/*

* 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 "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.s60tools.crashanalyser.containers;

import java.util.*;

import java.io.*;

import org.w3c.dom.Element;

import org.w3c.dom.NodeList;

import org.w3c.dom.Node;

import org.w3c.dom.NamedNodeMap;

/**

 * An event log class. Contains a list of all events found in XML.

 * 

 * Event log is part of MobileCrash data, which contains 30 latest 

 * window and key press events which occurred before the crash.

 * 

 * List of events example:

 * [window][Home screen...]

 * [key][Backspace key]

 * [window][Home screen...]

 * .

 * .

 * .

 *

 */

public final class EventLog {

	// XML tags

	public static final String TAG_EVENT = "event";

	public static final String ATTRIBUTE_TYPE = "type";

	public static final String TYPE_KEY = "key";

	// events list

	private final List<String[]> logEvents;

	/**

	 * Constructor

	 * @param events list of events

	 */

	private EventLog(List<String[]> events) {

		logEvents = events;

	}

	public List<String[]> getLogEvents() {

		return logEvents;

	}

	/**

	 * Writes events in to a buffer (e.g. a text file)

	 * @param out where to write

	 * @throws IOException

	 */

	public void writeTo(BufferedWriter out) throws IOException {

		writeLine(out,"");

		writeLine(out, "SYSTEM EVENT LOG:");

		writeLine(out, "-----------------");

		// if there are any events

		if (logEvents != null && !logEvents.isEmpty()) {

			int longestEventName = 0;

			// calculate the longest event name

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

				String[] event = logEvents.get(i);

				if (event[0].length() > longestEventName)

					longestEventName = event[0].length();

			}

			// print events

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

				String[] event = logEvents.get(i);

				String format = String.format("%%-%ds  %%s", longestEventName);

				String line = String.format(format, event[0], event[1]);

				writeLine(out, line);

			}

		}

	}

	/**

	 * Writes given line plus a line break.

	 * @param out where to write

	 * @param line what to write

	 * @throws IOException

	 */

	void writeLine(BufferedWriter out, String line) throws IOException {

		out.write(line);

		out.newLine();

	}

	/**

	 * Reads events from an XML element

	 * @param elementSegEventLog segeventlog tag

	 * @return a created EventLog class or null

	 */

	public static EventLog read(Element elementSegEventLog) {

		try {

			List<String[]> events = new ArrayList<String[]>();

			// get all event nodes

			NodeList children = elementSegEventLog.getChildNodes();

			if (children != null && children.getLength() > 0) {

				// go through all event nodes

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

					Node el = children.item(i);

					// node is event node

					if (TAG_EVENT.equals(el.getNodeName())) {

						String eventValue = el.getFirstChild().getNodeValue();

						NamedNodeMap attributes = el.getAttributes();

						// if node has attributes

						if (attributes != null && attributes.getLength() > 0) {

							Node typeAttribute = attributes.getNamedItem(ATTRIBUTE_TYPE);

							String type = typeAttribute.getNodeValue();

							events.add(new String[]{type, eventValue});

						}

					}

				}

			}

			return new EventLog(events);

		} catch (Exception e) {

			return null;

		}

	}

}