/*

 * Copyright (c) 2009, 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

 * 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 org.junit.Test;

import static org.junit.Assert.*;

/* @test

 * @summary unit tests for value-type conversion utilities

 * @compile -XDignore.symbol.file ValueConversionsTest.java

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

 */

/**

 *

 * @author jrose

 */

public class ValueConversionsTest {

    @Test

    public void testUnbox() throws Throwable {

        testUnbox(false);

    }

    @Test

    public void testUnboxCast() throws Throwable {

        testUnbox(true);

    }

    private void testUnbox(boolean doCast) throws Throwable {

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

            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 {

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

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

            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 {

        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 = dst.isAssignableFrom(src);

                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 {

        MethodHandle id = ValueConversions.identity();

        Object expResult = "foo";

        Object result = id.invokeExact(expResult);

        assertEquals(expResult, result);

    }

    @Test

    public void testConvert() throws Throwable {

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

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

            tval = nextTestValue(tval);

            if (tval == 0) {

                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 {

        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);

    }

}