/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package com.nokia.carbide.remoteconnections;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.Map;

import java.util.Map.Entry;

import org.eclipse.core.runtime.CoreException;

import org.eclipse.core.runtime.IConfigurationElement;

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Platform;

import org.eclipse.core.runtime.preferences.InstanceScope;

import org.eclipse.jface.resource.ImageDescriptor;

import org.eclipse.jface.viewers.IFilter;

import org.eclipse.swt.widgets.Control;

import org.eclipse.ui.PlatformUI;

import org.eclipse.ui.plugin.AbstractUIPlugin;

import org.osgi.framework.BundleContext;

import org.osgi.service.prefs.BackingStoreException;

import com.nokia.carbide.remoteconnections.interfaces.IConnectionTypeProvider;

import com.nokia.carbide.remoteconnections.interfaces.IConnectionsManager;

import com.nokia.carbide.remoteconnections.internal.api.IDeviceDiscoveryAgent;

import com.nokia.carbide.remoteconnections.internal.api.IDeviceDiscoveryAgent.IPrerequisiteStatus;

import com.nokia.carbide.remoteconnections.internal.registry.Registry;

import com.nokia.carbide.remoteconnections.internal.ui.DeviceDiscoveryPrequisiteErrorDialog;

import com.nokia.cpp.internal.api.utils.core.Logging;

import com.nokia.cpp.internal.api.utils.ui.WorkbenchUtils;

/**

 * The activator class controls the plug-in life cycle

 */

public class RemoteConnectionsActivator extends AbstractUIPlugin {

	// The plug-in ID

	public static final String PLUGIN_ID = "com.nokia.carbide.remoteConnections"; //$NON-NLS-1$

	private static final String DISCOVERY_AGENT_EXTENSION = PLUGIN_ID + ".deviceDiscoveryAgent"; //$NON-NLS-1$

	// The shared instance

	private static RemoteConnectionsActivator plugin;

	private Collection<IDeviceDiscoveryAgent> discoveryAgents;

	private static final String IGNORE_AGENT_LOAD_ERRORS_KEY = "ignoreAgentLoadErrors"; //$NON-NLS-1$

	/**

	 * The constructor

	 */

	public RemoteConnectionsActivator() {

	}

	public void start(BundleContext context) throws Exception {

		super.start(context);

		plugin = this;

		Registry instance = Registry.instance();

		instance.loadExtensions();

		instance.loadConnections();

			public void run() {

				if (!ignoreAgentLoadErrors())

					checkPrerequisites();

				loadAndStartDeviceDiscoveryAgents();

			}

	}

	private boolean ignoreAgentLoadErrors() {

		return getPreferenceStore().getBoolean(IGNORE_AGENT_LOAD_ERRORS_KEY);

	}

	private void checkPrerequisites() {

		if (WorkbenchUtils.isJUnitRunning())

			return;

		final Map<IDeviceDiscoveryAgent, IPrerequisiteStatus> agentToStatusMap = 

			new HashMap<IDeviceDiscoveryAgent, IPrerequisiteStatus>();

		// load the extensions just to check statuses

		Collection<IDeviceDiscoveryAgent> agents = new ArrayList<IDeviceDiscoveryAgent>();

		loadExtensions(DISCOVERY_AGENT_EXTENSION, null, agents, null);

		for (IDeviceDiscoveryAgent agent : agents) {

			IPrerequisiteStatus status = agent.getPrerequisiteStatus();

			if (!status.isOK()) {

				agentToStatusMap.put(agent, status);

			}

		}

		if (!agentToStatusMap.isEmpty()) {

			DeviceDiscoveryPrequisiteErrorDialog dlg = new DeviceDiscoveryPrequisiteErrorDialog(WorkbenchUtils.getSafeShell());

			for (Entry<IDeviceDiscoveryAgent, IPrerequisiteStatus> entry : agentToStatusMap.entrySet()) {

				IDeviceDiscoveryAgent agent = entry.getKey();

				IPrerequisiteStatus status = entry.getValue();

				dlg.addAgentData(agent.getDisplayName(), status.getErrorText(), status.getURL());

			}

			dlg.open();

			if (dlg.isDontAskAgainChecked())

				storeIgnoreAgentLoadErrorsFlag();

		}	

	}

	public void stop(BundleContext context) throws Exception {

		stopDeviceDiscoveryAgents();

		Registry.instance().storeConnections();

		Registry.instance().disposeConnections();

		plugin = null;

		super.stop(context);

	}

	private void storeIgnoreAgentLoadErrorsFlag() {

		getPreferenceStore().setValue(IGNORE_AGENT_LOAD_ERRORS_KEY, true);

		try {

			new InstanceScope().getNode(PLUGIN_ID).flush();

		} catch (BackingStoreException e) {

			logError(e);

		}

	}

	/**

	 * Returns the shared instance

	 *

	 * @return the shared instance

	 */

	public static RemoteConnectionsActivator getDefault() {

		return plugin;

	}

	/**

	 * Returns an image descriptor for the image file at the given

	 * plug-in relative path

	 *

	 * @param path the path

	 * @return the image descriptor

	 */

	public static ImageDescriptor getImageDescriptor(String path) {

		return imageDescriptorFromPlugin(PLUGIN_ID, path);

	}

	/**

	 * Return the implementation of IConnectionsManager

	 * @return IConnectionsManager

	 */

	public static IConnectionsManager getConnectionsManager() {

		return Registry.instance();

	}

	/**

	 * Return the implementation of IConnectionTypeProvider

	 * @return IConnectionTypeProvider

	 */

	public static IConnectionTypeProvider getConnectionTypeProvider() {

		return Registry.instance();

	}

	public static void logError(Throwable t) {

		Logging.log(plugin, Logging.newSimpleStatus(0, t));

	}

	public static void logMessage(String message, int type) {

		Logging.log(plugin, Logging.newStatus(plugin, type, message));

	}

	public static void setHelp(Control control, String id) {

		PlatformUI.getWorkbench().getHelpSystem().setHelp(control, PLUGIN_ID + id);		 //$NON-NLS-1$

	}

	private void loadAndStartDeviceDiscoveryAgents() {

		String loadError = Messages.getString("RemoteConnectionsActivator.DiscoveryAgentLoadError"); //$NON-NLS-1$

		discoveryAgents = new ArrayList<IDeviceDiscoveryAgent>();

		loadExtensions(DISCOVERY_AGENT_EXTENSION, loadError, discoveryAgents, new IFilter() {

			public boolean select(Object toTest) {

				if (toTest instanceof IDeviceDiscoveryAgent) {

					try {

						((IDeviceDiscoveryAgent) toTest).start();

						return true;

					} catch (Throwable e) {

						// since we launch arbitrary code, catch any exception to prevent killing the view

						logError(e);

					}

				}

				return false;

			}

		});

	}

	private void stopDeviceDiscoveryAgents() {

		for (IDeviceDiscoveryAgent agent : discoveryAgents) {

			try {

				agent.stop();

			} catch (CoreException e) {

				logError(e);

			}

		}

	}

	public static void log(String errorStr, Throwable t) {

		RemoteConnectionsActivator p = RemoteConnectionsActivator.getDefault();

		String error = errorStr;

		if (t != null) {

			error += " : " + t.getLocalizedMessage(); //$NON-NLS-1$

		}

		Logging.log(p, Logging.newStatus(p, IStatus.ERROR, error));

		if (t instanceof CoreException)

			Logging.log(p, ((CoreException) t).getStatus());

	}

	@SuppressWarnings("unchecked")

	public static <T> void loadExtensions(String extensionId, String loadError, Collection<T> extensionObjects, IFilter filter) {

		IConfigurationElement[] elements = 

			Platform.getExtensionRegistry().getConfigurationElementsFor(extensionId);

		for (IConfigurationElement element : elements) {

			try {

				T extObject = (T) element.createExecutableExtension("class"); //$NON-NLS-1$

				if (filter == null || filter.select(extObject))

					extensionObjects.add(extObject);

			} 

			catch (CoreException e) {

				if (loadError != null)

					RemoteConnectionsActivator.log(loadError, e);

			}

		}

	}

}