// main function to process the fade request //
var target = "";
var flashStatus = "off";
//var flashStart = "336699";
//var flashEnd = "003366";
var flashSteps = 10;
var flashSpeed = 1;

function colorFlash(id,element,begin,flashStart,flashEnd) {

	if (begin == "fadeUp" && flashStatus == "off") {
		flashStatus = "on";
		colorFade(id,element,flashStart,flashEnd,flashSteps,flashSpeed);
	}
	else if (begin == "fadeDown" && flashStatus == "on") {
		flashStatus = "off";
		colorFade(id,element,flashEnd,flashStart,flashSteps,flashSpeed);
	}
}

function colorFade(id,element,start,end,steps,speed) {


	var startrgb,endrgb,er,eg,eb,step,rint,gint,bint,step;
	target = document.getElementById(id);
	steps = steps || 20;
	speed = speed || 20;
	clearInterval(target.timer);
	endrgb = colorConv(end);
	er = endrgb[0];
	eg = endrgb[1];
	eb = endrgb[2];
	if(!target.r) {
		startrgb = colorConv(start);
		r = startrgb[0];
		g = startrgb[1];
		b = startrgb[2];
		target.r = r;
		target.g = g;
		target.b = b;
	}
	rint = Math.round(Math.abs(target.r-er)/steps);
	gint = Math.round(Math.abs(target.g-eg)/steps);
	bint = Math.round(Math.abs(target.b-eb)/steps);
	if(rint == 0) { rint = 1 }
	if(gint == 0) { gint = 1 }
	if(bint == 0) { bint = 1 }
	target.step = 1;
	target.timer = setInterval( function() { animateColor(id,element,start,end,steps,er,eg,eb,rint,gint,bint) }, speed);
}

// incrementally close the gap between the two colors //
function animateColor(id,element,start,end,steps,er,eg,eb,rint,gint,bint) {
	
	target = document.getElementById(id);
	var color;
	if(target.step <= steps) {
		var r = target.r;
		var g = target.g;
		var b = target.b;
		if(r >= er) {
			r = r - rint;
		} else {
			r = parseInt(r) + parseInt(rint);
		}
		if(g >= eg) {
			g = g - gint;
		} else {
			g = parseInt(g) + parseInt(gint);
		}
		if(b >= eb) {
			b = b - bint;
		} else {
			b = parseInt(b) + parseInt(bint);
		}
		color = 'rgb(' + r + ',' + g + ',' + b + ')';
		if(element == 'background') {
			target.style.backgroundColor = color;
		} else if(element == 'border') {
			target.style.borderColor = color;
		} else {
			target.style.color = color;
		}
		target.r = r;
		target.g = g;
		target.b = b;
		target.step = target.step + 1;
	}
	else {
		clearInterval(target.timer);
		color = 'rgb(' + er + ',' + eg + ',' + eb + ')';
		if(element == 'background') {
			target.style.backgroundColor = color;
		} else if(element == 'border') {
			target.style.borderColor = color;
		} else {
			target.style.color = color;
		}
		colorFlash(id,element,"fadeDown",start,end);
	}
}

// convert the color to rgb from hex //
function colorConv(color) {
	var rgb = [parseInt(color.substring(0,2),16), 
		parseInt(color.substring(2,4),16), 
		parseInt(color.substring(4,6),16)];
	return rgb;
}