/*

 * Copyright (c) 2005, 2010, 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 6324846

 * @summary Deque implementations must behave isomorphically

 * @author Martin Buchholz

 */

import java.util.*;

import java.util.concurrent.*;

public class ChorusLine {

    private interface Tweaker {

        void run(Deque<Integer> deq);

    }

    private final static Tweaker[] tweakers = {

        new Tweaker() { public void run(Deque<Integer> deq) {

            for (int i = 0; i < 7; i++)

                deq.addLast(i);

            deq.removeFirst();

            deq.removeFirst();

            deq.addLast(7);

            deq.addLast(8);

            Iterator<Integer> it = deq.descendingIterator();

            equal(it.next(), 8);

            it.remove();

            try {it.remove();}

            catch (IllegalStateException e) {pass();}

            catch (Throwable t) {unexpected(t);}

            deq.addLast(9);

            it = deq.descendingIterator();

            equal(it.next(), 9);

            equal(it.next(), 7);

            it.remove();

            try {it.remove();}

            catch (IllegalStateException e) {pass();}

            catch (Throwable t) {unexpected(t);}

            equal(it.next(), 6);

            System.out.println(deq);

        }},

        new Tweaker() { public void run(Deque<Integer> deq) {

            deq.clear();

            check(deq.isEmpty());

            check(deq.size() == 0);

            check(! deq.iterator().hasNext());

            check(! deq.descendingIterator().hasNext());

            try {deq.iterator().next(); fail();}

            catch (NoSuchElementException e) {pass();}

            catch (Throwable t) {unexpected(t);}

            try {deq.descendingIterator().next(); fail();}

            catch (NoSuchElementException e) {pass();}

            catch (Throwable t) {unexpected(t);}

        }},

        new Tweaker() { public void run(Deque<Integer> deq) {

            for (int i = 0; i < 11; i++)

                deq.add(i);

            Iterator<Integer> it = deq.iterator();

            equal(it.next(), 0);

            equal(it.next(), 1);

            it.remove();

            deq.addFirst(-1);

            deq.addFirst(-2);

            it = deq.iterator();

            equal(it.next(), -2);

            equal(it.next(), -1);

            equal(it.next(), 0);

            it.remove();

            it = deq.descendingIterator();

            try {it.remove(); fail();}

            catch (IllegalStateException e) {pass();}

            catch (Throwable t) {unexpected(t);}

            equal(it.next(), 10);

            it.remove();

            try {it.remove(); fail();}

            catch (IllegalStateException e) {pass();}

            catch (Throwable t) {unexpected(t);}

            equal(it.next(), 9);

            equal(it.next(), 8);

            it.remove();

            System.out.println(deq);

        }},

        new Tweaker() { public void run(Deque<Integer> deq) {

            while (deq.size() > 1) {

                Iterator<Integer> it = deq.iterator();

                it.next(); it.remove();

                it = deq.descendingIterator();

                it.next(); it.remove();

            }

            System.out.println(deq);

        }}};

    private static void realMain(String[] args) throws Throwable {

        Collection<Deque<Integer>> deqs = new ArrayDeque<Deque<Integer>>(3);

        deqs.add(new ArrayDeque<Integer>());

        deqs.add(new LinkedList<Integer>());

        deqs.add(new LinkedBlockingDeque<Integer>());

        deqs.add(new ConcurrentLinkedDeque<Integer>());

        equal(deqs);

        for (Tweaker tweaker : tweakers) {

            for (Deque<Integer> deq : deqs)

                tweaker.run(deq);

            equal(deqs);

        }

    }

    private static void equal(Iterable<Deque<Integer>> deqs) {

        Deque<Integer> prev = null;

        for (Deque<Integer> deq : deqs) {

            if (prev != null) {

                equal(prev.isEmpty(), deq.isEmpty());

                equal(prev.size(), deq.size());

                equal(prev.toString(), deq.toString());

            }

            prev = deq;

        }

        Deque<Iterator<Integer>> its = new ArrayDeque<Iterator<Integer>>();

        for (Deque<Integer> deq : deqs)

            its.addLast(deq.iterator());

        equal(its);

        Deque<Iterator<Integer>> dits = new ArrayDeque<Iterator<Integer>>();

        for (Deque<Integer> deq : deqs)

            dits.addLast(deq.descendingIterator());

        equal(dits);

    }

    private static void equal(Deque<Iterator<Integer>> its) {

        Iterator<Integer> it0 = its.remove();

        while (it0.hasNext()) {

            Integer i = it0.next();

            for (Iterator<Integer> it : its)

                equal(it.next(), i);

        }

        for (Iterator<Integer> it : its) {

            check(! it.hasNext());

            try {it.next(); fail();}

            catch (NoSuchElementException e) {pass();}

            catch (Throwable t) {unexpected(t);}

        }

    }

    //--------------------- Infrastructure ---------------------------

    static volatile int passed = 0, failed = 0;

    static void pass() {passed++;}

    static void fail() {failed++; Thread.dumpStack();}

    static void fail(String msg) {System.out.println(msg); fail();}

    static void unexpected(Throwable t) {failed++; t.printStackTrace();}

    static void check(boolean cond) {if (cond) pass(); else fail();}

    static void equal(Object x, Object y) {

        if (x == null ? y == null : x.equals(y)) pass();

        else fail(x + " not equal to " + y);}

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

        try {realMain(args);} catch (Throwable t) {unexpected(t);}

        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);

        if (failed > 0) throw new AssertionError("Some tests failed");}

}