/*
 * 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.ignite.internal.processors.rest.protocols.http.jetty;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Properties;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.IgniteSystemProperties;
import org.apache.ignite.internal.GridKernalContext;
import org.apache.ignite.internal.IgniteNodeAttributes;
import org.apache.ignite.internal.processors.rest.GridRestProtocolHandler;
import org.apache.ignite.internal.processors.rest.protocols.GridRestProtocolAdapter;
import org.apache.ignite.internal.util.typedef.C1;
import org.apache.ignite.internal.util.typedef.F;
import org.apache.ignite.internal.util.typedef.internal.S;
import org.apache.ignite.internal.util.typedef.internal.U;
import org.apache.ignite.spi.IgniteSpiException;
import org.eclipse.jetty.server.AbstractNetworkConnector;
import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.HttpConfiguration;
import org.eclipse.jetty.server.HttpConnectionFactory;
import org.eclipse.jetty.server.NetworkConnector;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.util.MultiException;
import org.eclipse.jetty.util.log.StdErrLog;
import org.eclipse.jetty.util.thread.QueuedThreadPool;
import org.eclipse.jetty.xml.XmlConfiguration;
import org.jetbrains.annotations.Nullable;
import org.xml.sax.SAXException;

import static org.apache.ignite.IgniteSystemProperties.IGNITE_JETTY_HOST;
import static org.apache.ignite.IgniteSystemProperties.IGNITE_JETTY_LOG_NO_OVERRIDE;
import static org.apache.ignite.IgniteSystemProperties.IGNITE_JETTY_PORT;
import static org.apache.ignite.spi.IgnitePortProtocol.TCP;

/**
 * Jetty REST protocol implementation.
 */
public class GridJettyRestProtocol extends GridRestProtocolAdapter {
    /**
     *
     */
    static {
        if (!IgniteSystemProperties.getBoolean(IGNITE_JETTY_LOG_NO_OVERRIDE)) {
            // See also https://www.eclipse.org/jetty/documentation/9.4.x/configuring-logging.html
            // It seems that using system properties should be fine.
            System.setProperty("org.eclipse.jetty.LEVEL", "WARN");
            System.setProperty("org.eclipse.jetty.util.log.LEVEL", "OFF");
            System.setProperty("org.eclipse.jetty.util.component.LEVEL", "OFF");

            try {
                Class<?> logCls = Class.forName("org.apache.log4j.Logger");

                String ctgrJetty = "org.eclipse.jetty";                         // WARN for this category.
                String ctgrJettyUtil = "org.eclipse.jetty.util.log";            // ERROR for this...
                String ctgrJettyUtilComp = "org.eclipse.jetty.util.component";  // ...and this.

                Object logJetty = logCls.getMethod("getLogger", String.class).invoke(logCls, ctgrJetty);
                Object logJettyUtil = logCls.getMethod("getLogger", String.class).invoke(logCls, ctgrJettyUtil);
                Object logJettyUtilComp = logCls.getMethod("getLogger", String.class).invoke(logCls, ctgrJettyUtilComp);

                Class<?> lvlCls = Class.forName("org.apache.log4j.Level");

                Object warnLvl = lvlCls.getField("WARN").get(null);
                Object errLvl = lvlCls.getField("ERROR").get(null);

                logJetty.getClass().getMethod("setLevel", lvlCls).invoke(logJetty, warnLvl);
                logJettyUtil.getClass().getMethod("setLevel", lvlCls).invoke(logJetty, errLvl);
                logJettyUtilComp.getClass().getMethod("setLevel", lvlCls).invoke(logJetty, errLvl);
            }
            catch (Exception ignored) {
                // No-op.
            }
        }
    }

    /** Jetty handler. */
    private GridJettyRestHandler jettyHnd;

    /** HTTP server. */
    private Server httpSrv;

    /**
     * @param ctx Context.
     */
    public GridJettyRestProtocol(GridKernalContext ctx) {
        super(ctx);
    }

    /** {@inheritDoc} */
    @Override public String name() {
        return "Jetty REST";
    }

    /** {@inheritDoc} */
    @SuppressWarnings("BusyWait")
    @Override public void start(GridRestProtocolHandler hnd) throws IgniteCheckedException {
        assert ctx.config().getConnectorConfiguration() != null;

        String jettyHost = System.getProperty(IGNITE_JETTY_HOST, ctx.config().getLocalHost());

        try {
            System.setProperty(IGNITE_JETTY_HOST, U.resolveLocalHost(jettyHost).getHostAddress());
        }
        catch (IOException e) {
            throw new IgniteCheckedException("Failed to resolve host to bind address: " + jettyHost, e);
        }

        jettyHnd = new GridJettyRestHandler(hnd, new C1<String, Boolean>() {
            @Override public Boolean apply(String tok) {
                return F.isEmpty(secretKey) || authenticate(tok);
            }
        }, log);

        String jettyPath = config().getJettyPath();

        final URL cfgUrl;

        if (jettyPath == null) {
            cfgUrl = null;

            if (log.isDebugEnabled())
                log.debug("Jetty configuration file is not provided, using defaults.");
        }
        else {
            cfgUrl = U.resolveIgniteUrl(jettyPath);

            if (cfgUrl == null)
                throw new IgniteSpiException("Invalid Jetty configuration file: " + jettyPath);
            else if (log.isDebugEnabled())
                log.debug("Jetty configuration file: " + cfgUrl);
        }

        loadJettyConfiguration(cfgUrl);

        AbstractNetworkConnector connector = getJettyConnector();

        try {
            host = InetAddress.getByName(connector.getHost());
        }
        catch (UnknownHostException e) {
            throw new IgniteCheckedException("Failed to resolve Jetty host address: " + connector.getHost(), e);
        }

        int initPort = connector.getPort();
        int portRange = config().getPortRange();
        int lastPort = portRange == 0 ? initPort : initPort + portRange - 1;

        for (port = initPort; port <= lastPort; port++) {
            connector.setPort(port);

            if (startJetty()) {
                if (log.isInfoEnabled())
                    log.info(startInfo());

                return;
            }
        }

        U.warn(log, "Failed to start Jetty REST server (possibly all ports in range are in use) " +
            "[firstPort=" + initPort + ", lastPort=" + lastPort + ']');
    }

    /**
     * Checks {@link org.apache.ignite.IgniteSystemProperties#IGNITE_JETTY_PORT} system property
     * and overrides default connector port if it present.
     * Then initializes {@code port} with the found value.
     *
     * @param con Jetty connector.
     */
    private void override(AbstractNetworkConnector con) {
        String host = System.getProperty(IGNITE_JETTY_HOST);

        if (!F.isEmpty(host))
            con.setHost(host);

        int currPort = con.getPort();

        Integer overridePort = Integer.getInteger(IGNITE_JETTY_PORT);

        if (overridePort != null && overridePort != 0)
            currPort = overridePort;

        con.setPort(currPort);
        port = currPort;
    }

    /**
     * @throws IgniteCheckedException If failed.
     * @return {@code True} if Jetty started.
     */
    @SuppressWarnings("IfMayBeConditional")
    private boolean startJetty() throws IgniteCheckedException {
        try {
            httpSrv.start();

            if (httpSrv.isStarted()) {
                for (Connector con : httpSrv.getConnectors()) {
                    int connPort = ((NetworkConnector)con).getPort();

                    if (connPort > 0)
                        ctx.ports().registerPort(connPort, TCP, getClass());
                }

                return true;
            }

            return  false;
        }
        catch (SocketException ignore) {
            if (log.isDebugEnabled())
                log.debug("Failed to bind HTTP server to configured port.");

            stopJetty();

            return false;
        }
        catch (MultiException e) {
            if (log.isDebugEnabled())
                log.debug("Caught multi exception: " + e);

            for (Object obj : e.getThrowables())
                if (!(obj instanceof SocketException))
                    throw new IgniteCheckedException("Failed to start Jetty HTTP server.", e);

            if (log.isDebugEnabled())
                log.debug("Failed to bind HTTP server to configured port.");

            stopJetty();

            return false;
        }
        catch (Exception e) {
            throw new IgniteCheckedException("Failed to start Jetty HTTP server.", e);
        }
    }

    /**
     * Loads jetty configuration from the given URL.
     *
     * @param cfgUrl URL to load configuration from.
     * @throws IgniteCheckedException if load failed.
     */
    private void loadJettyConfiguration(@Nullable URL cfgUrl) throws IgniteCheckedException {
        if (cfgUrl == null) {
            HttpConfiguration httpCfg = new HttpConfiguration();

            httpCfg.setSecureScheme("https");
            httpCfg.setSecurePort(8443);
            httpCfg.setSendServerVersion(true);
            httpCfg.setSendDateHeader(true);

            String srvPortStr = System.getProperty(IGNITE_JETTY_PORT, "8080");

            int srvPort;

            try {
                srvPort = Integer.parseInt(srvPortStr);
            }
            catch (NumberFormatException ignore) {
                throw new IgniteCheckedException("Failed to start Jetty server because IGNITE_JETTY_PORT system property " +
                    "cannot be cast to integer: " + srvPortStr);
            }

            httpSrv = new Server(new QueuedThreadPool(200, 20));

            ServerConnector srvConn = new ServerConnector(httpSrv, new HttpConnectionFactory(httpCfg));

            srvConn.setHost(System.getProperty(IGNITE_JETTY_HOST, "localhost"));
            srvConn.setPort(srvPort);
            srvConn.setIdleTimeout(30000L);
            srvConn.setReuseAddress(true);

            httpSrv.addConnector(srvConn);

            httpSrv.setStopAtShutdown(false);
        }
        else {
            XmlConfiguration cfg;

            try {
                cfg = new XmlConfiguration(cfgUrl);
            }
            catch (FileNotFoundException e) {
                throw new IgniteSpiException("Failed to find configuration file: " + cfgUrl, e);
            }
            catch (SAXException e) {
                throw new IgniteSpiException("Failed to parse configuration file: " + cfgUrl, e);
            }
            catch (IOException e) {
                throw new IgniteSpiException("Failed to load configuration file: " + cfgUrl, e);
            }
            catch (Exception e) {
                throw new IgniteSpiException("Failed to start HTTP server with configuration file: " + cfgUrl, e);
            }

            try {
                httpSrv = (Server)cfg.configure();
            }
            catch (Exception e) {
                throw new IgniteCheckedException("Failed to start Jetty HTTP server.", e);
            }
        }

        assert httpSrv != null;

        httpSrv.setHandler(jettyHnd);

        override(getJettyConnector());
    }

    /**
     * Checks that the only connector configured for the current jetty instance
     * and returns it.
     *
     * @return Connector instance.
     * @throws IgniteCheckedException If no or more than one connectors found.
     */
    private AbstractNetworkConnector getJettyConnector() throws IgniteCheckedException {
        if (httpSrv.getConnectors().length == 1) {
            Connector connector = httpSrv.getConnectors()[0];

            if (!(connector instanceof AbstractNetworkConnector))
                throw new IgniteCheckedException("Error in jetty configuration. Jetty connector should extend " +
                    "AbstractNetworkConnector class." );

            return (AbstractNetworkConnector)connector;
        }
        else
            throw new IgniteCheckedException("Error in jetty configuration [connectorsFound=" +
                httpSrv.getConnectors().length + "connectorsExpected=1]");
    }

    /**
     * Stops Jetty.
     */
    private void stopJetty() {
        // Jetty does not really stop the server if port is busy.
        try {
            if (httpSrv != null) {
                // If server was successfully started, deregister ports.
                if (httpSrv.isStarted())
                    ctx.ports().deregisterPorts(getClass());

                // Record current interrupted status of calling thread.
                boolean interrupted = Thread.interrupted();

                try {
                    httpSrv.stop();
                }
                finally {
                    // Reset interrupted flag on calling thread.
                    if (interrupted)
                        Thread.currentThread().interrupt();
                }
            }
        }
        catch (InterruptedException ignored) {
            if (log.isDebugEnabled())
                log.debug("Thread has been interrupted.");

            Thread.currentThread().interrupt();
        }
        catch (Exception e) {
            U.error(log, "Failed to stop Jetty HTTP server.", e);
        }
    }

    /** {@inheritDoc} */
    @Override public void stop() {
        stopJetty();

        httpSrv = null;
        jettyHnd = null;

        if (log.isInfoEnabled())
            log.info(stopInfo());
    }

    /** {@inheritDoc} */
    @Override protected String getAddressPropertyName() {
        return IgniteNodeAttributes.ATTR_REST_JETTY_ADDRS;
    }

    /** {@inheritDoc} */
    @Override protected String getHostNamePropertyName() {
        return IgniteNodeAttributes.ATTR_REST_JETTY_HOST_NAMES;
    }

    /** {@inheritDoc} */
    @Override protected String getPortPropertyName() {
        return IgniteNodeAttributes.ATTR_REST_JETTY_PORT;
    }

    /** {@inheritDoc} */
    @Override public String toString() {
        return S.toString(GridJettyRestProtocol.class, this);
    }
}