package org.apache.maven.archiva.xml;

 /*

  * 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 org.apache.commons.io.IOUtils;

 import org.apache.commons.lang.StringUtils;

 import org.dom4j.Attribute;

 import org.dom4j.Document;

 import org.dom4j.DocumentException;

 import org.dom4j.Element;

 import org.dom4j.Namespace;

 import org.dom4j.Node;

 import org.dom4j.QName;

 import org.dom4j.XPath;

 import org.dom4j.io.SAXReader;

 import java.io.File;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 /**

  * XMLReader - a set of common xml utility methods for reading content out of an xml file. 

  *

  * @version $Id: XMLReader.java 755323 2009-03-17 17:03:45Z brett $

  */

 public class XMLReader

 {

     private URL xmlUrl;

     private String documentType;

     private Document document;

     private Map<String, String> namespaceMap = new HashMap<String, String>();

     public XMLReader( String type, File file )

         throws XMLException

     {

         if ( !file.exists() )

         {

             throw new XMLException( "file does not exist: " + file.getAbsolutePath() );

         }

         if ( !file.isFile() )

         {

             throw new XMLException( "path is not a file: " + file.getAbsolutePath() );

         }

         if ( !file.canRead() )

         {

             throw new XMLException( "Cannot read xml file due to permissions: " + file.getAbsolutePath() );

         }

         try

         {

             init( type, file.toURL() );

         }

         catch ( MalformedURLException e )

         {

             throw new XMLException( "Unable to translate file " + file + " to URL: " + e.getMessage(), e );

         }

     }

     public XMLReader( String type, URL url )

         throws XMLException

     {

         init( type, url );

     }

     private void init( String type, URL url )

         throws XMLException

     {

         this.documentType = type;

         this.xmlUrl = url;

         InputStream in = null;

         SAXReader reader = new SAXReader();

         try

         {

             in = url.openStream();

             InputStreamReader inReader = new InputStreamReader( in, "UTF-8" );

             LatinEntityResolutionReader latinReader = new LatinEntityResolutionReader( inReader );

             this.document = reader.read( latinReader );

         }

         catch ( DocumentException e )

         {

             throw new XMLException( "Unable to parse " + documentType + " xml " + xmlUrl + ": " + e.getMessage(), e );

         }

         catch ( IOException e )

         {

             throw new XMLException( "Unable to open stream to " + url + ": " + e.getMessage(), e );

         }

         finally

         {

             IOUtils.closeQuietly( in );

         }

         Element root = this.document.getRootElement();

         if ( root == null )

         {

             throw new XMLException( "Invalid " + documentType + " xml: root element is null." );

         }

         if ( !StringUtils.equals( root.getName(), documentType ) )

         {

             throw new XMLException( "Invalid " + documentType + " xml: Unexpected root element <" + root.getName()

                 + ">, expected <" + documentType + ">" );

         }

     }

     public String getDefaultNamespaceURI()

     {

         Namespace namespace = this.document.getRootElement().getNamespace();

         return namespace.getURI();

     }

     public void addNamespaceMapping( String elementName, String uri )

     {

         this.namespaceMap.put( elementName, uri );

     }

     public Element getElement( String xpathExpr )

         throws XMLException

     {

         XPath xpath = createXPath( xpathExpr );

         Object evaluated = xpath.selectSingleNode( document );

         if ( evaluated == null )

         {

             return null;

         }

         if ( evaluated instanceof Element )

         {

             Element evalElem = (Element) evaluated;

             return evalElem;

         }

         else

         {

             // Unknown evaluated type.

             throw new XMLException( ".getElement( Expr: " + xpathExpr + " ) resulted in non-Element type -> ("

                 + evaluated.getClass().getName() + ") " + evaluated );

         }

     }

     private XPath createXPath( String xpathExpr )

     {

         XPath xpath = document.createXPath( xpathExpr );

         if ( !this.namespaceMap.isEmpty() )

         {

             xpath.setNamespaceURIs( this.namespaceMap );

         }

         return xpath;

     }

     public boolean hasElement( String xpathExpr )

         throws XMLException

     {

         XPath xpath = createXPath( xpathExpr );

         Object evaluated = xpath.selectSingleNode( document );

         if ( evaluated == null )

         {

             return false;

         }

         return true;

     }

     /**

      * Remove namespaces from entire document.

      */

     public void removeNamespaces()

     {

         removeNamespaces( this.document.getRootElement() );

     }

     /**

      * Remove namespaces from element recursively.

      */

     @SuppressWarnings("unchecked")

     public void removeNamespaces( Element elem )

     {

         elem.setQName( QName.get( elem.getName(), Namespace.NO_NAMESPACE, elem.getQualifiedName() ) );

         Node n;

         Iterator<Node> it = elem.elementIterator();

         while ( it.hasNext() )

         {

             n = it.next();

             switch ( n.getNodeType() )

             {

                 case Node.ATTRIBUTE_NODE:

                     ( (Attribute) n ).setNamespace( Namespace.NO_NAMESPACE );

                     break;

                 case Node.ELEMENT_NODE:

                     removeNamespaces( (Element) n );

                     break;

             }

         }

     }

     public String getElementText( Node context, String xpathExpr )

         throws XMLException

     {

         XPath xpath = createXPath( xpathExpr );

         Object evaluated = xpath.selectSingleNode( context );

         if ( evaluated == null )

         {

             return null;

         }

         if ( evaluated instanceof Element )

         {

             Element evalElem = (Element) evaluated;

             return evalElem.getTextTrim();

         }

         else

         {

             // Unknown evaluated type.

             throw new XMLException( ".getElementText( Node, Expr: " + xpathExpr

                 + " ) resulted in non-Element type -> (" + evaluated.getClass().getName() + ") " + evaluated );

         }

     }

     public String getElementText( String xpathExpr )

         throws XMLException

     {

         XPath xpath = createXPath( xpathExpr );

         Object evaluated = xpath.selectSingleNode( document );

         if ( evaluated == null )

         {

             return null;

         }

         if ( evaluated instanceof Element )

         {

             Element evalElem = (Element) evaluated;

             return evalElem.getTextTrim();

         }

         else

         {

             // Unknown evaluated type.

             throw new XMLException( ".getElementText( Expr: " + xpathExpr + " ) resulted in non-Element type -> ("

                 + evaluated.getClass().getName() + ") " + evaluated );

         }

     }

     @SuppressWarnings("unchecked")

     public List<Element> getElementList( String xpathExpr )

         throws XMLException

     {

         XPath xpath = createXPath( xpathExpr );

         Object evaluated = xpath.evaluate( document );

         if ( evaluated == null )

         {

             return null;

         }

         /* The xpath.evaluate(Context) method can return:

          *   1) A Collection or List of dom4j Nodes. 

          *   2) A single dom4j Node.

          */

         if ( evaluated instanceof List )

         {

             return (List<Element>) evaluated;

         }

         else if ( evaluated instanceof Node )

         {

             List<Element> ret = new ArrayList<Element>();

             ret.add( (Element) evaluated );

             return ret;

         }

         else

         {

             // Unknown evaluated type.

             throw new XMLException( ".getElementList( Expr: " + xpathExpr + " ) resulted in non-List type -> ("

                 + evaluated.getClass().getName() + ") " + evaluated );

         }

     }

     public List<String> getElementListText( String xpathExpr )

         throws XMLException

     {

         List<Element> elemList = getElementList( xpathExpr );

         if ( elemList == null )

         {

             return null;

         }

         List<String> ret = new ArrayList<String>();

         for ( Iterator<Element> iter = elemList.iterator(); iter.hasNext(); )

         {

             Element listelem = iter.next();

             ret.add( listelem.getTextTrim() );

         }

         return ret;

     }

 }