module.exports = function ( graph ){
  /** variable defs **/
  var prefixRepresentationModule = {};
  
  var currentPrefixModel;
  
  prefixRepresentationModule.updatePrefixModel = function (){
    currentPrefixModel = graph.options().prefixList();
  };
  
  
  prefixRepresentationModule.validURL = function ( url ){
    return validURL(url);
  };
  function validURL( str ){
    var urlregex = /^(https?|ftp):\/\/([a-zA-Z0-9.-]+(:[a-zA-Z0-9.&%$-]+)*@)*((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])){3}|([a-zA-Z0-9-]+\.)*[a-zA-Z0-9-]+\.(com|edu|gov|int|mil|net|org|biz|arpa|info|name|pro|aero|coop|museum|[a-zA-Z]{2}))(:[0-9]+)*(\/($|[a-zA-Z0-9.,?'\\+&%$#=~_-]+))*$/;
    return urlregex.test(str);
  }
  
  function splitURLIntoBaseAndResource( fullURL ){
    var splitedURL = { base: "", resource: "" };
    if ( fullURL === undefined ) {
      splitedURL = { base: "ERROR", resource: "NOT FOUND" };
      return splitedURL;
    }
    
    var resource, base;
    // check if there is a last hashTag
    if ( fullURL.indexOf("#") > -1 ) {
      resource = fullURL.substring(fullURL.lastIndexOf('#') + 1);
      base = fullURL.substring(0, fullURL.length - resource.length);
      // overwrite base if it is ontologyIri;
      if ( base === graph.options().getGeneralMetaObjectProperty('iri') ) {
        base = ":";
      }
      splitedURL.base = base;
      splitedURL.resource = resource;
    } else {
      resource = fullURL.substring(fullURL.lastIndexOf('/') + 1);
      base = fullURL.substring(0, fullURL.length - resource.length);
      // overwrite base if it is ontologyIri;
      if ( base === graph.options().getGeneralMetaObjectProperty('iri') ) {
        base = ":";
      }
      splitedURL.base = base;
      splitedURL.resource = resource;
    }
    return splitedURL;
  }
  
  prefixRepresentationModule.getPrefixRepresentationForFullURI = function ( fullURL ){
    prefixRepresentationModule.updatePrefixModel();
    var splittedURL = splitURLIntoBaseAndResource(fullURL);
    
    // lazy approach , for
    // loop over prefix model
    for ( var name in currentPrefixModel ) {
      if ( currentPrefixModel.hasOwnProperty(name) ) {
        // THIS IS CASE SENSITIVE!
        if ( currentPrefixModel[name] === splittedURL.base ) {
          return name + ":" + splittedURL.resource;
        }
      }
    }
    
    if ( splittedURL.base === ":" ) {
      return ":" + splittedURL.resource;
    }
    
    return fullURL;
  };
  
  
  return prefixRepresentationModule;
};