/**
 * Contains the logic for the export button.
 * @returns {{}}
 */
module.exports = function ( graph ){
  var exportTTLModule = {};
  var resultingTTLContent = "";
  var currentNodes;
  var currentProperties;
  var currentAxioms;
  var Map_ID2Node = {};
  var Map_ID2Prop = {};
  var prefixModule = webvowl.util.prefixTools(graph);
  
  exportTTLModule.requestExport = function (){
    prefixModule.updatePrefixModel();
    resultingTTLContent = "";
    currentNodes = graph.getClassDataForTtlExport();
    var i;
    for ( i = 0; i < currentNodes.length; i++ ) {
      Map_ID2Node[currentNodes[i].id()] = currentNodes[i];
    }
    currentProperties = graph.getPropertyDataForTtlExport();
    
    for ( i = 0; i < currentProperties.length; i++ ) {
      Map_ID2Prop[currentProperties[i].id()] = currentProperties[i];
    }
    
    
    prepareHeader();
    preparePrefixList();
    prepareOntologyDef();
    resultingTTLContent += "#################################################################\r\n\r\n";
    preparePrefixRepresentation();
    var property_success = exportProperties();
    var class_success = exportClasses();
    currentNodes = null;
    currentProperties = null;
    Map_ID2Node = {};
    Map_ID2Prop = {};
    if ( property_success === false || class_success === false )
      return false;
    return true;
    
  };
  
  function preparePrefixRepresentation(){
    var i;
    var allNodes = graph.getUnfilteredData().nodes;
    var allProps = graph.getUnfilteredData().properties;
    for ( i = 0; i < allNodes.length; i++ ) {
      var nodeIRI = prefixModule.getPrefixRepresentationForFullURI(allNodes[i].iri());
      if ( prefixModule.validURL(nodeIRI) === true )
        allNodes[i].prefixRepresentation = "<" + nodeIRI + ">";
      else
        allNodes[i].prefixRepresentation = nodeIRI;
    }
    for ( i = 0; i < allProps.length; i++ ) {
      var propIRI = prefixModule.getPrefixRepresentationForFullURI(allProps[i].iri());
      if ( prefixModule.validURL(propIRI) === true )
        allProps[i].prefixRepresentation = "<" + propIRI + ">";
      else
        allProps[i].prefixRepresentation = propIRI;
    }
  }
  
  function exportProperties(){
    if ( currentProperties.length === 0 ) return; // we dont need to write that
    resultingTTLContent += "###  Property Definitions (Number of Property) " + currentProperties.length + " ###\r\n";
    for ( var i = 0; i < currentProperties.length; i++ ) {
      
      resultingTTLContent += "#  --------------------------- Property " + i + "------------------------- \r\n";
      var addedElement = extractPropertyDescription(currentProperties[i]);
      resultingTTLContent += addedElement;
      //@ workaround for not supported elements
      if ( addedElement.indexOf("WHYEMPTYNAME") !== -1 ) {
        return false;
      }
    }
    return true;
  }
  
  
  function exportClasses(){
    if ( currentNodes.length === 0 ) return; // we dont need to write that
    resultingTTLContent += "###  Class Definitions (Number of Classes) " + currentNodes.length + " ###\r\n";
    for ( var i = 0; i < currentNodes.length; i++ ) {
      // check for node type here and return false
      resultingTTLContent += "#  --------------------------- Class  " + i + "------------------------- \r\n";
      var addedElement = extractClassDescription(currentNodes[i]);
      resultingTTLContent += addedElement;
      
      if ( addedElement.indexOf("WHYEMPTYNAME") !== -1 ) {
        return false;
      }
    }
    return true;
  }
  
  function getPresentAttribute( selectedElement, element ){
    var attr = selectedElement.attributes();
    return (attr.indexOf(element) >= 0);
  }
  
  function extractClassDescription( node ){
    var subject = node.prefixRepresentation;
    var predicate = "rdf:type";
    var object = node.type();
    if ( node.type() === "owl:equivalentClass" )
      object = "owl:Class";
    if ( node.type() === "owl:disjointUnionOf" )
      object = "owl:Class";
    if ( node.type() === "owl:unionOf" )
      object = "owl:Class";
    var arrayOfNodes = [];
    var arrayOfUnionNodes = [];
    
    if ( node.union() ) {
      var union = node.union();
      for ( var u = 0; u < union.length; u++ ) {
        var u_node = Map_ID2Node[union[u]];
        arrayOfUnionNodes.push(u_node);
      }
    }
    
    if ( node.disjointUnion() ) {
      var distUnion = node.disjointUnion();
      for ( var du = 0; du < distUnion.length; du++ ) {
        var du_node = Map_ID2Node[distUnion[du]];
        arrayOfNodes.push(du_node);
      }
    }
    
    var objectDef = subject + " " + predicate + " " + object;
    if ( getPresentAttribute(node, "deprecated") === true ) {
      objectDef += ", owl:DeprecatedProperty";
    }
    // equivalent class handeled using type itself!
    
    // check for equivalent classes;
    var indent = getIndent(subject);
    objectDef += "; \r\n";
    for ( var e = 0; e < node.equivalents().length; e++ ) {
      var eqIRI = prefixModule.getPrefixRepresentationForFullURI(node.equivalents()[e].iri());
      var eqNode_prefRepresentation = "";
      if ( prefixModule.validURL(eqIRI) === true )
        eqNode_prefRepresentation = "<" + eqIRI + ">";
      else
        eqNode_prefRepresentation = eqIRI;
      objectDef += indent + " owl:equivalentClass " + eqNode_prefRepresentation + " ;\r\n";
    }
    
    // if (getPresentAttribute(node,"equivalent")===true){
    //     objectDef+=", owl:EquivalentClass";
    // }
    
    // add Comments
    
    if ( node.commentForCurrentLanguage() ) {
      
      objectDef += indent + " rdfs:comment \"" + node.commentForCurrentLanguage() + "\" ;\r\n";
    }
    
    if ( node.annotations() ) {
      var annotations = node.annotations();
      for ( var an in annotations ) {
        if ( annotations.hasOwnProperty(an) ) {
          var anArrayObj = annotations[an];
          var anObj = anArrayObj[0];
          var an_ident = anObj.identifier;
          var an_val = anObj.value;
          
          if ( an_ident === "isDefinedBy" ) {
            objectDef += indent + " rdfs:isDefinedBy <" + an_val + "> ;\r\n";
          }
          if ( an_ident === "term_status" ) {
            objectDef += indent + " vs:term_status \"" + an_val + "\" ;\r\n";
          }
        }
      }
    }
    
    
    if ( arrayOfNodes.length > 0 ) {
      // add disjoint unionOf
      objectDef += indent + " owl:disjointUnionOf (";
      for ( var duE = 0; duE < arrayOfNodes.length; duE++ ) {
        var duIri = prefixModule.getPrefixRepresentationForFullURI(arrayOfNodes[duE].iri());
        var duNode_prefRepresentation = "";
        if ( prefixModule.validURL(duIri) === true )
          duNode_prefRepresentation = "<" + duIri + ">";
        else
          duNode_prefRepresentation = duIri;
        objectDef += indent + indent + duNode_prefRepresentation + " \n";
      }
      objectDef += ") ;\r\n";
    }
    
    if ( arrayOfUnionNodes.length > 0 ) {
      // add disjoint unionOf
      objectDef += indent + " rdfs:subClassOf [ rdf:type owl:Class ; \r\n";
      objectDef += indent + indent + " owl:unionOf ( ";
      
      for ( var uE = 0; uE < arrayOfUnionNodes.length; uE++ ) {
        
        if ( arrayOfUnionNodes[uE] && arrayOfUnionNodes[uE].iri() ) {
          var uIri = prefixModule.getPrefixRepresentationForFullURI(arrayOfUnionNodes[uE].iri());
          var uNode_prefRepresentation = "";
          if ( prefixModule.validURL(uIri) === true )
            uNode_prefRepresentation = "<" + uIri + ">";
          else
            uNode_prefRepresentation = uIri;
          objectDef += indent + indent + indent + uNode_prefRepresentation + " \n";
        }
      }
      objectDef += ") ;\r\n";
      
      
    }
    
    
    var allProps = graph.getUnfilteredData().properties;
    var myProperties = [];
    var i;
    for ( i = 0; i < allProps.length; i++ ) {
      if ( allProps[i].domain() === node &&
        (   allProps[i].type() === "rdfs:subClassOf" ||
        allProps[i].type() === "owl:allValuesFrom" ||
        allProps[i].type() === "owl:someValuesFrom")
      ) {
        myProperties.push(allProps[i]);
      }
      // special case disjoint with>> both domain and range get that property
      if ( (allProps[i].domain() === node) &&
        allProps[i].type() === "owl:disjointWith" ) {
        myProperties.push(allProps[i]);
      }
      
    }
    for ( i = 0; i < myProperties.length; i++ ) {
      // depending on the property we have to do some things;
      
      // special case
      if ( myProperties[i].type() === "owl:someValuesFrom" ) {
        objectDef += indent + " rdfs:subClassOf [ rdf:type owl:Restriction ; \r\n";
        objectDef += indent + "                   owl:onProperty " + myProperties[i].prefixRepresentation + ";\r\n";
        if ( myProperties[i].range().type() !== "owl:Thing" ) {
          objectDef += indent + "                   owl:someValuesFrom " + myProperties[i].range().prefixRepresentation + "\r\n";
        }
        objectDef += indent + "                 ];\r\n";
        continue;
      }
      
      if ( myProperties[i].type() === "owl:allValuesFrom" ) {
        objectDef += indent + " rdfs:subClassOf [ rdf:type owl:Restriction ; \r\n";
        objectDef += indent + "                   owl:onProperty " + myProperties[i].prefixRepresentation + ";\r\n";
        if ( myProperties[i].range().type() !== "owl:Thing" ) {
          objectDef += indent + "                   owl:allValuesFrom " + myProperties[i].range().prefixRepresentation + "\r\n";
        }
        objectDef += indent + "                 ];\r\n";
        continue;
      }
      
      if ( myProperties[i].range().type() !== "owl:Thing" ) {
        objectDef += indent + " " + myProperties[i].prefixRepresentation +
          " " + myProperties[i].range().prefixRepresentation + " ;\r\n";
        
        
      }
    }
    
    
    objectDef += general_Label_languageExtractor(indent, node.label(), "rdfs:label", true);
    return objectDef;
    
  }
  
  function extractPropertyDescription( property ){
    var subject = property.prefixRepresentation;
    if ( subject.length === 0 ) {
      console.log("THIS SHOULD NOT HAPPEN");
      var propIRI = prefixModule.getPrefixRepresentationForFullURI(property.iri());
      console.log("FOUND " + propIRI);
      
      
    }
    var predicate = "rdf:type";
    var object = property.type();
    
    var objectDef = subject + " " + predicate + " " + object;
    if ( getPresentAttribute(property, "deprecated") === true ) {
      objectDef += ", owl:DeprecatedProperty";
    }
    if ( getPresentAttribute(property, "functional") === true ) {
      objectDef += ", owl:FunctionalProperty";
    }
    if ( getPresentAttribute(property, "inverse functional") === true ) {
      objectDef += ", owl:InverseFunctionalProperty";
    }
    if ( getPresentAttribute(property, "symmetric") === true ) {
      objectDef += ", owl:SymmetricProperty";
    }
    if ( getPresentAttribute(property, "transitive") === true ) {
      objectDef += ", owl:TransitiveProperty";
    }
    var indent = getIndent(subject);
    
    if ( property.inverse() ) {
      objectDef += "; \r\n";
      objectDef += indent + " owl:inverseOf " + property.inverse().prefixRepresentation;
    }
    
    // check for domain and range;
    
    
    var closeStatement = false;
    var domain = property.domain();
    var range = property.range();
    
    
    objectDef += " ;\r\n";
    
    
    if ( property.commentForCurrentLanguage() ) {
      
      objectDef += indent + " rdfs:comment \"" + property.commentForCurrentLanguage() + "\" ;\r\n";
    }
    
    if ( property.superproperties() ) {
      var superProps = property.superproperties();
      for ( var sP = 0; sP < superProps.length; sP++ ) {
        var sPelement = superProps[sP];
        objectDef += indent + "rdfs:subPropertyOf " + sPelement.prefixRepresentation + ";\r\n";
      }
      // for (var an in annotations){
      //     if (annotations.hasOwnProperty(an)){
      //         var anArrayObj=annotations[an];
      //         var anObj=anArrayObj[0];
      //         var an_ident=anObj.identifier;
      //         var an_val=anObj.value;
      //         console.log(an_ident + " "+ an_val);
      //
      //         if (an_ident==="isDefinedBy"){
      //             objectDef+=indent+" rdfs:isDefinedBy <"+an_val+"> ;\r\n";
      //         }
      //         if (an_ident==="term_status"){
      //             objectDef+=indent+" vs:term_status \""+an_val+"\" ;\r\n";
      //         }
      //     }
      // }
      
    }
    
    if ( property.annotations() ) {
      var annotations = property.annotations();
      for ( var an in annotations ) {
        if ( annotations.hasOwnProperty(an) ) {
          var anArrayObj = annotations[an];
          var anObj = anArrayObj[0];
          var an_ident = anObj.identifier;
          var an_val = anObj.value;
          
          if ( an_ident === "isDefinedBy" ) {
            objectDef += indent + " rdfs:isDefinedBy <" + an_val + "> ;\r\n";
          }
          if ( an_ident === "term_status" ) {
            objectDef += indent + " vs:term_status \"" + an_val + "\" ;\r\n";
          }
        }
      }
    }
    
    
    if ( domain.type() === "owl:Thing" && range.type() === "owl:Thing" ) {
      // we do not write domain and range
      if ( typeof property.label() !== "object" && property.label().length === 0 ) {
        closeStatement = true;
      }
    }
    
    
    if ( closeStatement === true ) {
      var uobjectDef = objectDef.substring(0, objectDef.length - 2);
      objectDef = uobjectDef + " . \r\n";
      return objectDef;
    }
    // objectDef+="; \r\n";
    var labelDescription;
    
    
    if ( domain.type() === "owl:Thing" && range.type() === "owl:Thing" ) {
      labelDescription = general_Label_languageExtractor(indent, property.label(), "rdfs:label", true);
      objectDef += labelDescription;
    }
    else {
      // do not close the statement;
      labelDescription = general_Label_languageExtractor(indent, property.label(), "rdfs:label");
      objectDef += labelDescription;
      if ( domain.type() !== "owl:Thing" ) {
        objectDef += indent + " rdfs:domain " + domain.prefixRepresentation + ";\r\n";
      }
      if ( range.type() !== "owl:Thing" ) {
        objectDef += indent + " rdfs:range " + range.prefixRepresentation + ";\r\n";
      }
      
      // close statement now;
      
      var s_needUpdate = objectDef;
      var s_lastPtr = s_needUpdate.lastIndexOf(";");
      objectDef = s_needUpdate.substring(0, s_lastPtr) + " . \r\n";
    }
    
    return objectDef;
    
  }
  
  
  exportTTLModule.resultingTTL_Content = function (){
    return resultingTTLContent;
  };
  
  function getIndent( name ){
    if ( name === undefined ) {
      return "WHYEMPTYNAME?";
    }
    return new Array(name.length + 1).join(" ");
  }
  
  function prepareHeader(){
    resultingTTLContent += "#################################################################\r\n";
    resultingTTLContent += "###  Generated with the experimental alpha version of the TTL exporter of WebVOWL (version 1.1.7) " +
      " http://visualdataweb.de/webvowl/   ###\r\n";
    resultingTTLContent += "#################################################################\r\n\r\n";
    
  }
  
  function preparePrefixList(){
    var ontoIri = graph.options().getGeneralMetaObjectProperty('iri');
    var prefixList = graph.options().prefixList();
    var prefixDef = [];
    prefixDef.push('@prefix : \t\t<' + ontoIri + '> .');
    for ( var name in prefixList ) {
      if ( prefixList.hasOwnProperty(name) ) {
        prefixDef.push('@prefix ' + name + ': \t\t<' + prefixList[name] + '> .');
      }
    }
    prefixDef.push('@base \t\t\t<' + ontoIri + '> .\r\n');
    
    for ( var i = 0; i < prefixDef.length; i++ ) {
      resultingTTLContent += prefixDef[i] + '\r\n';
    }
  }
  
  function prepareOntologyDef(){
    var ontoIri = graph.options().getGeneralMetaObjectProperty('iri');
    var indent = getIndent('<' + ontoIri + '>');
    resultingTTLContent += '<' + ontoIri + '> rdf:type owl:Ontology ;\r\n' +
      getOntologyTitle(indent) +
      getOntologyDescription(indent) +
      getOntologyVersion(indent) +
      getOntologyAuthor(indent);
    
    // close the statement;
    var s_needUpdate = resultingTTLContent;
    var s_lastPtr = s_needUpdate.lastIndexOf(";");
    resultingTTLContent = s_needUpdate.substring(0, s_lastPtr) + " . \r\n";
  }
  
  function getOntologyTitle( indent ){
    return general_languageExtractor(indent, "title", "dc:title");
  }
  
  function getOntologyDescription( indent ){
    return general_languageExtractor(indent, "description", "dc:description");
  }
  
  function getOntologyAuthor( indent ){
    var languageElement = graph.options().getGeneralMetaObjectProperty('author');
    if ( languageElement ) {
      if ( typeof languageElement !== "object" ) {
        if ( languageElement.length === 0 )
          return ""; // an empty string
        var aString = indent + " dc:creator " + '"' + languageElement + '";\r\n';
        return aString;
      }
      // we assume this thing is an array;
      var authorString = indent + " dc:creator " + '"';
      for ( var i = 0; i < languageElement.length - 1; i++ ) {
        authorString += languageElement[i] + ", ";
      }
      authorString += languageElement[languageElement.length - 1] + '";\r\n';
      return authorString;
    } else {
      return ""; // an empty string
    }
  }
  
  function getOntologyVersion( indent ){
    var languageElement = graph.options().getGeneralMetaObjectProperty('version');
    if ( languageElement ) {
      if ( typeof languageElement !== "object" ) {
        if ( languageElement.length === 0 )
          return ""; // an empty string
      }
      return general_languageExtractor(indent, "version", "owl:versionInfo");
    } else return ""; // an empty string
  }
  
  function general_languageExtractor( indent, metaObjectDescription, annotationDescription, endStatement ){
    var languageElement = graph.options().getGeneralMetaObjectProperty(metaObjectDescription);
    
    if ( typeof languageElement === 'object' ) {
      
      var resultingLanguages = [];
      for ( var name in languageElement ) {
        if ( languageElement.hasOwnProperty(name) ) {
          var content = languageElement[name];
          if ( name === "undefined" ) {
            resultingLanguages.push(indent + " " + annotationDescription + ' "' + content + '"@en; \r\n');
          }
          else {
            resultingLanguages.push(indent + " " + annotationDescription + ' "' + content + '"@' + name + '; \r\n');
          }
        }
      }
      // create resulting titles;
      
      var resultingString = "";
      for ( var i = 0; i < resultingLanguages.length; i++ ) {
        resultingString += resultingLanguages[i];
      }
      if ( endStatement && endStatement === true ) {
        var needUpdate = resultingString;
        var lastPtr = needUpdate.lastIndexOf(";");
        return needUpdate.substring(0, lastPtr) + ". \r\n";
      } else {
        return resultingString;
      }
      
    } else {
      if ( endStatement && endStatement === true ) {
        var s_needUpdate = indent + " " + annotationDescription + ' "' + languageElement + '"@en; \r\n';
        var s_lastPtr = s_needUpdate.lastIndexOf(";");
        return s_needUpdate.substring(0, s_lastPtr) + " . \r\n";
      }
      return indent + " " + annotationDescription + ' "' + languageElement + '"@en;\r\n';
    }
  }
  
  function general_Label_languageExtractor( indent, label, annotationDescription, endStatement ){
    var languageElement = label;
    
    if ( typeof languageElement === 'object' ) {
      var resultingLanguages = [];
      for ( var name in languageElement ) {
        if ( languageElement.hasOwnProperty(name) ) {
          var content = languageElement[name];
          if ( name === "undefined" ) {
            resultingLanguages.push(indent + " " + annotationDescription + ' "' + content + '"@en; \r\n');
          }
          else {
            resultingLanguages.push(indent + " " + annotationDescription + ' "' + content + '"@' + name + '; \r\n');
          }
        }
      }
      // create resulting titles;
      var resultingString = "";
      for ( var i = 0; i < resultingLanguages.length; i++ ) {
        resultingString += resultingLanguages[i];
      }
      if ( endStatement && endStatement === true ) {
        var needUpdate = resultingString;
        var lastPtr = needUpdate.lastIndexOf(";");
        return needUpdate.substring(0, lastPtr) + " . \r\n";
      } else {
        return resultingString;
      }
      
    } else {
      if ( endStatement && endStatement === true ) {
        var s_needUpdate = indent + " " + annotationDescription + ' "' + languageElement + '"@en; \r\n';
        var s_lastPtr = s_needUpdate.lastIndexOf(";");
        return s_needUpdate.substring(0, s_lastPtr) + " . \r\n";
      }
      return indent + " " + annotationDescription + ' "' + languageElement + '"@en; \r\n';
    }
  }
  
  return exportTTLModule;
};