/*

* 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.*;

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

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

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

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Plugin;

import org.osgi.framework.Version;

import org.w3c.dom.*;

import org.xml.sax.SAXException;

import java.io.IOException;

import java.io.InputStream;

import java.text.MessageFormat;

import java.util.*;

import javax.xml.parsers.*;

/**

 * Reads connections element containing connection settings data as XML

 * @see Writer

 */

public class Reader {

	private static final String CONNECTIONS_ELEMENT = "connections"; //$NON-NLS-1$

	private static final String VERSION_ATTR = "version"; //$NON-NLS-1$

	private static final String CONNECTION_ELEMENT = "connection"; //$NON-NLS-1$

	private static final String ID_ATTR = "id"; //$NON-NLS-1$

	private static final String DISPLAY_NAME_ATTR = "displayName"; //$NON-NLS-1$

	private static final String TYPE_ATTR = "type"; //$NON-NLS-1$

	private static final String SETTINGS_ELEMENT = "settings"; //$NON-NLS-1$

	private static final String SETTING_ELEMENT = "setting"; //$NON-NLS-1$

	private static final String NAME_ATTR = "name"; //$NON-NLS-1$

	public static List<IConnection> readFromXML(IConnectionTypeProvider connectionTypeProvider, InputStream is) throws SAXException, IOException {

		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

		DocumentBuilder db = null;

		try {

			db = dbf.newDocumentBuilder();

		} 

		catch (ParserConfigurationException e) {

			Check.checkContract(false); // should never occur

		}

		Check.checkState(db != null);

		Document document = db.parse(is);

		is.close();

		NodeList connectionsNodes = document.getElementsByTagName(CONNECTIONS_ELEMENT);

		Check.checkContract(connectionsNodes.getLength() >= 1);

		// ignore all but first <connections> element (should only be one)

		Element connectionsElement = (Element) connectionsNodes.item(0);

		String versionStr = connectionsElement.getAttribute(VERSION_ATTR);

		Version version = Version.parseVersion(versionStr);

		if (version.getMajor() == 1)

			return readV1(connectionTypeProvider, connectionsElement);

		throw new IllegalArgumentException(

				MessageFormat.format(Messages.getString("Reader.UnknownVersionError"),  //$NON-NLS-1$

						new Object[] { versionStr }));

	}

	private static List<IConnection> readV1(IConnectionTypeProvider connectionTypeProvider, Element connectionsElement) {

		List<IConnection> connections = new ArrayList<IConnection>();

		NodeList connectionNodes = connectionsElement.getElementsByTagName(CONNECTION_ELEMENT);

		for (int i = 0; i < connectionNodes.getLength(); i++) {

			Element connectionElement = (Element) connectionNodes.item(i);

			String typeId = connectionElement.getAttribute(TYPE_ATTR);

			String id = connectionElement.getAttribute(ID_ATTR);

			String displayName = connectionElement.getAttribute(DISPLAY_NAME_ATTR);

			IConnectionType connectionType = connectionTypeProvider.getConnectionType(typeId);

			if (connectionType == null) {

				Plugin p = RemoteConnectionsActivator.getDefault();

				String message = 

					MessageFormat.format(Messages.getString("Reader.MissingConnectionTypeError"),  //$NON-NLS-1$

							new Object[] { id, typeId });

				Logging.log(p, Logging.newStatus(p, IStatus.WARNING, message));

				continue;

			}

			Map<String, String> settings = readSettingsV1(connectionElement); 

			IConnection connection = connectionType.getConnectionFactory().createConnection(settings);

			connection.setIdentifier(id);

			connection.setDisplayName(displayName);

			connections.add(connection);

		}

		return connections;

	}

	private static Map<String, String> readSettingsV1(Element connectionElement) {

		Map<String, String> settings = new HashMap<String, String>();

		NodeList settingsNodes = connectionElement.getElementsByTagName(SETTINGS_ELEMENT);

		Check.checkContract(settingsNodes.getLength() >= 1);

		// ignore all but first <settings> element (should only be one)

		Element settingsElement = (Element) settingsNodes.item(0);

		NodeList settingNodes = settingsElement.getElementsByTagName(SETTING_ELEMENT);

		for (int i = 0; i < settingNodes.getLength(); i++) {

			Element settingElement = (Element) settingNodes.item(i);

			String key = settingElement.getAttribute(NAME_ATTR);

			String value = settingElement.getTextContent();

			settings.put(key, value);

		}

		return settings;

	}

}