/*
    * 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 java.util.ArrayList;
  import java.util.List;
  
  import javax.servlet.Filter;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletResponse;
  
  import org.eclipse.jgit.http.server.HttpServerText;
  
  abstract class ServletBinderImpl implements ServletBinder {
  	private final List<Filter> filters;
  
  	private HttpServlet httpServlet;
  
  	ServletBinderImpl() {
  		this.filters = new ArrayList<>();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public ServletBinder through(Filter filter) {
  		if (filter == null)
  			throw new NullPointerException(HttpServerText.get().filterMustNotBeNull);
  		filters.add(filter);
  		return this;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void with(HttpServlet servlet) {
  		if (servlet == null)
  			throw new NullPointerException(HttpServerText.get().servletMustNotBeNull);
  		if (httpServlet != null)
  			throw new IllegalStateException(HttpServerText.get().servletWasAlreadyBound);
  		httpServlet = servlet;
  	}
  
  	/**
  	 * Get the servlet
  	 *
  	 * @return the configured servlet, or singleton returning 404 if none.
  	 */
  	protected HttpServlet getServlet() {
  		if (httpServlet != null) {
  			return httpServlet;
  		}
  		return new ErrorServlet(HttpServletResponse.SC_NOT_FOUND);
  	}
  
  	/**
  	 * Get filters
  	 *
  	 * @return the configured filters; zero-length array if none.
  	 */
  	protected Filter[] getFilters() {
  		return filters.toArray(new Filter[0]);
  	}
  
  	/** @return the pipeline that matches and executes this chain. */
  	abstract UrlPipeline create();
  }