/**
    * Copyright (C) 2014-2015 Philip Helger (www.helger.com)
    * philip[at]helger[dot]com
    *
    * 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.
   */
  package com.helger.schematron.xslt;
  
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.NotThreadSafe;
  import javax.xml.transform.ErrorListener;
  import javax.xml.transform.Templates;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerConfigurationException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.URIResolver;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.w3c.dom.Document;
  
  import com.helger.commons.io.resource.IReadableResource;
  import com.helger.commons.xml.serialize.read.DOMReader;
  import com.helger.commons.xml.transform.DefaultTransformURIResolver;
  import com.helger.commons.xml.transform.TransformSourceFactory;
  import com.helger.commons.xml.transform.XMLTransformerFactory;
  
  /**
   * This Schematron validator factory uses an existing, precompiled Schematron
   * XSLT for validation.
   *
   * @author Philip Helger
   */
  @NotThreadSafe
  final class SchematronProviderXSLTPrebuild implements ISchematronXSLTBasedProvider
  {
    private static final Logger s_aLogger = LoggerFactory.getLogger (SchematronProviderXSLTPrebuild.class);
    private Document m_aSchematronXSLTDoc;
    private Templates m_aSchematronXSLTTemplates;
  
    public SchematronProviderXSLTPrebuild (@Nullable final IReadableResource aXSLTResource,
                                           @Nullable final ErrorListener aCustomErrorListener,
                                           @Nullable final URIResolver aCustomURIResolver)
    {
      try
      {
        // Read XSLT file as XML
        m_aSchematronXSLTDoc = DOMReader.readXMLDOM (aXSLTResource);
  
        // compile result of read file
        final TransformerFactory aTF = XMLTransformerFactory.createTransformerFactory (aCustomErrorListener,
                                                                                       new DefaultTransformURIResolver (aCustomURIResolver));
        m_aSchematronXSLTTemplates = aTF.newTemplates (TransformSourceFactory.create (m_aSchematronXSLTDoc));
      }
      catch (final Exception ex)
      {
        s_aLogger.error ("XSLT read/compilation error for " + aXSLTResource, ex);
      }
    }
  
    public boolean isValidSchematron ()
    {
      return m_aSchematronXSLTTemplates != null;
    }
  
    @Nullable
    public Document getXSLTDocument ()
    {
      return m_aSchematronXSLTDoc;
    }
  
    @Nullable
    public Transformer getXSLTTransformer () throws TransformerConfigurationException
    {
      return m_aSchematronXSLTTemplates == null ? null : m_aSchematronXSLTTemplates.newTransformer ();
    }
  }