/*
 * Copyright 2015 Goldman Sachs.
 *
 * 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.gs.collections.impl.utility.internal;

import java.util.Iterator;

import com.gs.collections.api.RichIterable;
import com.gs.collections.api.collection.MutableCollection;
import com.gs.collections.api.list.MutableList;
import com.gs.collections.impl.factory.Lists;

public final class MutableCollectionIterate
{
    private MutableCollectionIterate()
    {
        throw new AssertionError("Suppress default constructor for noninstantiability");
    }

    public static <T> RichIterable<RichIterable<T>> chunk(MutableCollection<T> collection, int size)
    {
        if (size <= 0)
        {
            throw new IllegalArgumentException("Size for groups must be positive but was: " + size);
        }
        Iterator<T> iterator = collection.iterator();
        MutableList<RichIterable<T>> result = Lists.mutable.empty();
        while (iterator.hasNext())
        {
            MutableCollection<T> batch = collection.newEmpty();
            for (int i = 0; i < size && iterator.hasNext(); i++)
            {
                batch.add(iterator.next());
            }
            result.add(batch);
        }
        return result;
    }
}