/*

 * Copyright (c) 2008-2009 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:  Definitions for the class EpocReader

 *

 */

package com.nokia.s60tools.analyzetool.engine;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import org.eclipse.core.resources.IProject;

import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Status;

import org.eclipse.core.runtime.jobs.Job;

import com.nokia.s60tools.analyzetool.global.Constants;

import com.nokia.s60tools.analyzetool.global.Util;

import com.nokia.s60tools.analyzetool.ui.MainView;

/**

 * Creates new job for polling epocwind.out file

 * @author kihe

 *

 */

public class EpocReader extends Job{

	/** Epocwind.out file location*/

	private final String emulatorFileLocation;

	/**Is file listening active*/

	boolean alreadyStarted = false;

	/**Interval to read file contents*/

	static final int POLL_INTERVAL = 1000; // 1 second

	/**Epocwind.out file size*/

	long fileSize = -1;

	/**

	 * How many characters we have read

	 * We can assume that long is big enough to store character count

	 * because max size of long is 9223372036854775807l

	 */

	long readCharacters = 0;

	/**Project reference*/

	IProject project;

	/**Parent class reference*/

	MainView main;

	/**Flag to determinate do we still need to read changes from epocwind.out file*/

	boolean stillRun = true;

	/**

	 * Constructor

	 * @param projectRef Project reference

	 * @param parentClass Parent class reference

	 */

	public EpocReader(IProject projectRef, MainView parentClass)

	{

		super(Constants.OUTPUT_READER_TITLE);

		emulatorFileLocation = System.getenv("TEMP") + File.separator+ "epocwind.out";

		project = projectRef;

		main = parentClass;

	}

	/**

	 * Starts epocwind.out file reading

	 */

	public void start(){

		//if we are already listening epocwindout file => no need create new job

		if( alreadyStarted ) {

			return;

		}

		setPriority(Job.LONG);

		setUser(false);

		//start as soon as possible

		schedule();

		//update listening flag

		alreadyStarted = true;

		//open streams

		main.parser.openStreams(Util.getBldInfFolder(

				project, true));

	}

	/**

	 * Stops listening emulator

	 */

	public void stop() {

		alreadyStarted = false;

		fileSize = -1;

		readCharacters = 0;

		stillRun = false;

		cancel();

	}

	/**

	 * Reads the epocwind.out file if it has been changed since last time

	 */

	@Override

	protected IStatus run(IProgressMonitor arg0) {

		//stream which are used to read file content

		FileInputStream fis = null;

		BufferedReader br = null;

		//run while user stops the data capturing

		while(stillRun) {

			try {

				//create new file

				File epocFile = new File(emulatorFileLocation);

				//if file exists

				if (epocFile.exists()) {

					// emulator output is not read

					// so we need to thru existing data of emulator output,

					// because we are only interested of new data.

					if (fileSize == -1) {

						fileSize = epocFile.length();

						//open epocwind.out file

						fis = new FileInputStream(epocFile);

						br = new BufferedReader(new InputStreamReader(fis, "UTF-8"));

						//skip lines what we have already read

						br.skip(readCharacters);

						String line = "";

						// read all new lines of epocwind.out file

						while ((line = br.readLine()) != null) {

							//update read count

							readCharacters+=line.length()+2; //<== line feed character

						}

					// emulator output contains new/more information than what we are read

					} else if (epocFile.length() > fileSize) {

						//open epocwind.out file

						fis = new FileInputStream(epocFile);

						br = new BufferedReader(new InputStreamReader(fis, "UTF-8"));

						//skip lines what we have already read

						br.skip(readCharacters);

						String line = "";

						// read all new lines in epocwind.out

						while ((line = br.readLine()) != null) {

							//update read count

							readCharacters+=line.length()+2; //<== line feed character

							//transfer line to parser

							main.parser.parse(line);

						}

						//update size

						fileSize = epocFile.length();

						//tell AT UI to update online allocation count value

						main.updateAllocNumber();

					}else if (epocFile.length() < fileSize){

						fileSize = 0;

						readCharacters = 0;

					}

				}

				if( br != null ) {

					br.close();

					br = null;

				}

				if( fis != null ) {

					fis.close();

					fis = null;

				}

				//sleep this thread

				Thread.sleep(POLL_INTERVAL);

			} catch (InterruptedException ie) {

				//we can shallow the exception

				//because when this exception is raised we can exit

				cancel();

			} catch (Exception e) {

				e.printStackTrace();

				cancel();

			}

			finally{

				try{

					if(br != null ) {

						br.close();

					}

				}catch(IOException ioe ) {

					ioe.printStackTrace();

				}

				try{

					if(fis != null ) {

						fis.close();

					}

				}catch(IOException ioe ) {

					ioe.printStackTrace();

				}

			}

		}

		//parsing is finished

		return Status.OK_STATUS;

	}

}