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 * 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
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 *
 * 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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 */

/*
 * @test TestExistingLogFile
 * @summary Ensure log files are archived/appended/truncated properly.
 * @library /testlibrary
 * @run driver TestExistingLogFile
 */

import java.nio.file.Files;
import java.nio.file.Paths;

import jdk.test.lib.ProcessTools;
import jdk.test.lib.OutputAnalyzer;

import static jdk.test.lib.Asserts.assertEquals;
import static jdk.test.lib.Asserts.assertTrue;
import static jdk.test.lib.Asserts.assertFalse;

public class TestExistingLogFile {
    private static final String ARCHIVED_LOG_SUFFIX = ".0";
    private static final String BASE_XLOG_CMD = "-Xlog:logging=trace:";
    private static final String EXPECTED_LINE = "Log configuration fully initialized.";

    public static void main(String[] args) throws Exception {
        testArchiveMode();
        testAppendMode();
        testTruncateMode();
    }

    private static void testArchiveMode() throws Exception {
        final String logFile = "archived.log";
        final String archivedLogFile = logFile + ARCHIVED_LOG_SUFFIX;

        System.out.println("Testing archive mode");
        runVMTwice(BASE_XLOG_CMD + logFile);

        assertTrue(Files.exists(Paths.get(archivedLogFile)), "Archived log file not found.");
        assertEquals(1L, occurencesInFile(EXPECTED_LINE, logFile),
                "Log file should contain exactly one occurence of the expected line.");
        assertEquals(1L, occurencesInFile(EXPECTED_LINE, archivedLogFile),
                "Archived log file should contain exactly one occurence of the expected line.");

        // Run it twice again make sure two new archive files are created
        runVMTwice(BASE_XLOG_CMD + logFile);
        assertTrue(Files.exists(Paths.get(logFile + ".1")), "Second archived log file not found.");
        assertTrue(Files.exists(Paths.get(logFile + ".2")), "Third archived log file not found.");
    }

    private static void testAppendMode() throws Exception {
        final String logFile = "appended.log";
        final String archivedLogFile = logFile + ARCHIVED_LOG_SUFFIX;

        System.out.println("Testing append mode");
        runVMTwice(BASE_XLOG_CMD + logFile + "::mode=append");

        assertFalse(Files.exists(Paths.get(archivedLogFile)),
                "Log file was archived when it should have been appended.");
        assertEquals(2L, occurencesInFile(EXPECTED_LINE, logFile),
                "Appended log file should contain exactly two occurences of the expected line.");
    }

    private static void testTruncateMode() throws Exception {
        final String logFile = "truncated.log";
        final String archivedLogFile = logFile + ARCHIVED_LOG_SUFFIX;

        System.out.println("Testing truncate mode");
        runVMTwice(BASE_XLOG_CMD + logFile + "::mode=truncate");

        assertFalse(Files.exists(Paths.get(archivedLogFile)),
                "Log file was archived when it should have been truncated.");
        assertEquals(1L, occurencesInFile(EXPECTED_LINE, logFile),
                "Truncated log file should contain exactly one occurence of the expected line.");
    }

    private static long occurencesInFile(final String string, final String file) throws Exception {
        return Files.lines(Paths.get(file))
                .filter(s -> s.contains(string)).count();
    }

    private static void runVMTwice(final String options) throws Exception {
        for (int i = 0; i < 2; i++) {
            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(options, "-version");
            Process p = pb.start();
            OutputAnalyzer output = new OutputAnalyzer(p);
            output.shouldHaveExitValue(0);
        }
    }
}