/*

 * Copyright (c) 2018, 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.

 */

/*

 * @test

 * @summary This exercises String#repeat patterns and limits.

 * @run main/othervm -Xmx4G StringRepeat

 */

import java.nio.CharBuffer;

public class StringRepeat {

    public static void main(String... arg) {

        test1();

        test2();

    }

    /*

     * Varitions of repeat count.

     */

    static int[] REPEATS = {

        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,

        32, 64, 128, 256, 512, 1024, 64 * 1024, 1024 * 1024,

        16 * 1024 * 1024

    };

    /*

     * Varitions of Strings.

     */

    static String[] STRINGS = new String[] {

            "", "\0",  " ", "a", "$", "\u2022",

            "ab", "abc", "abcd", "abcde",

            "The quick brown fox jumps over the lazy dog."

    };

    /*

     * Repeat String function tests.

     */

    static void test1() {

        for (int repeat : REPEATS) {

            for (String string : STRINGS) {

                long limit = (long)string.length() * (long)repeat;

                if ((long)(Integer.MAX_VALUE >> 1) <= limit) {

                    break;

                }

                verify(string.repeat(repeat), string, repeat);

            }

        }

    }

    /*

     * Repeat String exception tests.

     */

    static void test2() {

        try {

            "abc".repeat(-1);

            throw new RuntimeException("No exception for negative repeat count");

        } catch (IllegalArgumentException ex) {

            // Correct

        }

        try {

            "abc".repeat(Integer.MAX_VALUE - 1);

            throw new RuntimeException("No exception for large repeat count");

        } catch (OutOfMemoryError ex) {

            // Correct

        }

    }

    static String truncate(String string) {

        if (string.length() < 80) {

            return string;

        }

        return string.substring(0, 80) + "...";

    }

    /*

     * Verify string repeat patterns.

     */

    static void verify(String result, String string, int repeat) {

        if (string.isEmpty() || repeat == 0) {

            if (!result.isEmpty()) {

                System.err.format("\"%s\".repeat(%d)%n", truncate(string), repeat);

                System.err.format("Result \"%s\"%n", truncate(result));

                System.err.format("Result expected to be empty, found string of length %d%n", result.length());

                throw new RuntimeException();

            }

        } else {

            int expected = 0;

            int count = 0;

            for (int offset = result.indexOf(string, expected);

                 0 <= offset;

                 offset = result.indexOf(string, expected)) {

                count++;

                if (offset != expected) {

                    System.err.format("\"%s\".repeat(%d)%n", truncate(string), repeat);

                    System.err.format("Result \"%s\"%n", truncate(result));

                    System.err.format("Repeat expected at %d, found at = %d%n", expected, offset);

                    throw new RuntimeException();

                }

                expected += string.length();

            }

            if (count != repeat) {

                System.err.format("\"%s\".repeat(%d)%n", truncate(string), repeat);

                System.err.format("Result \"%s\"%n", truncate(result));

                System.err.format("Repeat count expected to be %d, found %d%n", repeat, count);

                throw new RuntimeException();

            }

        }

    }

}