/*

 * Copyright (c) 2012, 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

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 */

import java.math.BigDecimal;

import java.math.RoundingMode;

/**

 * @test Test Math and StrictMath Floor Div / Modulo operations.

 * @bug 6282196

 * @summary Basic tests for Floor division and modulo methods for both Math

 * and StrictMath for int and long datatypes.

 */

public class DivModTests {

    /**

     * The count of test errors.

     */

    private static int errors = 0;

    /**

     * @param args the command line arguments are unused

     */

    public static void main(String[] args) {

        errors = 0;

        testIntFloorDivMod();

        testLongFloorDivMod();

        if (errors > 0) {

            throw new RuntimeException(errors + " errors found in DivMod methods.");

        }

    }

    /**

     * Report a test failure and increment the error count.

     * @param message the formatting string

     * @param args the variable number of arguments for the message.

     */

    static void fail(String message, Object... args) {

        errors++;

        System.out.printf(message, args);

    }

    /**

     * Test the integer floorDiv and floorMod methods.

     * Math and StrictMath tested and the same results are expected for both.

     */

    static void testIntFloorDivMod() {

        testIntFloorDivMod(4, 0, new ArithmeticException(), new ArithmeticException()); // Should throw ArithmeticException

        testIntFloorDivMod(4, 3, 1, 1);

        testIntFloorDivMod(3, 3, 1, 0);

        testIntFloorDivMod(2, 3, 0, 2);

        testIntFloorDivMod(1, 3, 0, 1);

        testIntFloorDivMod(0, 3, 0, 0);

        testIntFloorDivMod(4, -3, -2, -2);

        testIntFloorDivMod(3, -3, -1, 0);

        testIntFloorDivMod(2, -3, -1, -1);

        testIntFloorDivMod(1, -3, -1, -2);

        testIntFloorDivMod(0, -3, 0, 0);

        testIntFloorDivMod(-1, 3, -1, 2);

        testIntFloorDivMod(-2, 3, -1, 1);

        testIntFloorDivMod(-3, 3, -1, 0);

        testIntFloorDivMod(-4, 3, -2, 2);

        testIntFloorDivMod(-1, -3, 0, -1);

        testIntFloorDivMod(-2, -3, 0, -2);

        testIntFloorDivMod(-3, -3, 1, 0);

        testIntFloorDivMod(-4, -3, 1, -1);

        testIntFloorDivMod(Integer.MAX_VALUE, 1, Integer.MAX_VALUE, 0);

        testIntFloorDivMod(Integer.MAX_VALUE, -1, -Integer.MAX_VALUE, 0);

        testIntFloorDivMod(Integer.MAX_VALUE, 3, 715827882, 1);

        testIntFloorDivMod(Integer.MAX_VALUE - 1, 3, 715827882, 0);

        testIntFloorDivMod(Integer.MIN_VALUE, 3, -715827883, 1);

        testIntFloorDivMod(Integer.MIN_VALUE + 1, 3, -715827883, 2);

        testIntFloorDivMod(Integer.MIN_VALUE + 1, -1, Integer.MAX_VALUE, 0);

        // Special case of integer overflow

        testIntFloorDivMod(Integer.MIN_VALUE, -1, Integer.MIN_VALUE, 0);

    }

    /**

     * Test FloorDiv and then FloorMod with int data.

     */

    static void testIntFloorDivMod(int x, int y, Object divExpected, Object modExpected) {

        testIntFloorDiv(x, y, divExpected);

        testIntFloorMod(x, y, modExpected);

    }

    /**

     * Test FloorDiv with int data.

     */

    static void testIntFloorDiv(int x, int y, Object expected) {

        Object result = doFloorDiv(x, y);

        if (!resultEquals(result, expected)) {

            fail("FAIL: Math.floorDiv(%d, %d) = %s; expected %s%n", x, y, result, expected);

        }

        Object strict_result = doStrictFloorDiv(x, y);

        if (!resultEquals(strict_result, expected)) {

            fail("FAIL: StrictMath.floorDiv(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);

        }

    }

    /**

     * Test FloorMod with int data.

     */

    static void testIntFloorMod(int x, int y, Object expected) {

        Object result = doFloorMod(x, y);

        if (!resultEquals(result, expected)) {

            fail("FAIL: Math.floorMod(%d, %d) = %s; expected %s%n", x, y, result, expected);

        }

        Object strict_result = doStrictFloorMod(x, y);

        if (!resultEquals(strict_result, expected)) {

            fail("FAIL: StrictMath.floorMod(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);

        }

        try {

            // Verify result against double precision floor function

            int tmp = x / y;     // Force ArithmeticException for divide by zero

            double ff = x - Math.floor((double)x / (double)y) * y;

            int fr = (int)ff;

            boolean t = (fr == ((Integer)result));

            if (!result.equals(fr)) {

                fail("FAIL: Math.floorMod(%d, %d) = %s differs from Math.floor(x, y): %d%n", x, y, result, fr);

            }

        } catch (ArithmeticException ae) {

            if (y != 0) {

                fail("FAIL: Math.floorMod(%d, %d); unexpected %s%n", x, y, ae);

            }

        }

    }

    /**

     * Test the floorDiv and floorMod methods for primitive long.

     */

    static void testLongFloorDivMod() {

        testLongFloorDivMod(4L, 0L, new ArithmeticException(), new ArithmeticException()); // Should throw ArithmeticException

        testLongFloorDivMod(4L, 3L, 1L, 1L);

        testLongFloorDivMod(3L, 3L, 1L, 0L);

        testLongFloorDivMod(2L, 3L, 0L, 2L);

        testLongFloorDivMod(1L, 3L, 0L, 1L);

        testLongFloorDivMod(0L, 3L, 0L, 0L);

        testLongFloorDivMod(4L, -3L, -2L, -2L);

        testLongFloorDivMod(3L, -3L, -1L, 0l);

        testLongFloorDivMod(2L, -3L, -1L, -1L);

        testLongFloorDivMod(1L, -3L, -1L, -2L);

        testLongFloorDivMod(0L, -3L, 0L, 0L);

        testLongFloorDivMod(-1L, 3L, -1L, 2L);

        testLongFloorDivMod(-2L, 3L, -1L, 1L);

        testLongFloorDivMod(-3L, 3L, -1L, 0L);

        testLongFloorDivMod(-4L, 3L, -2L, 2L);

        testLongFloorDivMod(-1L, -3L, 0L, -1L);

        testLongFloorDivMod(-2L, -3L, 0L, -2L);

        testLongFloorDivMod(-3L, -3L, 1L, 0L);

        testLongFloorDivMod(-4L, -3L, 1L, -1L);

        testLongFloorDivMod(Long.MAX_VALUE, 1, Long.MAX_VALUE, 0L);

        testLongFloorDivMod(Long.MAX_VALUE, -1, -Long.MAX_VALUE, 0L);

        testLongFloorDivMod(Long.MAX_VALUE, 3L, Long.MAX_VALUE / 3L, 1L);

        testLongFloorDivMod(Long.MAX_VALUE - 1L, 3L, (Long.MAX_VALUE - 1L) / 3L, 0L);

        testLongFloorDivMod(Long.MIN_VALUE, 3L, Long.MIN_VALUE / 3L - 1L, 1L);

        testLongFloorDivMod(Long.MIN_VALUE + 1L, 3L, Long.MIN_VALUE / 3L - 1L, 2L);

        testLongFloorDivMod(Long.MIN_VALUE + 1, -1, Long.MAX_VALUE, 0L);

        // Special case of integer overflow

        testLongFloorDivMod(Long.MIN_VALUE, -1, Long.MIN_VALUE, 0L);

    }

    /**

     * Test the integer floorDiv and floorMod methods.

     * Math and StrictMath are tested and the same results are expected for both.

     */

    static void testLongFloorDivMod(long x, long y, Object divExpected, Object modExpected) {

        testLongFloorDiv(x, y, divExpected);

        testLongFloorMod(x, y, modExpected);

    }

    /**

     * Test FloorDiv with long arguments against expected value.

     * The expected value is usually a Long but in some cases  is

     * an ArithmeticException.

     *

     * @param x dividend

     * @param y modulus

     * @param expected expected value,

     */

    static void testLongFloorDiv(long x, long y, Object expected) {

        Object result = doFloorDiv(x, y);

        if (!resultEquals(result, expected)) {

            fail("FAIL: long Math.floorDiv(%d, %d) = %s; expected %s%n", x, y, result, expected);

        }

        Object strict_result = doStrictFloorDiv(x, y);

        if (!resultEquals(strict_result, expected)) {

            fail("FAIL: long StrictMath.floorDiv(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);

        }

    }

    /**

     * Test FloorMod of long arguments against expected value.

     * The expected value is usually a Long but in some cases  is

     * an ArithmeticException.

     *

     * @param x dividend

     * @param y modulus

     * @param expected expected value

     */

    static void testLongFloorMod(long x, long y, Object expected) {

        Object result = doFloorMod(x, y);

        if (!resultEquals(result, expected)) {

            fail("FAIL: long Math.floorMod(%d, %d) = %s; expected %s%n", x, y, result, expected);

        }

        Object strict_result = doStrictFloorMod(x, y);

        if (!resultEquals(strict_result, expected)) {

            fail("FAIL: long StrictMath.floorMod(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);

        }

        try {

            // Verify the result against BigDecimal rounding mode.

            BigDecimal xD = new BigDecimal(x);

            BigDecimal yD = new BigDecimal(y);

            BigDecimal resultD = xD.divide(yD, RoundingMode.FLOOR);

            resultD = resultD.multiply(yD);

            resultD = xD.subtract(resultD);

            long fr = resultD.longValue();

            if (!result.equals(fr)) {

                fail("FAIL: Long.floorMod(%d, %d) = %d is different than BigDecimal result: %d%n", x, y, result, fr);

            }

        } catch (ArithmeticException ae) {

            if (y != 0) {

                fail("FAIL: long Math.floorMod(%d, %d); unexpected ArithmeticException from bigdecimal");

            }

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doFloorDiv(int x, int y) {

        try {

            return Math.floorDiv(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doFloorDiv(long x, long y) {

        try {

            return Math.floorDiv(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doFloorMod(int x, int y) {

        try {

            return Math.floorMod(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doFloorMod(long x, long y) {

        try {

            return Math.floorMod(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doStrictFloorDiv(int x, int y) {

        try {

            return StrictMath.floorDiv(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doStrictFloorDiv(long x, long y) {

        try {

            return StrictMath.floorDiv(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doStrictFloorMod(int x, int y) {

        try {

            return StrictMath.floorMod(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Invoke floorDiv and return the result or any exception.

     * @param x the x value

     * @param y the y value

     * @return the result Integer or an exception.

     */

    static Object doStrictFloorMod(long x, long y) {

        try {

            return StrictMath.floorMod(x, y);

        } catch (ArithmeticException ae) {

            return ae;

        }

    }

    /**

     * Returns a boolean by comparing the result and the expected value.

     * The equals method is not defined for ArithmeticException but it is

     * desirable to have equals return true if the expected and the result

     * both threw the same exception (class and message.)

     *

     * @param result the result from testing the method

     * @param expected the expected value

     * @return true if the result is equal to the expected values; false otherwise.

     */

    static boolean resultEquals(Object result, Object expected) {

        if (result.getClass() != expected.getClass()) {

            fail("FAIL: Result type mismatch, %s; expected: %s%n",

                    result.getClass().getName(), expected.getClass().getName());

            return false;

        }

        if (result.equals(expected)) {

            return true;

        }

        // Handle special case to compare ArithmeticExceptions

        if (result instanceof ArithmeticException && expected instanceof ArithmeticException) {

            return true;

        }

        return false;

    }

}