/*
 * 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.tuscany.sca.node.equinox.launcher;

import static org.apache.tuscany.sca.node.equinox.launcher.NodeLauncherUtil.node;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.PosixParser;
import org.osgi.framework.BundleContext;

/**
 * A launcher for SCA nodes.
 *
 * Agruments:
 * [-config <equinoxConfiguration>]: The configuration folder for Equinox
 * [-bundles <osgiBundles>]: A list of bundles to be installed
 * [-c <compositeURI>]: The composite URI
 * [-t <ttl>]: Time to live in milliseconds before the node is started
 * contribution1 ... contributionN: A list of contribution files or URLs
 *
 * @version $Rev$ $Date$
 */
public class NodeLauncher {

    static final Logger logger = Logger.getLogger(NodeLauncher.class.getName());
    private EquinoxHost equinoxHost;
    private BundleContext bundleContext;

    /**
     * Constructs a new node launcher.
     */
    private NodeLauncher() {
        equinoxHost = new EquinoxHost();
        bundleContext = equinoxHost.start();
    }

    /**
     * Returns a new launcher instance.
     *
     * @return a new launcher instance
     */
    public static NodeLauncher newInstance() {
        return new NodeLauncher();
    }

    /**
     * Creates a new SCA node from the configuration URL
     *
     * @param configurationURL the URL of the node configuration which is the ATOM feed
     * that contains the URI of the composite and a collection of URLs for the contributions
     *
     * @return a new SCA node.
     * @throws LauncherException
     */
    public <T> T createNode(String configurationURL) throws LauncherException {
        return (T)node(configurationURL, null, null, null, bundleContext);
    }

    /**
     * Creates a new SCA OSGi Node.
     *
     * @param compositeURI the URI of the composite to use
     * @param contributions the URI of the contributions that provides the composites and related
     * artifacts. If the list is empty, then we will use the thread context classloader to discover
     * the contribution on the classpath
     *
     * @return a new SCA node.
     * @throws LauncherException
     */
    public <T> T createNode(String compositeURI, Contribution... contributions) throws LauncherException {
        return (T)node(null, compositeURI, null, contributions, bundleContext);
    }

    /**
     * Creates a new SCA OSGi Node.
     *
     * @param compositeURI the URI of the composite to use
     * @param compositeContent the XML content of the composite to use
     * @param contributions the URI of the contributions that provides the composites and related artifacts
     * @return a new SCA node.
     * @throws LauncherException
     */
    public <T> T createNode(String compositeURI, String compositeContent, Contribution... contributions)
        throws LauncherException {
        return (T)node(null, compositeURI, compositeContent, contributions, bundleContext);
    }

    public static void main(String[] args) throws Exception {
        CommandLineParser parser = new PosixParser();
        Options options = getCommandLineOptions();
        CommandLine cli = parser.parse(options, args);

        Object node = null;
        ShutdownThread shutdown = null;
        EquinoxHost equinox = null;
        try {

            if (cli.hasOption("config")) {
                System.setProperty("osgi.configuration.area", cli.getOptionValue("config"));
            }

            while (true) {
                if (cli.hasOption("node")) {
                    // Create a node from a configuration URI
                    String configurationURI = cli.getOptionValue("node");
                    logger.info("SCA Node configuration: " + configurationURI);

                    // Create a node launcher
                    NodeLauncher launcher = newInstance();
                    equinox = launcher.equinoxHost;

                    node = launcher.createNode(configurationURI);
                }
                else if (cli.hasOption("bundles")) {
                    /**
                     * osgi.bundles
                     * The comma-separated list of bundles which are automatically installed and optionally started once the system is up
                     * and running. Each entry is of the form:
                     * <URL | simple bundle location>[@ [<start-level>] [":start"]]
                     * If the start-level (>0 integer) is omitted then the framework will use the default start level for the bundle.
                     * If the "start" tag is added then the bundle will be marked as started after being installed. Simple bundle locations are
                     * interepreted as relative to the framework's parent directory. The start-level indicates the OSGi start level at which the
                     * bundle should run. If this value is not set, the system computes an appropriate default.
                     */
                    String bundles = cli.getOptionValue("bundles");
                    if (bundles != null) {
                        System.setProperty("osgi.bundles", cli.getOptionValue("bundles"));
                    }

                    // Create a node launcher
                    NodeLauncher launcher = newInstance();
                    equinox = launcher.equinoxHost;

                    /*
                    List<String> bundleFiles = cli.getArgList();
                    for (String bf : bundleFiles) {
                        File f = new File(bf);
                        equinox.installBundle(f.toURI().toURL(), null);
                    }
                    for (Bundle b : launcher.bundleContext.getBundles()) {
                        try {
                            if (b.getHeaders().get(Constants.FRAGMENT_HOST) == null) {
                                // Start the non-fragment bundle
                                b.start();
                            }
                        } catch (Exception e) {
                            logger.severe(NodeLauncherUtil.string(b, false) + " " + e.getMessage());
                            // logger.log(Level.SEVERE, e.getMessage(), e);
                        }
                    }
                    */

                }
                else {
                    // Create a node from a composite URI and a contribution location
                    String compositeURI = cli.getOptionValue("composite");
                    List<String> contribs = cli.getArgList();
                    Contribution[] contributions = null;
                    if (!contribs.isEmpty()) {
                        contributions = new Contribution[contribs.size()];
                        int index = 0;
                        for (String contrib : contribs) {
                            logger.info("SCA contribution: " + contrib);
                            URL url = null;
                            try {
                                url = new URL(contrib);
                            } catch (MalformedURLException e) {
                                url = new File(contrib).toURI().toURL();
                            }
                            contributions[index] = new Contribution("contribution-" + index, url.toString());
                            index++;
                        }
                    } else {
                        HelpFormatter formatter = new HelpFormatter();
                        formatter.setSyntaxPrefix("Usage: ");
                        formatter.printHelp("java " + NodeLauncher.class.getName()
                            + " [-config <equinoxConfiguration>]"
                            + " [-c <compositeURI>]"
                            + " [-b <bundles>]"
                            + " [-t <ttl>]"
                            + " contribution1 ... contributionN", options);
                        return;
                    }
                    // Create a node launcher
                    logger.info("SCA composite: " + compositeURI);
                    NodeLauncher launcher = newInstance();
                    equinox = launcher.equinoxHost;
                    node = launcher.createNode(compositeURI, contributions);
                }

                if (node != null) {
                    logger.info("Apache Tuscany SCA Node is starting...");

                    // Start the node
                    try {
                        node.getClass().getMethod("start").invoke(node);
                    } catch (Exception e) {
                        logger.log(Level.SEVERE, "SCA Node could not be started", e);
                        throw e;
                    }
                    logger.info("SCA Node is now started.");
                }
                // Install a shutdown hook
                shutdown = new ShutdownThread(node, equinox);
                Runtime.getRuntime().addShutdownHook(shutdown);

                long ttl = Long.parseLong(cli.getOptionValue("ttl", "-1"));
                if (ttl >= 0) {
                    logger.info("Waiting for " + ttl + " milliseconds ...");
                    Thread.sleep(ttl);
                    break; // Exit
                }

                // Wait until the "Enter" is pressed
                logger.info("Press 'q' to quit, 'r' to restart.");
                int k = 0;
                try {
                    while ((k != 'q') && (k != 'r')) {
                        k = System.in.read();
                    }
                } catch (IOException e) {

                    // Wait forever
                    Object lock = new Object();
                    synchronized (lock) {
                        lock.wait();
                    }
                }

                // Stop the node
                if (node != null) {
                    Object n = node;
                    node = null;
                    stopNode(n);
                }

                // Quit
                if (k == 'q') {
                    break;
                }

            }
        } finally {

            // Remove the shutdown hook
            if (shutdown != null) {
                Runtime.getRuntime().removeShutdownHook(shutdown);
            }

            // Stop the node
            if (node != null) {
                destroyNode(node);
            }
            if (equinox != null) {
                equinox.stop();
            }
        }
    }

    static Options getCommandLineOptions() {
        Options options = new Options();
        Option opt1 = new Option("c", "composite", true, "URI for the composite");
        opt1.setArgName("compositeURI");
        options.addOption(opt1);
        Option opt2 = new Option("n", "node", true, "URI for the node configuration");
        opt2.setArgName("nodeConfigurationURI");
        options.addOption(opt2);
        Option opt3 = new Option("config", "configuration", true, "Configuration");
        opt3.setArgName("equinoxConfiguration");
        options.addOption(opt3);
        Option opt4 = new Option("t", "ttl", true, "Time to live");
        opt4.setArgName("timeToLiveInMilliseconds");
        // opt4.setType(long.class);
        options.addOption(opt4);

        Option opt5 = new Option("b", "bundles", false, "OSGi bundles");
        opt4.setArgName("osgiBundles");
        options.addOption(opt5);

        return options;
    }

    public void destroy() {
        if (equinoxHost != null) {
            equinoxHost.stop();
            bundleContext = null;
        }
    }

    /**
     * Stop the given node.
     *
     * @param node
     * @throws Exception
     */
    private static void destroyNode(Object node) throws Exception {
        try {
            node.getClass().getMethod("stop").invoke(node);
            logger.info("SCA Node is now stopped.");
        } catch (Exception e) {
            logger.log(Level.SEVERE, "SCA Node could not be stopped", e);
            throw e;
        }
    }

    private static class ShutdownThread extends Thread {
        private Object node;
        private EquinoxHost equinox;

        public ShutdownThread(Object node, EquinoxHost equinox) {
            super();
            this.node = node;
            this.equinox = equinox;
        }

        @Override
        public void run() {
            try {
                destroyNode(node);
            } catch (Exception e) {
                // Ignore
            }
            try {
                equinox.stop();
            } catch (Exception e) {
                // Ignore
            }
        }
    }

    /**
     * Stop the given node.
     *
     * @param node
     * @throws Exception
     */
    private static void stopNode(Object node) throws Exception {
        try {
            node.getClass().getMethod("stop").invoke(node);
            logger.info("SCA Node is now stopped.");
        } catch (Exception e) {
            logger.log(Level.SEVERE, "SCA Node could not be stopped", e);
            throw e;
        }
    }
}