package org.apache.maven.plugin.changes.schema;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.
   */
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.util.Map;
  
  import org.apache.commons.io.input.XmlStreamReader;
  
  import javax.xml.transform.stream.StreamSource;
  import javax.xml.validation.Schema;
  import javax.xml.validation.SchemaFactory;
  import javax.xml.validation.Validator;
  
  import org.codehaus.plexus.util.FastMap;
  import org.codehaus.plexus.util.IOUtil;
  
  import org.xml.sax.SAXException;
  
  /**
   *
   * @author Olivier Lamy
   * @since 28 juil. 2008
   * @version $Id: DefaultChangesSchemaValidator.java 1396150 2012-10-09 18:15:29Z krosenvold $
   *
   * @plexus.component role="org.apache.maven.plugin.changes.schema.ChangesSchemaValidator" role-hint="default"
   */
  public class DefaultChangesSchemaValidator
      implements ChangesSchemaValidator
  {
  
      /** property schema */
      public static final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";
  
      public static final String CHANGES_SCHEMA_PATH = "META-INF/changes/xsd/";
  
      private Map compiledSchemas = new FastMap();
  
      public XmlValidationHandler validateXmlWithSchema( File file, String schemaVersion, boolean failOnValidationError )
          throws SchemaValidatorException
      {
          Reader reader = null;
          try
          {
              String schemaPath = CHANGES_SCHEMA_PATH + "changes-" + schemaVersion + ".xsd";
  
              Schema schema = getSchema( schemaPath );
  
              Validator validator = schema.newValidator();
  
              XmlValidationHandler baseHandler = new XmlValidationHandler( failOnValidationError );
  
              validator.setErrorHandler( baseHandler );
  
              reader = new XmlStreamReader( file );
  
              validator.validate( new StreamSource( reader ) );
  
              return baseHandler;
          }
          catch ( IOException e )
          {
              throw new SchemaValidatorException( "IOException : " + e.getMessage(), e );
          }
          catch ( SAXException e )
          {
              throw new SchemaValidatorException( "SAXException : " + e.getMessage(), e );
          }
          catch ( Exception e )
          {
              throw new SchemaValidatorException( "Exception : " + e.getMessage(), e );
          }
          finally
          {
              IOUtil.close( reader );
          }
      }
  
      public Schema getSchema( String schemaPath )
         throws SAXException
     {
         if ( this.compiledSchemas.containsKey( schemaPath ) )
         {
             return (Schema) this.compiledSchemas.get( schemaPath );
         }
         Schema schema = this.compileJAXPSchema( schemaPath );
 
         this.compiledSchemas.put( schemaPath, schema );
 
         return schema;
     }
 
     /**
      * @param uriSchema
      * @return Schema
      * @throws Exception
      */
     private Schema compileJAXPSchema( String uriSchema )
         throws SAXException, NullPointerException
     {
 
         InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream( uriSchema );
 
         if ( is == null )
         {
             throw new NullPointerException( " impossible to load schema with path " + uriSchema );
         }
 
         try
         {
             //newInstance de SchemaFactory not ThreadSafe
             return SchemaFactory.newInstance( W3C_XML_SCHEMA ).newSchema( new StreamSource( is ) );
         }
         finally
         {
             IOUtil.close( is );
         }
     }
 
     public void loadSchema( String uriSchema )
         throws SchemaValidatorException
     {
         try
         {
             this.getSchema( uriSchema );
         }
         catch ( SAXException e )
         {
             throw new SchemaValidatorException( "SAXException : " + e.getMessage(), e );
         }
 
     }
 }