/*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * 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 net.sf.nxqd.common;
  
  import net.sf.nxqd.NxqdException;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  
  import org.apache.xml.serialize.OutputFormat;
  import org.apache.xml.serialize.XMLSerializer;
  
  import org.xml.sax.SAXException;
  import org.xml.sax.InputSource;
  
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.transform.stream.StreamResult;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerFactory;
  
  import java.io.IOException;
  import java.io.StringReader;
  import java.io.StringWriter;
  
  import java.util.ArrayList;
  import java.util.Map;
  import java.util.Set;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Random;
  import java.util.Date;
  
  /**
   * The class <code>Utils</code> is n abstract class to centralise common
   * uility methods for use by all the classes.
   *
   * @author <a href="mailto:webhiker@sourceforge.net">webhiker</a>
   * @version 1.0
   */
  public abstract class NxqdUtils {
      private static DocumentBuilder documentBuilder;
      private static Transformer serializer;
      private static Random random = new Random();
  
      /**
       * The <code>docToString</code> method converts a <code>Document</code>
       * object into a <code>java.lang.String</code>.
       *
       * @param document a <code>org.w3c.dom.Document</code> value
       * @return a <code>String</code> value
       * @exception NxqdException if an error occurs
       */
      public static final String docToString(Node node) throws NxqdException {
  	if (node instanceof Document) {
  	    return docToString((Document)node);
  	}
  	try {
  	    // Use transformer for serialization.
  	    if (serializer==null) {
  		serializer = TransformerFactory.newInstance().newTransformer();
  	    }
  	    StringWriter sw = new StringWriter();
  	    // using the null transformation to write the tree fragment to standard output 
  	    serializer.transform(new DOMSource(node), new StreamResult(sw));
  	    
  	    return sw.toString();
      	}
  	catch (Exception t) {
  	    throw new NxqdException(t);
  	}
      }
  
      /**
       * The <code>docToString</code> method converts a <code>Document</code>
       * object into a <code>java.lang.String</code>.
       *
       * @param document a <code>org.w3c.dom.Document</code> value
       * @return a <code>String</code> value
       * @exception NxqdException if an error occurs
       */
      public static final String docToString(Document document) throws NxqdException {
  	try {
  	    // this code now pretty prints the xml
 	    OutputFormat format = new OutputFormat(document);
 	    format.setLineWidth(80);
 	    format.setIndenting(true);
 	    format.setIndent(3);
 	    StringWriter sw = new StringWriter();
 	    XMLSerializer serializer = new XMLSerializer(sw, format);
 	    serializer.serialize(document);
 	    return sw.toString();
 
 	}
 	catch (Exception t) {
 	    throw new NxqdException(t);
 	}
     }
     
     /**
      * The <code>docFromString</code> method converts a <code>java.lang.String</code>
      * object into a <code>org.w3c.dom.Document</code>.
      *
      * @param documentAsString a <code>String</code> value
      * @return a <code>Document</code> value
      * @exception NxqdException if an error occurs
      */
     public static final Document docFromString(String documentAsString) throws NxqdException {
 	try {
 	    if (documentBuilder==null) {
 		// Create a builder factory
 		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
 		factory.setValidating(false);
 		documentBuilder = factory.newDocumentBuilder();
 	    }
 	    
 	    // Create the builder and parse the file
 	    return documentBuilder.parse(new InputSource(new StringReader(documentAsString)));
 	} catch (SAXException e) {
 	    throw new NxqdException(e);
 	} catch (ParserConfigurationException e) {
 	    throw new NxqdException(e);
 	} catch (IOException e) {
 	    throw new NxqdException(e);
 	}
     }
 
     /**
      * The <code>gsoapResultObjectToList</code> method converts
      * the strange gsoap behaviour into something more
      * consistent, as gsoap returns sometimes null, a string or
      * a List, dpending on the number of results.
      *
      * @param result an <code>Object</code> value
      * @return a <code>List</code> value
      */
     public static List gsoapResultObjectToList(Object result) {
 	if (result == null) {
 	    return new ArrayList();
 	}
 	else {
 	    // for some reason, if only one item is found
 	    // it s returned as a String
 	    if (result instanceof String) {
 		List resultList = new ArrayList();
 		resultList.add(result.toString());
 		return resultList;
 	    }
 	    else {
 		return (List)result;
 	    }
 	}
     }
 
     public static String generateUniqueId() {
 	Date date = new Date();
         String id;
 	id  = Integer.toString(Math.abs(random.nextInt(10)));
 	id += Math.abs(random.nextInt(10));
 	id += Math.abs(random.nextInt(10));
 	id += Long.toString(date.getTime()-1124437000000L);
 	id += Math.abs(random.nextInt(10));
 	id += Math.abs(random.nextInt(10));
 	return id;
     }
 
     public static List getKeysAsList(final Map map) {
 	if (map==null) {
 	    return null;
 	}
 	if (map.size()==0) {
 	    return null;
 	}
  	String key;
  	List list = new ArrayList(map.size());
 	for (Iterator e = map.keySet().iterator(); e.hasNext() ;) {
  	    key = e.next().toString();
 	    list.add(key);
  	}
 	return list;
     }
     
     public static List getValuesAsList(final Map map) {
 	if (map==null) {
 	    return null;
 	}
 	if (map.size()==0) {
 	    return null;
 	}
  	String key;
  	List list = new ArrayList(map.size());
 	for (Iterator e = map.keySet().iterator(); e.hasNext() ;) {
  	    key = e.next().toString();
 	    list.add(map.get(key));
  	}
  	return list;
     }
 }