/*
 * Copyright (c) 2005, 2020, 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 jdk.internal.vm;

import java.io.IOException;
import java.util.Properties;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.jar.Attributes;
import java.util.*;

/*
 * Support class used by JVMTI and VM attach mechanism.
 */
public class VMSupport {

    private static Properties agentProps = null;
    /**
     * Returns the agent properties.
     */
    public static synchronized Properties getAgentProperties() {
        if (agentProps == null) {
            agentProps = new Properties();
            initAgentProperties(agentProps);
        }
        return agentProps;
    }
    private static native Properties initAgentProperties(Properties props);

    private static String convertToBytesStr(String str, boolean escapeSpace) throws Exception {
        str = str.replace("\n", "\\n")
                 .replace("\r", "\\r")
                 .replace("\t", "\\t")
                 .replace("\f", "\\f");
        if (escapeSpace) {
            str = str.replace(" ", "\\ ");
        }

        String result = "";
        for (char ch : str.toCharArray()) {
            result += ((ch < 0x20) || (ch > 0x7e)) ? String.format("\\u%04X", (int)ch)
                                                   : ch;
        }

        return result;
    }

    /**
     * Write the given properties list to a byte array and return it. Properties with
     * a key or value that is not a String is filtered out.
     */
    private static byte[] serializePropertiesToByteArray(Properties p) throws IOException {
        var joiner = new StringJoiner("\n");
        joiner.add((new Date()).toString());
        for (var entry : p.entrySet()) {
            var key = convertToBytes(entry.getKey().toString(), true);
            var value = convertToBytes(entry.getValue().toString(), false);
            joiner.add(key + "=" + value);
        }
        return joiner.toString().getBytes();
    }

    public static byte[] serializePropertiesToByteArray() throws IOException {
        return serializePropertiesToByteArray(System.getProperties());
    }

    public static byte[] serializeAgentPropertiesToByteArray() throws IOException {
        return serializePropertiesToByteArray(getAgentProperties());
    }

    /*
     * Returns true if the given JAR file has the Class-Path attribute in the
     * main section of the JAR manifest. Throws RuntimeException if the given
     * path is not a JAR file or some other error occurs.
     */
    public static boolean isClassPathAttributePresent(String path) {
        try {
            Manifest man = (new JarFile(path)).getManifest();
            if (man != null) {
                if (man.getMainAttributes().getValue(Attributes.Name.CLASS_PATH) != null) {
                    return true;
                }
            }
            return false;
        } catch (IOException ioe) {
            throw new RuntimeException(ioe.getMessage());
        }
    }

    /*
     * Return the temporary directory that the VM uses for the attach
     * and perf data files.
     *
     * It is important that this directory is well-known and the
     * same for all VM instances. It cannot be affected by configuration
     * variables such as java.io.tmpdir.
     */
    public static native String getVMTemporaryDirectory();
}