/*

 * Copyright (c) 2014, 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.

 */

package java.lang.invoke;

import sun.invoke.util.Wrapper;

import java.util.Arrays;

import java.util.Collections;

/* @test

 * @summary unit tests for varargs array methods: MethodHandleInfo.varargsArray(int),

 *          MethodHandleInfo.varargsArray(Class,int) & MethodHandleInfo.varargsList(int)

 *

 * @run main/bootclasspath java.lang.invoke.VarargsArrayTest

 * @run main/bootclasspath -DVarargsArrayTest.MAX_ARITY=255 -DVarargsArrayTest.START_ARITY=250

 *                         java.lang.invoke.VarargsArrayTest

 */

/* This might take a while and burn lots of metadata:

 * @run main/bootclasspath -DVarargsArrayTest.MAX_ARITY=255 -DVarargsArrayTest.EXHAUSTIVE=true java.lang.invoke.VarargsArrayTest

 */

public class VarargsArrayTest {

    private static final Class<?> CLASS = VarargsArrayTest.class;

    private static final int MAX_ARITY = Integer.getInteger(CLASS.getSimpleName()+".MAX_ARITY", 40);

    private static final int START_ARITY = Integer.getInteger(CLASS.getSimpleName()+".START_ARITY", 0);

    private static final boolean EXHAUSTIVE = Boolean.getBoolean(CLASS.getSimpleName()+".EXHAUSTIVE");

    public static void main(String[] args) throws Throwable {

        testVarargsArray();

        testVarargsReferenceArray();

        testVarargsPrimitiveArray();

    }

    public static void testVarargsArray() throws Throwable {

        final int MIN = START_ARITY;

        final int MAX = MAX_ARITY-2;  // 253+1 would cause parameter overflow with 'this' added

        for (int nargs = MIN; nargs <= MAX; nargs = nextArgCount(nargs, 17, MAX)) {

            MethodHandle target = MethodHandleImpl.varargsArray(nargs);

            Object[] args = new Object[nargs];

            for (int i = 0; i < nargs; i++)

                args[i] = "#"+i;

            Object res = target.invokeWithArguments(args);

            assertArrayEquals(args, (Object[])res);

        }

    }

    public static void testVarargsReferenceArray() throws Throwable {

        testTypedVarargsArray(Object[].class);

        testTypedVarargsArray(String[].class);

        testTypedVarargsArray(Number[].class);

    }

    public static void testVarargsPrimitiveArray() throws Throwable {

        testTypedVarargsArray(int[].class);

        testTypedVarargsArray(long[].class);

        testTypedVarargsArray(byte[].class);

        testTypedVarargsArray(boolean[].class);

        testTypedVarargsArray(short[].class);

        testTypedVarargsArray(char[].class);

        testTypedVarargsArray(float[].class);

        testTypedVarargsArray(double[].class);

    }

    private static int nextArgCount(int nargs, int density, int MAX) {

        if (EXHAUSTIVE)  return nargs + 1;

        if (nargs >= MAX)  return Integer.MAX_VALUE;

        int BOT = 20, TOP = MAX-5;

        if (density < 10) { BOT = 10; MAX = TOP-2; }

        if (nargs <= BOT || nargs >= TOP) {

            ++nargs;

        } else {

            int bump = Math.max(1, 100 / density);

            nargs += bump;

            if (nargs > TOP)  nargs = TOP;

        }

        return nargs;

    }

    private static void testTypedVarargsArray(Class<?> arrayType) throws Throwable {

        Class<?> elemType = arrayType.getComponentType();

        int MIN = START_ARITY;

        int MAX = MAX_ARITY-2;  // 253+1 would cause parameter overflow with 'this' added

        int density = 3;

        if (elemType == int.class || elemType == long.class)  density = 7;

        if (elemType == long.class || elemType == double.class) { MAX /= 2; MIN /= 2; }

        for (int nargs = MIN; nargs <= MAX; nargs = nextArgCount(nargs, density, MAX)) {

            Object[] args = makeTestArray(elemType, nargs);

            MethodHandle varargsArray = MethodHandleImpl.varargsArray(arrayType, nargs);

            MethodType vaType = varargsArray.type();

            assertEquals(arrayType, vaType.returnType());

            if (nargs != 0) {

                assertEquals(elemType, vaType.parameterType(0));

                assertEquals(elemType, vaType.parameterType(vaType.parameterCount()-1));

            }

            assertEquals(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)),

                         vaType);

            Object res = varargsArray.invokeWithArguments(args);

            assertEquals(res.getClass(), arrayType);

            String resString = toArrayString(res);

            assertEquals(Arrays.toString(args), resString);

            MethodHandle spreader = varargsArray.asSpreader(arrayType, nargs);

            MethodType stype = spreader.type();

            assert(stype == MethodType.methodType(arrayType, arrayType));

            if (nargs <= 5) {

                // invoke target as a spreader also:

                @SuppressWarnings("cast")

                Object res2 = spreader.invokeWithArguments((Object)res);

                String res2String = toArrayString(res2);

                assertEquals(Arrays.toString(args), res2String);

                // invoke the spreader on a generic Object[] array; check for error

                try {

                    Object res3 = spreader.invokeWithArguments((Object)args);

                    String res3String = toArrayString(res3);

                    assertTrue(arrayType.getName(), arrayType.isAssignableFrom(Object[].class));

                    assertEquals(Arrays.toString(args), res3String);

                } catch (ClassCastException ex) {

                    assertFalse(arrayType.getName(), arrayType.isAssignableFrom(Object[].class));

                }

            }

            if (nargs == 0) {

                // invoke spreader on null arglist

                Object res3 = spreader.invokeWithArguments((Object)null);

                String res3String = toArrayString(res3);

                assertEquals(Arrays.toString(args), res3String);

            }

        }

    }

    private static Object[] makeTestArray(Class<?> elemType, int len) {

        Wrapper elem = null;

        if (elemType.isPrimitive())

            elem = Wrapper.forPrimitiveType(elemType);

        else if (Wrapper.isWrapperType(elemType))

            elem = Wrapper.forWrapperType(elemType);

        Object[] args = new Object[len];

        for (int i = 0; i < len; i++) {

            Object arg = i * 100;

            if (elem == null) {

                if (elemType == String.class)

                    arg = "#"+arg;

                arg = elemType.cast(arg);  // just to make sure

            } else {

                switch (elem) {

                    case BOOLEAN: arg = (i % 3 == 0);           break;

                    case CHAR:    arg = 'a' + i;                break;

                    case LONG:    arg = (long)i * 1000_000_000; break;

                    case FLOAT:   arg = (float)i / 100;         break;

                    case DOUBLE:  arg = (double)i / 1000_000;   break;

                }

                arg = elem.cast(arg, elemType);

            }

            args[i] = arg;

        }

        return args;

    }

    private static String toArrayString(Object a) {

        if (a == null)  return "null";

        Class<?> elemType = a.getClass().getComponentType();

        if (elemType == null)  return a.toString();

        if (elemType.isPrimitive()) {

            switch (Wrapper.forPrimitiveType(elemType)) {

                case INT:      return Arrays.toString((int[])a);

                case BYTE:     return Arrays.toString((byte[])a);

                case BOOLEAN:  return Arrays.toString((boolean[])a);

                case SHORT:    return Arrays.toString((short[])a);

                case CHAR:     return Arrays.toString((char[])a);

                case FLOAT:    return Arrays.toString((float[])a);

                case LONG:     return Arrays.toString((long[])a);

                case DOUBLE:   return Arrays.toString((double[])a);

            }

        }

        return Arrays.toString((Object[])a);

    }

    public static void assertArrayEquals(Object[] arr1, Object[] arr2) {

        if (arr1 == null && arr2 == null)  return;

        if (arr1 != null && arr2 != null && arr1.length == arr2.length) {

            for (int i = 0; i < arr1.length; i++) {

                assertEquals(arr1[i], arr2[i]);

            }

            return;

        }

        throw new AssertionError(Arrays.deepToString(arr1) + " != " + Arrays.deepToString(arr2));

    }

    public static void assertEquals(Object o1, Object o2) {

        if (o1 == null && o2 == null)    return;

        if (o1 != null && o1.equals(o2)) return;

        throw new AssertionError(o1 + " != " + o2);

    }

    public static void assertTrue(String msg, boolean b) {

        if (!b) {

            throw new AssertionError(msg);

        }

    }

    public static void assertFalse(String msg, boolean b) {

        assertTrue(msg, !b);

    }

}