/*
 * Copyright (C) 2009 The Guava Authors
 *
 * 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 com.google.common.collect;

import java.util.Comparator;

import javax.annotation.Nullable;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

/**
 * List returned by {@code ImmutableSortedSet.asList()} when the set isn't
 * empty.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible(emulated = true)
@SuppressWarnings("serial")
final class ImmutableSortedAsList<E> extends RegularImmutableAsList<E> implements SortedIterable<E> {
	ImmutableSortedAsList(ImmutableSortedSet<E> backingSet, ImmutableList<E> backingList) {
		super(backingSet, backingList);
	}

	@Override
	ImmutableSortedSet<E> delegateCollection() {
		return (ImmutableSortedSet<E>) super.delegateCollection();
	}

	@Override
	public Comparator<? super E> comparator() {
		return delegateCollection().comparator();
	}

	// Override indexOf() and lastIndexOf() to be O(log N) instead of O(N).

	@GwtIncompatible("ImmutableSortedSet.indexOf")
	// TODO(cpovirk): consider manual binary search under GWT to preserve O(log N)
	// lookup
	@Override
	public int indexOf(@Nullable Object target) {
		int index = delegateCollection().indexOf(target);

		// TODO(kevinb): reconsider if it's really worth making feeble attempts at
		// sanity for inconsistent comparators.

		// The equals() check is needed when the comparator isn't compatible with
		// equals().
		return (index >= 0 && get(index).equals(target)) ? index : -1;
	}

	@GwtIncompatible("ImmutableSortedSet.indexOf")
	@Override
	public int lastIndexOf(@Nullable Object target) {
		return indexOf(target);
	}

	@Override
	public boolean contains(Object target) {
		// Necessary for ISS's with comparators inconsistent with equals.
		return indexOf(target) >= 0;
	}

	@GwtIncompatible("super.subListUnchecked does not exist; inherited subList is valid if slow")
	/*
	 * TODO(cpovirk): if we start to override indexOf/lastIndexOf under GWT, we'll
	 * want some way to override subList to return an ImmutableSortedAsList for
	 * better performance. Right now, I'm not sure there's any performance hit from
	 * our failure to override subListUnchecked under GWT
	 */
	@Override
	ImmutableList<E> subListUnchecked(int fromIndex, int toIndex) {
		return new RegularImmutableSortedSet<E>(super.subListUnchecked(fromIndex, toIndex), comparator()).asList();
	}
}
