/*
 * Data Hub Service (DHuS) - For Space data distribution.
 * Copyright (C) 2013,2014,2015 GAEL Systems
 *
 * This file is part of DHuS software sources.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package fr.gael.dhus.olingo.v1.entity;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;

import fr.gael.drb.DrbFactory;
import fr.gael.drb.DrbNode;
import fr.gael.drb.DrbSequence;
import fr.gael.drb.query.Query;

/**
 * Quicklook product must contains a quicklook
 */
public class QuicklookProduct extends Product
{
   // xpath_attributes is a set of xpath returning nodes (ClasscastException
   // overwise)
   private static String[] xpath_attributes = { "image/FormatName",
         "image/directory/Width", "image/directory/Height",
         "image/directory/NumBands" };

   /**
    * Build this Quicklook instance.
    * 
    * @param product
    * @throws NullPointerException is product contains no Quicklook.
    */
   public QuicklookProduct (fr.gael.dhus.database.object.Product product)
   {
      super (product);
   }

   @Override
   public String getId ()
   {
      return "Quicklook";
   }

   @Override
   public String getName ()
   {
      return "QL-" + product.getIdentifier ();
   }

   @Override
   public String getContentType ()
   {
      if (product.getQuicklookPath ().toLowerCase ().endsWith ("gif"))
         return "image/gif";
      else
         return "image/jpeg";
   }

   @Override
   public Long getContentLength ()
   {
      return product.getQuicklookSize ();
   }

   @Override
   public boolean requiresControl ()
   {
      return false;
   }

   @Override
   public Map<String, Product> getProducts ()
   {
      return new HashMap<String, Product> ();
   }

   @Override
   public Map<String, Node> getNodes ()
   {
      if (this.nodes == null)
      {
         Map<String, Node> nodes = new LinkedHashMap<String, Node> ();
         DrbNode parent = DrbFactory.openURI (getDownloadablePath ());
         if (parent != null) nodes.put (parent.getName (), new Node (parent));
         this.nodes = nodes;
      }
      return this.nodes;
   }

   /**
    * The returned list is immutable.
    */
   @Override
   public Map<String, Attribute> getAttributes ()
   {
      if (this.attributes == null)
      {
         Map<String, Attribute> attributes =
            new LinkedHashMap<String, Attribute> ();
         DrbNode node = DrbFactory.openURI (getDownloadablePath ());
         for (String xpath : xpath_attributes)
         {
            Query query = new Query (xpath);
            DrbSequence results = query.evaluate (node);
            if ( (results != null) && (results.getLength () > 0))
            {
               DrbNode result = (DrbNode) results.getItem (0);
               if (result.getValue () != null)
                  attributes.put (result.getName (),
                     new Attribute(result.getName(), result.getValue().toString(), null));
            }
         }
         this.attributes = attributes;
      }
      return this.attributes;
   }

   @Override
   public String getDownloadablePath ()
   {
      return product.getQuicklookPath ();
   }

   @Override
   public InputStream getInputStream () throws IOException
   {
      try
      {
         return new FileInputStream (product.getQuicklookPath ());
      }
      catch (Exception e)
      {
         throw new IOException ("Cannot get quicklook from product", e);
      }
   }
}