/*******************************************************************************
 * Copyright (c) 2007 Wind River Systems, Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Markus Schorn - initial API and implementation
 *******************************************************************************/ 

package org.eclipse.cdt.internal.core.pdom.indexer;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.cdt.core.CCorePlugin;
import org.eclipse.cdt.core.dom.IPDOMIndexer;
import org.eclipse.cdt.core.dom.IPDOMIndexerTask;
import org.eclipse.cdt.core.dom.IPDOMManager;
import org.eclipse.cdt.core.index.IIndexManager;
import org.eclipse.cdt.core.model.ICProject;
import org.eclipse.cdt.core.model.ITranslationUnit;
import org.eclipse.cdt.internal.core.index.IWritableIndex;
import org.eclipse.cdt.internal.core.index.IWritableIndexFragment;
import org.eclipse.cdt.internal.core.index.IWritableIndexManager;
import org.eclipse.cdt.internal.core.pdom.IndexerProgress;
import org.eclipse.cdt.internal.core.pdom.PDOMManager;
import org.eclipse.cdt.internal.core.pdom.WritablePDOM;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.osgi.util.NLS;

/**
 * A task for rebuilding an index, works for all indexers.
 */
public class PDOMRebuildTask implements IPDOMIndexerTask {
	protected static final String TRUE= String.valueOf(true);
	protected static final ITranslationUnit[] NO_TUS = new ITranslationUnit[0];
	
	private final IPDOMIndexer fIndexer;
	private final IndexerProgress fProgress;
	private volatile IPDOMIndexerTask fDelegate;

	public PDOMRebuildTask(IPDOMIndexer indexer) {
		fIndexer= indexer;
		fProgress= createProgress();
	}

	private IndexerProgress createProgress() {
		IndexerProgress progress= new IndexerProgress();
		progress.fTimeEstimate= 1000;
		return progress;
	}

	public IPDOMIndexer getIndexer() {
		return fIndexer;
	}

	public void run(IProgressMonitor monitor) throws InterruptedException {
		monitor.subTask(NLS.bind(Messages.PDOMIndexerTask_collectingFilesTask, 
				fIndexer.getProject().getElementName()));

		ICProject cproject= fIndexer.getProject();
		IProject project= cproject.getProject();
		if (project.isOpen() && project.exists()) {
			try {
				IWritableIndex index= ((IWritableIndexManager) CCorePlugin.getIndexManager()).getWritableIndex(cproject);
				if (index != null) {
					clearIndex(cproject, index);
					if (!IPDOMManager.ID_NO_INDEXER.equals(fIndexer.getID())) {
						createDelegate(cproject, monitor);
					}
				}
				// remove task-tags.
				TodoTaskUpdater.removeTasksFor(project);
			} catch (CoreException e) {
				CCorePlugin.log(e);
			} catch (InterruptedException e) {
			}
		}
		
		if (fDelegate != null) {
			fDelegate.run(monitor);
		}
	}
	
	private void clearIndex(ICProject project, IWritableIndex index) throws CoreException, InterruptedException {
		// First clear the pdom
		index.acquireWriteLock(0);
		try {
			index.clear();
			IWritableIndexFragment wf= index.getWritableFragment();
			if (wf instanceof WritablePDOM) {
				PDOMManager.writeProjectPDOMProperties((WritablePDOM) wf, project.getProject());
			}
		}
		finally {
			index.releaseWriteLock(0);
		}
	}

	private synchronized void createDelegate(ICProject project, IProgressMonitor monitor) throws CoreException {
		boolean allFiles= TRUE.equals(fIndexer.getProperty(IndexerPreferences.KEY_INDEX_ALL_FILES));
		List sources= new ArrayList();
		List headers= allFiles ? sources : null;
		TranslationUnitCollector collector= new TranslationUnitCollector(sources, headers, monitor);
		project.accept(collector);
		ITranslationUnit[] tus= (ITranslationUnit[]) sources.toArray(new ITranslationUnit[sources.size()]);
		fDelegate= fIndexer.createTask(tus, NO_TUS, NO_TUS);
		if (fDelegate instanceof PDOMIndexerTask) {
			final PDOMIndexerTask delegate = (PDOMIndexerTask) fDelegate;
			delegate.setUpdateFlags(IIndexManager.UPDATE_ALL);
			delegate.setParseUpFront();
		}
	}


	public synchronized IndexerProgress getProgressInformation() {
		return fDelegate != null ? fDelegate.getProgressInformation() : fProgress;
	}
}
