Copyright (c) 2004, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2004, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ant.internal.core;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import org.eclipse.ant.core.AntCorePlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.variables.IStringVariableManager;
import org.eclipse.core.variables.VariablesPlugin;
import org.osgi.framework.BundleContext;

public class AntCoreUtil {

	private static BundleContext fgContext = null;

	public static void setBundleContext(BundleContext context) {
		fgContext = context;
	}

	public static BundleContext getBundleContext() {
		return fgContext;
	}

	/*
	 * Helper method to ensure an array is converted into an ArrayList.
	 */
	public static ArrayList<String> getArrayList(String[] args) {
		if (args == null) {
			return null;
		}
		// We could be using Arrays.asList() here, but it does not specify
		// what kind of list it will return. We need a list that
		// implements the method List.remove(Object) and ArrayList does.
		ArrayList<String> result = new ArrayList<>(args.length);
		for (int i = 0; i < args.length; i++) {
			result.add(args[i]);
		}
		return result;
	}

	/*
	 * From a command line list, get the argument for the given parameter. The parameter and its argument are removed from the list.
	 * 
	 * @return <code>null</code> if the parameter is not found or an empty String if no arguments are found
	 */
	public static String getArgument(List<String> commands, String param) {
		if (commands == null) {
			return null;
		}
		int index = commands.indexOf(param);
		if (index == -1) {
			return null;
		}
		commands.remove(index);
		if (index == commands.size()) {// if this is the last command
			return IAntCoreConstants.EMPTY_STRING;
		}

		String command = commands.get(index);
		if (command.startsWith("-")) { //new parameter //$NON-NLS-1$
			return IAntCoreConstants.EMPTY_STRING;
		}
		commands.remove(index);
		return command;
	}

	public static void processMinusDProperties(List<String> commands, Map<String, String> userProperties) {
		Iterator<String> iter = commands.iterator();
		while (iter.hasNext()) {
			String arg = iter.next();
			if (arg.startsWith("-D")) { //$NON-NLS-1$
				String name = arg.substring(2, arg.length());
				String value = null;
				int posEq = name.indexOf("="); //$NON-NLS-1$
				if (posEq == 0) {
					value = name.substring(1);
					name = IAntCoreConstants.EMPTY_STRING;
				} else if (posEq > 0 && posEq != name.length() - 1) {
					value = name.substring(posEq + 1).trim();
					name = name.substring(0, posEq);
				}

				if (value == null) {
					// the user has specified something like "-Debug"
					continue;
				}

				userProperties.put(name, value);
				iter.remove();
			}
		}
	}

	public static File getFileRelativeToBaseDir(String fileName, String base, String buildFileLocation) {
		IPath path = new Path(fileName);
		if (!path.isAbsolute()) {
			if (base != null) {
				File baseDir = new File(base);
				// relative to the base dir
				path = new Path(baseDir.getAbsolutePath());
			} else {
				// relative to the build file location
				path = new Path(buildFileLocation);
				path = path.removeLastSegments(1);
			}
			path = path.addTrailingSeparator();
			path = path.append(fileName);
		}

		return path.toFile();
	}

	
Returns a list of Properties contained in the list of fileNames.
Params:
fileNames – 
           the names of the properties files to load from
base – 
           the base directory name
buildFileLocation – 
Throws:
IOException – 
Returns:
a list of Properties objects for each filename/**
	 * Returns a list of Properties contained in the list of fileNames.
	 * 
	 * @param fileNames
	 *            the names of the properties files to load from
	 * @param base
	 *            the base directory name
	 * @param buildFileLocation
	 * @return a list of {@link Properties} objects for each filename
	 * @throws IOException
	 */
	public static List<Properties> loadPropertyFiles(List<String> fileNames, String base, String buildFileLocation) throws IOException {
		ArrayList<Properties> allProperties = new ArrayList<>(fileNames.size());
		for (int i = 0; i < fileNames.size(); i++) {
			String filename = fileNames.get(i);
			File file = getFileRelativeToBaseDir(filename, base, buildFileLocation);
			Properties props = new Properties();
			try (FileInputStream fis = new FileInputStream(file)) {
				props.load(fis);
			}
			Enumeration<?> propertyNames = props.propertyNames();
			while (propertyNames.hasMoreElements()) {
				String name = (String) propertyNames.nextElement();
				String value = props.getProperty(name);
				props.remove(name);
				IStringVariableManager stringVariableManager = VariablesPlugin.getDefault().getStringVariableManager();
				try {
					name = stringVariableManager.performStringSubstitution(name);
					value = stringVariableManager.performStringSubstitution(value);
				}
				catch (CoreException e) {
					AntCorePlugin.log(e);
				}
				props.setProperty(name, value);
			}
			allProperties.add(props);
		}
		return allProperties;
	}
}