) - new Date(row_widget.options.start_date))*rel_x/1000;
				this.date_helper.set_value(row_widget.options.start_date.toJSON());
			}
			else
			{
				return false;
			}
		}
		if(rel_time < 0) return false;
		
		var interval = egw.preference('interval','calendar') || 30;
		this.date_helper.set_minutes(Math.round(rel_time / (60 * interval))*interval);

		return new Date(this.date_helper.getValue());
	},
		
	/**
	 * Code for implementing et2_IDetachedDOM
	 *
	 * @param {array} _attrs array to add further attributes to
	 */
	getDetachedAttributes: function(_attrs) {
		_attrs.push('start_date','end_date');
	},

	getDetachedNodes: function() {
		return [this.getDOMNode()];
	},

	setDetachedAttributes: function(_nodes, _values) {
		this.div = $j(_nodes[0]);

		if(_values.start_date)
		{
			this.set_start_date(_values.start_date);
		}
		if(_values.end_date)
		{
			this.set_end_date(_values.end_date);
		}
	},

	// Resizable interface
	resize: function (_height)
	{
		this.options.height = _height;
		this.div.css('height', this.options.height);
	}
});
et2_register_widget(et2_calendar_planner, ["calendar-planner"]);