/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.cassandra.cql3.restrictions;

import java.nio.ByteBuffer;
import java.util.*;

import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.cql3.QueryOptions;
import org.apache.cassandra.cql3.statements.Bound;
import org.apache.cassandra.db.ClusteringComparator;
import org.apache.cassandra.db.ClusteringPrefix;
import org.apache.cassandra.db.MultiCBuilder;
import org.apache.cassandra.db.filter.RowFilter;
import org.apache.cassandra.index.SecondaryIndexManager;

A set of single restrictions on the partition key.
This class can only contains SingleRestriction instances. Token restrictions will be handled by
TokenRestriction class or by the TokenFilter class if the query contains a mix of token
restrictions and single column restrictions on the partition key.
/**
 * A set of single restrictions on the partition key.
 * <p>This class can only contains <code>SingleRestriction</code> instances. Token restrictions will be handled by
 * <code>TokenRestriction</code> class or by the <code>TokenFilter</code> class if the query contains a mix of token
 * restrictions and single column restrictions on the partition key.
 */
final class PartitionKeySingleRestrictionSet extends RestrictionSetWrapper implements PartitionKeyRestrictions
{
    
The composite type.
/**
     * The composite type.
     */
    protected final ClusteringComparator comparator;

    public PartitionKeySingleRestrictionSet(ClusteringComparator comparator)
    {
        super(new RestrictionSet());
        this.comparator = comparator;
    }

    private PartitionKeySingleRestrictionSet(PartitionKeySingleRestrictionSet restrictionSet,
                                       SingleRestriction restriction)
    {
        super(restrictionSet.restrictions.addRestriction(restriction));
        this.comparator = restrictionSet.comparator;
    }

    private List<ByteBuffer> toByteBuffers(SortedSet<? extends ClusteringPrefix> clusterings)
    {
        List<ByteBuffer> l = new ArrayList<>(clusterings.size());
        for (ClusteringPrefix clustering : clusterings)
            l.add(CFMetaData.serializePartitionKey(clustering));
        return l;
    }

    @Override
    public PartitionKeyRestrictions mergeWith(Restriction restriction)
    {
        if (restriction.isOnToken())
        {
            if (isEmpty())
                return (PartitionKeyRestrictions) restriction;

            return new TokenFilter(this, (TokenRestriction) restriction);
        }

        return new PartitionKeySingleRestrictionSet(this, (SingleRestriction) restriction);
    }

    @Override
    public List<ByteBuffer> values(QueryOptions options)
    {
        MultiCBuilder builder = MultiCBuilder.create(comparator, hasIN());
        for (SingleRestriction r : restrictions)
        {
            r.appendTo(builder, options);
            if (builder.hasMissingElements())
                break;
        }
        return toByteBuffers(builder.build());
    }

    @Override
    public List<ByteBuffer> bounds(Bound bound, QueryOptions options)
    {
        MultiCBuilder builder = MultiCBuilder.create(comparator, hasIN());
        for (SingleRestriction r : restrictions)
        {
            r.appendBoundTo(builder, bound, options);
            if (builder.hasMissingElements())
                return Collections.emptyList();
        }
        return toByteBuffers(builder.buildBound(bound.isStart(), true));
    }

    @Override
    public boolean hasBound(Bound b)
    {
        if (isEmpty())
            return false;
        return restrictions.lastRestriction().hasBound(b);
    }

    @Override
    public boolean isInclusive(Bound b)
    {
        if (isEmpty())
            return false;
        return restrictions.lastRestriction().isInclusive(b);
    }

    @Override
    public void addRowFilterTo(RowFilter filter,
                               SecondaryIndexManager indexManager,
                               QueryOptions options)
    {
        for (SingleRestriction restriction : restrictions)
        {
             restriction.addRowFilterTo(filter, indexManager, options);
        }
    }

    @Override
    public boolean needFiltering(CFMetaData cfm)
    {
        if (isEmpty())
            return false;

        // slice or has unrestricted key component
        return hasUnrestrictedPartitionKeyComponents(cfm) || hasSlice() || hasContains();
    }

    @Override
    public boolean hasUnrestrictedPartitionKeyComponents(CFMetaData cfm)
    {
        return size() < cfm.partitionKeyColumns().size();
    }

    @Override
    public boolean hasSlice()
    {
        for (SingleRestriction restriction : restrictions)
        {
            if (restriction.isSlice())
                return true;
        }
        return false;
    }
}