(function($, core, undefined) {

var c_popup = 'nethelp-popup',
	c_popupHtml = c_popup + '-html',
	qname = 'popup-tasks';

var Popup = core.widget('popup', {
	options: {
		autoShow: true,
		popupClass: 'ui-corner-all ui-state-highlight',
		popupCss: {
			zIndex: 500
		},
		popupHtmlCss: {
			padding: 5
		},
		html: '',
		position: {}
	},
	//popup: undefined,     // will be defined in instance
	//popupHtml: undefined, // will be defined in instance
	_create: function() {
		var self = this,
			element = self.element,
			options = self.options,
			css = options.popupCss,
			body = element.closest('body'),
			t = element.closest('.' + c_popup),
			popup, popupHtml;
		if (t[0]) {
			css.zIndex = Math.max(css.zIndex, (parseInt(t.css('zIndex'), 10) || 0) + 1);
		}
		self.popup = popup = $('<div/>').hide()
			.appendTo(body)
			.addClass(c_popup)
			.addClass(options.popupClass)
			.css(css || {})
			.css('overflow', 'auto')
			.data('popup', self);
		self.popupHtml = popupHtml = $('<div/>')
			.appendTo(popup)
			.addClass(c_popupHtml)
			.css(options.popupHtmlCss || {});
		if (options.html) {
			popupHtml.html(options.html);
		}
		self.hide(); // reset state
		if (options.autoShow) {
			self.show(options.event);
			options.event = undefined;
		}
	},
	destroy: function() {
		this.popup.hide().remove();
	},
	isVisible: function() {
		return this.popup.css('display') !== 'none';
	},
	state: function() {
		return this._state;
	},
	show: function(event, reposition) {
		if (event != undefined && !event.type) {
			reposition = event;
			event = undefined;
		}
		var self = this;
		if (!reposition && self.isVisible()) {
			return;
		}
		self._state = 'showing';
		Popup.position(self.element, self.popup, $.extend({}, self.options.position, {
			visible: true,
			event: event,
			callback: function() {
				self._onshown.resolve();
				self._state = true;
			}
		}));
		return self;
	},
	hide: function() {
		var self = this;
		self.popup.hide();
		self._state = false;
		self._onshown = $.Deferred();
		return self;
	},
	toggle: function(event) {
		return this[this.isVisible() ? 'hide' : 'show'](event);
	},
	html: function(html) {
		var el = self.popupHtml;
		if (!arguments.length) {
			return el.html();
		}
		el.html(html);
		return self;
	},
	onShow: function(fn) {
		if (!this._onshown) {
			this._onshown = $.Deferred();
		}
		this._onshown.done(fn);
	}
});

$.extend(Popup, {
	positionOptions: {
		minHeight: 0,
		minWidth: 300,
		maxHeight: 400,
		maxWidth: 600
	},
	position: function(elem, popup, options) {
		/* required:
			elem = $(elem);
			popup = $(popup);
		*/
		options = $.extend(true, {}, Popup.positionOptions, options);
		var t = elem[0].ownerDocument,
			win = $(t.defaultView || t.parentWindow),
			winH = win.height(), winW = win.width(),
			event = options.event,
			callback = options.callback,
			area = {},
			pos = {},
			visible = 'visible' in options ? options.visible :
				popup.css('display') !== 'none',
			res;
		if (!$.isFunction(callback)) {
			callback = undefined;
		}
		function addTasks() {
			$.each($.makeArray(arguments), function(i, task) {
				elem.delay(10, qname).queue(qname, function(n) {
					if (res !== false) {
						res = task();
					}
					n();
				});
			});
		}
		function checkPos() {
			if (pos.top >= 0 && pos.left >= 0 && 
					pos.top + pos.height <= winH && pos.left + pos.width <= winW) {
				popup.hide().css({
					top: pos.top,
					left: pos.left,
					visibility: 'visible',
					display: visible ? 'block' : 'none'
				});
				if (callback) {
					callback();
				}
				return true;
			}
			popup.hide();
			return false;
		}

		if (event && 'pageX' in event) {
			area.left = area.right = event.pageX;
			t = parseInt(elem.css('fontSize'));
			area.top = event.pageY - t;
			area.bottom = event.pageY + t;
		}
		else {
			t = elem.offset();
			area.left = t.left;
			area.top = t.top;
			area.right = t.left + elem.outerWidth();
			area.bottom = t.top + elem.outerHeight();
		}

		//#region tasks
		addTasks(function() {
			var w = Math.min(Math.max(winW - area.left - 5, options.minWidth), options.maxWidth, winW - 5),
				h = Math.min(winH - 5, options.maxHeight);
			popup.hide().css({
				visibility: 'hidden',
				position: 'absolute',
				top: -100,
				left: -100,
				margin: 0,
				padding: 0,
				width: 'auto',
				height: 'auto',
				maxWidth: w,
				maxHeight: h
			}).show();
		}, function() {
			pos.top = area.bottom;
			pos.left = area.left;
			pos.height = popup.height();
			pos.width = popup.width();
			if (checkPos()) {
				return false;
			}
			pos.top = area.top - pos.height;
			if (checkPos()) {
				return false;
			}
		}, function() {
			var max = Math.min(winW, options.maxWidth), c = 0;
			popup.css({
				maxWidth: max
			});
			function itsMax() {
				var ontop = area.top > (winH - area.bottom);
				popup.css({
					width: pos.width,
					height: ontop ? area.top : winH - area.bottom - 5
				});
				addTasks(function() {
					popup.css({
						top: ontop ? 0 : area.bottom,
						left: Math.min(area.left, winW - pos.width - 5),
						visibility: 'visible',
						display: visible ? 'block' : 'none'
					});
					if (callback) {
						callback();
					}
				});
			}
			function step() {
				if (++c > 10000) {
					core.error('Popup.position: infinite recursion');
					return;
				}
				var w = pos.width + 10;
				if (w > max) {
					itsMax();
					return;
				}
				popup.hide().css({
					visibility: 'hidden',
					width: w
				}).show();
				addTasks(function() {
					pos.height = popup.height() + 5;
					pos.width = popup.width();
					pos.top = area.bottom;
					pos.left = winW - pos.width - 5;
					if (checkPos()) {
						return false;
					}
					pos.top = area.top - pos.height;
					pos.height -= 5;
					if (checkPos()) {
						return false;
					}
					step();
				});
			};
			step();
		});
		elem.dequeue(qname);
		//#endregion
	},
	globalEvent: function(e) {
		var target = e.target;
		$('.' + c_popup + ':visible', this).each(function(i, popup) {
			if (target != popup && !$.contains(popup, target)) {
				var w = $(popup).data('popup'), wel = w.element[0];
				if (target != wel && !$.contains(wel, target)) {
					w.hide();
				}
			}
		});
	}
});

$(function() {
	$('body').bind('mousedown keydown', function(e) {
		if (e.type === 'mousedown' || e.which === 13) {
			Popup.globalEvent.call(this, e);
		}
		else if (e.which === 27) {
			Popup.globalEvent.call(this, {});
		}
	});
});

})(jQuery, nethelp);