////////////////////////////////////////////////////////////////////////////////

 // checkstyle: Checks Java source code for adherence to a set of rules.

 // Copyright (C) 2001-2014  Oliver Burn

 //

 // This library is free software; you can redistribute it and/or

 // modify it under the terms of the GNU Lesser General Public

 // License as published by the Free Software Foundation; either

 // version 2.1 of the License, or (at your option) any later version.

 //

 // This library is distributed in the hope that it will be useful,

 // but WITHOUT ANY WARRANTY; without even the implied warranty of

 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 // Lesser General Public License for more details.

 //

 // You should have received a copy of the GNU Lesser General Public

 // License along with this library; if not, write to the Free Software

 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 ////////////////////////////////////////////////////////////////////////////////

 package com.puppycrawl.tools.checkstyle.filters;

 import java.io.File;

 import java.io.FileNotFoundException;

 import java.io.IOException;

 import java.net.MalformedURLException;

 import java.net.URI;

 import java.net.URISyntaxException;

 import java.net.URL;

 import java.util.Map;

 import java.util.regex.PatternSyntaxException;

 import javax.xml.parsers.ParserConfigurationException;

 import org.xml.sax.Attributes;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 import com.google.common.collect.Maps;

 import com.puppycrawl.tools.checkstyle.api.AbstractLoader;

 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;

 import com.puppycrawl.tools.checkstyle.api.FilterSet;

 /**

  * Loads a filter chain of suppressions.

  * @author Rick Giles

  */

 public final class SuppressionsLoader

     extends AbstractLoader

 {

     /** the public ID for the configuration dtd */

     private static final String DTD_PUBLIC_ID_1_0 =

         "-//Puppy Crawl//DTD Suppressions 1.0//EN";

     /** the resource for the configuration dtd */

     private static final String DTD_RESOURCE_NAME_1_0 =

         "com/puppycrawl/tools/checkstyle/suppressions_1_0.dtd";

     /** the public ID for the configuration dtd */

     private static final String DTD_PUBLIC_ID_1_1 =

         "-//Puppy Crawl//DTD Suppressions 1.1//EN";

     /** the resource for the configuration dtd */

     private static final String DTD_RESOURCE_NAME_1_1 =

         "com/puppycrawl/tools/checkstyle/suppressions_1_1.dtd";

     /**

      * the filter chain to return in getAFilterChain(),

      * configured during parsing

      */

     private final FilterSet mFilterChain = new FilterSet();

     /**

      * Creates a new <code>SuppressionsLoader</code> instance.

      * @throws ParserConfigurationException if an error occurs

      * @throws SAXException if an error occurs

      */

     private SuppressionsLoader()

         throws ParserConfigurationException, SAXException

     {

         super(createIdToResourceNameMap());

     }

     /**

      * Returns the loaded filter chain.

      * @return the loaded filter chain.

      */

     public FilterSet getFilterChain()

     {

         return mFilterChain;

     }

     @Override

     public void startElement(String aNamespaceURI,

                              String aLocalName,

                              String aQName,

                              Attributes aAtts)

         throws SAXException

     {

         if ("suppress".equals(aQName)) {

             //add SuppressElement filter to the filter chain

             final String files = aAtts.getValue("files");

             if (files == null) {

                 throw new SAXException("missing files attribute");

             }

             final String checks = aAtts.getValue("checks");

             final String modId = aAtts.getValue("id");

             if ((checks == null) && (modId == null)) {

                 throw new SAXException("missing checks and id attribute");

             }

             final SuppressElement suppress;

             try {

                 suppress = new SuppressElement(files);

                 if (modId != null) {

                     suppress.setModuleId(modId);

                 }

                 if (checks != null) {

                     suppress.setChecks(checks);

                 }

             }

             catch (final PatternSyntaxException e) {

                 throw new SAXException("invalid files or checks format");

             }

             final String lines = aAtts.getValue("lines");

             if (lines != null) {

                 suppress.setLines(lines);

             }

             final String columns = aAtts.getValue("columns");

             if (columns != null) {

                 suppress.setColumns(columns);

             }

             mFilterChain.addFilter(suppress);

         }

     }

     /**

      * Returns the suppression filters in a specified file.

      * @param aFilename name of the suppresssions file.

      * @return the filter chain of suppression elements specified in the file.

      * @throws CheckstyleException if an error occurs.

      */

     public static FilterSet loadSuppressions(String aFilename)

         throws CheckstyleException

     {

         try {

             // figure out if this is a File or a URL

             URI uri;

             try {

                 final URL url = new URL(aFilename);

                 uri = url.toURI();

             }

             catch (final MalformedURLException ex) {

                 uri = null;

             }

             catch (final URISyntaxException ex) {

                 // URL violating RFC 2396

                 uri = null;

             }

             if (uri == null) {

                 final File file = new File(aFilename);

                 if (file.exists()) {

                     uri = file.toURI();

                 }

                 else {

                     // check to see if the file is in the classpath

                     try {

                         final URL configUrl = SuppressionsLoader.class

                                 .getResource(aFilename);

                         if (configUrl == null) {

                             throw new FileNotFoundException(aFilename);

                         }

                         uri = configUrl.toURI();

                     }

                     catch (final URISyntaxException e) {

                         throw new FileNotFoundException(aFilename);

                     }

                 }

             }

             final InputSource source = new InputSource(uri.toString());

             return loadSuppressions(source, aFilename);

         }

         catch (final FileNotFoundException e) {

             throw new CheckstyleException("unable to find " + aFilename, e);

         }

     }

     /**

      * Returns the suppression filters in a specified source.

      * @param aSource the source for the suppressions.

      * @param aSourceName the name of the source.

      * @return the filter chain of suppression elements in aSource.

      * @throws CheckstyleException if an error occurs.

      */

     private static FilterSet loadSuppressions(

             InputSource aSource, String aSourceName)

         throws CheckstyleException

     {

         try {

             final SuppressionsLoader suppressionsLoader =

                 new SuppressionsLoader();

             suppressionsLoader.parseInputSource(aSource);

             return suppressionsLoader.getFilterChain();

         }

         catch (final FileNotFoundException e) {

             throw new CheckstyleException("unable to find " + aSourceName, e);

         }

         catch (final ParserConfigurationException e) {

             throw new CheckstyleException("unable to parse " + aSourceName, e);

         }

         catch (final SAXException e) {

             throw new CheckstyleException("unable to parse "

                     + aSourceName + " - " + e.getMessage(), e);

         }

         catch (final IOException e) {

             throw new CheckstyleException("unable to read " + aSourceName, e);

         }

         catch (final NumberFormatException e) {

             throw new CheckstyleException("number format exception "

                 + aSourceName + " - " + e.getMessage(), e);

         }

     }

     /**

      * Creates mapping between local resources and dtd ids.

      * @return map between local resources and dtd ids.

      */

     private static Map<String, String> createIdToResourceNameMap()

     {

         final Map<String, String> map = Maps.newHashMap();

         map.put(DTD_PUBLIC_ID_1_0, DTD_RESOURCE_NAME_1_0);

         map.put(DTD_PUBLIC_ID_1_1, DTD_RESOURCE_NAME_1_1);

         return map;

     }

 }