/*

 * 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.

 *

 */

/*

 * @test

 * @bug 6394004

 * @summary Test ForgetMeNot implementation feature (and more)

 * @author Martin Buchholz

 */

import java.util.*;

public class ForgetMeNot {

    private static void checkQ(PriorityQueue<Integer> q, Integer...elts) {

        check(Arrays.equals(q.toArray(), elts));

    }

    private static void noMoreElements(final Iterator<Integer> it) {

        for (int j = 0; j < 2; j++) {

            THROWS(NoSuchElementException.class,

                   new Fun() { void f() { it.next(); }});

            check(! it.hasNext());

        }

    }

    private static void removeIsCurrentlyIllegal(final Iterator<Integer> it) {

        for (int j = 0; j < 2; j++) {

            THROWS(IllegalStateException.class,

                   new Fun() { void f() { it.remove(); }});

        }

    }

    private static void remove(Iterator<Integer> it,

                               Queue<Integer> q) {

        int size = q.size();

        it.remove();

        removeIsCurrentlyIllegal(it);

        equal(size, q.size()+1);

    }

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

        final PriorityQueue<Integer> q = new PriorityQueue<Integer>();

        Iterator<Integer> it;

        //----------------------------------------------------------------

        // Empty

        //----------------------------------------------------------------

        checkQ(q);

        check(q.isEmpty());

        check(! q.contains(1));

        it = q.iterator();

        removeIsCurrentlyIllegal(it);

        noMoreElements(it);

        q.clear();

        check(q.isEmpty());

        //----------------------------------------------------------------

        // Singleton

        //----------------------------------------------------------------

        q.add(1);

        checkQ(q, 1);

        check(! q.isEmpty());

        check(q.contains(1));

        it = q.iterator();

        removeIsCurrentlyIllegal(it);

        check(it.hasNext());

        equal(it.next(), 1);

        noMoreElements(it);

        remove(it, q);

        check(q.isEmpty());

        noMoreElements(it);

        checkQ(q);

        q.clear();

        //----------------------------------------------------------------

        // @see PriorityQueue.forgetMeNot

        //----------------------------------------------------------------

        final Integer[] a = {0, 4, 1, 6, 7, 2, 3}; // Carefully chosen!

        q.addAll(Arrays.asList(a));

        checkQ(q, a);

        it = q.iterator();

        checkQ(q, a);

        removeIsCurrentlyIllegal(it);

        checkQ(q, a);

        check(it.hasNext());

        removeIsCurrentlyIllegal(it);

        checkQ(q, a);

        check(it.hasNext());

        equal(it.next(), 0);

        equal(it.next(), 4);

        equal(it.next(), 1);

        equal(it.next(), 6);

        check(it.hasNext());

        checkQ(q, a);

        remove(it, q);

        checkQ(q, 0, 3, 1, 4, 7, 2);

        check(it.hasNext());

        removeIsCurrentlyIllegal(it);

        equal(it.next(), 7);

        remove(it, q);

        checkQ(q, 0, 2, 1, 4, 3);

        check(it.hasNext());

        removeIsCurrentlyIllegal(it);

        check(it.hasNext());

        equal(it.next(), 3);

        equal(it.next(), 2);

        check(! it.hasNext());

        remove(it, q);

        checkQ(q, 0, 3, 1, 4);

        check(! it.hasNext());

        noMoreElements(it);

        removeIsCurrentlyIllegal(it);

    }

    //--------------------- 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");}

    private static abstract class Fun {abstract void f() throws Throwable;}

    static void THROWS(Class<? extends Throwable> k, Fun... fs) {

        for (Fun f : fs)

            try { f.f(); fail("Expected " + k.getName() + " not thrown"); }

            catch (Throwable t) {

                if (k.isAssignableFrom(t.getClass())) pass();

                else unexpected(t);}}

}