/*
 * Copyright 2014, Stratio.
 *
 * 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.stratio.cassandra.index.service;

import org.apache.cassandra.db.composites.CellName;
import org.apache.cassandra.db.composites.CellNameType;
import org.apache.cassandra.db.composites.Composite;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.lucene.index.FilteredTermsEnum;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.MultiTermQuery;
import org.apache.lucene.util.AttributeSource;
import org.apache.lucene.util.BytesRef;

import java.io.IOException;

/**
 * @author Andres de la Pena <adelapena@stratio.com>
 */
class ClusteringKeyQuery extends MultiTermQuery {

    private final ClusteringKeyMapper clusteringKeyMapper;
    private final Composite start;
    private final Composite stop;
    private final CellNameType type;

    public ClusteringKeyQuery(Composite start, Composite stop, ClusteringKeyMapper clusteringKeyMapper) {
        super(ClusteringKeyMapper.FIELD_NAME);
        this.start = start;
        this.stop = stop;
        this.clusteringKeyMapper = clusteringKeyMapper;
        this.type = clusteringKeyMapper.getType();
    }

    @Override
    protected TermsEnum getTermsEnum(Terms terms, AttributeSource atts) throws IOException {
        return new FullKeyDataRangeFilteredTermsEnum(terms.iterator(null));
    }

    @Override
    public String toString(String field) {
        return new ToStringBuilder(this).append("field", field)
                                        .append("start", start == null ? null : clusteringKeyMapper.toString(start))
                                        .append("stop", stop == null ? null : clusteringKeyMapper.toString(stop))
                                        .toString();
    }

    private class FullKeyDataRangeFilteredTermsEnum extends FilteredTermsEnum {

        public FullKeyDataRangeFilteredTermsEnum(TermsEnum tenum) {
            super(tenum);
            setInitialSeekTerm(new BytesRef());
        }

        @Override
        protected AcceptStatus accept(BytesRef term) {
            CellName clusteringKey = clusteringKeyMapper.clusteringKey(term);
            if (start != null && !start.isEmpty() && type.compare(start, clusteringKey) > 0) {
                return AcceptStatus.NO;
            }
            if (stop != null && !stop.isEmpty() && type.compare(stop, clusteringKey) < 0) {
                return AcceptStatus.NO;
            }
            return AcceptStatus.YES;
        }
    }
}