/*

 * Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies). 

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of "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:

 *

 * Connection handler handles the connecting and disconnecting

 *

 */

package com.nokia.traceviewer.api;

import java.util.List;

import org.eclipse.jface.preference.IPreferenceStore;

import org.eclipse.swt.widgets.Display;

import com.nokia.traceviewer.TraceViewerPlugin;

import com.nokia.traceviewer.action.ConnectAction;

import com.nokia.traceviewer.api.TraceViewerAPI.TVAPIError;

import com.nokia.traceviewer.engine.TraceProvider;

import com.nokia.traceviewer.engine.TraceViewerGlobals;

import com.nokia.traceviewer.engine.preferences.PreferenceConstants;

import com.nokia.traceviewer.internal.api.TraceViewerAPI2Impl;

/**

 * Connection handler handles the connecting and disconnecting

 * 

 */

final class ConnectionHandler {

	/**

	 * Old connection method

	 */

	private String oldConnectionMethod;

	/**

	 * Old connection parameters

	 */

	private String[] oldParameters;

	/**

	 * Old connection ID that was selected.

	 */

	private String oldSelectedConnectionID;

	/**

	 * Connect using current settings defined in TraceViewer's preferences

	 * 

	 * @return error code from TraceViewerAPI

	 */

	public TVAPIError connect() {

		TVAPIError errorcode = TVAPIError.NONE;

		// Check if already connected

		if (isAlreadyConnected()) {

			errorcode = TVAPIError.ALREADY_CONNECTED;

		} else {

			// If view exists and we are in UI thread, do the connecting through

			// the view action

			if (TraceViewerGlobals.getTraceViewer().getView() != null

					&& Display.getCurrent() != null) {

				ConnectAction action = ((ConnectAction) (TraceViewerGlobals

						.getTraceViewer().getView().getActionFactory()

						.getConnectAction()));

				errorcode = action.connect(false, true);

				// Connect through engine

			} else {

				changeDataFormat();

				boolean success = TraceViewerGlobals.getTraceViewer().connect();

				if (!success) {

					errorcode = TVAPIError.INVALID_CONNECTION_SETTINGS;

				}

				// If succeeded and view exists, change button

				if (success

						&& TraceViewerGlobals.getTraceViewer().getView() != null) {

					ConnectAction action = ((ConnectAction) (TraceViewerGlobals

							.getTraceViewer().getView().getActionFactory()

							.getConnectAction()));

					action.changeToDisconnectAction();

				}

			}

		}

		return errorcode;

	}

	/**

	 * Connect using given parameters. Possible connection methods can be found

	 * from TraceViewerAPI constants. Parameters should be given in this order:

	 * When using TCP connection, parameters are IP address port number and

	 * channel number in this order. When using USB serial connection, the only

	 * parameter is the COM port number. This function will also set given

	 * parameters to TraceViewer's connection preferences if the connecting

	 * succeeds.

	 * 

	 * @param connectionMethod

	 *            the connection method to use

	 * @param parameters

	 *            array of parameters

	 * @return error code from TraceViewerAPI

	 */

	public TVAPIError connect(int connectionMethod, String[] parameters) {

		TVAPIError errorcode = TVAPIError.NONE;

		// Check if already connected

		if (isAlreadyConnected()) {

			errorcode = TVAPIError.ALREADY_CONNECTED;

		} else {

			// Save old connection preferences

			saveConnectionPreferences();

			// Set new connection preferences

			boolean parametersOk = setNewConnectionPreferences(

					connectionMethod, parameters);

			if (parametersOk) {

				// If view exists and we are in UI thread, do the connecting

				// through the view action

				if (TraceViewerGlobals.getTraceViewer().getView() != null

						&& Display.getCurrent() != null) {

					ConnectAction action = ((ConnectAction) (TraceViewerGlobals

							.getTraceViewer().getView().getActionFactory()

							.getConnectAction()));

					errorcode = action.connect(false, false);

					// Connect through engine

				} else {

					changeDataFormat();

					boolean success = TraceViewerGlobals.getTraceViewer()

							.connect();

					if (success) {

						errorcode = TVAPIError.NONE;

					} else {

						errorcode = TVAPIError.INVALID_CONNECTION_SETTINGS;

					}

				}

				// Connecting failed

				if (errorcode != TVAPIError.NONE) {

					// Set old preferences back

					setOldPreferencesBack();

					// If succeeded and view exists, change button

				} else if (TraceViewerGlobals.getTraceViewer().getView() != null) {

					ConnectAction action = ((ConnectAction) (TraceViewerGlobals

							.getTraceViewer().getView().getActionFactory()

							.getConnectAction()));

					action.changeToDisconnectAction();

				}

			} else {

				// Set old preferences back

				setOldPreferencesBack();

				errorcode = TVAPIError.INVALID_CONNECTION_PARAMETERS;

			}

		}

		return errorcode;

	}

	/**

	 * Changes Data Format

	 */

	private void changeDataFormat() {

		// Get the TraceViewer preferenceStore

		IPreferenceStore store = TraceViewerPlugin.getDefault()

				.getPreferenceStore();

		// If there are more than one TraceProvider

		if (TraceViewerGlobals.getListOfTraceProviders().size() > 1) {

			String selectedConnectionType = store

					.getString(PreferenceConstants.CONNECTION_TYPE);

			// If the currently selected TraceProvider doesn't has selected

			// connection as preferred, try to find one that does

			if (!TraceViewerGlobals.getTraceProvider()

					.getPreferredConnectionType()

					.equals(selectedConnectionType)) {

				List<TraceProvider> traceProviders = TraceViewerGlobals

						.getListOfTraceProviders();

				// Go through list of TraceProviders

				for (int i = 0; i < traceProviders.size(); i++) {

					TraceProvider newProvider = traceProviders.get(i);

					if (newProvider.getPreferredConnectionType().equals(

							selectedConnectionType)) {

						store.setValue(PreferenceConstants.DATA_FORMAT,

								newProvider.getName());

						// Set new Trace provider

						TraceViewerGlobals.setTraceProvider(newProvider, true);

						break;

					}

				}

			}

		}

	}

	/**

	 * Sets new connection preferences

	 * 

	 * @param connectionMethod

	 *            connection method

	 * @param parameters

	 *            connection parameters

	 * @return true if succeeded, false if failed

	 */

	private boolean setNewConnectionPreferences(int connectionMethod,

			String[] parameters) {

		boolean succeeded = true;

		// Get the TraceViewer preferenceStore

		IPreferenceStore store = TraceViewerPlugin.getDefault()

				.getPreferenceStore();

		try {

			String connectionMethodStr = null;

			// TCP / IP

			if (connectionMethod == TraceViewerAPI.TVAPI_CONNECTION_TCP) {

				connectionMethodStr = PreferenceConstants.CONNECTION_TYPE_TCPIP;

				// There must be at least 2 parameters

				if (parameters != null && parameters.length > 1) {

					// Set IP address

					store.setValue(PreferenceConstants.IP_ADDRESS,

							parameters[0]);

					// Set port number

					store.setValue(PreferenceConstants.TCPIP_PORT,

							parameters[1]);

					// Check if there is channel specified

					if (parameters.length > 2) {

						// Set channel number

						store.setValue(PreferenceConstants.TCPIP_CHANNEL,

								parameters[2]);

					}

				} else {

					succeeded = false;

				}

				// USB Serial

			} else if (connectionMethod == TraceViewerAPI.TVAPI_CONNECTION_USB_SERIAL) {

				connectionMethodStr = PreferenceConstants.CONNECTION_TYPE_USB_SERIAL;

				// There must be at least 1 parameters

				if (parameters != null && parameters.length > 0) {

					// Set com port

					store.setValue(PreferenceConstants.USB_SERIAL_COM_PORT,

							parameters[0]);

				} else {

					succeeded = false;

				}

			}

			// Set the connection method

			if (succeeded) {

				store.setValue(PreferenceConstants.CONNECTION_TYPE,

						connectionMethodStr);

				// Old connection ID is not valid, since connection settings

				// have been changed.

				store.setValue(PreferenceConstants.SELECTED_CONNECTION_ID, ""); //$NON-NLS-1$

			}

		} catch (Exception e) {

			succeeded = false;

		}

		return succeeded;

	}

	/**

	 * Saves old connection preferences

	 */

	private void saveConnectionPreferences() {

		// Get the TraceViewer preferenceStore

		IPreferenceStore store = TraceViewerPlugin.getDefault()

				.getPreferenceStore();

		oldConnectionMethod = store

				.getString(PreferenceConstants.CONNECTION_TYPE);

		oldSelectedConnectionID = store

				.getString(PreferenceConstants.SELECTED_CONNECTION_ID);

		// TCP / IP connection

		if (oldConnectionMethod

				.equals(PreferenceConstants.CONNECTION_TYPE_TCPIP)) {

			oldParameters = new String[2];

			oldParameters[0] = store.getString(PreferenceConstants.IP_ADDRESS);

			oldParameters[1] = store.getString(PreferenceConstants.TCPIP_PORT);

			// USB Serial connection

		} else if (oldConnectionMethod

				.equals(PreferenceConstants.CONNECTION_TYPE_USB_SERIAL)) {

			oldParameters = new String[1];

			oldParameters[0] = store

					.getString(PreferenceConstants.USB_SERIAL_COM_PORT);

		}

	}

	/**

	 * Sets old connection preferences back to preference store

	 */

	private void setOldPreferencesBack() {

		// Get the TraceViewer preferenceStore

		IPreferenceStore store = TraceViewerPlugin.getDefault()

				.getPreferenceStore();

		// Set the connection method

		store

				.setValue(PreferenceConstants.CONNECTION_TYPE,

						oldConnectionMethod);

		// Set the selected connection ID

		store.setValue(PreferenceConstants.SELECTED_CONNECTION_ID,

				oldSelectedConnectionID);

		// TCP / IP connection

		if (oldConnectionMethod

				.equals(PreferenceConstants.CONNECTION_TYPE_TCPIP)) {

			store.setValue(PreferenceConstants.IP_ADDRESS, oldParameters[0]);

			store.setValue(PreferenceConstants.TCPIP_PORT, oldParameters[1]);

			// USB Serial connection

		} else if (oldConnectionMethod

				.equals(PreferenceConstants.CONNECTION_TYPE_USB_SERIAL)) {

			store.setValue(PreferenceConstants.USB_SERIAL_COM_PORT,

					oldParameters[0]);

		}

		// Resetting old connection settings

		oldConnectionMethod = null;

		oldParameters = null;

	}

	/**

	 * Checks if there are old connection preferences to restore.

	 * 

	 * @return <code>true</code> if are settings to restore, otherwise

	 *         <code>false</code>.

	 */

	public boolean hasRestorableConnectionPreferences() {

		return (oldConnectionMethod != null && oldParameters != null);

	}

	/**

	 * Disconnects from the target

	 * 

	 * @return error code from TraceViewerAPI

	 */

	public TVAPIError disconnect() {

		TVAPIError errorcode = TVAPIError.NONE;

		// Check if not connected

		if (!isAlreadyConnected()) {

			errorcode = TVAPIError.NOT_CONNECTED;

		} else {

			// Doing real disconnect only if client has been connected with

			// custom connection preferences

			// or there are no more registered clients left using the

			// connection.

			if (hasRestorableConnectionPreferences()

					|| !TraceViewerAPI2Impl.hasRegisteredClients()) {

				boolean disconnect;

				// If view exists and we are in UI thread, do the disconnecting

				// through the view action

				if (TraceViewerGlobals.getTraceViewer().getView() != null

						&& Display.getCurrent() != null) {

					ConnectAction action = ((ConnectAction) (TraceViewerGlobals

							.getTraceViewer().getView().getActionFactory()

							.getConnectAction()));

					disconnect = action.disconnect();

					// Disconnect through engine

				} else {

					disconnect = TraceViewerGlobals.getTraceViewer()

							.disconnect();

				}

				// Disconnection failed

				if (!disconnect) {

					errorcode = TVAPIError.DISCONNECTING_FAILED;

					// Disconnecting succeeded and view exists, change button

				} else if (TraceViewerGlobals.getTraceViewer().getView() != null) {

					ConnectAction action = ((ConnectAction) (TraceViewerGlobals

							.getTraceViewer().getView().getActionFactory()

							.getConnectAction()));

					action.changeToConnectAction();

				}

			}

		}

		// In case custom connection parameters were used in last connect...

		if (hasRestorableConnectionPreferences()) {

			// ... we are restoring the old settings back

			setOldPreferencesBack();

		}

		return errorcode;

	}

	/**

	 * Checks if the connection is already connected

	 * 

	 * @return true if already connected

	 */

	private boolean isAlreadyConnected() {

		boolean alreadyConnected = false;

		// Check if already connected

		if (TraceViewerGlobals.getTraceViewer().getConnection() != null) {

			if (TraceViewerGlobals.getTraceViewer().getConnection()

					.isConnected()) {

				alreadyConnected = true;

			}

		}

		return alreadyConnected;

	}

}