/*! 
 SpryWidgetProgressBar.js version 0.1.0 - Copyright (c) 2010. 
 Arnout Kazemier, 3rd-Eden.com All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

   * Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
   * Neither the name of Arnout Kazemier nor 3rd-Eden.com nor the names of its
     contributors may be used to endorse or promote products derived from this
     software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE. 
*/
var Spry;
if (!Spry) Spry = {};
if (!Spry.Widget) Spry.Widget = {};

Spry.Widget.ProgressBar = function( element, opts ){
	var that = this;
	
	Spry.Utils.Notifier.call(this);
	
	// Initialize the button object with the global defaults.
	Spry.Utils.setOptions(this, Spry.Widget.ProgressBar.config);
	
	// Override the defaults with any options passed into the constructor.
	Spry.Utils.setOptions(this, opts);
	
	this.version = "0.1.0";	// version number pattern: major, minor, bugfix
	this.element = Spry.$$( element )[0];
	this.bar = Spry.$$( "." + this.barClass, this.element );
	this.initialWidth = Spry.Effect.getDimensionsRegardlessOfDisplayState( this.bar[0] ).width;
	this.currentWidth = this.initialWidth;
	this.counter = 0;
	
	this.setPercentage( 
		// set the percentage to the supplied "default" percentage
		this.percentage, 
		
		// just do it quick so user will not notice it
		1, 
		
		// do we have a auto start ? if yes, complete the progress bar with the supplied duration
		this.autoStart ? function(){ that.setPercentage( 100, that.duration ); }: false );
	
	this.addObserver({
		onComplete: function(){
			if( that.hideOnComplete ){
				that.hide();
			}
		}
	});
};

// a linear transition
Spry.Widget.ProgressBar.defaultEaseFunc =  function(time, begin, change, duration){
	if (time > duration) return change + begin;
	return begin + (time / duration) * change;
};

Spry.Widget.ProgressBar.config = {
	
	// initial percentage of the bar
	percentage: 0,
	
	// default transition for the effect
	transition:	Spry.Widget.ProgressBar.defaultEaseFunc,
	
	// the default length of the animation
	duration: 2E3,
	
	// is the widget enabled or disabled
	autoStart: false,
	
	// if the progress bar should be hidden once it's completed
	hideOnComplete: true,
	
	// what className is used for the bar
	barClass: "bar"
};

Spry.Widget.ProgressBar.prototype = new Spry.Utils.Notifier();
Spry.Widget.ProgressBar.prototype.constructor = Spry.Widget.ProgressBar;

Spry.Widget.ProgressBar.prototype.setPercentage = function( percentage, duration, callback ){
	// makesure its a valid value
	percentage = this.cleanPercentage ( percentage ); 
	duration = duration || this.duration;
			
	var that = this,
		// are we increasing or decreasing
		increase = percentage >= this.percentage,
		
		// target width	
		to = this.initialWidth / 100 * percentage,	
		
		// diffence between the current and new percentage
		difference = increase ? percentage - this.percentage : this.percentage - percentage;
		
	// create sliding effect
	this.effect = new Spry.Effect.Slide( this.bar[0], {
			duration: duration,
			from: Spry.Effect.getDimensionsRegardlessOfDisplayState( this.bar[0] ).width + "px",
			to: to + "px",
			horizontal: true,
			transition: this.transition, 
			finish: callback || null 
	});
		
	this.currentWidth = to;
	this.percentage = percentage;
	
	// add events to the effect so we can fire off our custom notifications as well
	this.effect.addObserver({
		onPostEffect: function(){
			if( percentage === 100 ){
				that.notifyObservers( "onComplete" ); // the progressbar has been completed
			}
			
			// we set the percentage
			that.notifyObservers( "onPercentageChanged", ( that.counter = percentage ) );
			that.notifyObservers( "onPercentageSet", that.percentage );
		},
		
		onStep: function( effect, info ){			
			if( info.getElapsedMilliseconds() >= effect.increase && !( that.counter >= 100 ) ){
				effect.increase = effect.avg + effect.increase;
				
				var _percent = Math.floor( info.getElapsedMilliseconds() / effect.avg ),
					_difference;
					
				if( !effect.percent || effect.percent < _percent ){
					_difference = _percent - effect.percent || 1;
					effect.percent = _percent;
					
					that.notifyObservers( 
						"onPercentageChanged",
						( 
							that.counter = that.cleanPercentage( 
								increase ? ( that.counter + _difference ) : ( that.counter - _difference) 
							)
						)
					);
				}
			}			
		}		
	});
	
	// calculate the elapsed when the percentage needs to increased
	this.effect.avg = this.effect.increase= Math.round( duration / difference );
	
	// run the animation
	this.effect.start();
};

// prevent race conditions, so you can stop them at will... 
Spry.Widget.ProgressBar.prototype.stop = function(){
	this.effect.stop();
};

// when you stop, you might want to start it again.. go figure :0
Spry.Widget.ProgressBar.prototype.start = function(){
	this.effect.start();
};

// increase the value of the progress
Spry.Widget.ProgressBar.prototype.add = function( percentage, duration ){
	percentage = percentage ? this.cleanPercentage( percentage ) : 5;
	this.setPercentage( this.counter + percentage, duration );
};

// decrease the value of the progress
Spry.Widget.ProgressBar.prototype.remove = function( percentage, duration ){
	percentage = percentage ? this.cleanPercentage( percentage ) : 5;
	this.setPercentage( this.counter - percentage, duration );
};

// reset the progress bar back to 0;
Spry.Widget.ProgressBar.prototype.reset = function( ){
	var that = this;
	
	if( this.hidden ){
		this.show();
	}
	
	this.counter = 0;
	this.setPercentage( 0, 1, function(){ that.notifyObservers( "onReset" ); });
};

// complete the progress bar, fast
Spry.Widget.ProgressBar.prototype.complete = function( duration ){
	this.setPercentage( 100, duration || 200 );
};

// cleans out the percentage, parses down 100% to 100 and makes sure its between 0 and 100;
Spry.Widget.ProgressBar.prototype.cleanPercentage = function( value ){
	value = typeof value === "number" ? value : parseFloat( value.replace(/\%/g, '' ) );
	return value > 100 ? 100 : (value < 0 ? 0 : value); // percentage can't be higher than 100%
};

// returns the current percentage or the expected percentage
Spry.Widget.ProgressBar.prototype.getPercentage = function( total ){
	return total ? this.percentage : this.counter;
};

// shows the widget
Spry.Widget.ProgressBar.prototype.show = function(){
	this.element.style.display = "";
	this.hidden = false;
};

Spry.Widget.ProgressBar.prototype.hide = function(){
	this.element.style.display = "none";
	this.hidden = true;
};