/*
* Copyright (c) 2013, 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.
*
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import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.ArrayList;
import java.util.Arrays;

import com.oracle.java.testlibrary.*;
import sun.hotspot.WhiteBox;

class CompressedOopsErgoPrinter {
  public static void main(String[] args) throws Exception {
    WhiteBox wb = WhiteBox.getWhiteBox();
    wb.printCompressedOopsHeapInfo();
  }
}

final class HeapForCompressedOopsValues {
  public long maxHeapForCompressedOops;
}

class TestUseCompressedOopsErgoTools {

  public static boolean is64bitVM() {
    String val = System.getProperty("sun.arch.data.model");
    if (val == null) {
      throw new RuntimeException("Could not read sun.arch.data.model");
    }
    if (val.equals("64")) {
      return true;
    } else if (val.equals("32")) {
      return false;
    }
    throw new RuntimeException("Unexpected value " + val + " of sun.arch.data.model");
  }

  private static String[] join(String[] part1, String part2) {
    ArrayList<String> result = new ArrayList<String>();
    result.addAll(Arrays.asList(part1));
    result.add(part2);
    return result.toArray(new String[0]);
  }

  public static void checkCompressedOopsErgo(String[] gcflags) throws Exception {
    HeapForCompressedOopsValues v = new HeapForCompressedOopsValues();

    getMaxHeapForCompressedOops(gcflags, v);

    checkUseCompressedOops(gcflags, v.maxHeapForCompressedOops, true);
    checkUseCompressedOops(gcflags, v.maxHeapForCompressedOops - 1, true);
    checkUseCompressedOops(gcflags, v.maxHeapForCompressedOops + 1, false);

    // the use of HeapBaseMinAddress should not change the outcome
    checkUseCompressedOops(join(gcflags, "-XX:HeapBaseMinAddress=32G"), v.maxHeapForCompressedOops, true);
    checkUseCompressedOops(join(gcflags, "-XX:HeapBaseMinAddress=32G"), v.maxHeapForCompressedOops - 1, true);
    checkUseCompressedOops(join(gcflags, "-XX:HeapBaseMinAddress=32G"), v.maxHeapForCompressedOops + 1, false);

    // use a different object alignment
    getMaxHeapForCompressedOops(join(gcflags, "-XX:ObjectAlignmentInBytes=16"), v);

    checkUseCompressedOops(join(gcflags, "-XX:ObjectAlignmentInBytes=16"), v.maxHeapForCompressedOops, true);
    checkUseCompressedOops(join(gcflags, "-XX:ObjectAlignmentInBytes=16"), v.maxHeapForCompressedOops - 1, true);
    checkUseCompressedOops(join(gcflags, "-XX:ObjectAlignmentInBytes=16"), v.maxHeapForCompressedOops + 1, false);

    // use a different ClassMetaspaceSize
    getMaxHeapForCompressedOops(join(gcflags, "-XX:ClassMetaspaceSize=1G"), v);

    checkUseCompressedOops(join(gcflags, "-XX:ClassMetaspaceSize=1G"), v.maxHeapForCompressedOops, true);
    checkUseCompressedOops(join(gcflags, "-XX:ClassMetaspaceSize=1G"), v.maxHeapForCompressedOops - 1, true);
    checkUseCompressedOops(join(gcflags, "-XX:ClassMetaspaceSize=1G"), v.maxHeapForCompressedOops + 1, false);
  }

  private static void checkUseCompressedOops(String[] args, long heapsize, boolean expectUseCompressedOops) throws Exception {
     ArrayList<String> finalargs = new ArrayList<String>();
     finalargs.addAll(Arrays.asList(args));
     finalargs.add("-Xmx" + heapsize);
     finalargs.add("-XX:+PrintFlagsFinal");
     finalargs.add("-version");

     String output = expectValid(finalargs.toArray(new String[0]));

     boolean actualUseCompressedOops = getFlagBoolValue(" UseCompressedOops", output);

     if (expectUseCompressedOops != actualUseCompressedOops) {
       throw new RuntimeException("Expected use of compressed oops: " + expectUseCompressedOops + " but was: " + actualUseCompressedOops);
     }
  }

  private static long valueAfter(String source, String match) {
    int start = source.indexOf(match) + match.length();
    String tail = source.substring(start).split(" ")[0];
    return Long.parseLong(tail);
  }

  private static void getMaxHeapForCompressedOops(String[] args, HeapForCompressedOopsValues val) throws Exception {
    ArrayList<String> finalargs = new ArrayList<String>();

    String[] testVMopts = new String[] {
      "-XX:+UnlockDiagnosticVMOptions", "-XX:+WhiteBoxAPI",
      "-Xbootclasspath/a:.",
      "-cp", System.getProperty("java.class.path"),
    };

    finalargs.addAll(Arrays.asList(args));
    finalargs.addAll(Arrays.asList(testVMopts));
    finalargs.add(CompressedOopsErgoPrinter.class.getName());

    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(finalargs.toArray(new String[0]));
    OutputAnalyzer output = new OutputAnalyzer(pb.start());
    output.shouldHaveExitValue(0);

    // the output we watch for has the following format:
    //
    // "Max heap for compressed oops X Max heap alignment Y ClassMetaspaceSize Z Page size A"
    //
    // where X, Y, Z and A are sizes in bytes.

    Matcher m = Pattern.compile("Max heap for compressed oops \\d+ ClassMetaspaceSize \\d+").
      matcher(output.getStdout());
    if (!m.find()) {
      throw new RuntimeException("Could not find heap size string.");
    }
    String match = m.group();

    // parse actual values
    val.maxHeapForCompressedOops = valueAfter(match, "Max heap for compressed oops ");
  }

  private static boolean getFlagBoolValue(String flag, String where) {
    Matcher m = Pattern.compile(flag + "\\s+:?= (true|false)").matcher(where);
    if (!m.find()) {
      throw new RuntimeException("Could not find value for flag " + flag + " in output string");
    }
    String match = m.group();
    return match.substring(match.lastIndexOf(" ") + 1, match.length()).equals("true");
  }

  private static void shouldContainOrNot(OutputAnalyzer output, boolean contains, String message) throws Exception {
    if (contains) {
      output.shouldContain(message);
    } else {
      output.shouldNotContain(message);
    }
  }

  private static String expect(String[] flags, boolean hasWarning, boolean hasError, int errorcode) throws Exception {
    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
    OutputAnalyzer output = new OutputAnalyzer(pb.start());
    output.shouldHaveExitValue(errorcode);
    return output.getStdout();
  }

  private static String expectValid(String[] flags) throws Exception {
    return expect(flags, false, false, 0);
  }
}