define([
	"dojo/_base/array", // array.forEach array.map
	"dojo/_base/declare", // declare
	"dojo/cldr/supplemental", // cldrSupplemental.getFirstDayOfWeek
	"dojo/date", // date
	"dojo/date/locale",
	"dojo/date/stamp", // stamp.fromISOString
	"dojo/dom", // dom.setSelectable
	"dojo/dom-class", // domClass.contains
	"dojo/_base/lang", // lang.getObject, lang.hitch
	"dojo/on",
	"dojo/sniff", // has("ie") has("webkit")
	"dojo/string", // string.substitute
	"./_WidgetBase",
	"./_TemplatedMixin",
	"dojo/text!./templates/Calendar.html",
	"./a11yclick",	// not used directly, but template has ondijitclick in it
	"./hccss"    // not used directly, but sets CSS class on <body>
], function(array, declare, cldrSupplemental, date, locale, stamp, dom, domClass, lang, on, has, string, _WidgetBase, _TemplatedMixin, template){


	// module:
	//		dijit/CalendarLite

	var CalendarLite = declare("dijit.CalendarLite", [_WidgetBase, _TemplatedMixin], {
		// summary:
		//		Lightweight version of Calendar widget aimed towards mobile use
		//
		// description:
		//		A simple GUI for choosing a date in the context of a monthly calendar.
		//		This widget can't be used in a form because it doesn't serialize the date to an
		//		`<input>` field.  For a form element, use dijit/form/DateTextBox instead.
		//
		//		Note that the parser takes all dates attributes passed in the
		//		[RFC 3339 format](http://www.faqs.org/rfcs/rfc3339.html), e.g. `2005-06-30T08:05:00-07:00`
		//		so that they are serializable and locale-independent.
		//
		//		Also note that this widget isn't keyboard accessible; use dijit.Calendar for that
		// example:
		//	|	var calendar = new dijit.CalendarLite({}, dojo.byId("calendarNode"));
		//
		// example:
		//	|	<div data-dojo-type="dijit/CalendarLite"></div>

		// Template for main calendar
		templateString: template,

		// Template for cell for a day of the week (ex: M)
		dowTemplateString: '<th class="dijitReset dijitCalendarDayLabelTemplate" role="columnheader" scope="col"><span class="dijitCalendarDayLabel">${d}</span></th>',

		// Templates for a single date (ex: 13), and for a row for a week (ex: 20 21 22 23 24 25 26)
		dateTemplateString: '<td class="dijitReset" role="gridcell" data-dojo-attach-point="dateCells"><span class="dijitCalendarDateLabel" data-dojo-attach-point="dateLabels"></span></td>',
		weekTemplateString: '<tr class="dijitReset dijitCalendarWeekTemplate" role="row">${d}${d}${d}${d}${d}${d}${d}</tr>',

		// value: Date
		//		The currently selected Date, initially set to invalid date to indicate no selection.
		value: new Date(""),
		// TODO: for 2.0 make this a string (ISO format) rather than a Date

		// datePackage: String
		//		JavaScript namespace to find calendar routines.	 If unspecified, uses Gregorian calendar routines
		//		at dojo/date and dojo/date/locale.
		datePackage: "",
		//		TODO: for 2.0, replace datePackage with dateModule and dateLocalModule attributes specifying MIDs,
		//		or alternately just get rid of this completely and tell user to use module ID remapping
		//		via require

		// dayWidth: String
		//		How to represent the days of the week in the calendar header. See locale
		dayWidth: "narrow",

		// tabIndex: String
		//		Order fields are traversed when user hits the tab key
		tabIndex: "0",

		// currentFocus: Date
		//		Date object containing the currently focused date, or the date which would be focused
		//		if the calendar itself was focused.   Also indicates which year and month to display,
		//		i.e. the current "page" the calendar is on.
		currentFocus: new Date(),

		// Put the summary to the node with role=grid
		_setSummaryAttr: "gridNode",

		baseClass: "dijitCalendar dijitCalendarLite",

		_isValidDate: function(/*Date*/ value){
			// summary:
			//		Runs various tests on the value, checking that it's a valid date, rather
			//		than blank or NaN.
			// tags:
			//		private
			return value && !isNaN(value) && typeof value == "object" &&
				value.toString() != this.constructor.prototype.value.toString();
		},

		_getValueAttr: function(){
			// summary:
			//		Support get('value')

			// this.value is set to 1AM, but return midnight, local time for back-compat
			var storedVal = this._get("value");
			if(storedVal && !isNaN(storedVal)){
				var value = new this.dateClassObj(storedVal);
				value.setHours(0, 0, 0, 0);

				// If daylight savings pushes midnight to the previous date, fix the Date
				// object to point at 1am so it will represent the correct day. See #9366
				if(value.getDate() < storedVal.getDate()){
					value = this.dateModule.add(value, "hour", 1);
				}
				return value;
			}else{
				return null;
			}
		},

		_setValueAttr: function(/*Date|Number*/ value, /*Boolean*/ priorityChange){
			// summary:
			//		Support set("value", ...)
			// description:
			//		Set the current date and update the UI.  If the date is disabled, the value will
			//		not change, but the display will change to the corresponding month.
			// value:
			//		Either a Date or the number of seconds since 1970.
			// tags:
			//		protected
			if(typeof value == "string"){
				value = stamp.fromISOString(value);
			}
			value = this._patchDate(value);

			if(this._isValidDate(value) && !this.isDisabledDate(value, this.lang)){
				this._set("value", value);

				// Set focus cell to the new value.   Arguably this should only happen when there isn't a current
				// focus point.   This will also repopulate the grid to new month/year if necessary.
				this.set("currentFocus", value);

				// Mark the selected date
				this._markSelectedDates([value]);

				if(this._created && (priorityChange || typeof priorityChange == "undefined")){
					this.onChange(this.get('value'));
				}
			}else{
				// clear value, and mark all dates as unselected
				this._set("value", null);
				this._markSelectedDates([]);
			}
		},

		_patchDate: function(/*Date|Number*/ value){
			// summary:
			//		Convert Number into Date, or copy Date object.   Then, round to nearest day,
			//		setting to 1am to avoid issues when DST shift occurs at midnight, see #8521, #9366)
			if(value){
				value = new this.dateClassObj(value);
				value.setHours(1, 0, 0, 0);
			}
			return value;
		},

		_setText: function(node, text){
			// summary:
			//		This just sets the content of node to the specified text.
			//		Can't do "node.innerHTML=text" because of an IE bug w/tables, see #3434.
			// tags:
			//		private
			while(node.firstChild){
				node.removeChild(node.firstChild);
			}
			node.appendChild(node.ownerDocument.createTextNode(text));
		},

		_populateGrid: function(){
			// summary:
			//		Fills in the calendar grid with each day (1-31).
			//		Call this on creation, when moving to a new month.
			// tags:
			//		private

			var month = new this.dateClassObj(this.currentFocus);
			month.setDate(1);
			month = this._patchDate(month);	// needed if currentFocus is start or end of DST, see #17033

			var firstDay = month.getDay(),
				daysInMonth = this.dateModule.getDaysInMonth(month),
				daysInPreviousMonth = this.dateModule.getDaysInMonth(this.dateModule.add(month, "month", -1)),
				today = new this.dateClassObj(),
				dayOffset = cldrSupplemental.getFirstDayOfWeek(this.lang);
			if(dayOffset > firstDay){
				dayOffset -= 7;
			}

			// If they didn't provide a summary, change the default summary to match with the new month
			if(!this.summary){
				var monthNames = this.dateLocaleModule.getNames('months', 'wide', 'standAlone', this.lang, month)
				this.gridNode.setAttribute("summary", monthNames[month.getMonth()]);
			}

			// Mapping from date (as specified by number returned from Date.valueOf()) to corresponding <td>
			this._date2cell = {};

			// Iterate through dates in the calendar and fill in date numbers and style info
			array.forEach(this.dateCells, function(template, idx){
				var i = idx + dayOffset;
				var date = new this.dateClassObj(month),
					number, clazz = "dijitCalendar", adj = 0;

				if(i < firstDay){
					number = daysInPreviousMonth - firstDay + i + 1;
					adj = -1;
					clazz += "Previous";
				}else if(i >= (firstDay + daysInMonth)){
					number = i - firstDay - daysInMonth + 1;
					adj = 1;
					clazz += "Next";
				}else{
					number = i - firstDay + 1;
					clazz += "Current";
				}

				if(adj){
					date = this.dateModule.add(date, "month", adj);
				}
				date.setDate(number);

				if(!this.dateModule.compare(date, today, "date")){
					clazz = "dijitCalendarCurrentDate " + clazz;
				}

				if(this.isDisabledDate(date, this.lang)){
					clazz = "dijitCalendarDisabledDate " + clazz;
					template.setAttribute("aria-disabled", "true");
				}else{
					clazz = "dijitCalendarEnabledDate " + clazz;
					template.removeAttribute("aria-disabled");
					template.setAttribute("aria-selected", "false");
				}

				var clazz2 = this.getClassForDate(date, this.lang);
				if(clazz2){
					clazz = clazz2 + " " + clazz;
				}

				template.className = clazz + "Month dijitCalendarDateTemplate";

				// Each cell has an associated integer value representing it's date
				var dateVal = date.valueOf();
				this._date2cell[dateVal] = template;
				template.dijitDateValue = dateVal;

				// Set Date string (ex: "13").
				this._setText(this.dateLabels[idx], date.getDateLocalized ? date.getDateLocalized(this.lang) : date.getDate());
			}, this);
		},

		_populateControls: function(){
			// summary:
			//		Fill in localized month, and prev/current/next years
			// tags:
			//		protected

			var month = new this.dateClassObj(this.currentFocus);
			month.setDate(1);

			// set name of this month
			this.monthWidget.set("month", month);

			var y = month.getFullYear() - 1;
			var d = new this.dateClassObj();
			array.forEach(["previous", "current", "next"], function(name){
				d.setFullYear(y++);
				this._setText(this[name + "YearLabelNode"],
					this.dateLocaleModule.format(d, {selector: 'year', locale: this.lang}));
			}, this);
		},

		goToToday: function(){
			// summary:
			//		Sets calendar's value to today's date
			this.set('value', new this.dateClassObj());
		},

		constructor: function(params /*===== , srcNodeRef =====*/){
			// summary:
			//		Create the widget.
			// params: Object|null
			//		Hash of initialization parameters for widget, including scalar values (like title, duration etc.)
			//		and functions, typically callbacks like onClick.
			//		The hash can contain any of the widget's properties, excluding read-only properties.
			// srcNodeRef: DOMNode|String?
			//		If a srcNodeRef (DOM node) is specified, replace srcNodeRef with my generated DOM tree

			this.dateModule = params.datePackage ? lang.getObject(params.datePackage, false) : date;
			this.dateClassObj = this.dateModule.Date || Date;
			this.dateLocaleModule = params.datePackage ? lang.getObject(params.datePackage + ".locale", false) : locale;
		},

		_createMonthWidget: function(){
			// summary:
			//		Creates the drop down button that displays the current month and lets user pick a new one

			return CalendarLite._MonthWidget({
				id: this.id + "_mddb",
				lang: this.lang,
				dateLocaleModule: this.dateLocaleModule
			}, this.monthNode);
		},

		buildRendering: function(){
			// Markup for days of the week (referenced from template)
			var d = this.dowTemplateString,
				dayNames = this.dateLocaleModule.getNames('days', this.dayWidth, 'standAlone', this.lang),
				dayOffset = cldrSupplemental.getFirstDayOfWeek(this.lang);
			this.dayCellsHtml = string.substitute([d, d, d, d, d, d, d].join(""), {d: ""}, function(){
				return dayNames[dayOffset++ % 7];
			});

			// Markup for dates of the month (referenced from template), but without numbers filled in
			var r = string.substitute(this.weekTemplateString, {d: this.dateTemplateString});
			this.dateRowsHtml = [r, r, r, r, r, r].join("");

			// Instantiate from template.
			// dateCells and dateLabels arrays filled when _Templated parses my template.
			this.dateCells = [];
			this.dateLabels = [];
			this.inherited(arguments);

			dom.setSelectable(this.domNode, false);

			var dateObj = new this.dateClassObj(this.currentFocus);

			this.monthWidget = this._createMonthWidget();

			this.set('currentFocus', dateObj, false);	// draw the grid to the month specified by currentFocus
		},

		postCreate: function(){
			this.inherited(arguments);
			this._connectControls();
		},

		_connectControls: function(){
			// summary:
			//		Set up connects for increment/decrement of months/years
			// tags:
			//		protected

			var connect = lang.hitch(this, function(nodeProp, part, amount){
				this[nodeProp].dojoClick = true;
				return on(this[nodeProp], "click", lang.hitch(this, function(){
					this._setCurrentFocusAttr(this.dateModule.add(this.currentFocus, part, amount));
				}));
			});

			this.own(
				connect("incrementMonth", "month", 1),
				connect("decrementMonth", "month", -1),
				connect("nextYearLabelNode", "year", 1),
				connect("previousYearLabelNode", "year", -1)
			);
		},

		_setCurrentFocusAttr: function(/*Date*/ date, /*Boolean*/ forceFocus){
			// summary:
			//		If the calendar currently has focus, then focuses specified date,
			//		changing the currently displayed month/year if necessary.
			//		If the calendar doesn't have focus, updates currently
			//		displayed month/year, and sets the cell that will get focus
			//		when Calendar is focused.
			// forceFocus:
			//		If true, will focus() the cell even if calendar itself doesn't have focus

			var oldFocus = this.currentFocus,
				oldCell = this._getNodeByDate(oldFocus);
			date = this._patchDate(date);

			this._set("currentFocus", date);

			// If the focus is on a different month than the current calendar month, switch the displayed month.
			// Also will populate the grid initially, on Calendar creation.
			if(!this._date2cell || this.dateModule.difference(oldFocus, date, "month") != 0){
				this._populateGrid();
				this._populateControls();
				this._markSelectedDates([this.value]);
			}

			// set tabIndex=0 on new cell, and focus it (but only if Calendar itself is focused)
			var newCell = this._getNodeByDate(date);
			newCell.setAttribute("tabIndex", this.tabIndex);
			if(this.focused || forceFocus){
				newCell.focus();
			}

			// set tabIndex=-1 on old focusable cell
			if(oldCell && oldCell != newCell){
				if(has("webkit")){    // see #11064 about webkit bug
					oldCell.setAttribute("tabIndex", "-1");
				}else{
					oldCell.removeAttribute("tabIndex");
				}
			}
		},

		focus: function(){
			// summary:
			//		Focus the calendar by focusing one of the calendar cells
			this._setCurrentFocusAttr(this.currentFocus, true);
		},

		_onDayClick: function(/*Event*/ evt){
			// summary:
			//		Handler for day clicks, selects the date if appropriate
			// tags:
			//		protected
			evt.stopPropagation();
			evt.preventDefault();
			for(var node = evt.target; node && !node.dijitDateValue; node = node.parentNode){
				;
			}
			if(node && !domClass.contains(node, "dijitCalendarDisabledDate")){
				this.set('value', node.dijitDateValue);
			}
		},

		_getNodeByDate: function(/*Date*/ value){
			// summary:
			//		Returns the cell corresponding to the date, or null if the date is not within the currently
			//		displayed month.
			value = this._patchDate(value);
			return value && this._date2cell ? this._date2cell[value.valueOf()] : null;
		},

		_markSelectedDates: function(/*Date[]*/ dates){
			// summary:
			//		Marks the specified cells as selected, and clears cells previously marked as selected.
			//		For CalendarLite at most one cell is selected at any point, but this allows an array
			//		for easy subclassing.

			// Function to mark a cell as selected or unselected
			function mark(/*Boolean*/ selected, /*DomNode*/ cell){
				domClass.toggle(cell, "dijitCalendarSelectedDate", selected);
				cell.setAttribute("aria-selected", selected ? "true" : "false");
			}

			// Clear previously selected cells.
			array.forEach(this._selectedCells || [], lang.partial(mark, false));

			// Mark newly selected cells.  Ignore dates outside the currently displayed month.
			this._selectedCells = array.filter(array.map(dates, this._getNodeByDate, this), function(n){
				return n;
			});
			array.forEach(this._selectedCells, lang.partial(mark, true));
		},

		onChange: function(/*Date*/ /*===== date =====*/){
			// summary:
			//		Called only when the selected date has changed
		},

		isDisabledDate: function(/*===== dateObject, locale =====*/){
			// summary:
			//		May be overridden to disable certain dates in the calendar e.g. `isDisabledDate=dojo.date.locale.isWeekend`
			// dateObject: Date
			// locale: String?
			// tags:
			//		extension
			/*=====
			 return false; // Boolean
			 =====*/
		},

		getClassForDate: function(/*===== dateObject, locale =====*/){
			// summary:
			//		May be overridden to return CSS classes to associate with the date entry for the given dateObject,
			//		for example to indicate a holiday in specified locale.
			// dateObject: Date
			// locale: String?
			// tags:
			//		extension

			/*=====
			 return ""; // String
			 =====*/
		}
	});

	CalendarLite._MonthWidget = declare("dijit.CalendarLite._MonthWidget", _WidgetBase, {
		// summary:
		//		Displays name of current month padded to the width of the month
		//		w/the longest name, so that changing months doesn't change width.
		//
		//		Create as:
		// |	new Calendar._MonthWidget({
		// |			lang: ...,
		// |			dateLocaleModule: ...
		// |		})

		_setMonthAttr: function(month){
			// summary:
			//		Set the current month to display as a label
			var monthNames = this.dateLocaleModule.getNames('months', 'wide', 'standAlone', this.lang, month),
				spacer =
					(has("ie") == 6 ? "" : "<div class='dijitSpacer'>" +
						array.map(monthNames,function(s){
							return "<div>" + s + "</div>";
						}).join("") + "</div>");

			// Set name of current month and also fill in spacer element with all the month names
			// (invisible) so that the maximum width will affect layout.   But not on IE6 because then
			// the center <TH> overlaps the right <TH> (due to a browser bug).
			this.domNode.innerHTML =
				spacer +
					"<div class='dijitCalendarMonthLabel dijitCalendarCurrentMonthLabel'>" +
					monthNames[month.getMonth()] + "</div>";
		}
	});

	return CalendarLite;
});
