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/**
 * 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.github.dm.rf.android.internal;

import android.annotation.TargetApi;
import android.util.SparseLongArray;

import com.github.dm.rf.android.entry.IntSparseLongEntry;
import com.github.dm.rf.android.entry.ParcelableIntSparseLongEntry;
import com.github.dm.rf.android.entry.SparseEntries;
import com.github.dm.rf.android.entry.SparseLongArrayEntry;

import java.util.NoSuchElementException;

/**
 * Implementation of a {@link SparseIterator} of
 * {@link SparseLongArrayEntry} elements.
 * 
 * To let this class implement both the iterator and the entry is a precise design choice in order
 * to achieve the highest performance and the lowest memory usage.

 * The drawback is that the iterated entries cannot be copied and used outside the
 * for use. Fortunately, that is not the common behavior of iteration.

 * To work around the just described issue, each entry con generate an immutable copy of itself
 * storing only the key and value objects but losing any reference to the backing sparse
 * collection.
 * 
 * Created by davide-maestroni on 3/10/14.
 */
@TargetApi(18)
class SparseLongArrayIterator extends AbstractSparseIterator
        implements SparseLongArrayEntry {

    private final SparseLongArray mSparseArray;

    private int mPosition;

    private long mValue;

    public SparseLongArrayIterator(final SparseLongArray array) {

        super(array.size());

        mSparseArray = array;
    }

    @Override
    @SuppressWarnings("EqualsWhichDoesntCheckParameterClass")
    public boolean equals(final Object o) {

        return SparseEntries.equal(this, o);
    }

    @Override
    public int hashCode() {

        return SparseEntries.hashCode(this);
    }

    @Override
    public String toString() {

        return getKey() + "=" + getValue();
    }

    @Override
    public int getIndex() {

        return mPosition;
    }

    @Override
    public int getKey() {

        return mSparseArray.keyAt(mPosition);
    }

    @Override
    public long getValue() {

        return mValue;
    }

    @Override
    public void setValue(final long value) {

        mSparseArray.put(getKey(), value);

        mValue = value;
    }

    @Override
    public IntSparseLongEntry toImmutable() {

        return SparseEntries.entry(getKey(), mValue);
    }

    @Override
    public ParcelableIntSparseLongEntry toParcelable() {

        return SparseEntries.parcelableEntry(getKey(), mValue);
    }

    @Override
    protected SparseLongArrayEntry getElementAt(final int position) {

        try {

            mValue = mSparseArray.valueAt(position);

        } catch (final IndexOutOfBoundsException e) {

            throw new NoSuchElementException();
        }

        mPosition = position;

        return this;
    }

    @Override
    protected void removeElement() {

        mSparseArray.removeAt(mPosition);
    }
}