/*
    * This file is part of dependency-check-core.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * Copyright (c) 2013 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.xml.suppression;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.util.List;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.parsers.SAXParser;
  import org.owasp.dependencycheck.utils.XmlUtils;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  import org.xml.sax.XMLReader;
  
  /**
   * A simple validating parser for XML Suppression Rules.
   *
   * @author Jeremy Long
   */
  public class SuppressionParser {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(SuppressionParser.class);
      /**
       * The suppression schema file location.
       */
      public static final String SUPPRESSION_SCHEMA = "schema/dependency-suppression.1.1.xsd";
      /**
       * The old suppression schema file location.
       */
      private static final String OLD_SUPPRESSION_SCHEMA = "schema/suppression.xsd";
  
      /**
       * Parses the given XML file and returns a list of the suppression rules
       * contained.
       *
       * @param file an XML file containing suppression rules
       * @return a list of suppression rules
       * @throws SuppressionParseException thrown if the XML file cannot be parsed
       */
      public List<SuppressionRule> parseSuppressionRules(File file) throws SuppressionParseException {
          FileInputStream fis = null;
          try {
              fis = new FileInputStream(file);
              return parseSuppressionRules(fis);
          } catch (IOException ex) {
              LOGGER.debug("", ex);
              throw new SuppressionParseException(ex);
          } catch (SAXException ex) {
              try {
                  if (fis != null) {
                      try {
                          fis.close();
                      } catch (IOException ex1) {
                          LOGGER.debug("Unable to close stream", ex1);
                      }
                  }
                  fis = new FileInputStream(file);
              } catch (FileNotFoundException ex1) {
                  throw new SuppressionParseException(ex);
              }
              try {
                  return parseSuppressionRules(fis, OLD_SUPPRESSION_SCHEMA);
              } catch (SAXException ex1) {
                  throw new SuppressionParseException(ex);
              }
          } finally {
              if (fis != null) {
                  try {
                      fis.close();
                  } catch (IOException ex) {
                      LOGGER.debug("Unable to close stream", ex);
                  }
              }
         }
     }
 
     /**
      * Parses the given XML stream and returns a list of the suppression rules
      * contained.
      *
      * @param inputStream an InputStream containing suppression rules
      * @return a list of suppression rules
      * @throws SuppressionParseException thrown if the XML cannot be parsed
      * @throws SAXException thrown if the XML cannot be parsed
      */
     public List<SuppressionRule> parseSuppressionRules(InputStream inputStream) throws SuppressionParseException, SAXException {
         return parseSuppressionRules(inputStream, SUPPRESSION_SCHEMA);
     }
 
     /**
      * Parses the given XML stream and returns a list of the suppression rules
      * contained.
      *
      * @param inputStream an InputStream containing suppression rules
      * @param schema the schema used to validate the XML stream
      * @return a list of suppression rules
      * @throws SuppressionParseException thrown if the XML cannot be parsed
      * @throws SAXException thrown if the XML cannot be parsed
      */
     private List<SuppressionRule> parseSuppressionRules(InputStream inputStream, String schema) throws SuppressionParseException, SAXException {
         InputStream schemaStream = null;
         try {
             schemaStream = this.getClass().getClassLoader().getResourceAsStream(schema);
             final SuppressionHandler handler = new SuppressionHandler();
             final SAXParser saxParser = XmlUtils.buildSecureSaxParser(schemaStream);
             final XMLReader xmlReader = saxParser.getXMLReader();
             xmlReader.setErrorHandler(new SuppressionErrorHandler());
             xmlReader.setContentHandler(handler);
             final Reader reader = new InputStreamReader(inputStream, "UTF-8");
             final InputSource in = new InputSource(reader);
             xmlReader.parse(in);
             return handler.getSuppressionRules();
         } catch (ParserConfigurationException ex) {
             LOGGER.debug("", ex);
             throw new SuppressionParseException(ex);
         } catch (SAXException ex) {
             if (ex.getMessage().contains("Cannot find the declaration of element 'suppressions'.")) {
                 throw ex;
             } else {
                 LOGGER.debug("", ex);
                 throw new SuppressionParseException(ex);
             }
         } catch (FileNotFoundException ex) {
             LOGGER.debug("", ex);
             throw new SuppressionParseException(ex);
         } catch (IOException ex) {
             LOGGER.debug("", ex);
             throw new SuppressionParseException(ex);
         } finally {
             if (schemaStream != null) {
                 try {
                     schemaStream.close();
                 } catch (IOException ex) {
                     LOGGER.debug("Error closing suppression file stream", ex);
                 }
             }
         }
     }
 }