/*******************************************************************************
 * Copyright (c) 2005-2008 Polarion Software.
 * 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:
 *    Igor Burilo - Initial API and implementation
 *******************************************************************************/

package org.eclipse.team.svn.core;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.resources.IResourceDeltaVisitor;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.team.svn.core.operation.CompositeOperation;
import org.eclipse.team.svn.core.operation.IActionOperation;
import org.eclipse.team.svn.core.operation.LoggedOperation;
import org.eclipse.team.svn.core.operation.local.AbstractWorkingCopyOperation;
import org.eclipse.team.svn.core.operation.local.RefreshResourcesOperation;
import org.eclipse.team.svn.core.operation.local.RevertOperation;
import org.eclipse.team.svn.core.resource.ILocalResource;
import org.eclipse.team.svn.core.svnstorage.SVNRemoteStorage;
import org.eclipse.team.svn.core.utility.FileUtility;
import org.eclipse.team.svn.core.utility.ProgressMonitorUtility;

/**
 * Handles file replacement as file modification, i.e. if file which is under
 * version control is deleted and then it was added file with the same name then
 * treat this file as modified but not as replaced
 * 
 * @author Igor Burilo
 */
public class FileReplaceListener implements IResourceChangeListener {

	public void resourceChanged(IResourceChangeEvent event) {
		try {
			final List<IFile> added = new ArrayList<IFile>();			
			event.getDelta().accept(new IResourceDeltaVisitor() {
				public boolean visit(IResourceDelta delta) throws CoreException {
					// replacement does not send addition event, but CHANGE event is sent in its place
					if (delta.getResource().getType() == IResource.FILE && (delta.getKind() == IResourceDelta.ADDED || delta.getKind() == IResourceDelta.CHANGED)) {
						added.add((IFile)delta.getResource());
					}					
					return true;
				}			
			});			
			if (!added.isEmpty()) {
				this.processResources(added.toArray(new IResource[0]));
			}
		} catch (CoreException e) {
			LoggedOperation.reportError(this.getClass().getName(), e);
		}
	}

	protected void processResources(IResource []resources) {
		AbstractWorkingCopyOperation mainOp = new AbstractWorkingCopyOperation("Operation_FileReplaceListener", SVNMessages.class, resources) { //$NON-NLS-1$
			protected void runImpl(IProgressMonitor monitor) throws Exception {																				
				for (final IResource file : this.operableData()) {														
					if (monitor.isCanceled()) {
						return;
					}				

					ILocalResource local = SVNRemoteStorage.instance().asLocalResource(file);								
					if (!(IStateFilter.SF_DELETED.accept(local) || IStateFilter.SF_PREREPLACEDREPLACED.accept(local))) {
						continue;
					}
					IResource parent = file.getParent();
					ILocalResource localParent = SVNRemoteStorage.instance().asLocalResource(parent);
					if (IStateFilter.SF_DELETED.accept(localParent)) {
						continue;
					}									
					
					boolean hasError = true;
					File originalFile = new File(FileUtility.getWorkingCopyPath(file));
					File tmpFile = new File(originalFile + ".svntmp"); //$NON-NLS-1$
					//used for restore
					File fileWithOriginalContent = originalFile;
					try {							
						if (tmpFile.exists()) {
							tmpFile.delete();
						}											
						if (originalFile.renameTo(tmpFile)) {
							fileWithOriginalContent = tmpFile;
							RevertOperation revertOp = new RevertOperation(new IResource[]{file}, false);
							ProgressMonitorUtility.doTask(revertOp, monitor, 100, 60);													
							if (revertOp.getExecutionState() == IActionOperation.OK) {			
								if (!originalFile.delete()) {
									throw new Exception("Failed to delete file: " + originalFile); //$NON-NLS-1$
								}
								if (!tmpFile.renameTo(originalFile)) {
									throw new Exception("Failed to rename file: " + originalFile); //$NON-NLS-1$
								}
								fileWithOriginalContent = originalFile;
								hasError = false;
							} else {
								this.reportStatus(revertOp.getStatus());
							}								
						} else {
							throw new Exception("Failed to rename file: " + originalFile.getAbsolutePath()); //$NON-NLS-1$
						}
					} catch (Throwable t) {
						this.reportStatus(IStatus.ERROR, null, t);
					} finally {
						/*
						 * Restore
						 */
						if (hasError) {
							if (fileWithOriginalContent.equals(tmpFile)) {
								originalFile.delete();
								tmpFile.renameTo(originalFile);
							} else if (fileWithOriginalContent.equals(originalFile)) {
								tmpFile.delete();	
							}								
						}
					}
				}									
			}	
		};			
		
		CompositeOperation cmpOp = new CompositeOperation(mainOp.getId(), mainOp.getMessagesClass());
		cmpOp.add(mainOp);
		cmpOp.add(new RefreshResourcesOperation(resources));			
		ProgressMonitorUtility.doTaskScheduledDefault(cmpOp);
	}
}