/**
    * Copyright (C) 2005-2009 Alfresco Software Limited.
    *
    * This file is part of the Spring Surf Extension project.
    *
    * 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 org.springframework.extensions.webscripts.connector;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.dom4j.Document;
  import org.dom4j.Element;
  import org.dom4j.io.OutputFormat;
  import org.dom4j.io.XMLWriter;
  import org.springframework.extensions.config.RemoteConfigElement.EndpointDescriptor;
  import org.springframework.extensions.surf.util.StringBuilderWriter;
  
  /**
   * A basic implementation of a persistent credential vault where
   * credentials are stored in XML on disk.
   * 
   * Note:  You should never use anything like this in production.  Rather,
   * it is suitable for test suites (locally and within test frameworks).
   * 
   * It also is a useful example of another kind of credential vault
   * 
   * @author muzquiano
   */
  public class XMLCredentialVault extends AbstractPersistentCredentialVault
  {
      private static Log logger = LogFactory.getLog(XMLCredentialVault.class);
      
      protected String location;
      
      /**
       * Instantiates a new XML credential vault.
       * 
       * @param id the id
       */
      public XMLCredentialVault(String id)
      {
          super(id);
      }
          
      public void setLocation(String location)
      {
          this.location = location;
      }
      
      public String getLocation()
      {
          return this.location;
      }
                  
      /* (non-Javadoc)
       * @see org.alfresco.connector.CredentialVault#load()
       */
      public boolean load()
      {
          boolean success = false;
          
          File file = new File(getLocation() + "/" + this.id + ".xml");
          if(file.exists())
          {
              StringBuilder contents = new StringBuilder();
              try 
              {
                  BufferedReader input = new BufferedReader(new FileReader(file));
                  try
                  {
                      String line = null;
      
                      while (( line = input.readLine()) != null)
                      {
                          contents.append(line);
                          contents.append(System.getProperty("line.separator"));
                      }
                      
                      // get the xml
                     String xml = contents.toString();
                     
                     // deserialize
                     deserialize(xml);
                     
                     // mark that the load was successful
                     success = true;
                 }
                 finally 
                 {
                     input.close();
                 }
             }
             catch (IOException ex)
             {
                 ex.printStackTrace();
             }   
         }
         else
         {
             if(logger.isDebugEnabled())
             {
                 logger.debug("Unable to load XML Credential Vault");
                 logger.debug("Not found: " + file.getAbsolutePath());
             }
         }
         
         return success;
     }
 
     /* (non-Javadoc)
      * @see org.alfresco.connector.CredentialVault#save()
      */
     public boolean save()
     {
         boolean success = false;
         
         String xml = serialize();
         
         File file = new File(getLocation() + "/" + this.id + ".xml");
         if(file.exists())
         {
             file.delete();
         }
         
         FileWriter fw = null;
         try
         {
             fw = new FileWriter(file, true);
             fw.write(xml);
             
             // mark that the save was successful
             success = true;
         }
         catch(Exception ex)
         {
             ex.printStackTrace();
         }
         finally
         {
             if(fw != null)
             {
                 try { fw.close(); } catch(Exception ex) { }
             }
         }
         
         return success;
     }
         
     /**
      * Serialize.
      * 
      * @return the string
      */
     protected String serialize()
     {
         Element rootElement = org.dom4j.DocumentHelper.createElement("vault");
         rootElement.addAttribute("id", this.id);
         
         Document d = org.dom4j.DocumentHelper.createDocument(rootElement);
         
         // walk through all of the endpoints
         Iterator it = credentialsMap.keySet().iterator();
         while(it.hasNext())
         {
             String endpointId = (String) it.next();
             
             EndpointDescriptor descriptor = getRemoteConfig().getEndpointDescriptor(endpointId);
             if(descriptor.getPersistent())
             {    
                 // store it
                 Element endpointElement = rootElement.addElement("endpoint");
                 endpointElement.addAttribute("id", endpointId);
                             
                 Credentials credentials = retrieve(endpointId);
     
                 String[] keys = credentials.getPropertyKeys();
                 for(int i = 0; i < keys.length; i++)
                 {
                     String value = (String) credentials.getProperty(keys[i]);
                     
                     Element credentialElement = endpointElement.addElement("credential");
                     credentialElement.addAttribute("id", keys[i]);
                     credentialElement.setText(value);
                 }
             }
         }
 
         return toXML(d, true);
     }
     
     /**
      * Deserialize.
      * 
      * @param xml the xml
      */
     protected void deserialize(String xml)
     {
         // reset the map
         //credentialsMap = new HashMap<String, Credentials>(16, 1.0f);
         
         // doc
         Document d = null;
         try
         {
             d = org.dom4j.DocumentHelper.parseText(xml);
             
             Element rootElement = d.getRootElement();
             this.id = rootElement.attributeValue("id");
             
             List endpoints = rootElement.elements("endpoint");
             for(int i = 0; i < endpoints.size(); i++)
             {
                 Element endpointElement = (Element) endpoints.get(i);
                 String endpointId = endpointElement.attributeValue("id");
                 
                 // check whether this endpoint id is a persistent one
                 EndpointDescriptor descriptor = getRemoteConfig().getEndpointDescriptor(endpointId);
                 if(descriptor.getPersistent())
                 {                
                     // create the credentials object
                     Credentials credz = newCredentials(endpointId);
                     
                     // populate
                     List credentialsList = endpointElement.elements("credential");
                     for(int k = 0; k < credentialsList.size(); k++)
                     {
                         Element credential = (Element) credentialsList.get(k);
                         
                         String credentialId = credential.attributeValue("id");
                         String credentialValue = credential.getTextTrim();
                         
                         credz.setProperty(credentialId, credentialValue);
                     }
                 
                     // set onto map
                     store(credz);
                 }
             }
         }
         catch(Exception ex)
         {
             ex.printStackTrace();
         }
     }
     
     /* (non-Javadoc)
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString()
     {
         return "XMLCredentialVault - " + location;
     }        
     
     /**
      * Converts the document to XML.  The pretty switch can be used to produce
      * human readable, or pretty, XML.
      * 
      * @param document the document
      * @param pretty whether to produce human readable XML
      * 
      * @return the string
      */
     public static String toXML(Document document, boolean pretty)
     {
         String xml = null;
         
         if (pretty)
         {
             OutputFormat format = OutputFormat.createPrettyPrint();
             format.setSuppressDeclaration(false);
 
             StringBuilderWriter writer = new StringBuilderWriter(256);
             XMLWriter xmlWriter = new XMLWriter(writer, format);
             try
             {
                 xmlWriter.write(document);
                 xmlWriter.flush();
                 xml = writer.toString();
             }
             catch (IOException ioe)
             {
                 /**
                  * If this exception occurs, we'll log a note to the console
                  * and then proceed to serialze the old fashioned way.
                  */
                 logger.debug(ioe);
             }
         }
 
         /**
          * If the XML wasn't created already, we'll serialize the
          * standard way.
          */
         if (xml == null)
         {
             xml = document.asXML();
         }
         
         return xml;
     }
     
 }