/*

* 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:

*

* Property file management engine

*

*/

package com.nokia.tracebuilder.engine.propertyfile;

import java.io.File;

import java.io.OutputStream;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.OutputKeys;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import com.nokia.tracebuilder.engine.TraceBuilderEngine;

import com.nokia.tracebuilder.engine.TraceBuilderErrorMessages;

import com.nokia.tracebuilder.engine.TraceBuilderGlobals;

import com.nokia.tracebuilder.engine.TraceBuilderErrorCodes.TraceBuilderErrorCode;

import com.nokia.tracebuilder.engine.project.ProjectEngine;

import com.nokia.tracebuilder.file.FileUtils;

import com.nokia.tracebuilder.model.TraceBuilderException;

import com.nokia.tracebuilder.model.TraceConstantTable;

import com.nokia.tracebuilder.model.TraceConstantTableEntry;

import com.nokia.tracebuilder.model.TraceModel;

import com.nokia.tracebuilder.model.TraceModelListener;

import com.nokia.tracebuilder.model.TraceObject;

import com.nokia.tracebuilder.model.TraceProcessingListener;

import com.nokia.tracebuilder.project.ProjectUtils;

import com.nokia.tracebuilder.source.SourceConstants;

/**

 * Property file management engine

 * 

 */

public final class PropertyFileEngine extends TraceBuilderEngine implements

		TraceModelListener, TraceProcessingListener {

	/**

	 * Trace model

	 */

	private TraceModel model;

	/**

	 * Model processing flag prevents unnecessary saves

	 */

	private boolean processing;

	/**

	 * Backup created flag. This is initially set to false and when backup is

	 * created, changes to true

	 */

	private boolean backupCreated;

	/**

	 * Constructor

	 * 

	 * @param model

	 *            the trace model

	 */

	public PropertyFileEngine(TraceModel model) {

		this.model = model;

		model.addModelListener(this);

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.engine.TraceBuilderEngine#projectOpened()

	 */

	@Override

	public void projectOpened() {

		TracePropertyFile propertyFile = model

				.getExtension(TracePropertyFile.class);

		if (propertyFile == null) {

			String fileName = null;

			try {

				fileName = ProjectUtils.getLocationForFile(model,

						ProjectEngine.traceFolderName,

						PropertyFileConstants.PROPERTY_FILE_NAME, false);

			} catch (TraceBuilderException e) {

				// Model should always be open when traceProjectOpened is

				// called

			}

			if (fileName != null) {

				propertyFile = parsePropertyFile(fileName);

				// Backup flag is reset when model is opened

				backupCreated = false;

			}

		}

		if (propertyFile == null) {

			String msg = Messages

					.getString("PropertyFileEngine.FailedToAttachFile"); //$NON-NLS-1$

			TraceBuilderGlobals.getEvents().postErrorMessage(msg, null, true);

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.engine.TraceBuilderEngine#projectClosing()

	 */

	@Override

	public void projectClosed() {

		model.removeExtensions(TracePropertyFile.class);

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.engine.TraceBuilderEngine#exportProject()

	 */

	@Override

	public void exportProject() {

	}

	/**

	 * Parses the property file

	 * 

	 * @param fileName

	 *            the file path

	 * @return the property file

	 */

	private TracePropertyFile parsePropertyFile(String fileName) {

		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

		factory.setValidating(false);

		DocumentBuilder builder;

		TracePropertyFile propertyFile = null;

		try {

			builder = factory.newDocumentBuilder();

			File file = new File(fileName);

			if (file.exists()) {

				try {

					PropertyFileParser parser = new PropertyFileParser(model,

							fileName, builder);

					parser.parse();

					propertyFile = new TracePropertyFile(file.getParent(),

							parser.getDocument());

					propertyFile.setProperties(parser.getGroupProperties(),

							parser.getTraceProperties());

				} catch (TraceBuilderException e) {

					// Problem parsing document -> Backup and create new

					TraceBuilderGlobals.getEvents().postError(e);

					createBackup(fileName);

				}

			}

			if (propertyFile == null) {

				propertyFile = new TracePropertyFile(file.getParent(), builder

						.newDocument());

			}

			model.addExtension(propertyFile);

		} catch (ParserConfigurationException e) {

		}

		return propertyFile;

	}

	/**

	 * Writes the property file

	 */

	private void writePropertyFile() {

		if (!processing) {

			TracePropertyFile propertyFile = model

					.getExtension(TracePropertyFile.class);

			if (propertyFile != null) {

				// Backup flag is checked. If not set, a backup is created and

				// the flag is set. The flag is reset when project is re-opened

				String path = propertyFile.getAbsolutePath();

				if (!backupCreated) {

					createBackup(path);

					backupCreated = true;

				}

				try {

					// Uses XML API to write the property file

					OutputStream fos = FileUtils.createOutputStream(new File(

							path));

					Transformer transformer = TransformerFactory.newInstance()

							.newTransformer();

					transformer.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$

					transformer.transform(new DOMSource(propertyFile

							.getDocument()), new StreamResult(fos));

					fos.close();

					propertyFile.postFileWrittenEvent(path);

				} catch (Exception e) {

					String msg = TraceBuilderErrorMessages.getErrorMessage(

							TraceBuilderErrorCode.CANNOT_WRITE_PROJECT_FILE,

							null);

					TraceBuilderGlobals.getEvents().postErrorMessage(msg, e, true);

				}

			}

		}

	}

	/**

	 * Creates a backup of the property file

	 * 

	 * @param path

	 *            the file to be backed up

	 */

	private void createBackup(String path) {

		boolean backup = false;

		File file = new File(path);

		if (file.exists()) {

			boolean allexist = true;

			// Checks the existing backup files and renames the old file to

			// largest available number starting from 0

			File f = null;

			for (int i = 0; i < PropertyFileConstants.BACKUP_COUNT && allexist; i++) {

				f = new File(path + i + PropertyFileConstants.BACKUP_EXTENSION);

				if (!f.exists()) {

					backup = FileUtils.copyFile(file, f);

					allexist = false;

				}

			}

			if (allexist) {

				// If all backups from 0 to 9 exist, the old ones are moved

				// back 1 step. The new file is renamed to *9.h

				for (int i = 0; i < PropertyFileConstants.BACKUP_COUNT; i++) {

					f = new File(path + i

							+ PropertyFileConstants.BACKUP_EXTENSION);

					if (i == 0) {

						f.delete();

					} else {

						f.renameTo(new File(path + (i - 1)

								+ PropertyFileConstants.BACKUP_EXTENSION));

					}

				}

				f = new File(path + PropertyFileConstants.LAST_BACKUP);

				backup = FileUtils.copyFile(file, f);

			}

			if (f != null && backup) {

				String msg = Messages

						.getString("PropertyFileEngine.PropertyFileBackUpPrefix") //$NON-NLS-1$

						+ FileUtils.convertSeparators(

								SourceConstants.FORWARD_SLASH_CHAR, f

										.getAbsolutePath(), false);

				TraceBuilderGlobals.getEvents().postInfoMessage(msg, null);

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceModelListener#

	 *      objectAdded(com.nokia.tracebuilder.model.TraceObject,

	 *      com.nokia.tracebuilder.model.TraceObject)

	 */

	public void objectAdded(TraceObject owner, TraceObject object) {

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceModelListener#

	 *      objectCreationComplete(com.nokia.tracebuilder.model.TraceObject)

	 */

	public void objectCreationComplete(TraceObject object) {

		if (model.isValid()) {

			if (object instanceof TraceConstantTable

					|| object instanceof TraceConstantTableEntry) {

				TracePropertyFile propertyFile = model

						.getExtension(TracePropertyFile.class);

				if (propertyFile != null) {

					propertyFile.addElement(object);

					writePropertyFile();

				}

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceModelListener#

	 *      objectRemoved(com.nokia.tracebuilder.model.TraceObject,

	 *      com.nokia.tracebuilder.model.TraceObject)

	 */

	public void objectRemoved(TraceObject owner, TraceObject object) {

		if (model.isValid()) {

			if (object instanceof TraceConstantTable

					|| object instanceof TraceConstantTableEntry) {

				TracePropertyFile propertyFile = model

						.getExtension(TracePropertyFile.class);

				if (propertyFile != null) {

					propertyFile.removeElement(object);

					writePropertyFile();

				}

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceModelListener#

	 *      propertyUpdated(com.nokia.tracebuilder.model.TraceObject, int)

	 */

	public void propertyUpdated(TraceObject object, int property) {

		if (object.isComplete()

				&& (object instanceof TraceConstantTable || object instanceof TraceConstantTableEntry)) {

			TracePropertyFile propertyFile = model

					.getExtension(TracePropertyFile.class);

			if (propertyFile != null) {

				propertyFile.updateElement(object);

				writePropertyFile();

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceProcessingListener#processingComplete(boolean)

	 */

	public void processingComplete(boolean changed) {

		processing = false;

		if (changed) {

			writePropertyFile();

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracebuilder.model.TraceProcessingListener#processingStarted()

	 */

	public void processingStarted() {

		processing = true;

	}

}