/*!
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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 Lesser General Public License for more details.
 *
 * Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.platform.web.servlet;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.platform.api.cache.ICacheExpirationRegistry;
import org.pentaho.platform.api.cache.ILastModifiedCacheItem;
import org.pentaho.platform.engine.core.system.PentahoSystem;
import org.pentaho.platform.engine.services.SoapHelper;
import org.pentaho.platform.util.messages.LocaleHelper;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

/**
 * User: rfellows Date: 10/25/11 Time: 2:36 PM
 */
public class CacheExpirationService extends ServletBase {

  private static final Log logger = LogFactory.getLog( CacheExpirationService.class );
  private ICacheExpirationRegistry cacheExpirationRegistry;

  public CacheExpirationService() {
  }

  @Override
  public Log getLogger() {
    return logger;
  }

  @Override
  protected void doGet( HttpServletRequest req, HttpServletResponse resp ) throws ServletException, IOException {
    doPost( req, resp );
  }

  @Override
  protected void doPost( HttpServletRequest request, HttpServletResponse response ) throws ServletException,
    IOException {
    if ( cacheExpirationRegistry == null ) {
      cacheExpirationRegistry = PentahoSystem.get( ICacheExpirationRegistry.class, null );
    }
    OutputStream outputStream = response.getOutputStream();

    try {
      response.setContentType( "text/xml" ); //$NON-NLS-1$
      response.setStatus( HttpServletResponse.SC_OK );
      outputStream.write( SoapHelper.getSoapHeader().getBytes( LocaleHelper.getSystemEncoding() ) );
      outputStream.write( SoapHelper.openSoapResponse().getBytes( LocaleHelper.getSystemEncoding() ) );

      outputStream.write( getXml().getBytes( LocaleHelper.getSystemEncoding() ) );

      outputStream.write( SoapHelper.closeSoapResponse().getBytes( LocaleHelper.getSystemEncoding() ) );
      outputStream.write( SoapHelper.getSoapFooter().getBytes( LocaleHelper.getSystemEncoding() ) );

    } finally {
      outputStream.close();
    }
  }

  /**
   * this should only be used for granular unit testing. The ICacheExpirationRegistry is provided by PentahoSystem if
   * this is never called
   * 
   * @param registry
   */
  public void setExpirationRegistry( ICacheExpirationRegistry registry ) {
    this.cacheExpirationRegistry = registry;
  }

  public String getXml() {
    StringBuilder sb = new StringBuilder();
    sb.append( "<cache-expiration-items>" );
    if ( cacheExpirationRegistry != null ) {
      List<ILastModifiedCacheItem> cacheItems = cacheExpirationRegistry.getCachedItems();
      for ( ILastModifiedCacheItem item : cacheItems ) {
        sb.append( "<cache-item>" ); //$NON-NLS-1$
        sb.append( "<key>" ); //$NON-NLS-1$
        sb.append( item.getCacheKey() ); //$NON-NLS-1$
        sb.append( "</key>" ); //$NON-NLS-1$
        sb.append( "<last-modified>" ); //$NON-NLS-1$
        sb.append( Long.toString( item.getLastModified() ) );
        sb.append( "</last-modified>" ); //$NON-NLS-1$
        sb.append( "</cache-item>" ); //$NON-NLS-1$
      }
    }
    sb.append( "</cache-expiration-items>" ); //$NON-NLS-1$
    return sb.toString();
  }

}