/*******************************************************************************
 * Copyright (c) 2004, 2010 Spring IDE Developers
 * 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:
 *     Spring IDE Developers - initial API and implementation
 *******************************************************************************/
package org.springframework.ide.eclipse.ui.viewers;

import java.util.Collection;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.springframework.ide.eclipse.ui.SpringUIPlugin;

/**
 * Viewer filter for file selection dialogs. The filter is not case sensitive. Folders are only shown if, searched
 * recursively, contain at least one file which has one of the specified file suffixes.
 * @author Torsten Juergeleit
 * @author Christian Dupuis
 */
public class FileSuffixFilter extends ViewerFilter {

	private String[] allowedFileSuffixes;

	/**
	 * Creates new instance of filter.
	 * 
	 * @param allowedFileSuffixes list of file suffixes the filter has to recognize or <code>null</code> if all files
	 * are allowed
	 */
	public FileSuffixFilter(String[] allowedFileSuffixes) {
		this.allowedFileSuffixes = allowedFileSuffixes;
	}

	public FileSuffixFilter(Collection<String> allowedFileSuffixes) {
		this(allowedFileSuffixes.toArray(new String[allowedFileSuffixes.size()]));
	}

	public FileSuffixFilter() {
		allowedFileSuffixes = null;
	}

	@Override
	public boolean select(Viewer viewer, Object parent, Object element) {
		if (element instanceof IFile) {
			return hasAllowedFileSuffix(((IFile) element).getFullPath()) && selectFile((IFile) element);
		}
		else if (element instanceof IContainer) { // IProject, IFolder
			try {
				if (!".settings".equals(((IContainer) element).getName())) {
					for (IResource resource : ((IContainer) element).members()) {
						// recursive! Only show containers that contain a configs
						if (select(viewer, parent, resource)) {
							return true;
						}
					}
				}
			}
			catch (CoreException e) {
				SpringUIPlugin.log(e.getStatus());
			}
		}
		return false;
	}

	/**
	 * Template method to be overridden by subclasses to post process file selecting.
	 */
	protected boolean selectFile(IFile element) {
		return true;
	}

	protected boolean hasAllowedFileSuffix(IPath path) {
		if (allowedFileSuffixes == null) {
			return true;
		}
		String fileName = path.lastSegment();
		if (fileName != null) {
			for (String allowedSuffix : allowedFileSuffixes) {
				if (fileName.endsWith(allowedSuffix)) {
					return true;
				}
			}
		}
		return false;
	}
}