/*

 * Copyright (c) 2009, 2011, 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 test.sun.invoke.util;

import sun.invoke.util.ValueConversions;

import sun.invoke.util.Wrapper;

import java.lang.invoke.MethodType;

import java.lang.invoke.MethodHandle;

import java.io.Serializable;

import java.util.Arrays;

import java.util.Collections;

import org.junit.Test;

import static org.junit.Assert.*;

/* @test

 * @summary unit tests for value-type conversion utilities

 * @ignore This test requires a special compilation environment to access sun.inovke.util.  Run by hand.

 * @run junit/othervm test.sun.invoke.util.ValueConversionsTest

 * @run junit/othervm

 *          -DValueConversionsTest.MAX_ARITY=255 -DValueConversionsTest.START_ARITY=250

 *              test.sun.invoke.util.ValueConversionsTest

 */

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

// @run junit/othervm -DValueConversionsTest.MAX_ARITY=255 -DValueConversionsTest.EXHAUSTIVE=true test.sun.invoke.util.ValueConversionsTest

/**

 *

 * @author jrose

 */

public class ValueConversionsTest {

    private static final Class<?> CLASS = ValueConversionsTest.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");

    @Test

    public void testUnbox() throws Throwable {

        testUnbox(false);

    }

    @Test

    public void testUnboxCast() throws Throwable {

        testUnbox(true);

    }

    private void testUnbox(boolean doCast) throws Throwable {

        //System.out.println("unbox");

        for (Wrapper dst : Wrapper.values()) {

            //System.out.println(dst);

            for (Wrapper src : Wrapper.values()) {

                testUnbox(doCast, dst, src);

            }

        }

    }

    private void testUnbox(boolean doCast, Wrapper dst, Wrapper src) throws Throwable {

        boolean expectThrow = !doCast && !dst.isConvertibleFrom(src);

        if (dst == Wrapper.OBJECT || src == Wrapper.OBJECT)  return;  // must have prims

        if (dst == Wrapper.OBJECT)

            expectThrow = false;  // everything (even VOID==null here) converts to OBJECT

        try {

            for (int n = -5; n < 10; n++) {

                Object box = src.wrap(n);

                switch (src) {

                    case VOID:   assertEquals(box, null); break;

                    case OBJECT: box = box.toString(); break;

                    case SHORT:  assertEquals(box.getClass(), Short.class); break;

                    default:     assertEquals(box.getClass(), src.wrapperType()); break;

                }

                MethodHandle unboxer;

                if (doCast)

                    unboxer = ValueConversions.unboxCast(dst.primitiveType());

                else

                    unboxer = ValueConversions.unbox(dst.primitiveType());

                Object expResult = (box == null) ? dst.zero() : dst.wrap(box);

                Object result = null;

                switch (dst) {

                    case INT:     result = (int)     unboxer.invokeExact(box); break;

                    case LONG:    result = (long)    unboxer.invokeExact(box); break;

                    case FLOAT:   result = (float)   unboxer.invokeExact(box); break;

                    case DOUBLE:  result = (double)  unboxer.invokeExact(box); break;

                    case CHAR:    result = (char)    unboxer.invokeExact(box); break;

                    case BYTE:    result = (byte)    unboxer.invokeExact(box); break;

                    case SHORT:   result = (short)   unboxer.invokeExact(box); break;

                    case OBJECT:  result = (Object)  unboxer.invokeExact(box); break;

                    case BOOLEAN: result = (boolean) unboxer.invokeExact(box); break;

                    case VOID:    result = null;     unboxer.invokeExact(box); break;

                }

                if (expectThrow) {

                    expResult = "(need an exception)";

                }

                assertEquals("(doCast,expectThrow,dst,src,n,box)="+Arrays.asList(doCast,expectThrow,dst,src,n,box),

                             expResult, result);

            }

        } catch (RuntimeException ex) {

            if (expectThrow)  return;

            System.out.println("Unexpected throw for (doCast,expectThrow,dst,src)="+Arrays.asList(doCast,expectThrow,dst,src));

            throw ex;

        }

    }

    @Test

    public void testBox() throws Throwable {

        //System.out.println("box");

        for (Wrapper w : Wrapper.values()) {

            if (w == Wrapper.VOID)  continue;  // skip this; no unboxed form

            //System.out.println(w);

            for (int n = -5; n < 10; n++) {

                Object box = w.wrap(n);

                MethodHandle boxer = ValueConversions.box(w.primitiveType());

                Object expResult = box;

                Object result = null;

                switch (w) {

                    case INT:     result = boxer.invokeExact(/*int*/n); break;

                    case LONG:    result = boxer.invokeExact((long)n); break;

                    case FLOAT:   result = boxer.invokeExact((float)n); break;

                    case DOUBLE:  result = boxer.invokeExact((double)n); break;

                    case CHAR:    result = boxer.invokeExact((char)n); break;

                    case BYTE:    result = boxer.invokeExact((byte)n); break;

                    case SHORT:   result = boxer.invokeExact((short)n); break;

                    case OBJECT:  result = boxer.invokeExact((Object)n); break;

                    case BOOLEAN: result = boxer.invokeExact((n & 1) != 0); break;

                }

                assertEquals("(dst,src,n,box)="+Arrays.asList(w,w,n,box),

                             expResult, result);

            }

        }

    }

    @Test

    public void testCast() throws Throwable {

        //System.out.println("cast");

        Class<?>[] types = { Object.class, Serializable.class, String.class, Number.class, Integer.class };

        Object[] objects = { new Object(), Boolean.FALSE,      "hello",      (Long)12L,    (Integer)6    };

        for (Class<?> dst : types) {

            MethodHandle caster = ValueConversions.cast(dst);

            assertEquals(caster.type(), ValueConversions.identity().type());

            for (Object obj : objects) {

                Class<?> src = obj.getClass();

                boolean canCast;

                if (dst.isInterface()) {

                    canCast = true;

                } else {

                    canCast = dst.isAssignableFrom(src);

                    assertEquals(canCast, dst.isInstance(obj));

                }

                //System.out.println("obj="+obj+" <: dst="+dst);

                try {

                    Object result = caster.invokeExact(obj);

                    if (canCast)

                        assertEquals(obj, result);

                    else

                        assertEquals("cast should not have succeeded", dst, obj);

                } catch (ClassCastException ex) {

                    if (canCast)

                        throw ex;

                }

            }

        }

    }

    @Test

    public void testIdentity() throws Throwable {

        //System.out.println("identity");

        MethodHandle id = ValueConversions.identity();

        Object expResult = "foo";

        Object result = id.invokeExact(expResult);

        // compiler bug:  ValueConversions.identity().invokeExact("bar");

        assertEquals(expResult, result);

    }

    @Test

    public void testConvert() throws Throwable {

        //System.out.println("convert");

        for (long tval = 0, ctr = 0;;) {

            if (++ctr > 99999)  throw new AssertionError("too many test values");

            // next test value:

            //System.out.println(Long.toHexString(tval)); // prints 3776 test patterns

            tval = nextTestValue(tval);

            if (tval == 0) {

                //System.out.println("test value count = "+ctr);  // 3776 = 8*59*8

                break;  // repeat

            }

        }

        for (Wrapper src : Wrapper.values()) {

            for (Wrapper dst : Wrapper.values()) {

                testConvert(src, dst, 0);

            }

        }

    }

    static void testConvert(Wrapper src, Wrapper dst, long tval) throws Throwable {

        //System.out.println(src+" => "+dst);

        boolean testSingleCase = (tval != 0);

        final long tvalInit = tval;

        MethodHandle conv = ValueConversions.convertPrimitive(src, dst);

        MethodType convType;

        if (src == Wrapper.VOID)

            convType = MethodType.methodType(dst.primitiveType() /* , void */);

        else

            convType = MethodType.methodType(dst.primitiveType(), src.primitiveType());

        assertEquals(convType, conv.type());

        MethodHandle converter = conv.asType(conv.type().changeReturnType(Object.class));

        for (;;) {

            long n = tval;

            Object testValue = src.wrap(n);

            Object expResult = dst.cast(testValue, dst.primitiveType());

            Object result;

            switch (src) {

                case INT:     result = converter.invokeExact((int)n); break;

                case LONG:    result = converter.invokeExact(/*long*/n); break;

                case FLOAT:   result = converter.invokeExact((float)n); break;

                case DOUBLE:  result = converter.invokeExact((double)n); break;

                case CHAR:    result = converter.invokeExact((char)n); break;

                case BYTE:    result = converter.invokeExact((byte)n); break;

                case SHORT:   result = converter.invokeExact((short)n); break;

                case OBJECT:  result = converter.invokeExact((Object)n); break;

                case BOOLEAN: result = converter.invokeExact((n & 1) != 0); break;

                case VOID:    result = converter.invokeExact(); break;

                default:  throw new AssertionError();

            }

            assertEquals("(src,dst,n,testValue)="+Arrays.asList(src,dst,"0x"+Long.toHexString(n),testValue),

                         expResult, result);

            if (testSingleCase)  break;

            // next test value:

            tval = nextTestValue(tval);

            if (tval == tvalInit)  break;  // repeat

        }

    }

    static long tweakSign(long x) {

        // Assuming that x is mostly zeroes, make those zeroes follow bit #62 (just below the sign).

        // This function is self-inverse.

        final long MID_SIGN_BIT = 62;

        long sign = -((x >>> MID_SIGN_BIT) & 1);  // all ones or all zeroes

        long flip = (sign >>> -MID_SIGN_BIT);  // apply the sign below the mid-bit

        return x ^ flip;

    }

    static long nextTestValue(long x) {

        // Produce 64 bits with three component bitfields:  [ high:3 | mid:58 | low:3 ].

        // The high and low fields vary through all possible bit patterns.

        // The middle field is either all zero or has a single bit set.

        // For better coverage of the neighborhood of zero, an internal sign bit is xored downward also.

        long ux = tweakSign(x);  // unsign the middle field

        final long LOW_BITS  = 3, LOW_BITS_MASK  = (1L << LOW_BITS)-1;

        final long HIGH_BITS = 3, HIGH_BITS_MASK = ~(-1L >>> HIGH_BITS);

        if ((ux & LOW_BITS_MASK) != LOW_BITS_MASK) {

            ++ux;

        } else {

            ux &= ~LOW_BITS_MASK;

            long midBit = (ux & ~HIGH_BITS_MASK);

            if (midBit == 0)

                midBit = (1L<<LOW_BITS);  // introduce a low bit

            ux += midBit;

        }

        return tweakSign(ux);

    }

    @Test

    public void testVarargsArray() throws Throwable {

        //System.out.println("varargsArray");

        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 = ValueConversions.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);

        }

    }

    @Test

    public void testVarargsReferenceArray() throws Throwable {

        //System.out.println("varargsReferenceArray");

        testTypedVarargsArray(Object[].class);

        testTypedVarargsArray(String[].class);

        testTypedVarargsArray(Number[].class);

    }

    @Test

    public void testVarargsPrimitiveArray() throws Throwable {

        //System.out.println("varargsPrimitiveArray");

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

        //System.out.println(arrayType.getSimpleName());

        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 = ValueConversions.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);

            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;

        }

        //System.out.println(elemType.getName()+Arrays.toString(args));

        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);

    }

    @Test

    public void testVarargsList() throws Throwable {

        //System.out.println("varargsList");

        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, 7, MAX)) {

            MethodHandle target = ValueConversions.varargsList(nargs);

            Object[] args = new Object[nargs];

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

                args[i] = "#"+i;

            Object res = target.invokeWithArguments(args);

            assertEquals(Arrays.asList(args), res);

        }

    }

}