var steps = 4;
var wkendBorder = '1px dashed #CCCCCC';
var MonthNames = new Array(TXT_JANUARY,TXT_FEBRUARY,TXT_MARCH,TXT_APRIL,TXT_MAY,TXT_JUNE,TXT_JULY,TXT_AUGUST,TXT_SEPTEMBER,TXT_OCTOBER,TXT_NOVEMBER,TXT_DECEMBER);
var MonthAbbr = new Array(TXT_JAN,TXT_FEB,TXT_MAR,TXT_APR,TXT_MAY_SHORT,TXT_JUN,TXT_JUL,TXT_AUG,TXT_SEP,TXT_OCT,TXT_NOV,TXT_DEC);
var DayAbbr = new Array(TXT_SUN_SHORT,TXT_MON_SHORT,TXT_TUE_SHORT,TXT_WED_SHORT,TXT_THU_SHORT,TXT_FRI_SHORT,TXT_SAT_SHORT);
var SelectedBarDate = null;
var prevMonthON = 'i/cal/left1.gif';
var prevMonthOFF = 'i/cal/leftOff.gif';

var getElement = function(id){ return (document.all ? document.all[id] : document.getElementById(id)); }

var BarChart = $.Class.create({
	accessor:null,
	chartData:null,
	maxVal:0,
	labelID:null,
	targetID:null,
	prevMonthImgId:null,
	month:null,
	year:null,
	selectedDate:null,
	init: function(accessor, targetId, labelId, prevMonthImgId){
		this.accessor = accessor;
		this.chartData = new Array();
		this.maxVal = 0;
		this.labelID = labelId;
		this.targetID = targetId;
		this.prevMonthImgId = prevMonthImgId;
		this.month = null;
		this.year = null;
	},
	setMonthYear: function(m, y){
		if(this.month != m || this.year != y){
			this.month = m;
			this.year = y;
			this.selectedDate = null;
			this.chartData = new Array();
			var dt = new Date(this.year, this.month-1, 1);
			while(dt.getMonth() == (this.month-1)){
				this.chartData.push(null);
				dt.setDate(dt.getDate() + 1);
			}
		}
	},
	addItem: function(item){
		var itemDate = item.outbound.dateValue;
		if(itemDate && itemDate.getMonth() == this.month-1 && itemDate.getFullYear() == this.year){
			var index = itemDate.getDate() - 1;
			if(this.chartData && (this.chartData[index] == null ||
				item.value < this.chartData[index].value)){
				this.chartData[index] = item;
			}
		}
	},
	drawChart: function(){
		var container = getElement(this.targetID);
		if(!container)
			return;

		this.writeMonthLabel(this.month, this.year);
		this.setMaxVal();
		
		var html = '';
		html += '<div style="float:left;width:5%;">' + this.getYAxisHtml() + '</div>';
		html += '<div style="float:left;width:94%;">' + this.getChartHtml(this.month, this.year) + '</div>';
		container.innerHTML = html;
	},
	writeMonthLabel: function(m, y){
		var monthLabel = getElement(this.labelID);
		if(!monthLabel){ return; }
		
		var now = new Date();
		var nextImg = IMG_ROOT + 'i/cal/right1.gif';
		var prevImg = '';
		var prevCss = '';
		var prevClick = 'void(0)';
		if(m == (now.getMonth() + 1) && y == now.getFullYear()){
			prevImg = IMG_ROOT + prevMonthOFF;
			prevCss = '';
			prevClick = 'void(0)';
		}
		else{
			prevImg = IMG_ROOT + prevMonthON;
			prevCss = 'monthButton';
			prevClick = this.accessor + '.prevMonth()'
		}
		
		var prevMonth = '<img src="' + prevImg + '" onclick="' + prevClick + '" class="' + prevCss + '" align="absmiddle" />';
		var nextMonth = '<img src="' + nextImg + '" onclick="' + this.accessor + '.nextMonth()" class="monthButton" align="absmiddle" />';
		monthLabel.innerHTML = prevMonth + '&nbsp; ' + MonthNames[(m-1)] + ' ' + y + ' &nbsp;' + nextMonth;
	},
	setMaxVal: function(){
		this.maxVal = 0;
		for(var i = 0; i < this.chartData.length; i++){
			if(this.chartData[i] && this.chartData[i].value > this.maxVal)
				this.maxVal = this.chartData[i].value;
		}
		
		var power = parseInt((Math.log(this.maxVal))/(Math.log(10))) - 1;
		var factor = (power == 0 ? 5 : Math.pow(10, power));
		this.maxVal =  Math.ceil(this.maxVal/(steps*factor))*(steps*factor);
	},
	getYAxisHtml: function(){
		var yAxisHtml = '';
		if(isNaN(this.maxVal)){ return '&nbsp;'; }
		
		var interval = this.maxVal/steps;
		for(var i = steps; i > 0; i--){
			var val = parseInt(interval*i);
			yAxisHtml += '<div class="horizBar">' + val + '&nbsp;</div>';
		}
		return yAxisHtml;
	},
	getChartHtml: function(m, y){
		var barHtml = '<table class="chartTable" cellpadding="0" cellspacing=0><tr>';
		var labelHtml = '<table class="labelTable" cellpadding=0 cellspacing=0><tr>';
		var maxHeight = steps*40;
		for(var i = 0; i < this.chartData.length; i++){
			var height = 0;
			var date = new Date(y, (m-1), (i+1));
			var item = this.chartData[i];
			var barCSS = 'bar';
			var barDiv = '&nbsp;';
			var extraProps = '';

			dayOfWeek = date.getDay();
			if(dayOfWeek == 6 || dayOfWeek == 0){
				barCSS = 'weekendBar';
				var border = (dayOfWeek == 0 ? 'border-right:' + wkendBorder : 'border-left:' + wkendBorder); 
				extraProps += ' style="' + border + '"';
			}
			
			if(this.selectedDate && date.getDate() == this.selectedDate){
				barCSS = 'dayBar';
			}

			if(item != null){
				height = Math.ceil(maxHeight*(item.value/this.maxVal));
				if(height > 0){
					barDiv = '<div class="' + barCSS + '"';
					barDiv += ' style="height:' + height + 'px;"';
					barDiv += ' onmouseover="showTooltip(this, ' + this.accessor + '.getTooltipHtml(' + i + '), event)"';
					barDiv += ' onclick="' + this.accessor + '.setDate(' + date.getDate() + ');hideTooltip(event);"></div>';
				}
			}
			
			labelHtml += '<td class="labelCell">' + date.getDate() + '</td>';
			barHtml += '<td class="barCell"' + extraProps + '>' + barDiv + '</td>';
		}
		
		labelHtml += '</tr></table>';
		barHtml += '</tr></table>';

		return (barHtml + labelHtml);
	},
	setSelectedDay: function(date){
		if(this.selectedDate != date){ this.selectedDate = date; }
	}
});