/*

 * Copyright (c) 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.

 */

/**

 * @test

 * @bug 8005698

 * @run testng SpliteratorCollisions

 * @summary Spliterator traversing and splitting hash maps containing colliding hashes

 * @author Brent Christian

 */

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

import java.util.ArrayDeque;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.Deque;

import java.util.HashMap;

import java.util.HashSet;

import java.util.LinkedHashMap;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Spliterator;

import java.util.TreeSet;

import java.util.function.Consumer;

import java.util.function.Function;

import java.util.function.LongConsumer;

import java.util.function.Supplier;

import java.util.function.UnaryOperator;

import static org.testng.Assert.*;

import static org.testng.Assert.assertEquals;

@Test

public class SpliteratorCollisions {

    private static List<Integer> SIZES = Arrays.asList(0, 1, 10, 100, 1000);

    private static class SpliteratorDataBuilder<T> {

        List<Object[]> data;

        List<T> exp;

        Map<T, T> mExp;

        SpliteratorDataBuilder(List<Object[]> data, List<T> exp) {

            this.data = data;

            this.exp = exp;

            this.mExp = createMap(exp);

        }

        Map<T, T> createMap(List<T> l) {

            Map<T, T> m = new LinkedHashMap<>();

            for (T t : l) {

                m.put(t, t);

            }

            return m;

        }

        void add(String description, Collection<?> expected, Supplier<Spliterator<?>> s) {

            description = joiner(description).toString();

            data.add(new Object[]{description, expected, s});

        }

        void add(String description, Supplier<Spliterator<?>> s) {

            add(description, exp, s);

        }

        void addCollection(Function<Collection<T>, ? extends Collection<T>> c) {

            add("new " + c.apply(Collections.<T>emptyList()).getClass().getName() + ".spliterator()",

                () -> c.apply(exp).spliterator());

        }

        void addList(Function<Collection<T>, ? extends List<T>> l) {

            // @@@ If collection is instance of List then add sub-list tests

            addCollection(l);

        }

        void addMap(Function<Map<T, T>, ? extends Map<T, T>> m) {

            String description = "new " + m.apply(Collections.<T, T>emptyMap()).getClass().getName();

            add(description + ".keySet().spliterator()", () -> m.apply(mExp).keySet().spliterator());

            add(description + ".values().spliterator()", () -> m.apply(mExp).values().spliterator());

            add(description + ".entrySet().spliterator()", mExp.entrySet(), () -> m.apply(mExp).entrySet().spliterator());

        }

        StringBuilder joiner(String description) {

            return new StringBuilder(description).

                    append(" {").

                    append("size=").append(exp.size()).

                    append("}");

        }

    }

    static Object[][] spliteratorDataProvider;

    @DataProvider(name = "HashableIntSpliterator")

    public static Object[][] spliteratorDataProvider() {

        if (spliteratorDataProvider != null) {

            return spliteratorDataProvider;

        }

        List<Object[]> data = new ArrayList<>();

        for (int size : SIZES) {

            List<HashableInteger> exp = listIntRange(size, false);

            SpliteratorDataBuilder<HashableInteger> db = new SpliteratorDataBuilder<>(data, exp);

            // Maps

            db.addMap(HashMap::new);

            db.addMap(LinkedHashMap::new);

            // Collections that use HashMap

            db.addCollection(HashSet::new);

            db.addCollection(LinkedHashSet::new);

            db.addCollection(TreeSet::new);

        }

        return spliteratorDataProvider = data.toArray(new Object[0][]);

    }

    static Object[][] spliteratorDataProviderWithNull;

    @DataProvider(name = "HashableIntSpliteratorWithNull")

    public static Object[][] spliteratorNullDataProvider() {

        if (spliteratorDataProviderWithNull != null) {

            return spliteratorDataProviderWithNull;

        }

        List<Object[]> data = new ArrayList<>();

        for (int size : SIZES) {

            List<HashableInteger> exp = listIntRange(size, true);

            exp.add(0, null);

            SpliteratorDataBuilder<HashableInteger> db = new SpliteratorDataBuilder<>(data, exp);

            // Maps

            db.addMap(HashMap::new);

            db.addMap(LinkedHashMap::new);

            // TODO: add this back in if we decide to keep TreeBin in WeakHashMap

            //db.addMap(WeakHashMap::new);

            // Collections that use HashMap

            db.addCollection(HashSet::new);

            db.addCollection(LinkedHashSet::new);

//            db.addCollection(TreeSet::new);

        }

        return spliteratorDataProviderWithNull = data.toArray(new Object[0][]);

    }

    final static class HashableInteger implements Comparable<HashableInteger> {

        final int value;

        final int hashmask; //yes duplication

        HashableInteger(int value, int hashmask) {

            this.value = value;

            this.hashmask = hashmask;

        }

        @Override

        public boolean equals(Object obj) {

            if (obj instanceof HashableInteger) {

                HashableInteger other = (HashableInteger) obj;

                return other.value == value;

            }

            return false;

        }

        @Override

        public int hashCode() {

            return value % hashmask;

        }

        @Override

        public int compareTo(HashableInteger o) {

            return value - o.value;

        }

        @Override

        public String toString() {

            return Integer.toString(value);

        }

    }

    private static List<HashableInteger> listIntRange(int upTo, boolean withNull) {

        List<HashableInteger> exp = new ArrayList<>();

        if (withNull) {

            exp.add(null);

        }

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

            exp.add(new HashableInteger(i, 10));

        }

        return Collections.unmodifiableList(exp);

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testNullPointerException(String description, Collection exp, Supplier<Spliterator> s) {

        executeAndCatch(NullPointerException.class, () -> s.get().forEachRemaining(null));

        executeAndCatch(NullPointerException.class, () -> s.get().tryAdvance(null));

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testNullPointerExceptionWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        executeAndCatch(NullPointerException.class, () -> s.get().forEachRemaining(null));

        executeAndCatch(NullPointerException.class, () -> s.get().tryAdvance(null));

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testForEach(String description, Collection exp, Supplier<Spliterator> s) {

        testForEach(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testForEachWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testForEach(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testTryAdvance(String description, Collection exp, Supplier<Spliterator> s) {

        testTryAdvance(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testTryAdvanceWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testTryAdvance(exp, s, (Consumer<Object> b) -> b);

    }

/* skip this test until 8013649 is fixed

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testMixedTryAdvanceForEach(String description, Collection exp, Supplier<Spliterator> s) {

        testMixedTryAdvanceForEach(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testMixedTryAdvanceForEachWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testMixedTryAdvanceForEach(exp, s, (Consumer<Object> b) -> b);

    }

*/

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitAfterFullTraversal(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitAfterFullTraversal(s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitAfterFullTraversalWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitAfterFullTraversal(s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitOnce(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitOnce(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitOnceWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitOnce(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitSixDeep(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitSixDeep(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitSixDeepWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitSixDeep(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliterator")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitUntilNull(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitUntilNull(exp, s, (Consumer<Object> b) -> b);

    }

    @Test(dataProvider = "HashableIntSpliteratorWithNull")

    @SuppressWarnings({"unchecked", "rawtypes"})

    public void testSplitUntilNullWithNull(String description, Collection exp, Supplier<Spliterator> s) {

        testSplitUntilNull(exp, s, (Consumer<Object> b) -> b);

    }

    private static <T, S extends Spliterator<T>> void testForEach(

            Collection<T> exp,

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        S spliterator = supplier.get();

        long sizeIfKnown = spliterator.getExactSizeIfKnown();

        boolean isOrdered = spliterator.hasCharacteristics(Spliterator.ORDERED);

        ArrayList<T> fromForEach = new ArrayList<>();

        spliterator = supplier.get();

        Consumer<T> addToFromForEach = boxingAdapter.apply(fromForEach::add);

        spliterator.forEachRemaining(addToFromForEach);

        // Assert that forEach now produces no elements

        spliterator.forEachRemaining(boxingAdapter.apply(e -> fail("Spliterator.forEach produced an element after spliterator exhausted: " + e)));

        // Assert that tryAdvance now produce no elements

        spliterator.tryAdvance(boxingAdapter.apply(e -> fail("Spliterator.tryAdvance produced an element after spliterator exhausted: " + e)));

        // assert that size, tryAdvance, and forEach are consistent

        if (sizeIfKnown >= 0) {

            assertEquals(sizeIfKnown, exp.size());

        }

        if (exp.contains(null)) {

            assertTrue(fromForEach.contains(null));

        }

        assertEquals(fromForEach.size(), exp.size());

        assertContents(fromForEach, exp, isOrdered);

    }

    private static <T, S extends Spliterator<T>> void testTryAdvance(

            Collection<T> exp,

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        S spliterator = supplier.get();

        long sizeIfKnown = spliterator.getExactSizeIfKnown();

        boolean isOrdered = spliterator.hasCharacteristics(Spliterator.ORDERED);

        spliterator = supplier.get();

        ArrayList<T> fromTryAdvance = new ArrayList<>();

        Consumer<T> addToFromTryAdvance = boxingAdapter.apply(fromTryAdvance::add);

        while (spliterator.tryAdvance(addToFromTryAdvance)) { }

        // Assert that forEach now produces no elements

        spliterator.forEachRemaining(boxingAdapter.apply(e -> fail("Spliterator.forEach produced an element after spliterator exhausted: " + e)));

        // Assert that tryAdvance now produce no elements

        spliterator.tryAdvance(boxingAdapter.apply(e -> fail("Spliterator.tryAdvance produced an element after spliterator exhausted: " + e)));

        // assert that size, tryAdvance, and forEach are consistent

        if (sizeIfKnown >= 0) {

            assertEquals(sizeIfKnown, exp.size());

        }

        assertEquals(fromTryAdvance.size(), exp.size());

        assertContents(fromTryAdvance, exp, isOrdered);

    }

    private static <T, S extends Spliterator<T>> void testMixedTryAdvanceForEach(

            Collection<T> exp,

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        S spliterator = supplier.get();

        long sizeIfKnown = spliterator.getExactSizeIfKnown();

        boolean isOrdered = spliterator.hasCharacteristics(Spliterator.ORDERED);

        // tryAdvance first few elements, then forEach rest

        ArrayList<T> dest = new ArrayList<>();

        spliterator = supplier.get();

        Consumer<T> addToDest = boxingAdapter.apply(dest::add);

        for (int i = 0; i < 10 && spliterator.tryAdvance(addToDest); i++) { }

        spliterator.forEachRemaining(addToDest);

        // Assert that forEach now produces no elements

        spliterator.forEachRemaining(boxingAdapter.apply(e -> fail("Spliterator.forEach produced an element after spliterator exhausted: " + e)));

        // Assert that tryAdvance now produce no elements

        spliterator.tryAdvance(boxingAdapter.apply(e -> fail("Spliterator.tryAdvance produced an element after spliterator exhausted: " + e)));

        if (sizeIfKnown >= 0) {

            assertEquals(sizeIfKnown, dest.size());

        }

        assertEquals(dest.size(), exp.size());

        if (isOrdered) {

            assertEquals(dest, exp);

        }

        else {

            assertContentsUnordered(dest, exp);

        }

    }

    private static <T, S extends Spliterator<T>> void testSplitAfterFullTraversal(

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        // Full traversal using tryAdvance

        Spliterator<T> spliterator = supplier.get();

        while (spliterator.tryAdvance(boxingAdapter.apply(e -> { }))) { }

        Spliterator<T> split = spliterator.trySplit();

        assertNull(split);

        // Full traversal using forEach

        spliterator = supplier.get();

        spliterator.forEachRemaining(boxingAdapter.apply(e -> {

        }));

        split = spliterator.trySplit();

        assertNull(split);

        // Full traversal using tryAdvance then forEach

        spliterator = supplier.get();

        spliterator.tryAdvance(boxingAdapter.apply(e -> { }));

        spliterator.forEachRemaining(boxingAdapter.apply(e -> {

        }));

        split = spliterator.trySplit();

        assertNull(split);

    }

    private static <T, S extends Spliterator<T>> void testSplitOnce(

            Collection<T> exp,

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        S spliterator = supplier.get();

        long sizeIfKnown = spliterator.getExactSizeIfKnown();

        boolean isOrdered = spliterator.hasCharacteristics(Spliterator.ORDERED);

        ArrayList<T> fromSplit = new ArrayList<>();

        Spliterator<T> s1 = supplier.get();

        Spliterator<T> s2 = s1.trySplit();

        long s1Size = s1.getExactSizeIfKnown();

        long s2Size = (s2 != null) ? s2.getExactSizeIfKnown() : 0;

        Consumer<T> addToFromSplit = boxingAdapter.apply(fromSplit::add);

        if (s2 != null)

            s2.forEachRemaining(addToFromSplit);

        s1.forEachRemaining(addToFromSplit);

        if (sizeIfKnown >= 0) {

            assertEquals(sizeIfKnown, fromSplit.size());

            if (s1Size >= 0 && s2Size >= 0)

                assertEquals(sizeIfKnown, s1Size + s2Size);

        }

        assertContents(fromSplit, exp, isOrdered);

    }

    private static <T, S extends Spliterator<T>> void testSplitSixDeep(

            Collection<T> exp,

            Supplier<S> supplier,

            UnaryOperator<Consumer<T>> boxingAdapter) {

        S spliterator = supplier.get();

        boolean isOrdered = spliterator.hasCharacteristics(Spliterator.ORDERED);

        for (int depth=0; depth < 6; depth++) {

            List<T> dest = new ArrayList<>();

            spliterator = supplier.get();

            assertSpliterator(spliterator);

            // verify splitting with forEach

            visit(depth, 0, dest, spliterator, boxingAdapter, spliterator.characteristics(), false);

            assertContents(dest, exp, isOrdered);

            // verify splitting with tryAdvance

            dest.clear();

            spliterator = supplier.get();

            visit(depth, 0, dest, spliterator, boxingAdapter, spliterator.characteristics(), true);

            assertContents(dest, exp, isOrdered);

        }

    }

    private static <T, S extends Spliterator<T>> void visit(int depth, int curLevel,

                                                            List<T> dest, S spliterator, UnaryOperator<Consumer<T>> boxingAdapter,

                                                            int rootCharacteristics, boolean useTryAdvance) {

        if (curLevel < depth) {

            long beforeSize = spliterator.getExactSizeIfKnown();

            Spliterator<T> split = spliterator.trySplit();

            if (split != null) {

                assertSpliterator(split, rootCharacteristics);

                assertSpliterator(spliterator, rootCharacteristics);

                if ((rootCharacteristics & Spliterator.SUBSIZED) != 0 &&

                    (rootCharacteristics & Spliterator.SIZED) != 0) {

                    assertEquals(beforeSize, split.estimateSize() + spliterator.estimateSize());

                }

                visit(depth, curLevel + 1, dest, split, boxingAdapter, rootCharacteristics, useTryAdvance);

            }

            visit(depth, curLevel + 1, dest, spliterator, boxingAdapter, rootCharacteristics, useTryAdvance);

        }

        else {

            long sizeIfKnown = spliterator.getExactSizeIfKnown();

            if (useTryAdvance) {

                Consumer<T> addToDest = boxingAdapter.apply(dest::add);

                int count = 0;

                while (spliterator.tryAdvance(addToDest)) {

                    ++count;

                }

                if (sizeIfKnown >= 0)

                    assertEquals(sizeIfKnown, count);

                // Assert that forEach now produces no elements

                spliterator.forEachRemaining(boxingAdapter.apply(e -> fail("Spliterator.forEach produced an element after spliterator exhausted: " + e)));

                Spliterator<T> split = spliterator.trySplit();

                assertNull(split);

            }

            else {

                List<T> leafDest = new ArrayList<>();

                Consumer<T> addToLeafDest = boxingAdapter.apply(leafDest::add);

                spliterator.forEachRemaining(addToLeafDest);

                if (sizeIfKnown >= 0)