/*
 * 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.felix.deploymentadmin.spi;

import org.apache.felix.deploymentadmin.AbstractDeploymentPackage;
import org.apache.felix.deploymentadmin.BundleInfoImpl;
import org.osgi.framework.Bundle;
import org.osgi.framework.FrameworkEvent;
import org.osgi.framework.FrameworkListener;
import org.osgi.service.log.LogService;
import org.osgi.service.packageadmin.PackageAdmin;

/**
 * Command that starts all bundles described in the source deployment package of
 * a deployment session.
 */
public class StartBundleCommand extends Command {
    private final RefreshPackagesMonitor m_refreshMonitor = new RefreshPackagesMonitor();

    protected void doExecute(DeploymentSessionImpl session) throws Exception {
        AbstractDeploymentPackage source = session.getSourceAbstractDeploymentPackage();
        PackageAdmin packageAdmin = session.getPackageAdmin();
        RefreshPackagesListener listener = new RefreshPackagesListener();
        LogService log = session.getLog();

        session.getBundleContext().addFrameworkListener(listener);
        packageAdmin.refreshPackages(null);
        m_refreshMonitor.waitForRefresh();
        session.getBundleContext().removeFrameworkListener(listener);

        // start source bundles
        BundleInfoImpl[] bundleInfos = source.getOrderedBundleInfos();
        for (int i = 0; i < bundleInfos.length; i++) {
            BundleInfoImpl bundleInfoImpl = bundleInfos[i];
            if (!bundleInfoImpl.isCustomizer()) {
                String symbolicName = bundleInfoImpl.getSymbolicName();

                Bundle bundle = source.getBundle(symbolicName);
                if (bundle != null) {
                    if (isFragmentBundle(bundle)) {
                        log.log(LogService.LOG_INFO, "Skipping fragment bundle '" + symbolicName + "'");
                    }
                    else {
                        try {
                            bundle.start();
                        }
                        catch (Exception be) {
                            log.log(LogService.LOG_WARNING, "Could not start bundle '" + symbolicName + "'", be);
                        }
                    }
                }
                else {
                    log.log(LogService.LOG_WARNING, "Could not start bundle '" + symbolicName + "' because it is not present in the framework");
                }
            }
        }
    }

    /**
     * RefreshPackagesListener is only listing to FrameworkEvents of the type
     * PACKAGES_REFRESHED. It will notify any object waiting the completion of a
     * refreshpackages() call.
     */
    private class RefreshPackagesListener implements FrameworkListener {
        public void frameworkEvent(FrameworkEvent event) {
            if (event.getType() == FrameworkEvent.PACKAGES_REFRESHED) {
                m_refreshMonitor.proceed();
            }
        }
    }

    /**
     * Use this monitor when its desired to wait for the completion of the
     * asynchronous PackageAdmin.refreshPackages() call.
     */
    private static class RefreshPackagesMonitor {
        private static final int REFRESH_TIMEOUT = 10000;

        private volatile boolean m_alreadyNotified = false;

        /**
         * Waits for the completion of the PackageAdmin.refreshPackages() call.
         * Because its not sure whether all OSGi framework implementations
         * implement this method as specified we have build in a timeout. So if
         * a event about the completion of the refreshpackages() is never
         * received, we continue after the timeout whether the refresh was done
         * or not.
         */
        public synchronized void waitForRefresh() {
            if (!m_alreadyNotified) {
                try {
                    wait(REFRESH_TIMEOUT);
                }
                catch (InterruptedException ie) {}
                finally {
                    m_alreadyNotified = false;
                }
            }
            else {
                // just reset the misted notification variable, this Monitor
                // object might be reused.
                m_alreadyNotified = false;
            }
        }

        /**
         * After a PACKAGES_REFRESHED event notify all the parties interested in
         * the completion of the PackageAdmin.refreshPackages() call.
         */
        public synchronized void proceed() {
            m_alreadyNotified = true;
            notifyAll();
        }
    }
}