/*

* Copyright (c) 2008 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.internal.registry;

import com.nokia.carbide.remoteconnections.Messages;

import com.nokia.carbide.remoteconnections.RemoteConnectionsActivator;

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

import com.nokia.carbide.remoteconnections.ui.ClientServiceSiteUI;

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

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

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

import org.eclipse.core.runtime.*;

import org.eclipse.jface.viewers.IFilter;

import java.io.*;

import java.text.MessageFormat;

import java.util.*;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * A registry of connection type and service extensions

 */

public class Registry implements IConnectionTypeProvider, IConnectionsManager {

	private static final String FILTER_EXTENSION = RemoteConnectionsActivator.PLUGIN_ID + ".extensionFilter"; //$NON-NLS-1$

	private static final String CONNECTION_TYPE_EXTENSION = RemoteConnectionsActivator.PLUGIN_ID + ".connectionType"; //$NON-NLS-1$

	private static final String SERVICE_EXTENSION = RemoteConnectionsActivator.PLUGIN_ID + ".service"; //$NON-NLS-1$

	private static final String CONNECTED_SERVICE_FACTORY_EXTENSION = RemoteConnectionsActivator.PLUGIN_ID + ".connectedServiceFactory"; //$NON-NLS-1$

	private static final String CONNECTION_DATA_XML = "connectionData.xml"; //$NON-NLS-1$

	private static final String NAME_SUFFIX_PATTERN = "(.+) \\((\\d+)\\)"; //$NON-NLS-1$

	private static final String NAME_FMT = "{0} ({1})"; //$NON-NLS-1$

	private static Registry instance;

	private List<IExtensionFilter> extensionFilters;

	private Map<String, IConnectionType> connectionTypeIdMap;

	private ArrayList<IService> services;

	private Map<IConnectionType, Collection<IService>> connectionTypeToServices;

	private Map<IConnection, List<IConnectedService>> connectionToConnectedServices;

	private ListenerList<IConnectionsManagerListener> listeners;

	private List<IConnectedServiceFactory> connectedServiceFactories;

	public static Registry instance() {

		if (instance == null) {

			instance = new Registry();

		}

		return instance;

	}

	private Registry() {

		// private because is singleton

		connectionToConnectedServices = new HashMap<IConnection, List<IConnectedService>>();

	}

	public void loadExtensions() {

		loadExtensionFilters();

		loadConnectionTypeExtensions();

		loadServiceExtensions();

		loadConnectedServiceFactoryExtensions();

		mapConnectionTypeToServices();

	}

	private void loadConnectedServiceFactoryExtensions() {

		connectedServiceFactories = new ArrayList<IConnectedServiceFactory>();

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

		loadExtensions(CONNECTED_SERVICE_FACTORY_EXTENSION, loadError, connectedServiceFactories, null);

	}

	private void loadExtensionFilters() {

		extensionFilters = new ArrayList<IExtensionFilter>();

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

		loadExtensions(FILTER_EXTENSION, loadError, extensionFilters, null);

	}

	private void loadConnectionTypeExtensions() {

		List<IConnectionType> connectionTypeExtensions = new ArrayList<IConnectionType>();

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

		loadExtensions(CONNECTION_TYPE_EXTENSION, loadError, connectionTypeExtensions, new IFilter() {

			public boolean select(Object toTest) {

				return acceptConnectionType(((IConnectionType) toTest).getIdentifier());

			}

		});

		connectionTypeIdMap = new HashMap<String, IConnectionType>();

		for (IConnectionType connectionType : connectionTypeExtensions) {

			connectionTypeIdMap.put(connectionType.getIdentifier(), connectionType);

		}

	}

	private boolean acceptConnectionType(String connectionTypeId) {

		for (IExtensionFilter extensionFilter : extensionFilters) {

			if (!extensionFilter.acceptConnectionType(connectionTypeId))

				return false;

		}

		return true;

	}

	private void loadServiceExtensions() {

		services = new ArrayList<IService>();

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

		loadExtensions(SERVICE_EXTENSION, loadError, services, new IFilter() {

			public boolean select(Object toTest) {

				return acceptService(((IService) toTest).getIdentifier());

			}

		});

	}

	private boolean acceptService(String serviceId) {

		for (IExtensionFilter extensionFilter : extensionFilters) {

			if (!extensionFilter.acceptService(serviceId))

				return false;

		}

		return true;

	}

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

		IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();

		IExtensionPoint extensionPoint = extensionRegistry.getExtensionPoint(extensionId);

		IExtension[] extensions = extensionPoint.getExtensions();

		for (int i = 0; i < extensions.length; i++) {

			IExtension extension = extensions[i];

			IConfigurationElement[] elements = extension.getConfigurationElements();

			Check.checkContract(elements.length == 1);

			IConfigurationElement element = elements[0];

			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)

					log(loadError, e);

			}

		}

	}

	private void mapConnectionTypeToServices() {

		connectionTypeToServices = new HashMap<IConnectionType, Collection<IService>>();

		Set<String> connectionTypeIds = connectionTypeIdMap.keySet();

		for (IService service : services) {

			Collection<String> compatibleConnectionTypeIds = getCompatibleConnectionTypeIds(service);

			String serviceId = service.getIdentifier();

			for (String connectionTypeId : compatibleConnectionTypeIds) {

				if (connectionTypeIds.contains(connectionTypeId)) {

					IConnectionType connectionType = connectionTypeIdMap.get(connectionTypeId);

					if (!connectionTypeToServices.containsKey(connectionType)) {

						connectionTypeToServices.put(connectionType, 

								new TreeSet<IService>(new Comparator<IService>() {

							public int compare(IService o1, IService o2) {

								return o1.getDisplayName().compareToIgnoreCase(o2.getDisplayName());

							}

						}));

					}

					Set<IService> servicesForConnectionType = 

						(Set<IService>) connectionTypeToServices.get(connectionType);

					if (acceptConnectedService(serviceId, connectionTypeId))

						servicesForConnectionType.add(service);

				}

			}

		}

	}

	public Collection<String> getCompatibleConnectionTypeIds(IService service) {

		Collection<String> compatibleConnectionTypeIds = new HashSet<String>();

		for (IConnectedServiceFactory factory : connectedServiceFactories) {

			compatibleConnectionTypeIds.addAll(factory.getCompatibleConnectionTypeIds(service));

		}

		return compatibleConnectionTypeIds;

	}

	private boolean acceptConnectedService(String serviceId, String connectionTypeId) {

		boolean accept = true;

		for (IExtensionFilter extensionFilter : extensionFilters) {

			if (!extensionFilter.acceptConnectedService(connectionTypeId, serviceId)) {

				accept = false;

				break;

			}

		}

		return accept;

	}

	private 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());

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#loadConnections()

	 */

	public void loadConnections() {

		File connectionStorageFile = getConnectionStorageFile();

		if (!connectionStorageFile.exists())

			return;

		connectionToConnectedServices = new HashMap<IConnection, List<IConnectedService>>();

		try {

			List<IConnection> connections = Reader.readFromXML(this, new FileInputStream(connectionStorageFile));

			for (IConnection connection : connections) {

				List<IConnectedService> connectedServices = createConnectedServicesForConnection(connection);

				connectionToConnectedServices.put(connection, connectedServices);

			}

			fireConnectionStoreChanged();

		} 

		catch (Exception e) {

			log(Messages.getString("Registry.ConnectionLoadError"), e); //$NON-NLS-1$

		}

	}

	private List<IConnectedService> createConnectedServicesForConnection(IConnection connection) {

		List<IConnectedService> connectedServices = new ArrayList<IConnectedService>();

		for (IService service : getCompatibleServices(connection.getConnectionType())) {

			IConnectedService connectedService = createConnectedService(service, connection);

			connectedServices.add(connectedService);

		}

		return connectedServices;

	}

	public IConnectedService createConnectedService(IService service, IConnection connection) {

		// use first created connected service returned from a factory

		for (IConnectedServiceFactory factory : connectedServiceFactories) {

			IConnectedService connectedService = factory.createConnectedService(service, connection);

			if (connectedService != null)

				return connectedService;

		}

		log(MessageFormat.format(

				Messages.getString("Registry.ConnectedServiceFactoryError"), //$NON-NLS-1$

				service.getDisplayName(), connection.getConnectionType().getDisplayName()), null);

		return null;

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#storeConnections()

	 */

	public void storeConnections() {

		try {

			OutputStream os = new FileOutputStream(getConnectionStorageFile());

			Writer.writeToXML(os, connectionToConnectedServices.keySet());

		} 

		catch (Exception e) {

			log(Messages.getString("Registry.ConnectionStoreError"), e); //$NON-NLS-1$

		}

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#addConnectionStoreChangedListener(com.nokia.carbide.remoteconnections.registry.Registry.IConnectionStoreChangedListener)

	 */

	public void addConnectionStoreChangedListener(IConnectionsManagerListener listener) {

		if (listeners == null)

			listeners = new ListenerList<IConnectionsManagerListener>();

		listeners.add(listener);

	}

	public void removeConnectionStoreChangedListener(IConnectionsManagerListener listener) {

		if (listeners != null)

			listeners.remove(listener);

	}

	private void fireConnectionStoreChanged() {

		if (listeners == null)

			return;

		for (IConnectionsManagerListener listener : listeners) {

			listener.connectionStoreChanged();

		}

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionTypeProvider#getConnectionType(java.lang.String)

	 */

	public IConnectionType getConnectionType(String identifier) {

		Check.checkContract(connectionTypeIdMap != null);

		return connectionTypeIdMap.get(identifier);

	}

	public Collection<IConnectionType> getConnectionTypes() {

		return connectionTypeIdMap.values();

	}

	public Collection<IService> getCompatibleServices(IConnectionType connectionType) {

		Check.checkContract(connectionTypeToServices != null);

		Collection<IService> services = connectionTypeToServices.get(connectionType);

		if (services != null)

			return services;

		return Collections.EMPTY_LIST;

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#addConnection(com.nokia.carbide.remoteconnections.extensions.IConnection)

	 */

	public void addConnection(IConnection connection) {

		ensureUniqueId(connection);

		ensureUniqueName(connection);

		List<IConnectedService> connectedServices = createConnectedServicesForConnection(connection);

		connectionToConnectedServices.put(connection, connectedServices);

		fireConnectionStoreChanged();

	}

	private void ensureUniqueId(IConnection connection) {

		String id = connection.getIdentifier();

		if (id == null || id.length() == 0 || connectionIdInUse(id))

			connection.setIdentifier(getUniqueConnectionId());

	}

	public String getUniqueConnectionId() {

		return UUID.randomUUID().toString();

	}

	private boolean connectionIdInUse(String id) {

		boolean used = false;

		for (IConnection c : connectionToConnectedServices.keySet()) {

			if (c.getIdentifier().equals(id)) {

				used = true;

				break;

			}

		}

		return used;

	}

	private void ensureUniqueName(IConnection connection) {

		String name = connection.getDisplayName();

		if (name == null)

			connection.setDisplayName(connection.getIdentifier());

		if (connectionNameInUse(name)) {

			// check if already has the suffix " (num)"

			Pattern pattern = Pattern.compile(NAME_SUFFIX_PATTERN);

			Matcher matcher = pattern.matcher(name);

			boolean hasSuffix = matcher.matches();

			String namePart;

			int number;

			if (hasSuffix) { // extract the name part and the number to increment

				namePart = matcher.group(1);

				String numberPart = matcher.group(2);

				number = Integer.parseInt(numberPart); // all digits, so should not throw

				number = (number <= 1) ? 2 : number++;

			}

			else { // just use the name and add the number starting with 2

				namePart = name;

				number = 2;

			}

			while (true) {

				String newName = MessageFormat.format(NAME_FMT, new Object[] { namePart, number++ });

				if (!connectionNameInUse(newName)) {

					connection.setDisplayName(newName);

					break;

				}

			}

		}

	}

	public boolean connectionNameInUse(String name) {

		boolean used = false;

		for (IConnection c : connectionToConnectedServices.keySet()) {

			if (c.getDisplayName().equals(name)) {

				used = true;

				break;

			}

		}

		return used;

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#removeConnection(com.nokia.carbide.remoteconnections.extensions.IConnection)

	 */

	public void removeConnection(IConnection connection) {

		disposeConnection(connection);

		connectionToConnectedServices.remove(connection);

		fireConnectionStoreChanged();

	}

	private void disposeConnection(IConnection connection) {

		List<IConnectedService> connectedServices = connectionToConnectedServices.get(connection);

		for (IConnectedService connectedService : connectedServices) {

			connectedService.dispose();

		}

		connection.dispose();

	}

	/* (non-Javadoc)

	 * @see com.nokia.carbide.remoteconnections.registry.IConnectionStore#getConnections()

	 */

	public Collection<IConnection> getConnections() {

		return connectionToConnectedServices.keySet();

	}

	public Collection<IConnectedService> getConnectedServices(IConnection connection) {

		return connectionToConnectedServices.get(connection);

	}

	private File getConnectionStorageFile() {

		IPath path = RemoteConnectionsActivator.getDefault().getStateLocation().append(CONNECTION_DATA_XML);

		return path.toFile();

	}

	public void disposeConnections() {

		for (IConnection connection : connectionToConnectedServices.keySet()) {

			disposeConnection(connection);

		}

		connectionToConnectedServices.clear();

	}

	private void fireDisplayChanged() {

		if (listeners == null)

			return;

		for (IConnectionsManagerListener listener : listeners) {

			listener.displayChanged();

		}

	}

	public void updateDisplays() {

		fireDisplayChanged();

	}

	public IClientServiceSiteUI getClientSiteUI(IService service) {

		return new ClientServiceSiteUI(service);

	}

	public Collection<IService> getServices() {

		return services;

	}

	public IService findServiceByID(String id) {

		for (IService service : services) {

			if (service.getIdentifier().equals(id))

				return service;

		}

		return null;

	}

}