/*

* 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.model;

import java.io.*;

import java.util.*;

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 org.eclipse.core.runtime.jobs.ILock;

import org.eclipse.swt.widgets.Display;

import com.nokia.s60tools.crashanalyser.data.*;

import com.nokia.s60tools.crashanalyser.interfaces.*;

/**

 * This class is responsible for providing crash files to MainView's content provider.

 * This class read workspace specific crash files from disk and prepares them for main view. 

 *

 */

public class CrashFileManager extends Job {

	List<CrashFileBundle> crashFiles = null;

	INewCrashFilesObserver filesObserver = null;

	ErrorLibrary errorLibrary = null;

	ILock accessLock = null;

	boolean restart = false;

	boolean jobRunning = false;

	/**

	 * Constructor

	 * @param observer observer for new files

	 */

	public CrashFileManager(INewCrashFilesObserver observer) {

		super("CrashAnalyser - Reading Files");

		filesObserver = observer;

		accessLock = Job.getJobManager().newLock();

		setPriority(Job.LONG);

		setUser(false);

	}

	protected IStatus run(IProgressMonitor monitor) {

		accessLock.acquire();

		try {

			jobRunning = true;

			// create array for crash files if it doesn't exist yet

			if (crashFiles == null) {

				crashFiles = new ArrayList<CrashFileBundle>();

			// array exists, remove non-existing files

			} else {

				// remove no longer existing files

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

					CrashFileBundle file = crashFiles.get(i);

					if (!file.exists()) {

						crashFiles.remove(i);

						i--;

					}

				}

			}

		} catch (Exception e) {

			e.printStackTrace();

		} finally {

			accessLock.release();

		}

		// get crash files folder e.g. C:\My_Workspace\.metadata\.plugins\com.nokia.s60tools.crashanalyser\CrashFiles

		File cFilesFolder = new File(DecoderEngine.getCrashFilesFolder());

		if (cFilesFolder.exists() && cFilesFolder.isDirectory()) {

			// get crash file folders (CrashFiles are under numeric folders, e.g. ..\CrashFiles\1, ...\CrashFiles\2, etc.

			File[] folders = cFilesFolder.listFiles();

			if (folders != null) {

				// go through all folders

				for (int j = 0; j < folders.length; j++) {

					File cFolder = folders[j];

					if (cFolder.isDirectory()) {

						accessLock.acquire();

						try {

							// create dummy bundle for comparing purposes

							CrashFileBundle dummy = CrashFileBundle.createDummyBundle(cFolder.getAbsolutePath());

							// if array already contains this bundle, remove it and add it again, so that data is updated 

							if (crashFiles.contains(dummy)) {

								accessLock.release();

								CrashFileBundle bundle = new CrashFileBundle(cFolder.getAbsolutePath(), errorLibrary);

								if (bundle.hasFiles()) {

									accessLock.acquire();

									crashFiles.remove(dummy);

									crashFiles.add(bundle);

								}

							// array doesn't contain this bundle, add it

							} else {

								accessLock.release();

								CrashFileBundle bundle = new CrashFileBundle(cFolder.getAbsolutePath(), errorLibrary);

								if (bundle.hasFiles()) {

									accessLock.acquire();

									crashFiles.add(bundle);

								}

							}

						} catch (Exception e) {

							e.printStackTrace();

						} finally {

							accessLock.release();

						}

					}

				}

			}

		}

		// notify observer to update it's view

		filesObserver.crashFilesUpdated();

		accessLock.acquire();

		// we have received new files while reading files, 

		// read files immediately again

		if (restart) {

			restart = false;

			accessLock.release();

			reSchedule();

		} else {

			jobRunning = false;

			accessLock.release();

		}

		return Status.OK_STATUS;

	}

	/**

	 * Schedules job asynchronously

	 */

	void reSchedule() {

		Runnable refreshRunnable = new Runnable(){

			public void run(){

				schedule(100);

			}

		};

		Display.getDefault().asyncExec(refreshRunnable);        		

	}

	/**

	 * Returns all read crash files. Can also return "No files"-bundle or "Waiting"-bundle.

	 * @param library error library

	 * @return list of crash files

	 */

	public CrashFileBundle[] getCrashFiles(ErrorLibrary library) {

		try {

			// do nothing until we get a valid ErrorLibrary, return "Waiting"-bundle

			if (library == null) {

				CrashFileBundle[] cFiles = new CrashFileBundle[1];

				cFiles[0] = new CrashFileBundle(false);

				return cFiles;

			}

			// crash files has not yet been read, start reading process,

			// and return "reading files"-bundle.

			if (crashFiles == null) {

				errorLibrary = library;

				reSchedule();

				CrashFileBundle[] cFiles = new CrashFileBundle[1];

				cFiles[0] = new CrashFileBundle(false);

				return cFiles;

			// files are up to date, return files

			} else {

				accessLock.acquire();

				try {

					// there are no files, return "No files"-bundle

					if (crashFiles.isEmpty()) {

						CrashFileBundle[] cFiles = new CrashFileBundle[1];

						cFiles[0] = new CrashFileBundle(true);

						return cFiles;

					// there are files, return them

					} else {

						return crashFiles.toArray(new CrashFileBundle[crashFiles.size()]);

					}

				} catch (Exception e) {

					e.printStackTrace();

				} finally {

					accessLock.release();

				}

				// if something went wrong, return "No files"-bundle 

				CrashFileBundle[] cFiles = new CrashFileBundle[1];

				cFiles[0] = new CrashFileBundle(true);

				return cFiles;

			}

		} catch (Exception e) {

			e.printStackTrace();

			return null;

		}

	}

	/**

	 * Starts reading all files from files system

	 */

	public void refresh() {

		accessLock.acquire();

		try {

			// if we are currently reading files, 

			if (jobRunning) {

				restart = true;

			// we are not reading files at the moment, schedule job

			} else {

				if (errorLibrary != null) {

					reSchedule();

				}

			}

		} catch (Exception e) {

			e.printStackTrace();

		} finally {

			accessLock.release();

		}

	}

}