/**
    * 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 java.io.InputStream;
  import java.util.Locale;
  import java.util.Map;
  
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.NotThreadSafe;
  import javax.xml.transform.ErrorListener;
  import javax.xml.transform.Source;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.URIResolver;
  import javax.xml.transform.dom.DOMResult;
  
  import org.oclc.purl.dsdl.svrl.SchematronOutputType;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  
  import com.helger.commons.ValueEnforcer;
  import com.helger.commons.annotation.ReturnsMutableCopy;
  import com.helger.commons.collection.CollectionHelper;
  import com.helger.commons.io.IHasInputStream;
  import com.helger.commons.io.resource.IReadableResource;
  import com.helger.commons.io.stream.StreamHelper;
  import com.helger.commons.lang.GenericReflection;
  import com.helger.commons.state.EValidity;
  import com.helger.commons.string.ToStringGenerator;
  import com.helger.commons.xml.XMLFactory;
  import com.helger.commons.xml.serialize.write.XMLWriter;
  import com.helger.commons.xml.transform.LoggingTransformErrorListener;
  import com.helger.commons.xml.transform.TransformSourceFactory;
  import com.helger.schematron.AbstractSchematronResource;
  import com.helger.schematron.svrl.SVRLReader;
  import com.helger.schematron.xslt.validator.ISchematronXSLTValidator;
  import com.helger.schematron.xslt.validator.SchematronXSLTValidatorDefault;
  
  /**
   * Abstract implementation of a Schematron resource that is based on XSLT
   * transformations.
   *
   * @author Philip Helger
   * @param <IMPLTYPE>
   *        Implementation type
   */
  @NotThreadSafe
  public abstract class AbstractSchematronXSLTBasedResource <IMPLTYPE extends AbstractSchematronXSLTBasedResource <IMPLTYPE>> extends AbstractSchematronResource
  {
    private static final Logger s_aLogger = LoggerFactory.getLogger (AbstractSchematronXSLTBasedResource.class);
  
    protected ErrorListener m_aCustomErrorListener;
    protected URIResolver m_aCustomURIResolver;
    protected Map <String, ?> m_aCustomParameters;
    private ISchematronXSLTValidator m_aXSLTValidator = new SchematronXSLTValidatorDefault ();
  
    public AbstractSchematronXSLTBasedResource (@Nonnull final IReadableResource aSCHResource)
    {
      super (aSCHResource);
    }
  
    @Nonnull
    protected final IMPLTYPE thisAsT ()
    {
      // Avoid the unchecked cast warning in all places
      return GenericReflection.<AbstractSchematronXSLTBasedResource <IMPLTYPE>, IMPLTYPE> uncheckedCast (this);
    }
  
    @Nullable
    public ErrorListener getErrorListener ()
    {
      return m_aCustomErrorListener;
    }
  
    @Nonnull
    public IMPLTYPE setErrorListener (@Nullable final ErrorListener aCustomErrorListener)
    {
      m_aCustomErrorListener = aCustomErrorListener;
      return thisAsT ();
    }
  
   @Nullable
   public URIResolver getURIResolver ()
   {
     return m_aCustomURIResolver;
   }
 
   @Nonnull
   public IMPLTYPE setURIResolver (@Nullable final URIResolver aCustomURIResolver)
   {
     m_aCustomURIResolver = aCustomURIResolver;
     return thisAsT ();
   }
 
   public boolean hasParameters ()
   {
     return CollectionHelper.isNotEmpty (m_aCustomParameters);
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public Map <String, ?> getParameters ()
   {
     return CollectionHelper.newOrderedMap (m_aCustomParameters);
   }
 
   @Nonnull
   public IMPLTYPE setParameters (@Nullable final Map <String, ?> aCustomParameters)
   {
     m_aCustomParameters = CollectionHelper.newOrderedMap (aCustomParameters);
     return thisAsT ();
   }
 
   /**
    * @return The XSLT provider passed in the constructor. May be
    *         <code>null</code>.
    */
   @Nullable
   public abstract ISchematronXSLTBasedProvider getXSLTProvider ();
 
   /**
    * @return The XSLT validator to be used. Never <code>null</code>.
    */
   @Nonnull
   public ISchematronXSLTValidator getXSLTValidator ()
   {
     return m_aXSLTValidator;
   }
 
   @Nonnull
   public IMPLTYPE setXSLTValidator (@Nonnull final ISchematronXSLTValidator aXSLTValidator)
   {
     ValueEnforcer.notNull (aXSLTValidator, "XSLTValidator");
     m_aXSLTValidator = aXSLTValidator;
     return thisAsT ();
   }
 
   public final boolean isValidSchematron ()
   {
     final ISchematronXSLTBasedProvider aXSLTProvider = getXSLTProvider ();
     return aXSLTProvider != null && aXSLTProvider.isValidSchematron ();
   }
 
   @Nonnull
   public EValidity getSchematronValidity (@Nonnull final IHasInputStream aXMLResource) throws Exception
   {
     ValueEnforcer.notNull (aXMLResource, "XMLResource");
 
     final InputStream aIS = aXMLResource.getInputStream ();
     if (aIS == null)
     {
       // Resource not found
       s_aLogger.warn ("XML resource " + aXMLResource + " does not exist!");
       return EValidity.INVALID;
     }
 
     try
     {
       // InputStream to Source
       return getSchematronValidity (TransformSourceFactory.create (aIS));
     }
     finally
     {
       // Ensure InputStream is closed
       StreamHelper.close (aIS);
     }
   }
 
   @Nonnull
   public EValidity getSchematronValidity (@Nonnull final Source aXMLSource) throws Exception
   {
     // We don't have a short circuit here - apply the full validation
     final SchematronOutputType aSO = applySchematronValidationToSVRL (aXMLSource);
     if (aSO == null)
       return EValidity.INVALID;
 
     // And now filter all elements that make the passed source invalid
     return m_aXSLTValidator.getSchematronValidity (aSO);
   }
 
   @Nullable
   public Document applySchematronValidation (@Nonnull final IHasInputStream aXMLResource) throws Exception
   {
     ValueEnforcer.notNull (aXMLResource, "XMLResource");
 
     final InputStream aIS = aXMLResource.getInputStream ();
     if (aIS == null)
     {
       // Resource not found
       s_aLogger.warn ("XML resource " + aXMLResource + " does not exist!");
       return null;
     }
 
     try
     {
       return applySchematronValidation (TransformSourceFactory.create (aIS));
     }
     finally
     {
       StreamHelper.close (aIS);
     }
   }
 
   @Nullable
   public Document applySchematronValidation (@Nonnull final Node aXMLResource) throws Exception
   {
     ValueEnforcer.notNull (aXMLResource, "XMLResource");
 
     return applySchematronValidation (TransformSourceFactory.create (aXMLResource));
   }
 
   @Nullable
   public final Document applySchematronValidation (@Nonnull final Source aXMLSource) throws TransformerException
   {
     ValueEnforcer.notNull (aXMLSource, "XMLSource");
 
     final ISchematronXSLTBasedProvider aXSLTProvider = getXSLTProvider ();
     if (aXSLTProvider == null || !aXSLTProvider.isValidSchematron ())
     {
       // We cannot progress because of invalid Schematron
       return null;
     }
 
     // Create result document
     final Document ret = XMLFactory.newDocument ();
 
     // Create the transformer object from the templates specified in the
     // constructor
     final Transformer aTransformer = aXSLTProvider.getXSLTTransformer ();
 
     // Apply customizations
     // Ensure an error listener is present
     if (m_aCustomErrorListener != null)
       aTransformer.setErrorListener (m_aCustomErrorListener);
     else
       aTransformer.setErrorListener (new LoggingTransformErrorListener (Locale.US));
 
     // Set the optional URI Resolver
     if (m_aCustomURIResolver != null)
       aTransformer.setURIResolver (m_aCustomURIResolver);
 
     // Set all custom parameters
     if (m_aCustomParameters != null)
       for (final Map.Entry <String, ?> aEntry : m_aCustomParameters.entrySet ())
         aTransformer.setParameter (aEntry.getKey (), aEntry.getValue ());
 
     // Debug print the created XSLT document
     if (false)
       System.out.println (XMLWriter.getXMLString (aXSLTProvider.getXSLTDocument ()));
 
     // Do the main transformation
     aTransformer.transform (aXMLSource, new DOMResult (ret));
 
     // Debug print the created SVRL document
     if (false)
       System.out.println (XMLWriter.getXMLString (ret));
 
     return ret;
   }
 
   @Nullable
   public SchematronOutputType applySchematronValidationToSVRL (@Nonnull final IHasInputStream aXMLResource) throws Exception
   {
     final Document aDoc = applySchematronValidation (aXMLResource);
     return aDoc == null ? null : SVRLReader.readXML (aDoc);
   }
 
   @Nullable
   public SchematronOutputType applySchematronValidationToSVRL (@Nonnull final Source aXMLSource) throws Exception
   {
     final Document aDoc = applySchematronValidation (aXMLSource);
     return aDoc == null ? null : SVRLReader.readXML (aDoc);
   }
 
   @Nullable
   public SchematronOutputType applySchematronValidationToSVRL (@Nonnull final Node aXMLSource) throws Exception
   {
     final Document aDoc = applySchematronValidation (aXMLSource);
     return aDoc == null ? null : SVRLReader.readXML (aDoc);
   }
 
   @Override
   public String toString ()
   {
     return ToStringGenerator.getDerived (super.toString ()).append ("XSLTValidator", m_aXSLTValidator).toString ();
   }
 }