/**
 * 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.apache.activemq.transport;

import java.io.File;
import java.net.InetAddress;
import java.net.URI;
import java.util.Map;

import org.apache.activemq.util.InetAddressUtil;
import org.apache.activemq.util.IntrospectionSupport;
import org.eclipse.jetty.ee11.servlet.security.ConstraintMapping;
import org.eclipse.jetty.ee11.servlet.security.ConstraintSecurityHandler;
import org.eclipse.jetty.security.Constraint;
import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.util.resource.ResourceFactory;
import org.eclipse.jetty.xml.XmlConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

abstract public class WebTransportServerSupport extends TransportServerSupport {

    private final static Logger LOG = LoggerFactory.getLogger(WebTransportServerSupport.class);

    protected URI bindAddress;
    protected Server server;
    protected Connector connector;
    protected SocketConnectorFactory socketConnectorFactory;
    protected String host;
    protected final HttpOptions httpOptions = new HttpOptions();
    protected final JettyOptions jettyOptions = new JettyOptions();

    public WebTransportServerSupport(URI location) {
        super(location);
    }

    private <T> void setConnectorProperty(String name, Class<T> type, T value) throws Exception {
        connector.getClass().getMethod("set" + name, type).invoke(connector, value);
    }

    protected void createServer() {
        LOG.info("Starting Jetty server");
        if (jettyOptions.getConfig() != null) {
            try (ResourceFactory.Closeable resourceFactory = ResourceFactory.closeable()) {
                LOG.info("Configuring Jetty server using {}", jettyOptions.getConfig());
                File file = new File(jettyOptions.getConfig());
                if (!file.exists()) {
                    throw new IllegalArgumentException("Jetty XML not found: " + file.getAbsolutePath());
                }
                XmlConfiguration xmlConfiguration = new XmlConfiguration(resourceFactory.newResource(file.getPath()));
                server = (Server) xmlConfiguration.configure();
            } catch (Throwable t) {
                throw new IllegalStateException("Jetty configuration can't be loaded", t);
            }
        } else {
            server = new Server();
        }
        try {
            server.getClass().getMethod("setStopTimeout", Long.TYPE).invoke(server, 30_000L);
        } catch (Throwable t) {
            //ignore, jetty 8.
        }
    }

    public URI bind() throws Exception {
        URI bind = getBindLocation();
        String bindHost = bind.getHost();
        bindHost = (bindHost == null || bindHost.length() == 0) ? "localhost" : bindHost;
        InetAddress addr = InetAddress.getByName(bindHost);
        host = addr.getCanonicalHostName();
        if (server.getConnectors().length == 0) {
            LOG.info("Creating Jetty connector");
            setConnectorProperty("Host", String.class, host);
            setConnectorProperty("Port", Integer.TYPE, bindAddress.getPort());
            server.addConnector(connector);
        } else {
            LOG.info("Using Jetty configured connector");
            connector = server.getConnectors()[0];
            for (Connector c : server.getConnectors()) {
                if (c.getName() != null && c.getName().equalsIgnoreCase("activemq")) {
                    connector = c;
                }
            }
            setConnectorProperty("Host", String.class, host);
            setConnectorProperty("Port", Integer.TYPE, bindAddress.getPort());
            server.addConnector(connector);
        }
        if (addr.isAnyLocalAddress()) {
            host = InetAddressUtil.getLocalHostName();
        }
        URI boundUri = new URI(bind.getScheme(), bind.getUserInfo(), host, bindAddress.getPort(), bind.getPath(), bind.getQuery(), bind.getFragment());
        setConnectURI(boundUri);
        return boundUri;
    }

    protected void configureTraceMethod(ConstraintSecurityHandler securityHandler,
            boolean enableTrace) {

        // TRACE is disabled by default (Cross-Site Tracing protection). In EE11 the servlet-spec
        // ServletConstraint is gone; ConstraintMapping takes the core immutable Constraint. A
        // FORBIDDEN constraint on TRACE yields 403; ALLOWED serves it when explicitly enabled.
        ConstraintMapping traceMapping = new ConstraintMapping();
        traceMapping.setConstraint(enableTrace ? Constraint.ALLOWED : Constraint.FORBIDDEN);
        traceMapping.setMethod("TRACE");
        traceMapping.setPathSpec("/");
        securityHandler.addConstraintMapping(traceMapping);

        // All other methods are allowed.
        ConstraintMapping allowMapping = new ConstraintMapping();
        allowMapping.setConstraint(Constraint.ALLOWED);
        allowMapping.setMethodOmissions(new String[]{ "TRACE" });
        allowMapping.setPathSpec("/");
        securityHandler.addConstraintMapping(allowMapping);
    }

    public void setHttpOptions(Map<String, Object> options) {
        if (options != null) {
            IntrospectionSupport.setProperties(this.httpOptions, options);
        }
    }

    public void setJettyOptions(Map<String, Object> options) {
        if (options != null) {
            IntrospectionSupport.setProperties(this.jettyOptions, options);
        }
    }

    protected static class HttpOptions {
        private boolean enableTrace = false;

        public boolean isEnableTrace() {
            return enableTrace;
        }

        public void setEnableTrace(boolean enableTrace) {
            this.enableTrace = enableTrace;
        }
    }

    protected static class JettyOptions {
        private String config;

        public String getConfig() {
            return config;
        }

        public void setConfig(String config) {
            this.config = config;
        }
    }

}
