/*
 * 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.search.condition;

import com.google.common.base.MoreObjects;
import com.stratio.cassandra.lucene.schema.Schema;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.Query;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.LinkedList;
import java.util.List;

import static org.apache.lucene.search.BooleanClause.Occur.*;

/**
 * A {@link Condition} that matches documents matching boolean combinations of other queries, e.g. {@link
 * MatchCondition}s, {@link RangeCondition}s or other {@link BooleanCondition}s.
 *
 * @author Andres de la Pena {@literal <adelapena@stratio.com>}
 */
public class BooleanCondition extends Condition {

    private static final Logger logger = LoggerFactory.getLogger(BooleanCondition.class);

    /** The mandatory conditions. */
    public final List<Condition> must;

    /** The optional conditions. */
    public final List<Condition> should;

    /** The mandatory not conditions. */
    public final List<Condition> not;

    /**
     * Returns a new {@link BooleanCondition} compound by the specified {@link Condition}s.
     *
     * @param boost The boost for this query clause. Documents matching this clause will (in addition to the normal
     * weightings) have their score multiplied by {@code boost}. If {@code null}, then {@link #DEFAULT_BOOST} is used as
     * default.
     * @param must the mandatory {@link Condition}s
     * @param should the optional {@link Condition}s
     * @param not the mandatory not {@link Condition}s
     */
    public BooleanCondition(Float boost, List<Condition> must, List<Condition> should, List<Condition> not) {

        super(boost);
        this.must = must == null ? new LinkedList<>() : must;
        this.should = should == null ? new LinkedList<>() : should;
        this.not = not == null ? new LinkedList<>() : not;
    }

    /** {@inheritDoc} */
    @Override
    public Query query(Schema schema) {
        BooleanQuery.Builder builder = new BooleanQuery.Builder();
        for (Condition condition : must) {
            builder.add(condition.query(schema), MUST);
        }
        for (Condition condition : should) {
            builder.add(condition.query(schema), SHOULD);
        }
        for (Condition condition : not) {
            builder.add(condition.query(schema), MUST_NOT);
        }
        if (must.isEmpty() && should.isEmpty() && !not.isEmpty()) {
            logger.warn("Performing resource-intensive pure negation search");
            builder.add(new MatchAllDocsQuery(), FILTER);
        }
        Query query = builder.build();
        query.setBoost(boost);
        return query;
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
                          .add("boost", boost)
                          .add("must", must)
                          .add("should", should)
                          .add("not", not)
                          .toString();
    }
}