/*
 * Copyright (c) 2016 the original author or authors.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Etienne Studer & Donát Csikós (Gradle Inc.) - initial API and implementation and initial documentation
 */

package org.eclipse.buildship.stsmigration;

import org.eclipse.core.runtime.preferences.ConfigurationScope;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.service.prefs.BackingStoreException;

import java.lang.reflect.Field;

/**
 * Represents the STS migration plugin.
 */
public final class StsMigrationPlugin extends AbstractUIPlugin {

    public static final String PLUGIN_ID = "org.eclipse.buildship.stsmigration";

    private static final String STS_PLUGIN_ID = "org.springsource.ide.eclipse.gradle.core";
    private static final String NOTIFICATION_MUTED_PROPERTY = "notification.muted";

    private static StsMigrationPlugin plugin;
    private static InternalStsMigrationState stsMigrationState;

    @Override
    public void start(BundleContext context) throws Exception {
        super.start(context);
        plugin = this;
        stsMigrationState = new InternalStsMigrationState();
    }

    @Override
    public void stop(BundleContext context) throws Exception {
        stsMigrationState = null;
        plugin = null;
        super.stop(context);
    }

    public static StsMigrationPlugin getInstance() {
        return plugin;
    }

    public static StsMigrationState getStsMigrationState() {
        return stsMigrationState;
    }

    /**
     * Keeps track of of the sts migration state.
     */
    private static final class InternalStsMigrationState implements StsMigrationState {

        @Override
        public boolean isStsPluginInstalled() {
            BundleContext bundleContext = getInstance().getBundle().getBundleContext();
            for (Bundle bundle : bundleContext.getBundles()) {
                if (STS_PLUGIN_ID.equals(bundle.getSymbolicName())) {
                    return true;
                }
            }
            return false;
        }

        @Override
        public boolean isNotificationMuted() {
            return getConfigurationScope().getNode(StsMigrationPlugin.PLUGIN_ID).getBoolean(NOTIFICATION_MUTED_PROPERTY, false);
        }

        @Override
        public void setNotificationMuted(boolean muted) {
            IEclipsePreferences node = getConfigurationScope().getNode(StsMigrationPlugin.PLUGIN_ID);
            node.putBoolean(NOTIFICATION_MUTED_PROPERTY, muted);
            try {
                node.flush();
            } catch (BackingStoreException e) {
                throw new RuntimeException(e);
            }
        }

        private ConfigurationScope getConfigurationScope() {
            // in older Eclipse versions the {@code ConfigurationScope.INSTANCE} field does not exist
            try {
                Field field = ConfigurationScope.class.getField("INSTANCE");
                return (ConfigurationScope) field.get(null);
            } catch (Exception e1) {
                try {
                    return ConfigurationScope.class.newInstance();
                } catch (Exception e2) {
                    throw new RuntimeException(e2);
                }
            }
        }

    }

}