/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.krakenapps.http.internal.handler;

import org.osgi.service.http.NamespaceException;
import javax.servlet.ServletException;
import javax.servlet.Servlet;
import javax.servlet.Filter;
import java.util.HashMap;
import java.util.Map;
import java.util.Arrays;

public final class HandlerRegistry {
	private final Map<Servlet, ServletHandler> servletMap;
	private final Map<Filter, FilterHandler> filterMap;
	private final Map<String, Servlet> aliasMap;
	private ServletHandler[] servlets;
	private FilterHandler[] filters;

	public HandlerRegistry() {
		this.servletMap = new HashMap<Servlet, ServletHandler>();
		this.filterMap = new HashMap<Filter, FilterHandler>();
		this.aliasMap = new HashMap<String, Servlet>();
		this.servlets = new ServletHandler[0];
		this.filters = new FilterHandler[0];
	}

	public ServletHandler[] getServlets() {
		return this.servlets;
	}

	public FilterHandler[] getFilters() {
		return this.filters;
	}

	public synchronized void addServlet(ServletHandler handler) throws ServletException,
			NamespaceException {
		if (this.servletMap.containsKey(handler.getServlet())) {
			throw new ServletException("Servlet instance already registered");
		}

		if (this.aliasMap.containsKey(handler.getAlias())) {
			throw new NamespaceException("Servlet with alias already registered");
		}

		handler.init();
		this.servletMap.put(handler.getServlet(), handler);
		this.aliasMap.put(handler.getAlias(), handler.getServlet());
		updateServletArray();
	}

	public synchronized void addFilter(FilterHandler handler) throws ServletException {
		if (this.filterMap.containsKey(handler.getFilter())) {
			throw new ServletException("Filter instance already registered");
		}

		handler.init();
		this.filterMap.put(handler.getFilter(), handler);
		updateFilterArray();
	}

	public synchronized void removeServlet(Servlet servlet) {
		ServletHandler handler = this.servletMap.remove(servlet);
		if (handler != null) {
			updateServletArray();
			this.aliasMap.remove(handler.getAlias());
			handler.destroy();
		}
	}

	public synchronized void removeFilter(Filter filter) {
		FilterHandler handler = this.filterMap.remove(filter);
		if (handler != null) {
			updateFilterArray();
			handler.destroy();
		}
	}

	public synchronized Servlet getServletByAlias(String alias) {
		return this.aliasMap.get(alias);
	}

	public synchronized void removeAll() {
		for (ServletHandler handler : this.servletMap.values()) {
			handler.destroy();
		}

		for (FilterHandler handler : this.filterMap.values()) {
			handler.destroy();
		}

		this.servletMap.clear();
		this.filterMap.clear();
		this.aliasMap.clear();

		updateServletArray();
		updateFilterArray();
	}

	private void updateServletArray() {
		ServletHandler[] tmp = this.servletMap.values().toArray(
				new ServletHandler[this.servletMap.size()]);
		Arrays.sort(tmp);
		this.servlets = tmp;
	}

	private void updateFilterArray() {
		FilterHandler[] tmp = this.filterMap.values().toArray(
				new FilterHandler[this.filterMap.size()]);
		Arrays.sort(tmp);
		this.filters = tmp;
	}
}