MdExtFormParser = function (){

  this.qstr = '';
  this.AND = ' ';
  this.OR = ' OR ';

  this.parseTextField = function(s, name, lk){
  	if(!s) return '';
  	s = s.replace(/\s+/g, " ");
    if(s.indexOf(this.OR)==-1) var tokens=[s];
    else var tokens = s.split(this.OR);
    for(var i=0;i<tokens.length;i++){
     	if(tokens[i].indexOf(this.AND)>-1){
    		var atokens = tokens[i].split(this.AND);
    		for(var j=0;j<atokens.length;j++){
    			if(lk) atokens[j] = name+" like '*" + atokens[j].trim() + "*'";
    			else atokens[j] = name+"='"+atokens[j].trim()+"'";
    		}
    		tokens[i] = "("+atokens.join(" AND ")+")";
    	}
    	else{
    		if(lk) tokens[i]= name+" like '*"+tokens[i].trim()+"*'";
    		else tokens[i]= name+"='"+tokens[i].trim()+"'";
    	}
    }
    s = tokens.join(" OR ");
    if(tokens.length>1) s = "("+s+")";
    return s;
  }
  
  this.add = function(s){
   	if(!s) return;
  	if(this.qstr) this.qstr += " AND ";
  	this.qstr += s;   	
  }

  this.addQuery = function(str, name, lk, parse){
  	if(str){ 
  	  if(parse) this.add(this.parseTextField(str,name,lk));
  	  else {
  	    if(lk) this.add(name+" like '*"+str+"*'");
  	    else this.add(name+"='"+str+"'");
      }  
  	}	
  }

  this.parse = function(f){
  	//console.log(f);
  	this.qstr = '';
    this.addQuery(f.anytext,f.ttype,true, true);
    this.addQuery(f.keywords,'subject',true);
    this.addQuery(f.onege,'subject',true);
    this.addQuery(f.hierarchyLevelName,'HierarchyLevelName',true);
    this.addQuery(f.party,'OrganisationName',false);
    this.addQuery(f.role,'role',false);
    if(f.bbox){
    	if(f.inside=="on") this.addQuery(f.bbox,'ibbox',false);
    	else this.addQuery(f.bbox,'bbox',false);
    }	
	if(f.tempFrom) this.add("TempExtent_begin>="+AdvancedSearch.SearchForm.date2iso(f.tempFrom));
	if(f.tempTo) this.add("TempExtent_end<="+AdvancedSearch.SearchForm.date2iso(f.tempTo));
	if(f.dateType){
		var dtype = f.dateType.substr(0,1).toUpperCase()+f.dateType.substr(1);
		if(f.dateFrom) this.add(dtype+"Date>="+AdvancedSearch.SearchForm.date2iso(f.dateFrom));
		if(f.dateTo) this.add(dtype+"Date<="+AdvancedSearch.SearchForm.date2iso(f.dateTo));
	}	
	if(f.modifiedFrom) this.add("modified>="+AdvancedSearch.SearchForm.date2iso(f.modifiedFrom));
	if(f.modifiedTo) this.add("modified<="+AdvancedSearch.SearchForm.date2iso(f.modifiedTo));
	if(f.scale1) this.add("Denominator>="+f.scale1);
	if(f.scale2) this.add("Denominator<="+f.scale2);
	if(f.hlevel){
		if(f.hlevel=='data'){ 
			this.add("(type=dataset OR type=series)");
			this.addQuery(f.topic,'TopicCategory',false);
		}	
		else if(f.hlevel=='map'){ 
			//this.add("type=application");
			this.add("hierarchyLevelName=MapContext");
		}	
		else if(f.hlevel=='service'){
			this.addQuery(f.hlevel,'type',false);
			this.addQuery(f.serviceType,'ServiceType',false);
		}	
	}
	this.addQuery(f.language,'language',false);	
	this.addQuery(f.specification,'SpecificationTitle',true);	
    return this.qstr;
  } 
}; //end class