/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.releng.generators;

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

/**
 * Defines common behaviour for PDE Core applications.
 */
public abstract class AbstractApplication {

/**
 * Starting point for application logic.
 */
protected abstract void run() throws Exception;

/*
 * @see IPlatformRunnable#run(Object)
 */
public Object run(Object args) throws Exception {
	processCommandLine(getArrayList((String[]) args));
	try {
		run();
	} catch (Exception e) {
		e.printStackTrace(System.out);
	}
	return null;
}

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


/**
 * Looks for interesting command line arguments.
 */
protected void processCommandLine(List commands) {
}

/**
 * From a command line list, get the array of arguments of a given parameter.
 * The parameter and its arguments are removed from the list.
 * @return null if the parameter is not found or has no arguments
 */
protected String[] getArguments(List commands, String param) {
	int index = commands.indexOf(param);
	if (index == -1)
		return null;
	commands.remove(index);
	if (index == commands.size()) // if this is the last command
		return null;
	List args = new ArrayList(commands.size());
	while (index < commands.size()) { // while not the last command
		String command = (String) commands.get(index);
		if (command.startsWith("-")) // is it a new parameter?
			break;
		args.add(command);
		commands.remove(index);
	}
	if (args.isEmpty())
		return null;
	return (String[]) args.toArray(new String[args.size()]);
}


}