/**
 * Progress bar
 *
 * The progress bar is accurate to four decimal places. This translates
 * one-hundredth of a percent.
 *
 * @copyright 2007-2008 silverorange
 */
function SwatProgressBar(id, orientation, value)
{
	this.id = id;
	this.orientation = orientation;
	this.value = value;

	this.pulse_step = 0.05;
	this.pulse_position = 0;
	this.pulse_width = 0.15;
	this.pulse_direction = 1;

	this.full      = document.getElementById(this.id + '_full');
	this.empty     = document.getElementById(this.id + '_empty');
	this.text      = document.getElementById(this.id + '_text');
	this.container = document.getElementById(this.id);

	this.changeValueEvent = new YAHOO.util.CustomEvent('changeValue');
	this.pulseEvent       = new YAHOO.util.CustomEvent('pulse');

	this.animation  = null;

	YAHOO.util.Event.onDOMReady(function() {
		// Hack for Gecko and WebKit to load background images for full part of
		// progress bar. If the bar starts at zero, these browsers don't load
		// the background image, even when the bar's value changes.
		this.full_stubb = document.createElement('div');
		this.full_stubb.className = this.full.className;
		this.full_stubb.style.width = '100px';
		this.full_stubb.style.height = '100px';
		this.full_stubb.style.position = 'absolute';
		this.full_stubb.style.top = '-10000px';
		document.body.appendChild(this.full_stubb);
	}, this, true);
}

SwatProgressBar.ORIENTATION_LEFT_TO_RIGHT = 1;
SwatProgressBar.ORIENTATION_RIGHT_TO_LEFT = 2;
SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP = 3;
SwatProgressBar.ORIENTATION_TOP_TO_BOTTOM = 4;

SwatProgressBar.EPSILON = 0.0001;

SwatProgressBar.ANIMATION_DURATION = 0.5;

SwatProgressBar.prototype.setValue = function(value)
{
	if (this.value == value)
		return;

	this.value = value;

	var full_width = 100 * value;
	var empty_width = 100 - (100 * value);
	full_width = (full_width > 100) ? 100 : full_width;
	empty_width = (empty_width < 0) ? 0 : empty_width;

	// reset position if bar was set to pulse-mode
	if (this.orientation !== SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP)
		this.full.style.position = 'static';

	// reset empty div if bar was set to pulse mode
	this.empty.style.display = 'block';

	switch (this.orientation) {
	case SwatProgressBar.ORIENTATION_LEFT_TO_RIGHT:
	case SwatProgressBar.ORIENTATION_RIGHT_TO_LEFT:
	default:
		this.full.style.width = full_width + '%';
		this.empty.style.width = empty_width + '%';
		break;

	case SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP:
		this.full.style.top = empty_width + '%';
		this.empty.style.top = '-' + full_width + '%';
		// fall through

	case SwatProgressBar.ORIENTATION_TOP_TO_BOTTOM:
		this.full.style.height = full_width + '%';
		this.empty.style.height = empty_width + '%';
		break;
	}

	this.changeValueEvent.fire(this.value);
}

SwatProgressBar.prototype.setValueWithAnimation = function(value)
{
	if (this.value == value)
		return;

	var old_full_width = 100 * this.value;
	var old_empty_width = 100 - (100 * this.value);
	old_full_width = (old_full_width > 100) ? 100 : old_full_width;
	old_empty_width = (old_empty_width < 0) ? 0 : old_empty_width;

	// set new value
	this.value = value;

	var new_full_width = 100 * value;
	var new_empty_width = 100 - (100 * value);
	new_full_width = (new_full_width > 100) ? 100 : new_full_width;
	new_empty_width = (new_empty_width < 0) ? 0 : new_empty_width;

	// reset position if bar was set to pulse-mode
	if (this.orientation !== SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP)
		this.full.style.position = 'static';

	// reset empty div if bar was set to pulse mode
	this.empty.style.display = 'block';

	var full_attributes  = {};

	switch (this.orientation) {
	case SwatProgressBar.ORIENTATION_LEFT_TO_RIGHT:
	case SwatProgressBar.ORIENTATION_RIGHT_TO_LEFT:
	default:
		full_attributes['width'] = {
			from: old_full_width,
			to:   new_full_width,
			unit: '%'
		};
		break;

	case SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP:
		full_attributes['top'] = {
			from: old_empty_width,
			to:   new_empty_width,
			unit: '%'
		};
		// fall through

	case SwatProgressBar.ORIENTATION_TOP_TO_BOTTOM:
		full_attributes['height'] = {
			from: old_full_width,
			to:   new_full_width,
			unit: '%'
		};
		break;
	}

	// stop existing animation
	if (this.animation !== null && this.animation.isAnimated()) {
		this.animation.stop();
	}

	this.animation = new YAHOO.util.Anim(this.full, full_attributes,
		SwatProgressBar.ANIMATION_DURATION);

	// Synchronize empty div resizing with full div animation. Don't do
	// this with a separate animation.
	this.animation.onTween.subscribe(function() {
		var percent = this.animation.currentFrame / this.animation.totalFrames;

		var full_percent = old_full_width +
			((new_full_width - old_full_width) * percent);

		var empty_percent = 100.00 - full_percent;

		switch (this.orientation) {
		case SwatProgressBar.ORIENTATION_LEFT_TO_RIGHT:
		case SwatProgressBar.ORIENTATION_RIGHT_TO_LEFT:
		default:
			this.empty.style.width = empty_percent + '%';
			break;

		case SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP:
			this.empty.style.top = -full_percent + '%';
			// fall through

		case SwatProgressBar.ORIENTATION_TOP_TO_BOTTOM:
			this.empty.style.height = empty_percent + '%';
			break;
		}
	}, this, true);

	this.animation.animate();

	this.changeValueEvent.fire(this.value);
}

SwatProgressBar.prototype.setText = function(text)
{
	if (this.text.innerText) {
		this.text.innerText = text;
	} else {
		this.text.textContent = text;
	}
}

SwatProgressBar.prototype.getValue = function()
{
	return this.value;
}

SwatProgressBar.prototype.pulse = function()
{
	this.full.style.position = 'relative';
	this.empty.style.display = 'none';

	switch (this.orientation) {
	case SwatProgressBar.ORIENTATION_LEFT_TO_RIGHT:
	default:
		this.full.style.width = (this.pulse_width * 100) + '%';
		this.full.style.left = (this.pulse_position * 100) + '%';
		break;

	case SwatProgressBar.ORIENTATION_RIGHT_TO_LEFT:
		this.full.style.width = (this.pulse_width * 100) + '%';
		this.full.style.left = '-' + (this.pulse_position * 100) + '%';
		break;

	case SwatProgressBar.ORIENTATION_BOTTOM_TO_TOP:
		this.full.style.height = (this.pulse_width * 100) + '%';
		this.full.style.top =
			((1 - (this.pulse_position + this.pulse_width)) * 100) + '%';

		break;

	case SwatProgressBar.ORIENTATION_TOP_TO_BOTTOM:
		this.full.style.height = (this.pulse_width * 100) + '%';
		this.full.style.top = (this.pulse_position * 100) + '%';
		break;
	}

	var new_pulse_position =
		this.pulse_position + this.pulse_step * this.pulse_direction;

	if (this.pulse_direction ==  1 &&
		this.compare(new_pulse_position + this.pulse_width, 1) > 0)
		this.pulse_direction = -1;

	if (this.pulse_direction == -1 && this.compare(new_pulse_position, 0) < 0)
		this.pulse_direction = 1;

	this.pulse_position += (this.pulse_step * this.pulse_direction);

	this.pulseEvent.fire();

	// preserve precision across multiple calls to pulse()
	this.pulse_position =
		Math.round(this.pulse_position / SwatProgressBar.EPSILON) *
		SwatProgressBar.EPSILON;
}

SwatProgressBar.prototype.compare = function(x, y)
{
	if (Math.abs(x - y) < SwatProgressBar.EPSILON) return 0;
	if (x > y) return 1;
	return -1;
}