/*
 * Copyright (c) 2006 Sam Collett (http://www.texotela.co.uk)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 */
 
/*
 * A time picker for jQuery
 * Based on original timePicker by Sam Collet (http://www.texotela.co.uk)
 * @name     timePicker
 * @version  0.1 
 * @author   Anders Fajerson (http://perifer.se)
 * @example  $("#mytime").timePicker();
 * @example  $("#mytime").timePicker({step:30, startTime:"15:00", endTime:"18:00"}); 
 */

(function($){
	
	$.fn.timePicker = function(options) {
		// Build main options before element iteration
		var settings = $.extend({}, $.fn.timePicker.defaults, options);  
		
		return this.each(function() {
			$.timePicker(this, settings);
		});
	};
	
	$.timePicker = function (elm, settings) {
		var elm = $(elm)[0];  
		return elm.timePicker || (elm.timePicker = new jQuery._timePicker(elm, settings));
	};
	
	$._timePicker = function(elm, settings) {
		
		var tpOver = false;
		var startTime = normaliseTime(settings.startTime);
		var endTime = normaliseTime(settings.endTime);
		
		$(elm).attr('autocomplete', 'OFF'); // Disable browser autocomplete
		
		var times = [];
		var time = new Date(startTime); // Create a new date object.
		while(time <= endTime) {
			times[times.length] = formatTime(time, settings);
			time = new Date(time.setMinutes(time.getMinutes() + settings.step));
		}

		var $tpDiv = $('<div class="time-picker'+ (settings.show24Hours ? '' : ' time-picker-12hours') +'"></div>');
		var $tpList = $('<ul></ul>');
		
		// Build the list.
		for(var i = 0; i < times.length; i++) {
			$tpList.append("<li>" + times[i] + "</li>");
		}
		$tpDiv.append($tpList);
		// Store element offset.
		var elmOffset = $(elm).offset();
		// Append the timPicker to the body and position it.
		$tpDiv.appendTo('body').css({'top':elmOffset.top, 'left':elmOffset.left}).hide();
		
		$("li", $tpList).unbind().mouseover(function() {
			$("li.selected", $tpDiv).removeClass("selected");  // TODO: only needs to run once.
			$(this).addClass("selected");
		}).mousedown(function() {
			 tpOver = true;
		}).click(function() {
			setTimeVal(elm, this, $tpDiv, settings);
			tpOver = false;
		});
		
		// Store ananymous function in variable since it's used twice.
		var showPicker = function() {
			$tpDiv.show(); // Show picker.
			$tpDiv.mouseover(function() { // Have to use mouseover instead of mousedown because of Opera
				tpOver = true;
			}).mouseout(function() {
				tpOver = false;
			});
			$("li", $tpDiv).removeClass("selected");
			
			// Try to find a time in the list that matches the entered time.
			var time = this.value ? timeStringToDate(this.value, settings) : startTime;
			var startMin = startTime.getHours() * 60 + startTime.getMinutes();
			var min = (time.getHours() * 60 + time.getMinutes()) - startMin;
			var steps = Math.round(min / settings.step);
			var roundTime = normaliseTime(new Date(2001, 0, 0, 0, (steps * settings.step + (startMin)), 0));
			roundTime = (startTime < roundTime && roundTime < endTime) ? roundTime : startTime;
			
			var $matchedTime = $("li:contains(" + formatTime(roundTime, settings) + ")", $tpDiv);
			
			if ($matchedTime.length) {
				$matchedTime.addClass("selected");
				// Scroll to matched time.
				$tpDiv[0].scrollTop = $matchedTime[0].offsetTop;
			}
		};
		
		$(elm).unbind().focus(showPicker).click(showPicker)
		// Hide timepicker on blur
		.blur(function() {
			if (!tpOver && $tpDiv[0].parentNode) { // Don't remove when timePicker is clicked or when already removed
				$tpDiv.hide();
			}
		})
		
		// Key support
		.keypress(function(e) {
			switch (e.keyCode) {
				case 38: // Up arrow.
				case 63232: // Safari up arrow.
					var $selected = $("li.selected", $tpList);
					var prev = $selected.prev().addClass("selected")[0];
					if (prev) {
						$selected.removeClass("selected");
						$tpDiv[0].scrollTop = prev.offsetTop;
					}
					return false;
					break;
				case 40: // Down arrow.
				case 63233: // Safari down arrow.
					var $selected = $("li.selected", $tpList);
					var next = $selected.length ? $selected.next().addClass("selected")[0] : $("li:first").addClass("selected")[0];
					if (next) {
						$selected.removeClass("selected");
						$tpDiv[0].scrollTop = next.offsetTop;
					}
					return false;
					break;
				case 13: // Enter
					if (!$tpDiv.is(":hidden")) {
						var sel = $("li.selected", $tpList)[0];
						setTimeVal(elm, sel, $tpDiv, settings);
						return false;
					}
					break;
			}
		});
		
		// Helper function to get an inputs current time as Date object.
		// Returns a Date object.
		this.getTime = function() {
			return timeStringToDate(elm.value, settings);
		};
		// Helper function to set a time input.
		// Takes a Date object.
		this.setTime = function(time) {
			elm.value = formatTime(normaliseTime(time), settings);
			// Trigger element's change events.
			$(elm).change();
		};
		
	}; // End fn;   
	
	// Plugin defaults.
	$.fn.timePicker.defaults = {
		step:60,
		startTime: new Date(0, 0, 0, 0, 0, 0),
		endTime: new Date(0, 0, 0, 23, 30, 0),
		separator: ':',
		show24Hours: false
	};
	
	// Private functions.
	
	function setTimeVal(elm, sel, $tpDiv, settings) {
		// Update input field
		elm.value = $(sel).text();
		// Trigger element's change events.
		$(elm).change();
		// Keep focus for all but IE (which doesn't like it)
		if (!$.browser.msie) {
			elm.focus();
		}
		// Hide picker
		$tpDiv.hide();
	}
	
	function formatTime(time, settings) {
		var h = time.getHours();
		var hours = settings.show24Hours ? h : (((h + 11) % 12) + 1);
		var minutes = time.getMinutes();
		return formatNumber(hours) + settings.separator + formatNumber(minutes) + (settings.show24Hours ? '' : ((h < 12) ? ' AM' : ' PM'));
	}
	
	function formatNumber(value) {
		return (value < 10 ? '0' : '') + value;
	}
	
	function timeStringToDate(input, settings) {
		if (input) {
			var array = input.split(settings.separator);
			var hours = parseFloat(array[0]);
			var minutes = parseFloat(array[1]);
			var time = new Date(0, 0, 0, hours, minutes, 0);
			return normaliseTime(time);
		}
		return null;
	}
	
	/* Normalise time object to a common date. */
	function normaliseTime(time) {
		time.setFullYear(2001);
		time.setMonth(0);
		time.setDate(0);
		return time;
	}
	
})(jQuery);