/*******************************************************************************
 *  Copyright (c) 2011  Oracle. 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: 
 *  	Oracle - initial API and implementation
 *******************************************************************************/
package org.eclipse.jpt.common.core.internal.libval;

import static org.eclipse.jst.common.project.facet.core.internal.FacetedProjectFrameworkJavaPlugin.PLUGIN_ID;
import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jpt.common.core.internal.JptCommonCoreMessages;
import org.eclipse.osgi.util.NLS;


public class LibValUtil {
	
	public static IStatus validate(Iterable<IPath> libraryPaths, Set<String> classNames) {
		Set<String> classFileNames = new HashSet<String>();
		Map<String,String> classFileNameToClassName = new HashMap<String,String>();
		for (String className : classNames) {
			String classFileName = className.replace('.', '/') + ".class"; //$NON-NLS-1$
			classFileNames.add(classFileName);
			classFileNameToClassName.put(classFileName, className);
		}
		
		final Map<String,Integer> classAppearanceCounts = new HashMap<String,Integer>();
		
		for (String classFileName : classFileNames) {
			classAppearanceCounts.put(classFileName, 0);
		}
		
		for (IPath libraryPath : libraryPaths) {
			final File file = libraryPath.toFile();
			
			if (file.exists()) {
				ZipFile zip = null;
				
				try {
					zip = new ZipFile(file);
					
					for (Enumeration<? extends ZipEntry> itr = zip.entries(); itr.hasMoreElements(); ) {
						final ZipEntry zipEntry = itr.nextElement();
						final String name = zipEntry.getName();
						
						Integer count = classAppearanceCounts.get(name);
						
						if (count != null) {
							classAppearanceCounts.put(name, count + 1);
						}
					}
				}
				catch (IOException e) {}
				finally {
					if (zip != null) {
						try {
							zip.close();
						}
						catch (IOException e) {}
					}
				}
			}
		}
		
		for (Map.Entry<String,Integer> entry : classAppearanceCounts.entrySet()) {
			final int count = entry.getValue();
			
			if (count == 0) {
				final String classFileName = entry.getKey();
				final String className = classFileNameToClassName.get(classFileName);
				final String message = 
						NLS.bind(JptCommonCoreMessages.USER_LIBRARY_VALIDATOR__CLASS_NOT_FOUND, className);
				return new Status(IStatus.ERROR, PLUGIN_ID, message);
			}
		}
		
		return Status.OK_STATUS;
	}
}