package com.jsql.util;
   
   import com.jsql.model.InjectionModel;
   import com.jsql.model.exception.JSqlException;
   import org.apache.commons.lang3.StringUtils;
   import org.apache.logging.log4j.LogManager;
   import org.apache.logging.log4j.Logger;
   import org.w3c.dom.Document;
   import org.w3c.dom.Node;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  
  import javax.xml.XMLConstants;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  import java.io.IOException;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.util.regex.Pattern;
  
  public class SoapUtil {
      
      /**
       * Log4j logger sent to view.
       */
      private static final Logger LOGGER = LogManager.getRootLogger();
  
      private final InjectionModel injectionModel;
      
      public SoapUtil(InjectionModel injectionModel) {
          
          this.injectionModel = injectionModel;
      }
  
      public boolean testParameters(boolean hasFoundInjection) {
  
          if (!hasFoundInjection) {
              LOGGER.log(LogLevelUtil.CONSOLE_DEFAULT, "Checking SOAP params...");
          } else {
              return true;
          }
  
          if (
              this.injectionModel.getMediatorUtils().getPreferencesUtil().isCheckingAllSoapParam()
              && this.injectionModel.getMediatorUtils().getParameterUtil().isRequestSoap()
          ) {
              try {
                  var doc = SoapUtil.convertToDocument(this.injectionModel.getMediatorUtils().getParameterUtil().getRawRequest());
                  LOGGER.log(LogLevelUtil.CONSOLE_DEFAULT, "Parsing SOAP from Request...");
                  
                  return this.isTextNodeInjectable(doc, doc.getDocumentElement());
                  
              } catch (Exception e) {
                  LOGGER.log(LogLevelUtil.CONSOLE_DEFAULT, "SOAP not detected");
              }
          }
          
          return false;
      }
      
      public static Document convertToDocument(String xmlStr) throws ParserConfigurationException, SAXException, IOException {
          
          var factory = DocumentBuilderFactory.newInstance();
          
          factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, StringUtils.EMPTY);
          factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_SCHEMA, StringUtils.EMPTY);
          factory.setAttribute(XMLConstants.FEATURE_SECURE_PROCESSING, Boolean.TRUE);
          factory.setExpandEntityReferences(false);
  
          var builder = factory.newDocumentBuilder();
          
          return builder.parse(new InputSource(new StringReader(xmlStr)));
      }
  
      public boolean isTextNodeInjectable(Document doc, Node node) {
          
          var nodeList = node.getChildNodes();
  
          for (var i = 0; i < nodeList.getLength(); i++) {
              
              var currentNode = nodeList.item(i);
              
              if (currentNode.getNodeType() == Node.ELEMENT_NODE) {
                  //calls this method for all the children which is Element
                  if (this.isTextNodeInjectable(doc, currentNode)) {
                      return true;
                  }
              } else if (currentNode.getNodeType() == Node.TEXT_NODE) {
                  
                  SoapUtil.removeInjectionPoint(doc, doc.getDocumentElement());
                  
                  currentNode.setTextContent(currentNode.getTextContent().replace(InjectionModel.STAR, StringUtils.EMPTY) + InjectionModel.STAR);
                  
                  this.injectionModel.getMediatorUtils().getParameterUtil().initializeRequest(SoapUtil.convertDocumentToString(doc));
                  
                 try {
                     LOGGER.log(
                         LogLevelUtil.CONSOLE_INFORM,
                         "Checking SOAP Request injection for {}={}",
                         () -> currentNode.getParentNode().getNodeName(),
                         () -> currentNode.getTextContent().replace(InjectionModel.STAR, StringUtils.EMPTY)
                     );
                     
                     if (this.injectionModel.getMediatorMethod().getRequest().testParameters()) {
                         return true;
                     }
                 } catch (JSqlException e) {
                     // Injection failure
                     LOGGER.log(
                         LogLevelUtil.CONSOLE_ERROR,
                         String.format(
                             "No SOAP Request injection for %s=%s",
                             currentNode.getParentNode().getNodeName(),
                             currentNode.getTextContent().replace(InjectionModel.STAR, StringUtils.EMPTY)
                         )
                     );
                 }
             }
         }
         
         return false;
     }
 
     public static void removeInjectionPoint(Document doc, Node node) {
         
         var nodeList = node.getChildNodes();
         
         for (var i = 0; i < nodeList.getLength(); i++) {
             
             var currentNode = nodeList.item(i);
             
             if (currentNode.getNodeType() == Node.ELEMENT_NODE) {
                 //calls this method for all the children which is Element
                 SoapUtil.removeInjectionPoint(doc, currentNode);
             } else if (currentNode.getNodeType() == Node.TEXT_NODE) {
                 currentNode.setTextContent(
                     currentNode
                     .getTextContent()
                     .replaceAll(Pattern.quote(InjectionModel.STAR) + "*$", StringUtils.EMPTY)
                 );
             }
         }
     }
     
     private static String convertDocumentToString(Document doc) {
         
         var transformerFactory = TransformerFactory.newInstance();
         transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, StringUtils.EMPTY);
         transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, StringUtils.EMPTY);
         
         String output = null;
         
         try {
             var transformer = transformerFactory.newTransformer();
             var writer = new StringWriter();
             transformer.transform(new DOMSource(doc), new StreamResult(writer));
             output = writer.getBuffer().toString();
             
         } catch (TransformerException e) {
             // ignore
         }
         
         return output;
     }
 }