/*
    * 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 edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.nio.charset.StandardCharsets;
  import java.util.List;
  import javax.annotation.concurrent.NotThreadSafe;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.parsers.SAXParser;
  import org.apache.commons.io.ByteOrderMark;
  import org.apache.commons.io.input.BOMInputStream;
  
  import org.owasp.dependencycheck.utils.FileUtils;
  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 Hint Rules.
   *
   * @author Jeremy Long
   */
  @NotThreadSafe
  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_1_2 = "schema/dependency-hint.1.2.xsd";
  
      /**
       * The schema for the hint XML files.
       */
      private static final String HINT_SCHEMA_1_1 = "schema/dependency-hint.1.1.xsd";
  
      /**
       * The schema for the hint XML files.
       */
      private static final String HINT_SCHEMA_1_3 = "schema/dependency-hint.1.3.xsd";
  
      /**
       * The schema for the hint XML files.
       */
      private static final String HINT_SCHEMA_1_4 = "schema/dependency-hint.1.4.xsd";
  
      /**
       * The hint rules.
       */
      private List<HintRule> hintRules;
      /**
       * The vendor duplicating hint rules.
       */
      private List<VendorDuplicatingHintRule> vendorDuplicatingHintRules;
 
     /**
      * Returns the hint rules.
      *
      * @return the hint rules
      */
     @SuppressWarnings({"EI_EXPOSE_REP", "EI_EXPOSE_REP2"})
     public List<HintRule> getHintRules() {
         return hintRules;
     }
 
     /**
      * Returns the vendor duplicating hint rules.
      *
      * @return the vendor duplicating hint rules
      */
     public List<VendorDuplicatingHintRule> getVendorDuplicatingHintRules() {
         return vendorDuplicatingHintRules;
     }
 
     /**
      * Parses the given XML file and returns a list of the hints contained.
      *
      * @param file an XML file containing hints
      * @throws HintParseException thrown if the XML file cannot be parsed
      */
     @SuppressFBWarnings(justification = "try with resources will clean up the input stream", value = {"OBL_UNSATISFIED_OBLIGATION"})
     public void parseHints(File file) throws HintParseException {
         try (InputStream fis = new FileInputStream(file)) {
             parseHints(fis);
         } catch (SAXException | IOException ex) {
             LOGGER.debug("", ex);
             throw new HintParseException(ex);
         }
     }
 
     /**
      * Parses the given XML stream and returns a list of the hint rules
      * contained.
      *
      * @param inputStream an InputStream containing hint rules
      * @throws HintParseException thrown if the XML cannot be parsed
      * @throws SAXException thrown if the XML cannot be parsed
      */
     public void parseHints(InputStream inputStream) throws HintParseException, SAXException {
         try (
                 InputStream schemaStream14 = FileUtils.getResourceAsStream(HINT_SCHEMA_1_4);
                 InputStream schemaStream13 = FileUtils.getResourceAsStream(HINT_SCHEMA_1_3);
                 InputStream schemaStream12 = FileUtils.getResourceAsStream(HINT_SCHEMA_1_2);
                 InputStream schemaStream11 = FileUtils.getResourceAsStream(HINT_SCHEMA_1_1)) {
 
             final BOMInputStream bomStream = BOMInputStream.builder().setInputStream(inputStream).get();
             final ByteOrderMark bom = bomStream.getBOM();
             final String defaultEncoding = StandardCharsets.UTF_8.name();
             final String charsetName = bom == null ? defaultEncoding : bom.getCharsetName();
 
             final HintHandler handler = new HintHandler();
             final SAXParser saxParser = XmlUtils.buildSecureSaxParser(schemaStream14, schemaStream13, schemaStream12, schemaStream11);
             final XMLReader xmlReader = saxParser.getXMLReader();
             xmlReader.setErrorHandler(new HintErrorHandler());
             xmlReader.setContentHandler(handler);
             try (Reader reader = new InputStreamReader(bomStream, charsetName)) {
                 final InputSource in = new InputSource(reader);
                 xmlReader.parse(in);
                 this.hintRules = handler.getHintRules();
                 this.vendorDuplicatingHintRules = handler.getVendorDuplicatingHintRules();
             }
         } catch (ParserConfigurationException | IOException 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);
             }
         }
     }
 }