/*
 * Licensed to STRATIO (C) under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership.  The STRATIO (C) licenses this file
 * to you 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.stratio.cassandra.lucene.util;

import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.PartitionColumns;
import org.apache.cassandra.db.rows.Row;
import org.apache.cassandra.db.rows.RowIterator;

import java.util.Collections;
import java.util.Iterator;

/**
 * {@link RowIterator} representing a single CQL {@link Row}.
 *
 * @author Andres de la Pena {@literal <adelapena@stratio.com>}
 */
public class SimpleRowIterator implements RowIterator {

    private final CFMetaData metadata;
    private final DecoratedKey key;
    private final PartitionColumns columns;
    private final Row staticRow;
    private final Row row;
    private final Iterator<Row> rows;

    /**
     * Builds a new {@link SimpleRowIterator} from the current position of the specified {@link RowIterator}. Any other
     * rows in the specified iterator won't be read.
     *
     * @param iterator the {@link Row} iterator
     */
    public SimpleRowIterator(RowIterator iterator) {
        this.metadata = iterator.metadata();
        this.key = iterator.partitionKey();
        this.columns = iterator.columns();
        this.staticRow = iterator.staticRow();
        this.row = iterator.next();
        this.rows = Collections.singletonList(row).iterator();
    }

    /** {@inheritDoc} */
    @Override
    public CFMetaData metadata() {
        return metadata;
    }

    /** {@inheritDoc} */
    @Override
    public boolean isReverseOrder() {
        return false;
    }

    /** {@inheritDoc} */
    @Override
    public PartitionColumns columns() {
        return columns;
    }

    /** {@inheritDoc} */
    @Override
    public DecoratedKey partitionKey() {
        return key;
    }

    /** {@inheritDoc} */
    @Override
    public Row staticRow() {
        return staticRow;
    }

    /** {@inheritDoc} */
    @Override
    public void close() {

    }

    /** {@inheritDoc} */
    @Override
    public boolean hasNext() {
        return rows.hasNext();
    }

    /** {@inheritDoc} */
    @Override
    public Row next() {
        return rows.next();
    }

    /**
     * Returns the decorated {@link Row}.
     *
     * @return the decorated {@link Row}
     */
    public Row getRow() {
        return row;
    }
}