/*

 * 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 test.java.lang.invoke.MethodHandles;

import com.oracle.testlibrary.jsr292.Helper;

import jdk.testlibrary.Asserts;

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandles;

import java.lang.invoke.MethodType;

import java.lang.reflect.Array;

import java.util.*;

import java.util.function.BiFunction;

import java.util.function.Function;

import java.util.function.Supplier;

/* @test

 * @library /lib/testlibrary/jsr292 /lib/testlibrary/

 * @compile CatchExceptionTest.java

 * @run main/othervm -esa test.java.lang.invoke.MethodHandles.CatchExceptionTest

 */

public class CatchExceptionTest {

    private static final List<Class<?>> ARGS_CLASSES;

    protected static final int MAX_ARITY = Helper.MAX_ARITY - 1;

    static {

        Class<?> classes[] = {

                Object.class,

                long.class,

                int.class,

                byte.class,

                Integer[].class,

                double[].class,

                String.class,

        };

        List<Class<?>> list = new ArrayList<>(MAX_ARITY);

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

            list.add(classes[Helper.RNG.nextInt(classes.length)]);

        }

        ARGS_CLASSES = Collections.unmodifiableList(list);

    }

    private final TestCase testCase;

    private final int nargs;

    private final int argsCount;

    private final MethodHandle catcher;

    private int dropped;

    private MethodHandle thrower;

    public CatchExceptionTest(TestCase testCase, final boolean isVararg, final int argsCount,

            final int catchDrops) {

        this.testCase = testCase;

        this.dropped = catchDrops;

        if (Helper.IS_VERBOSE) {

            System.out.printf("CatchException::CatchException(%s, isVararg=%b " +

                            "argsCount=%d catchDrops=%d)%n",

                    testCase, isVararg, argsCount, catchDrops

            );

        }

        MethodHandle thrower = testCase.thrower;

        int throwerLen = thrower.type().parameterCount();

        List<Class<?>> classes;

        int extra = Math.max(0, argsCount - throwerLen);

        classes = getThrowerParams(isVararg, extra);

        this.argsCount = throwerLen + classes.size();

        thrower = Helper.addTrailingArgs(thrower, this.argsCount, classes);

        if (isVararg && argsCount > throwerLen) {

            MethodType mt = thrower.type();

            Class<?> lastParam = mt.parameterType(mt.parameterCount() - 1);

            thrower = thrower.asVarargsCollector(lastParam);

        }

        this.thrower = thrower;

        this.dropped = Math.min(this.argsCount, catchDrops);

        catcher = testCase.getCatcher(getCatcherParams());

        nargs = Math.max(2, this.argsCount);

    }

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

        for (CatchExceptionTest test : TestFactory.MANDATORY_TEST_CASES) {

            test.runTest();

        }

        TestFactory factory = new TestFactory();

        CatchExceptionTest test;

        while ((test = factory.nextTest()) != null ) {

            test.runTest();

        }

    }

    private List<Class<?>> getThrowerParams(boolean isVararg, int argsCount) {

        boolean unmodifiable = true;

        List<Class<?>> classes;

        classes = ARGS_CLASSES.subList(0,

                Math.min(argsCount, (MAX_ARITY / 2) - 1));

        int extra = 0;

        if (argsCount >= MAX_ARITY / 2) {

            classes = new ArrayList<>(classes);

            unmodifiable = false;

            extra = (int) classes.stream().filter(Helper::isDoubleCost).count();

            int i = classes.size();

            while (classes.size() + extra < argsCount) {

                Class<?> aClass = ARGS_CLASSES.get(i);

                if (Helper.isDoubleCost(aClass)) {

                    ++extra;

                    if (classes.size() + extra >= argsCount) {

                        break;

                    }

                }

                classes.add(aClass);

            }

        }

        if (isVararg && classes.size() > 0) {

            if (unmodifiable) {

                classes = new ArrayList<>(classes);

            }

            int last = classes.size() - 1;

            Class<?> aClass = classes.get(classes.size() - 1);

            aClass = Array.newInstance(aClass, 2).getClass();

            classes.set(last, aClass);

        }

        return classes;

    }

    private List<Class<?>> getCatcherParams() {

        int catchArgc = 1 + this.argsCount - dropped;

        List<Class<?>> result = new ArrayList<>(

                thrower.type().parameterList().subList(0, catchArgc - 1));

        // prepend throwable

        result.add(0, testCase.throwableClass);

        return result;

    }

    private void runTest() {

        Helper.clear();

        Object[] args = Helper.randomArgs(

                argsCount, thrower.type().parameterArray());

        Object arg0 = Helper.MISSING_ARG;

        Object arg1 = testCase.thrown;

        if (argsCount > 0) {

            arg0 = args[0];

        }

        if (argsCount > 1) {

            args[1] = arg1;

        }

        Asserts.assertEQ(nargs, thrower.type().parameterCount());

        if (argsCount < nargs) {

            Object[] appendArgs = {arg0, arg1};

            appendArgs = Arrays.copyOfRange(appendArgs, argsCount, nargs);

            thrower = MethodHandles.insertArguments(

                    thrower, argsCount, appendArgs);

        }

        Asserts.assertEQ(argsCount, thrower.type().parameterCount());

        MethodHandle target = MethodHandles.catchException(

                testCase.filter(thrower), testCase.throwableClass,

                testCase.filter(catcher));

        Asserts.assertEQ(thrower.type(), target.type());

        Asserts.assertEQ(argsCount, target.type().parameterCount());

        Object returned;

        try {

            returned = target.invokeWithArguments(args);

        } catch (Throwable ex) {

            testCase.assertCatch(ex);

            returned = ex;

        }

        testCase.assertReturn(returned, arg0, arg1, dropped, args);

    }

}

class TestFactory {

    public static final List<CatchExceptionTest> MANDATORY_TEST_CASES = new ArrayList<>();

    private static final int MIN_TESTED_ARITY = 10;

    static {

        for (int[] args : new int[][]{

                {0, 0},

                {MIN_TESTED_ARITY, 0},

                {MIN_TESTED_ARITY, MIN_TESTED_ARITY},

                {CatchExceptionTest.MAX_ARITY, 0},

                {CatchExceptionTest.MAX_ARITY, CatchExceptionTest.MAX_ARITY},

        }) {

                MANDATORY_TEST_CASES.addAll(createTests(args[0], args[1]));

        }

    }

    private int count;

    private int args;

    private int dropArgs;

    private int currentMaxDrops;

    private int maxArgs;

    private int maxDrops;

    private int constructor;

    private int constructorSize;

    private boolean isVararg;

    public TestFactory() {

        if (Helper.IS_THOROUGH) {

            maxArgs = maxDrops = CatchExceptionTest.MAX_ARITY;

        } else {

            maxArgs = MIN_TESTED_ARITY

                    + Helper.RNG.nextInt(CatchExceptionTest.MAX_ARITY

                            - MIN_TESTED_ARITY)

                    + 1;

            maxDrops = MIN_TESTED_ARITY

                    + Helper.RNG.nextInt(maxArgs - MIN_TESTED_ARITY)

                    + 1;

            args = 1;

        }

        if (Helper.IS_VERBOSE) {

            System.out.printf("maxArgs = %d%nmaxDrops = %d%n",

                    maxArgs, maxDrops);

        }

        constructorSize = TestCase.CONSTRUCTORS.size();

    }

    private static List<CatchExceptionTest> createTests(int argsCount,

            int catchDrops) {

        if (catchDrops > argsCount || argsCount < 0 || catchDrops < 0) {

            throw new IllegalArgumentException("argsCount = " + argsCount

                    + ", catchDrops = " + catchDrops

            );

        }

        List<CatchExceptionTest> result = new ArrayList<>(

                TestCase.CONSTRUCTORS.size());

        for (Supplier<TestCase> constructor : TestCase.CONSTRUCTORS) {

            result.add(new CatchExceptionTest(constructor.get(),

                    /* isVararg = */ true,

                    argsCount,

                    catchDrops));

            result.add(new CatchExceptionTest(constructor.get(),

                    /* isVararg = */ false,

                    argsCount,

                    catchDrops));

        }

        return result;

    }

    /**

     * @return next test from test matrix:

     * {varArgs, noVarArgs} x TestCase.rtypes x TestCase.THROWABLES x {1, .., maxArgs } x {1, .., maxDrops}

     */

    public CatchExceptionTest nextTest() {

        if (constructor < constructorSize) {

            return createTest();

        }

        constructor = 0;

        count++;

        if (!Helper.IS_THOROUGH && count > Helper.TEST_LIMIT) {

            System.out.println("test limit is exceeded");

            return null;

        }

        if (dropArgs <= currentMaxDrops) {

            if (dropArgs == 1) {

                if (Helper.IS_THOROUGH || Helper.RNG.nextBoolean()) {

                    ++dropArgs;

                    return createTest();

                } else if (Helper.IS_VERBOSE) {

                    System.out.printf(

                            "argsCount=%d : \"drop\" scenarios are skipped%n",

                            args);

                }

            } else {

                ++dropArgs;

                return createTest();

            }

        }

        if (args <= maxArgs) {

            dropArgs = 1;

            currentMaxDrops = Math.min(args, maxDrops);

            ++args;

            return createTest();

        }

        return null;

    }

    private CatchExceptionTest createTest() {

        if (!Helper.IS_THOROUGH) {

            return new CatchExceptionTest(

                    TestCase.CONSTRUCTORS.get(constructor++).get(),

                    Helper.RNG.nextBoolean(), args, dropArgs);

        } else {

           if (isVararg) {

               isVararg = false;

               return new CatchExceptionTest(

                       TestCase.CONSTRUCTORS.get(constructor++).get(),

                       isVararg, args, dropArgs);

           } else {

               isVararg = true;

               return new CatchExceptionTest(

                       TestCase.CONSTRUCTORS.get(constructor).get(),

                       isVararg, args, dropArgs);

           }

        }

    }

}

class TestCase<T> {

    private static enum ThrowMode {

        NOTHING,

        CAUGHT,

        UNCAUGHT,

        ADAPTER

    }

    @SuppressWarnings("unchecked")

    public static final List<Supplier<TestCase>> CONSTRUCTORS;

    private static final MethodHandle FAKE_IDENTITY;

    private static final MethodHandle THROW_OR_RETURN;

    private static final MethodHandle CATCHER;

    static {

        try {

            MethodHandles.Lookup lookup = MethodHandles.lookup();

            THROW_OR_RETURN = lookup.findStatic(

                    TestCase.class,

                    "throwOrReturn",

                    MethodType.methodType(Object.class, Object.class,

                            Throwable.class)

            );

            CATCHER = lookup.findStatic(

                    TestCase.class,

                    "catcher",

                    MethodType.methodType(Object.class, Object.class));

            FAKE_IDENTITY = lookup.findVirtual(

                    TestCase.class, "fakeIdentity",

                    MethodType.methodType(Object.class, Object.class));

        } catch (NoSuchMethodException | IllegalAccessException e) {

            throw new Error(e);

        }

        PartialConstructor[] constructors = {

                create(Object.class, Object.class::cast),

                create(String.class, Objects::toString),

                create(int[].class, x -> new int[]{Objects.hashCode(x)}),

                create(long.class,

                        x -> Objects.hashCode(x) & (-1L >>> 32)),

                create(void.class, TestCase::noop)};

        Throwable[] throwables = {

                new ClassCastException("testing"),

                new java.io.IOException("testing"),

                new LinkageError("testing")};

        List<Supplier<TestCase>> list = new ArrayList<>(constructors.length *

                throwables.length * ThrowMode.values().length);

        //noinspection unchecked

        for (PartialConstructor f : constructors) {

            for (ThrowMode mode : ThrowMode.values()) {

                for (Throwable t : throwables) {

                    list.add(f.apply(mode, t));

                }

            }

        }

        CONSTRUCTORS = Collections.unmodifiableList(list);

    }

    public final Class<T> rtype;

    public final ThrowMode throwMode;

    public final Throwable thrown;

    public final Class<? extends Throwable> throwableClass;

    /**

     * MH which takes 2 args (Object,Throwable), 1st is the return value,

     * 2nd is the exception which will be thrown, if it's supposed in current

     * {@link #throwMode}.

     */

    public final MethodHandle thrower;

    private final Function<Object, T> cast;

    protected MethodHandle filter;

    private int fakeIdentityCount;

    private TestCase(Class<T> rtype, Function<Object, T> cast,

            ThrowMode throwMode, Throwable thrown)

            throws NoSuchMethodException, IllegalAccessException {

        this.cast = cast;

        filter = MethodHandles.lookup().findVirtual(

                Function.class,

                "apply",

                MethodType.methodType(Object.class, Object.class))

                              .bindTo(cast);

        this.rtype = rtype;

        this.throwMode = throwMode;

        this.throwableClass = thrown.getClass();

        switch (throwMode) {

            case NOTHING:

                this.thrown = null;

                break;

            case ADAPTER:

            case UNCAUGHT:

                this.thrown = new Error("do not catch this");

                break;

            default:

                this.thrown = thrown;

        }

        MethodHandle throwOrReturn = THROW_OR_RETURN;

        if (throwMode == ThrowMode.ADAPTER) {

            MethodHandle fakeIdentity = FAKE_IDENTITY.bindTo(this);

            for (int i = 0; i < 10; ++i) {

                throwOrReturn = MethodHandles.filterReturnValue(

                        throwOrReturn, fakeIdentity);

            }

        }

        thrower = throwOrReturn.asType(MethodType.genericMethodType(2));

    }

    private static Void noop(Object x) {

        return null;

    }

    private static <T2> PartialConstructor create(

            Class<T2> rtype, Function<Object, T2> cast) {

        return (t, u) -> () -> {

            try {

                return new TestCase<>(rtype, cast, t, u);

            } catch (NoSuchMethodException | IllegalAccessException e) {

                throw new Error(e);

            }

        };

    }

    private static <T extends Throwable>

    Object throwOrReturn(Object normal, T exception) throws T {

        if (exception != null) {

            Helper.called("throwOrReturn/throw", normal, exception);

            throw exception;

        }

        Helper.called("throwOrReturn/normal", normal, exception);

        return normal;

    }

    private static <T extends Throwable>

    Object catcher(Object o) {

        Helper.called("catcher", o);

        return o;

    }

    public MethodHandle filter(MethodHandle target) {

        return MethodHandles.filterReturnValue(target, filter);

    }

    public MethodHandle getCatcher(List<Class<?>> classes) {

        return MethodHandles.filterReturnValue(Helper.AS_LIST.asType(

                        MethodType.methodType(Object.class, classes)),

                CATCHER

        );

    }

    @Override

    public String toString() {

        return "TestCase{" +

                "rtype=" + rtype +

                ", throwMode=" + throwMode +

                ", throwableClass=" + throwableClass +

                '}';

    }

    public String callName() {

        return "throwOrReturn/" +

                (throwMode == ThrowMode.NOTHING

                        ? "normal"

                        : "throw");

    }

    public void assertReturn(Object returned, Object arg0, Object arg1,

            int catchDrops, Object... args) {

        int lag = 0;

        if (throwMode == ThrowMode.CAUGHT) {

            lag = 1;

        }

        Helper.assertCalled(lag, callName(), arg0, arg1);

        if (throwMode == ThrowMode.NOTHING) {

            assertEQ(cast.apply(arg0), returned);

        } else if (throwMode == ThrowMode.CAUGHT) {

            List<Object> catchArgs = new ArrayList<>(Arrays.asList(args));

            // catcher receives an initial subsequence of target arguments:

            catchArgs.subList(args.length - catchDrops, args.length).clear();

            // catcher also receives the exception, prepended:

            catchArgs.add(0, thrown);

            Helper.assertCalled("catcher", catchArgs);

            assertEQ(cast.apply(catchArgs), returned);

        }

        Asserts.assertEQ(0, fakeIdentityCount);

    }

    private void assertEQ(T t, Object returned) {

        if (rtype.isArray()) {

            Asserts.assertEQ(t.getClass(), returned.getClass());

            int n = Array.getLength(t);

            Asserts.assertEQ(n, Array.getLength(returned));

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

                Asserts.assertEQ(Array.get(t, i), Array.get(returned, i));

            }

        } else {

            Asserts.assertEQ(t, returned);

        }

    }

    private Object fakeIdentity(Object x) {

        System.out.println("should throw through this!");

        ++fakeIdentityCount;

        return x;

    }