/*
    * Copyright (C) 2009-2010, Google Inc. and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.http.server.glue;
  
  import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
  
  import java.io.IOException;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  /**
   * Generic container servlet to manage routing to different pipelines.
   * <p>
   * Callers can create and configure a new processing pipeline by using one of
   * the {@link #serve(String)} or {@link #serveRegex(String)} methods to allocate
   * a binder for a particular URL pattern.
   * <p>
   * Registered filters and servlets are initialized lazily, usually during the
   * first request. Once initialized the bindings in this servlet cannot be
   * modified without destroying the servlet and thereby destroying all registered
   * filters and servlets.
   */
  public class MetaServlet extends HttpServlet {
  	private static final long serialVersionUID = 1L;
  
  	private final MetaFilter filter;
  
  	/**
  	 * Empty servlet with no bindings.
  	 */
  	public MetaServlet() {
  		this(new MetaFilter());
  	}
  
  	/**
  	 * Initialize a servlet wrapping a filter.
  	 *
  	 * @param delegateFilter
  	 *            the filter being wrapped by the servlet.
  	 */
  	protected MetaServlet(MetaFilter delegateFilter) {
  		filter = delegateFilter;
  	}
  
  	/**
  	 * Get delegate filter
  	 *
  	 * @return filter this servlet delegates all routing logic to.
  	 */
  	protected MetaFilter getDelegateFilter() {
  		return filter;
  	}
  
  	/**
  	 * Construct a binding for a specific path.
  	 *
  	 * @param path
  	 *            pattern to match.
  	 * @return binder for the passed path.
  	 */
  	public ServletBinder serve(String path) {
  		return filter.serve(path);
  	}
  
  	/**
  	 * Construct a binding for a regular expression.
  	 *
  	 * @param expression
  	 *            the regular expression to pattern match the URL against.
  	 * @return binder for the passed expression.
  	 */
  	public ServletBinder serveRegex(String expression) {
  		return filter.serveRegex(expression);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void init(ServletConfig config) throws ServletException {
  		String name = filter.getClass().getName();
  		ServletContext ctx = config.getServletContext();
  		filter.init(new NoParameterFilterConfig(name, ctx));
  	}
  
  	/** {@inheritDoc} */
 	@Override
 	public void destroy() {
 		filter.destroy();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	protected void service(HttpServletRequest req, HttpServletResponse res)
 			throws ServletException, IOException {
 		filter.doFilter(req, res,
 				(ServletRequest request, ServletResponse response) -> {
 					((HttpServletResponse) response).sendError(SC_NOT_FOUND);
 				});
 	}
 
 	/**
 	 * Configure a newly created binder.
 	 *
 	 * @param b
 	 *            the newly created binder.
 	 * @return binder for the caller, potentially after adding one or more
 	 *         filters into the pipeline.
 	 */
 	protected ServletBinder../../../../org/eclipse/jgit/http/server/glue/ServletBinder.html#ServletBinder">ServletBinder register(ServletBinder b) {
 		return filter.register(b);
 	}
 }