/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016.  All rights reserved.

Contact:
     SYSTAP, LLC DBA Blazegraph
     2501 Calvert ST NW #106
     Washington, DC 20008
     licenses@blazegraph.com

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.

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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package com.bigdata.rdf.sail.webapp;

import java.util.Properties;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bigdata.journal.ITx;
import com.bigdata.rdf.sail.CreateKBTask;
import com.bigdata.util.NV;

/**
 * Extended to report the correct HTTP response to the client.
 */
class RestApiCreateKBTask extends AbstractDelegateRestApiTask<Void> {

   public RestApiCreateKBTask(final HttpServletRequest req,
         final HttpServletResponse resp, final String namespace,
         final Properties properties) {

      super(req, resp, namespace, ITx.UNISOLATED, new CreateKBTask(namespace,
            properties));

   }

   @Override
   public Void call() throws Exception {

      // Pre-condition check while holding locks.
      {

         // Resolve the namespace.  See BLZG-2023, BLZG-2041.
         // Note: We have a lock on the unisolated view of the namespace using the concurrency manager.
         final boolean exists = getIndexManager().getResourceLocator().locate(namespace, ITx.UNISOLATED) != null;

         if (exists) {
            /*
             * The namespace already exists.
             * 
             * Note: The response code is defined as 409 (Conflict) since 1.3.2.
             */
            throw new HttpOperationException(HttpServletResponse.SC_CONFLICT,
                  BigdataServlet.MIME_TEXT_PLAIN, "EXISTS: " + namespace);
         }

      }

      // Create namespace.
      super.call();

      /*
       * Note: The response code is defined as 201 (Created) since 1.3.2.
       */

      /**
       * Generate the absolute location of the new resource.
       * 
       * @see <a href="http://trac.bigdata.com/ticket/1187"> CREATE DATA SET
       *      does not report Location header </a>
       */
      final String locationURI;
      {
         // Obtain the reconstructed request URI.
         final StringBuffer sb = req.getRequestURL();
         if (sb.charAt(sb.length() - 1) != '/') {
            // Add trailing '/' iff not present.
            sb.append('/');
         }
         // append the name of the newly created namespace.
         sb.append(namespace);
         /*
          * append /sparql to get the SPARQL end point. This end point may be
          * used for query, update, service description, etc.
          */
         sb.append("/sparql");
         locationURI = sb.toString();
      }

      buildResponse(HttpServletResponse.SC_CREATED,
            MultiTenancyServlet.MIME_TEXT_PLAIN, "CREATED: " + namespace,
            new NV("Location", locationURI)
            );

      return null;

   }

   @Override
   final public boolean isReadOnly() {
      return false;
   }

}