/*
 * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.svm.core.properties;

import java.util.Arrays;

import org.graalvm.nativeimage.ImageSingletons;

import com.oracle.svm.core.jdk.SystemPropertiesSupport;

public final class RuntimePropertyParser {

    private static final String PROPERTY_PREFIX = "-D";

    
Parses all arguments to find those that set Java system properties (those that start with
"-D"). Any such matches are removed from the argument list and the corresponding system
property is set. The returned array of arguments are those that should be passed through to
the application.
/**
     * Parses all arguments to find those that set Java system properties (those that start with
     * "-D"). Any such matches are removed from the argument list and the corresponding system
     * property is set. The returned array of arguments are those that should be passed through to
     * the application.
     */
    public static String[] parse(String[] args) {
        int newIdx = 0;
        for (int oldIdx = 0; oldIdx < args.length; oldIdx++) {
            String arg = args[oldIdx];
            if (arg.startsWith(PROPERTY_PREFIX) && parseProperty(arg.substring(PROPERTY_PREFIX.length()))) {
                // Option consumed
            } else {
                assert newIdx <= oldIdx;
                args[newIdx] = arg;
                newIdx++;
            }
        }
        if (newIdx == args.length) {
            /* We can be allocation free and just return the original arguments. */
            return args;
        } else {
            return Arrays.copyOf(args, newIdx);
        }
    }

    private static boolean parseProperty(String property) {
        int splitIndex = property.indexOf('=');
        if (splitIndex == -1) {
            return false;
        }

        String key = property.substring(0, splitIndex);
        String value = property.substring(splitIndex + 1);

        ImageSingletons.lookup(SystemPropertiesSupport.class).initializeProperty(key, value);

        return true;
    }
}