/*
 * Copyright (C) 2017 Sebastiano Vigna
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package it.unimi.dsi.fastutil.ints;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertTrue;

import java.util.function.Consumer;

import org.junit.Test;

import it.unimi.dsi.fastutil.Hash;
import it.unimi.dsi.fastutil.HashCommon;
import it.unimi.dsi.fastutil.ints.Int2IntMap.Entry;

public class Int2IntLinkedOpenHashMapTest {
	@Test
	public void testContainsValue() {
		final Int2IntLinkedOpenHashMap m = new Int2IntLinkedOpenHashMap(Hash.DEFAULT_INITIAL_SIZE);
		assertEquals(0, m.put(0, 2));
		assertEquals(0, m.put(1, 3));
		assertTrue(m.containsValue(2));
		assertTrue(m.containsValue(3));
		assertFalse(m.containsValue(4));
		assertTrue(m.containsKey(0));
		assertTrue(m.containsKey(1));
		assertFalse(m.containsKey(2));
	}

	@Test
	public void testFirstLast0() {
		Int2IntLinkedOpenHashMap s;

		s = new Int2IntLinkedOpenHashMap(Hash.DEFAULT_INITIAL_SIZE);
		for (int i = 1; i < 100; i++) {
			assertEquals(0, s.put(i, i));
		}
		for (int i = 1; i < 100; i++) {
			assertEquals(i, s.removeFirstInt());
		}
		assertTrue(s.isEmpty());

		s = new Int2IntLinkedOpenHashMap(Hash.DEFAULT_INITIAL_SIZE);
		for (int i = 0; i < 100; i++) {
			assertEquals(0, s.put(i, i));
		}
		for (int i = 100; i-- != 0; ) {
			assertEquals(i, s.removeLastInt());
		}
		assertTrue(s.isEmpty());

		s = new Int2IntLinkedOpenHashMap(Hash.DEFAULT_INITIAL_SIZE);
		for (int i = 100; i-- != 0; ) {
			assertEquals(0, s.put(i, i));
		}
		for (int i = 0; i < 100; i++) {
			assertEquals(i, s.removeLastInt());
		}
		assertTrue(s.isEmpty());

		s = new Int2IntLinkedOpenHashMap(Hash.DEFAULT_INITIAL_SIZE);
		for (int i = 100; i-- != 0; ) {
			assertEquals(0, s.put(i, i));
		}
		for (int i = 100; i-- != 0; ) {
			assertEquals(i, s.removeFirstInt());
		}
		assertTrue(s.isEmpty());
	}

	@Test
	public void testWrapAround() {
		final Int2IntLinkedOpenHashMap m = new Int2IntLinkedOpenHashMap(4, .5f);
		assertEquals(8, m.n);
		// The following code inverts HashCommon.phiMix() and places strategically keys in slots 6, 7 and 0
		m.put(HashCommon.invMix(6), 0);
		m.put(HashCommon.invMix(7), 0);
		m.put(HashCommon.invMix(6 + 8), 0);
		assertNotEquals(0, m.key[0]);
		assertNotEquals(0, m.key[6]);
		assertNotEquals(0, m.key[7]);
		final IntOpenHashSet keys = new IntOpenHashSet(m.keySet());
		final IntIterator iterator = m.keySet().iterator();
		final IntOpenHashSet t = new IntOpenHashSet();
		t.add(iterator.nextInt());
		t.add(iterator.nextInt());
		// Originally, this remove would move the entry in slot 0 in slot 6 and we would return the entry in 0 twice
		iterator.remove();
		t.add(iterator.nextInt());
		assertEquals(keys, t);
	}

	@Test
	public void testWrapAround2() {
		final Int2IntLinkedOpenHashMap m = new Int2IntLinkedOpenHashMap(4, .75f);
		assertEquals(8, m.n);
		// The following code inverts HashCommon.phiMix() and places strategically keys in slots 4, 5, 6, 7 and 0
		m.put(HashCommon.invMix(4), 0);
		m.put(HashCommon.invMix(5), 0);
		m.put(HashCommon.invMix(4 + 8), 0);
		m.put(HashCommon.invMix(5 + 8), 0);
		m.put(HashCommon.invMix(4 + 16), 0);
		assertNotEquals(0, m.key[0]);
		assertNotEquals(0, m.key[4]);
		assertNotEquals(0, m.key[5]);
		assertNotEquals(0, m.key[6]);
		assertNotEquals(0, m.key[7]);
		//System.err.println(Arraym.toString(m.key));
		final IntOpenHashSet keys = new IntOpenHashSet(m.keySet());
		final IntIterator iterator = m.keySet().iterator();
		final IntOpenHashSet t = new IntOpenHashSet();
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		//System.err.println(Arraym.toString(m.key));
		// Originally, this remove would move the entry in slot 0 in slot 6 and we would return the entry in 0 twice
		assertTrue(t.add(iterator.nextInt()));
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		assertEquals(3, m.size());
		assertEquals(keys, t);
	}

	@Test
	public void testWrapAround3() {
		final Int2IntLinkedOpenHashMap m = new Int2IntLinkedOpenHashMap(4, .75f);
		assertEquals(8, m.n);
		// The following code inverts HashCommon.phiMix() and places strategically keys in slots 5, 6, 7, 0 and 1
		m.put(HashCommon.invMix(5), 0);
		m.put(HashCommon.invMix(5 + 8), 0);
		m.put(HashCommon.invMix(5 + 16), 0);
		m.put(HashCommon.invMix(5 + 32), 0);
		m.put(HashCommon.invMix(5 + 64), 0);
		assertNotEquals(0, m.key[5]);
		assertNotEquals(0, m.key[6]);
		assertNotEquals(0, m.key[7]);
		assertNotEquals(0, m.key[0]);
		assertNotEquals(0, m.key[1]);
		//System.err.println(Arraym.toString(m.key));
		final IntOpenHashSet keys = new IntOpenHashSet(m.keySet());
		final IntIterator iterator = m.keySet().iterator();
		final IntOpenHashSet t = new IntOpenHashSet();
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		// Originally, this remove would move the entry in slot 0 in slot 6 and we would return the entry in 0 twice
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		//System.err.println(Arraym.toString(m.key));
		assertTrue(t.add(iterator.nextInt()));
		iterator.remove();
		assertEquals(0, m.size());
		assertEquals(keys, t);
	}

	@Test
	public void testEntrySetForEach() {
		final int[] a = new int[1000];
		for(int i = 0; i < 1000; i++) a[i] = a.length - 1 - i;
		final Int2IntLinkedOpenHashMap m = new Int2IntLinkedOpenHashMap(a, a);
		m.int2IntEntrySet().forEach(new Consumer<Int2IntMap.Entry>() {
			int i = a.length;
			@Override
			public void accept(final Entry t) {
				assertEquals(--i, t.getIntKey());
			}
		});
		m.int2IntEntrySet().fastForEach(new Consumer<Int2IntMap.Entry>() {
			int i = a.length;
			@Override
			public void accept(final Entry t) {
				assertEquals(--i, t.getIntKey());
			}
		});
	}

	@Test
	public void testRemoveLast() {
		final Int2IntLinkedOpenHashMap s = new Int2IntLinkedOpenHashMap();
		s.put(0, 0);
		s.removeLastInt();
		assertFalse(s.int2IntEntrySet().iterator().hasNext());
	}
}
