/*
 * Copyright (C) 2008 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 static com.google.common.base.Preconditions.checkNotNull;

import java.util.Comparator;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Supplier;

/**
 * Implementation of {@code Table} whose iteration ordering across row keys is
 * sorted by their natural ordering or by a supplied comparator. Note that
 * iterations across the columns keys for a single row key may or may not be
 * ordered, depending on the implementation. When rows and columns are both
 * sorted, it's easier to use the {@link TreeBasedTable} subclass.
 *
 * <p>
 * The {@link #rowKeySet} method returns a {@link SortedSet} and the
 * {@link #rowMap} method returns a {@link SortedMap}, instead of the
 * {@link Set} and {@link Map} specified by the {@link Table} interface.
 *
 * <p>
 * Null keys and values are not supported.
 *
 * <p>
 * See the {@link StandardTable} superclass for more information about the
 * behavior of this class.
 *
 * @author Jared Levy
 */
@GwtCompatible
class StandardRowSortedTable<R, C, V> extends StandardTable<R, C, V> implements RowSortedTable<R, C, V> {
	/*
	 * TODO(jlevy): Consider adding headTable, tailTable, and subTable methods,
	 * which return a Table view with rows keys in a given range. Create a
	 * RowSortedTable subinterface with the revised methods?
	 */

	StandardRowSortedTable(SortedMap<R, Map<C, V>> backingMap, Supplier<? extends Map<C, V>> factory) {
		super(backingMap, factory);
	}

	private SortedMap<R, Map<C, V>> sortedBackingMap() {
		return (SortedMap<R, Map<C, V>>) backingMap;
	}

	/**
	 * {@inheritDoc}
	 *
	 * <p>
	 * This method returns a {@link SortedSet}, instead of the {@code Set} specified
	 * in the {@link Table} interface.
	 */
	@Override
	public SortedSet<R> rowKeySet() {
		return (SortedSet<R>) rowMap().keySet();
	}

	/**
	 * {@inheritDoc}
	 *
	 * <p>
	 * This method returns a {@link SortedMap}, instead of the {@code Map} specified
	 * in the {@link Table} interface.
	 */
	@Override
	public SortedMap<R, Map<C, V>> rowMap() {
		return (SortedMap<R, Map<C, V>>) super.rowMap();
	}

	@Override
	SortedMap<R, Map<C, V>> createRowMap() {
		return new RowSortedMap();
	}

	private class RowSortedMap extends RowMap implements SortedMap<R, Map<C, V>> {
		@Override
		public SortedSet<R> keySet() {
			return (SortedSet<R>) super.keySet();
		}

		@Override
		SortedSet<R> createKeySet() {
			return new Maps.SortedKeySet<R, Map<C, V>>(this);
		}

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

		@Override
		public R firstKey() {
			return sortedBackingMap().firstKey();
		}

		@Override
		public R lastKey() {
			return sortedBackingMap().lastKey();
		}

		@Override
		public SortedMap<R, Map<C, V>> headMap(R toKey) {
			checkNotNull(toKey);
			return new StandardRowSortedTable<R, C, V>(sortedBackingMap().headMap(toKey), factory).rowMap();
		}

		@Override
		public SortedMap<R, Map<C, V>> subMap(R fromKey, R toKey) {
			checkNotNull(fromKey);
			checkNotNull(toKey);
			return new StandardRowSortedTable<R, C, V>(sortedBackingMap().subMap(fromKey, toKey), factory).rowMap();
		}

		@Override
		public SortedMap<R, Map<C, V>> tailMap(R fromKey) {
			checkNotNull(fromKey);
			return new StandardRowSortedTable<R, C, V>(sortedBackingMap().tailMap(fromKey), factory).rowMap();
		}
	}

	private static final long serialVersionUID = 0;
}
