package org.eclipse.tm.internal.tcf;

import org.osgi.framework.Bundle;

import org.osgi.framework.BundleActivator;

import org.osgi.framework.BundleContext;

import org.osgi.service.packageadmin.PackageAdmin;

import org.osgi.util.tracker.ServiceTracker;

public class Activator implements  BundleActivator {

    private static final String TCF_INTEGRATION_BUNDLE_ID = "org.eclipse.tm.tcf";

    public void start(BundleContext context) throws Exception {

        /*

         * Activate TCF Eclipse integration bundle "org.eclipse.tm.tcf".

         * It must be activated explicitly, because default activation through

         * class loading may never happen - most client don't need classes from that bundle.

         */

        ServiceTracker tracker = new ServiceTracker(context, PackageAdmin.class.getName(), null);

        tracker.open();

        Bundle[] bundles = ((PackageAdmin)tracker.getService()).getBundles(TCF_INTEGRATION_BUNDLE_ID, null);

        int cnt = 0;

        if (bundles != null) {

            for (Bundle bundle : bundles) {

                if ((bundle.getState() & (Bundle.INSTALLED | Bundle.UNINSTALLED)) == 0) {

                    bundle.start(Bundle.START_TRANSIENT);

                    cnt++;

                }

            }

        }

        if (cnt != 1) throw new Exception("Invalid or missing bundle: " + TCF_INTEGRATION_BUNDLE_ID);

    }

    public void stop(BundleContext context) throws Exception {

    }

}