/*

 * 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.

 *

 * 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.

 */

import java.util.Arrays;

import jdk.testlibrary.Utils;

import static jdk.testlibrary.Asserts.*;

/**

 * The helper class for parsing following output from command 'jstat -gcutil':

 *

 *  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT

 *  100.00   0.00  64.68  13.17  73.39  33.46      2    0.003     1    0.156    0.158

 *  100.00   0.00  76.54  13.17  73.39  33.46      2    0.003     1    0.156    0.158

 *  100.00   0.00  83.49  13.17  73.39  33.46      2    0.003     1    0.156    0.158

 *  100.00   0.00  84.53  13.17  73.39  33.46      2    0.003     1    0.156    0.158

 *  100.00   0.00  85.57  13.17  73.39  33.46      2    0.003     1    0.156    0.158

 *

 *  It will be verified that numerical values have defined types and are reasonable,

 *  for example percentage should fit within 0-100 interval.

 */

public class JstatGCUtilParser {

    public enum GcStatisticsType {

        INTEGER, DOUBLE, PERCENTAGE, PERCENTAGE_OR_DASH;

    }

    public enum GcStatistics {

        S0(GcStatisticsType.PERCENTAGE),

        S1(GcStatisticsType.PERCENTAGE),

        E(GcStatisticsType.PERCENTAGE),

        O(GcStatisticsType.PERCENTAGE),

        M(GcStatisticsType.PERCENTAGE),

        CCS(GcStatisticsType.PERCENTAGE_OR_DASH),

        YGC(GcStatisticsType.INTEGER),

        YGCT(GcStatisticsType.DOUBLE),

        FGC(GcStatisticsType.INTEGER),

        FGCT(GcStatisticsType.DOUBLE),

        GCT(GcStatisticsType.DOUBLE);

        private final GcStatisticsType type;

        private GcStatistics(GcStatisticsType type) {

            this.type = type;

        }

        private GcStatisticsType getType() {

            return type;

        }

        public static boolean isHeadline(String... valueArray) {

            if (valueArray.length != values().length) {

                return false;

            }

            int headersCount = 0;

            for (int i = 0; i < values().length; i++) {

                if (valueArray[i].equals(values()[i].toString())) {

                    headersCount++;

                }

            }

            if (headersCount != values().length) {

                return false;

            }

            return true;

        }

        private static void verifyLength(String... valueArray) throws Exception {

            assertEquals(valueArray.length, values().length,

                    "Invalid number of data columns: " + Arrays.toString(valueArray));

        }

        public static void verify(String... valueArray) throws Exception {

            verifyLength(valueArray);

            for (int i = 0; i < values().length; i++) {

                GcStatisticsType type = values()[i].getType();

                String value = valueArray[i].trim();

                if (type.equals(GcStatisticsType.INTEGER)) {

                    Integer.parseInt(value);

                    break;

                }

                if (type.equals(GcStatisticsType.DOUBLE)) {

                    Double.parseDouble(value);

                    break;

                }

                if (type.equals(GcStatisticsType.PERCENTAGE_OR_DASH) &&

                        value.equals("-")) {

                    break;

                }

                double percentage = Double.parseDouble(value);

                assertTrue(0 <= percentage && percentage <= 100,

                        "Not a percentage: " + value);

            }

        }

    }

    private final String output;

    public JstatGCUtilParser(String output) {

        this.output = output;

    }

    public String getOutput() {

        return output;

    }

    /**

     * The function will discard any lines that come before the header line.

     * This can happen if the JVM outputs a warning message for some reason

     * before running jstat.

     */

    public void parse(int samples) throws Exception {

        boolean headlineFound = false;

        int datalineCount = 0;

        String[] lines = output.split(Utils.NEW_LINE);

        for (String line : lines) {

            line = line.replaceAll("\\s+", " ").trim();

            String[] valueArray = line.split(" ");

            if (!headlineFound) {

                headlineFound = GcStatistics.isHeadline(valueArray);

                continue;

            }

            GcStatistics.verify(valueArray);

            datalineCount++;

        }

        assertTrue(headlineFound, "No or invalid headline found, expected: " +

                Utils.NEW_LINE + Arrays.toString(GcStatistics.values()).replaceAll(",", " "));

        assertEquals(samples, datalineCount,

                "Expected " + samples + " samples, got " + datalineCount);

    }

}