/*
 * Copyright (c) 2014, 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.
 *
 * 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.java.testlibrary;

import java.util.HashMap;
import java.util.Map;

public class PrintFlagsFinalGetter {
    
    /**
     * Get values of the properies by their names via -XX:+PrintFlagsFinal 
     * option. Also System.getProperty("test.vm.opts") will be passed to VM in 
     * coupe with -XX:+PrintFlagsFinal
     * @param names of options to read values from 
     * @return map of names of the properties and their values
     */
    public static Map<String,Object> getWithVMOpts(String ... names) 
            throws Exception {
        if (System.getProperty("test.vm.opts") == null) {
            throw new RuntimeException("Property -Dtest.vm.opts is not set. " + 
                "You better set it the same as the options that are passed " + 
                "to the VM");
        }
        return getFlagsFinal(names, System.getProperty("test.vm.opts"));
    }
    
    /**
     * Get values of the properies by their names via -XX:+PrintFlagsFinal 
     * option
     * @param names of options to read values from 
     * @param vmOpts additional options to pass to the VM while starting it with
     * -XX:+PrintFlagsFinal
     * @return map of names of the properties and their values
     */
    public static Map<String,Object> getFlagsFinal( String [] names, 
            String vmOpts) throws Exception {
        HashMap<String,Object> nameVal = new HashMap<>();
        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(vmOpts, 
            "-XX:+PrintFlagsFinal",
            "-version"
            );
        OutputAnalyzer out = new OutputAnalyzer(pb.start());
        for (String name : names) {
            String npat = ".* " + name + " .* :?= ";
            String val = null;
            if ((val = out.firstMatch(npat + "(true|false).*", 1)) != null) {
                nameVal.put(name, Boolean.parseBoolean(val));
            } else if ((val = out.firstMatch(npat + "((\\d+)\\.(\\d+)).*", 1)) 
                       != null) {
                nameVal.put(name, Double.parseDouble(val));
            } else if ((val = out.firstMatch(npat + "(\\d+).*", 1)) != null) {
                nameVal.put(name, Integer.parseInt(val));
            } else if ((val = out.firstMatch(npat + "(\\S*) \\{.*", 1)) 
                       != null) {
                nameVal.put(name, val);
            } else {
                System.err.println("Can't match value of '" + name + 
                    "' in FinalFlags. It may be empty or whitespaces");
                nameVal.put(name, "");
            }
        }
        return nameVal;
    }
}