//-----------------------------------------------------------
//Hash table

Hashtable.prototype.hash = null;
Hashtable.prototype.keys = null;
Hashtable.prototype.location = null;

function Hashtable(){
	this.hash = new Array();
	this.keys = new Array();

	this.location = 0;
}

Hashtable.prototype.get = function (key){
	return this.hash[key];
}

Hashtable.prototype.put = function (key, value){
	if (value == null)
		return null;

	if (this.hash[key] == null)
		this.keys[this.keys.length] = key;

	this.hash[key] = value;
}

Hashtable.prototype.remove = function (key){
	for (var i = 0; i < this.keys.length; i++){
		//did we found our key?
		if (key == this.keys[i]){
			//remove it from the hash
			this.hash[this.keys[i]] = null;
			//and throw away the key...
			this.keys.splice(i ,1);
			return;
		}
	}
}

Hashtable.prototype.size = function (){
    return this.keys.length;
}
//--------------------------------------------------------
// Array binary search
Array.prototype.binarySearch = function(item)
{
  var left = -1,
      right = this.length,
      mid;

  while(right - left > 1)
  {
    mid = (left + right) >>> 1;
    if(this[mid] < item)
      left = mid;
    else
      right = mid;
  }

  if(this[right] != item)
    return -(right + 1);

  return right;
}

//--------------------------------------------------------
//Keywords extractor

KeyWordExtractor.prototype.regword=/\w{2,}/gim;
function KeyWordExtractor(){
	this.words=new Hashtable();
	this.enStopWords = new Array("a", "about", "above", "across", "after", "afterwards", "again", "against", "all", "almost", "alone", "along", "already", "also", "although", "always", "am", "among", "amongst", "amoungst", "amount", "an", "and", "another", "any", "anyhow", "anyone", "anything", "anyway", "anywhere", "are", "around", "as", "at", "back", "be", "became", "because", "become", "becomes", "becoming", "been", "before", "beforehand", "behind", "being", "below", "beside", "besides", "between", "beyond", "bill", "both", "bottom", "but", "by", "call", "can", "cannot", "cant", "co", "computer", "con", "could", "couldnt", "cry", "de", "describe", "detail", "do", "done", "down", "due", "during", "each", "eg", "eight", "either", "eleven", "else", "elsewhere", "empty", "enough", "etc", "even", "ever", "every", "everyone", "everything", "everywhere", "except", "few", "fifteen", "fify", "fill", "find", "fire", "first", "five", "for", "former", "formerly", "forty", "found", "four", "from", "front", "full", "further", "get", "give", "go", "had", "has", "hasnt", "have", "he", "hence", "her", "here", "hereafter", "hereby", "herein", "hereupon", "hers", "herself", "him", "himself", "his", "how", "however", "hundred", "i", "ie", "if", "in", "inc", "indeed", "interest", "into", "is", "it", "its", "itself", "keep", "last", "latter", "latterly", "least", "less", "ltd", "made", "many", "may", "me", "meanwhile", "might", "mill", "mine", "more", "moreover", "most", "mostly", "move", "much", "must", "my", "myself", "name", "namely", "neither", "never", "nevertheless", "next", "nine", "no", "nobody", "none", "noone", "nor", "not", "nothing", "now", "nowhere", "of", "off", "often", "on", "once", "one", "only", "onto", "or", "other", "others", "otherwise", "our", "ours", "ourselves", "out", "over", "own", "part", "per", "perhaps", "please", "put", "rather", "re", "same", "see", "seem", "seemed", "seeming", "seems", "serious", "several", "she", "should", "show", "side", "since", "sincere", "six", "sixty", "so", "some", "somehow", "someone", "something", "sometime", "sometimes", "somewhere", "still", "such", "system", "take", "ten", "than", "that", "the", "their", "them", "themselves", "then", "thence", "there", "thereafter", "thereby", "therefore", "therein", "thereupon", "these", "they", "thick", "thin", "third", "this", "those", "though", "three", "through", "throughout", "thru", "thus", "to", "together", "too", "top", "toward", "towards", "twelve", "twenty", "two", "un", "under", "until", "up", "upon", "us", "very", "via", "was", "we", "well", "were", "what", "whatever", "when", "whence", "whenever", "where", "whereafter", "whereas", "whereby", "wherein", "whereupon", "wherever", "whether", "which", "while", "whither", "who", "whoever", "whole", "whom", "whose", "why", "will", "with", "within", "without", "would", "yet", "you", "your", "yours", "yourself", "yourselves" );
}

function WordItem(Word, Rank){
	this.Word=Word;
	this.Rank=Rank;
}

function AddText(Text,Rank){
	var elem=Text.match(this.regword);
	
	var pos=0;
	
	for(i=0;i<elem.length;i++){
	   var s=elem[i].toLowerCase();
	   
	   var r = Rank*100;
	   pos++;
	   var j = pos / 4;
	   if (j < 50) r -= j; 
	   else r -= 50;     
	   if(this.enStopWords.binarySearch(s)<0){
	   	if(this.words.get(s)==null){
	   		this.words.put(s,r);
	   	} else {
	   		this.words.put(s,this.words.get(s)+r);
	   	}
	   }
	   
	}
	

}

function GetSortedList(){

	var wlist=new Array();
	
	for(i=0;i<this.words.keys.length;i++){
	   wlist[wlist.length]=new WordItem(this.words.keys[i],this.words.get(this.words.keys[i]));
	}
	wlist.sort(function(a,b){return -(a.Rank-b.Rank);});
	
	//for(i=0;i<wlist.length;i++){
	//   document.write(wlist[i].Word+": "+wlist[i].Rank+"<br>");	
	//}
	
	return wlist;

}

KeyWordExtractor.prototype.AddText=AddText;
KeyWordExtractor.prototype.GetSortedList=GetSortedList;

var kw=new KeyWordExtractor();





//-----------------------------------------------------------