function Rsvp(text, targetDiv, settings, slider, viewerTa){
	this._text = text;
	this._targetDiv = targetDiv;
	this._slider = slider;
	this._viewerTa = viewerTa;
	
	this.changeSettings(settings);
	
	this._initializeFromText(text);
	
	this._nextWordIndex = 0;
	this._curTimeout = null;
	
	this.sliderEventDisabled = false;
	
	this._playing = false;
	
	this._destroyed = false;
}

Rsvp.fn = Rsvp.prototype;

Rsvp.fn._initializeFromText = function(text){
	// match a word and a bunch of non-word-stuff
	// "g" is important if we want lastIndex to be remembered in match object
	var regex = new RegExp("([^\\s]+)\\s+", "mg");

	this._words = [];
	this._wordPositions = [];
	
	var match = null;
	var i = 0;
	var lastLastIndex = 0;
	while((match = regex.exec(text)) != null){
		this._words[i] = match[1];
		this._wordPositions[i] = lastLastIndex;
		lastLastIndex = regex.lastIndex;
		i++;
	}
	
	// last word if there's some text remaining
	this._words[i] = text.substring(lastLastIndex);
	this._wordPositions[i] = lastLastIndex;
	
	i++;
	
	// To make the final iteration in selectRange work
	this._wordPositions[i] = text.length-1;
}

Rsvp.fn.destroy = function(){
	this.pause();
	
	this._destroyed = true;
}

Rsvp.fn.changeSettings = function(settings){
	this._numLines = settings.numLines;
	this._wordsPerLine = settings.wordsPerLine;
	this._groupsPerMinute = settings.groupsPerMinute;
	
	this._wordsPerGroup = this._numLines * this._wordsPerLine;
	
	this._msPerGroup = 60 * 1000 / this._groupsPerMinute;
}

Rsvp.fn.incrementSpeed = function(wpm_plus){
	this._groupsPerMinute += wpm_plus;

	if(this._groupsPerMinute < 1){
		alert("Minimum at 1 group per minute");
		this._groupsPerMinute = 1;
	}

	this._msPerGroup = 60 * 1000 / this._groupsPerMinute;

	return this._groupsPerMinute;
}

Rsvp.fn.start = function(){
	this._playing = true;
	
	this.nextFrame();
}

Rsvp.fn.nextFrame = function(){
	this.showTextRange();
	
	// Adjust slider
	this.sliderEventDisabled = true;
	
	var pos = (this._nextWordIndex - this._wordsPerGroup)
				/ (this._words.length - this._wordsPerGroup)
				* 200;
	$(this._slider).slider("moveTo", Math.round(pos), 0);
	
	this.sliderEventDisabled = false;
	
	
	// Timer for next frame
	if(this._playing && this._nextWordIndex < this._words.length){
		this.setTimeout();
	}
}

Rsvp.fn.moveToPercentage = function(percent){
	var startWord = Math.floor(percent * this._words.length);
	
	// Round to correct start word (ie. if wordsPerGroup = 4,
	// we want groups to start at 0, 4, 8, ...)
	startWord -= startWord % this._wordsPerGroup;
	
	this.showTextRange(startWord);
}

Rsvp.fn.showTextRange = function(firstWordIndex){
	if(firstWordIndex === undefined)
		firstWordIndex = this._nextWordIndex;
	
	this._nextWordIndex = firstWordIndex;
	
	var resHtml = "";
	var firstWordBeginPos = this._wordPositions[firstWordIndex];
	for(var i=0; i<this._numLines; i++){
		for(var j=0; j<this._wordsPerLine; j++){
			if(this._nextWordIndex >= this._words.length){
				this._playing = false;
				break;
			}
			
			resHtml += this._words[this._nextWordIndex] + " ";
			
			this._nextWordIndex++;
		}
		
		if(this._nextWordIndex >= this._words.length){
			this._playing = false;
			break;
		}
		
		resHtml += "<br/>";
	}
	var lastWordEndPos = this._wordPositions[this._nextWordIndex];
	
	this.selectRangeInViewer(firstWordBeginPos, lastWordEndPos);
	
	$(this._targetDiv).html(resHtml);
}

Rsvp.fn.setTimeout = function(){
	if(this._destroyed)
		// no more setting of timeout after this point...
		// otherwise it might conflict with another object
		return;

	// make sure the old timeout is cleared, otherwise timers compete
	if(this._curTimeout)
		clearTimeout(this._curTimeout);
	
	var self = this;

	this._curTimeout = setTimeout(
			function(){ self.nextFrame(); },
			this._msPerGroup
		);
}

Rsvp.fn.pause = function(){
	clearTimeout(this._curTimeout);
	
	this._playing = false;
}

Rsvp.fn.playOrResume = function(){
	this._playing = true;
	
	this.setTimeout();
}

Rsvp.fn.rewind = function(){
	this._nextWordIndex = 0;
	
	this.nextFrame();
}

Rsvp.fn.selectRangeInViewer = function(start, end){
	var ta = $(this._viewerTa).get(0);

	if(!$(this._viewerTa).is(":visible")){
		return;
	}

	if (ta.createTextRange) {
		var oRange = ta.createTextRange();
		oRange.collapse(true);
		oRange.moveStart("character", start);
		oRange.moveEnd("character", end-start);
		oRange.select();
		
	} else if (ta.setSelectionRange) {
		ta.setSelectionRange(start,start+1);
	
		// causes scrolling to caret position in IE, seen there:
		// http://bytes.com/forum/thread496726.html
		// Only works in Firefox... Opera and Safari won't collaborate
		if(window.KeyEvent){
			var ev = document.createEvent ('KeyEvents');
			ev.initKeyEvent('keypress', true, true, window,
								false, false, false, false, 0,
								ta.value.charCodeAt(start));
			ta.dispatchEvent(ev);
		}
		
		ta.setSelectionRange(start, end);
	}
	//$(this._viewerTa).blur();

}