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/*
 * Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
 *
 * 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.querydsl.lucene4;

import org.apache.lucene.index.Term;
import org.apache.lucene.search.FuzzyQuery;
import org.apache.lucene.util.automaton.LevenshteinAutomata;

import com.querydsl.core.types.Path;
import com.querydsl.core.types.dsl.BooleanExpression;

/**
 * Utility methods to create filter expressions for Lucene queries that are not covered by the
 * Querydsl standard expression model
 *
 * @author tiwe
 *
 */
public final class LuceneExpressions {

    /**
     * Create a fuzzy query
     *
     * @param path path
     * @param value value to match
     * @return condition
     */
    public static BooleanExpression fuzzyLike(Path path, String value) {
        Term term = new Term(path.getMetadata().getName(), value);
        return new QueryElement(new FuzzyQuery(term));
    }

    /**
     * Create a fuzzy query
     *
     * @param path path
     * @param value value to match
     * @param maxEdits must be >= 0 and <= {@link LevenshteinAutomata#MAXIMUM_SUPPORTED_DISTANCE}.
     * @return condition
     */
    public static BooleanExpression fuzzyLike(Path path, String value, int maxEdits) {
        Term term = new Term(path.getMetadata().getName(), value);
        return new QueryElement(new FuzzyQuery(term, maxEdits));
    }

    /**
     * Create a fuzzy query
     *
     * @param path path
     * @param value value to match
     * @param maxEdits must be >= 0 and <= {@link LevenshteinAutomata#MAXIMUM_SUPPORTED_DISTANCE}.
     * @param prefixLength length of common (non-fuzzy) prefix
     * @return condition
     */
    public static BooleanExpression fuzzyLike(Path path, String value,
            int maxEdits, int prefixLength) {
        Term term = new Term(path.getMetadata().getName(), value);
        return new QueryElement(new FuzzyQuery(term, maxEdits, prefixLength));
    }

    private LuceneExpressions() { }

}