/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.http;

import java.net.MalformedURLException;
import java.util.Hashtable;

import javax.servlet.RequestDispatcher;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.osgi.service.http.HttpContext;


public class ResourceRegistration implements Registration {

  // private fields

  private final String alias;
  private final HttpContext httpContext;
  private final ServletContextManager contextManager;
  private final ServletContext context;
  private final ServletConfig config;


  // constructors

  public ResourceRegistration(final String alias,
                              final String realPath,
                              final HttpContext httpContext,
                              final ServletContextManager contextManager) {

    this.alias = alias;
    this.httpContext = httpContext;
    this.contextManager = contextManager;

    context = contextManager.getServletContext(httpContext, realPath);
    config = new ServletConfigImpl(new Hashtable(), context);
  }


  // private methods

  private boolean exists(String path) {

    if (path.startsWith(alias)) {
      try {
        return context.getResource(path.substring(alias.length())) != null;
      } catch (MalformedURLException ignore) { }
    }

    return false;
  }


  // implements Registration

  public RequestDispatcherImpl getRequestDispatcher(String uri) {

    if (!exists(uri))
      return null;

    RequestDispatcherImpl dispatcher =
        new RequestDispatcherImpl(alias, null, httpContext, config);
    dispatcher.setURI(uri);

    return dispatcher;
  }

  public void destroy() {
    contextManager.ungetServletContext(context);
  }

} // ResourceRegistration