/*
    * 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) 2016 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.xml.hints;
  
  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 javax.xml.parsers.ParserConfigurationException;
  import javax.xml.parsers.SAXParser;
  import javax.xml.parsers.SAXParserFactory;
  
  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 Hint Rules.
   *
   * @author Jeremy Long
   */
  public class HintParser {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(HintParser.class);
      /**
       * JAXP Schema Language. Source:
       * http://docs.oracle.com/javase/tutorial/jaxp/sax/validation.html
       */
      public static final String JAXP_SCHEMA_LANGUAGE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
      /**
       * W3C XML Schema. Source:
       * http://docs.oracle.com/javase/tutorial/jaxp/sax/validation.html
       */
      public static final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";
      /**
       * JAXP Schema Source. Source:
       * http://docs.oracle.com/javase/tutorial/jaxp/sax/validation.html
       */
      public static final String JAXP_SCHEMA_SOURCE = "http://java.sun.com/xml/jaxp/properties/schemaSource";
  
      /**
       * The schema for the hint XML files.
       */
      private static final String HINT_SCHEMA = "schema/dependency-hint.1.1.xsd";
  
      /**
       * Parses the given XML file and returns a list of the hints contained.
       *
       * @param file an XML file containing hints
       * @return a list of hint rules
       * @throws HintParseException thrown if the XML file cannot be parsed
       */
      public Hints parseHints(File file) throws HintParseException {
          FileInputStream fis = null;
          try {
              fis = new FileInputStream(file);
              return parseHints(fis);
          } catch (IOException ex) {
              LOGGER.debug("", ex);
              throw new HintParseException(ex);
          } catch (SAXException ex) {
              throw new HintParseException(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 hint rules
       * contained.
      *
      * @param inputStream an InputStream containing hint rules
      * @return a list of hint rules
      * @throws HintParseException thrown if the XML cannot be parsed
      * @throws SAXException thrown if the XML cannot be parsed
      */
     public Hints parseHints(InputStream inputStream) throws HintParseException, SAXException {
         InputStream schemaStream = null;
         try {
             schemaStream = this.getClass().getClassLoader().getResourceAsStream(HINT_SCHEMA);
             final HintHandler handler = new HintHandler();
             final SAXParserFactory factory = SAXParserFactory.newInstance();
             factory.setNamespaceAware(true);
             factory.setValidating(true);
             final SAXParser saxParser = factory.newSAXParser();
             saxParser.setProperty(HintParser.JAXP_SCHEMA_LANGUAGE, HintParser.W3C_XML_SCHEMA);
             saxParser.setProperty(HintParser.JAXP_SCHEMA_SOURCE, new InputSource(schemaStream));
             final XMLReader xmlReader = saxParser.getXMLReader();
             xmlReader.setErrorHandler(new HintErrorHandler());
             xmlReader.setContentHandler(handler);
 
             final Reader reader = new InputStreamReader(inputStream, "UTF-8");
             final InputSource in = new InputSource(reader);
 
             xmlReader.parse(in);
             final Hints hints = new Hints();
             hints.setHintRules(handler.getHintRules());
             hints.setVendorDuplicatingHintRules(handler.getVendorDuplicatingHintRules());
             return hints;
         } catch (ParserConfigurationException ex) {
             LOGGER.debug("", ex);
             throw new HintParseException(ex);
         } catch (SAXException ex) {
             if (ex.getMessage().contains("Cannot find the declaration of element 'hints'.")) {
                 throw ex;
             } else {
                 LOGGER.debug("", ex);
                 throw new HintParseException(ex);
             }
         } catch (FileNotFoundException ex) {
             LOGGER.debug("", ex);
             throw new HintParseException(ex);
         } catch (IOException ex) {
             LOGGER.debug("", ex);
             throw new HintParseException(ex);
         } finally {
             if (schemaStream != null) {
                 try {
                     schemaStream.close();
                 } catch (IOException ex) {
                     LOGGER.debug("Error closing hint file stream", ex);
                 }
             }
         }
     }
 }