001/*
002 *  Copyright 2024 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.plugins.repository.query.expression;
017
018import java.util.ArrayList;
019import java.util.Arrays;
020import java.util.Collection;
021import java.util.Objects;
022import java.util.stream.Collectors;
023
024import org.apache.commons.lang.StringUtils;
025
026/**
027 * Constructs an {@link Expression} corresponding to a logical operator between several {@link Expression}.
028 */
029public abstract class AbstractLogicalExpression extends ArrayList<Expression> implements Expression
030{
031    /**
032     * Creates the logical expression.
033     * @param exprs the operands
034     */
035    public AbstractLogicalExpression(Collection<Expression> exprs)
036    {
037        super(exprs);
038    }
039    
040    /**
041     * Creates the logical expression.
042     * @param exprs the operands
043     */
044    public AbstractLogicalExpression(Expression ... exprs)
045    {
046        super(Arrays.asList(exprs));
047    }
048    
049    public String build()
050    {
051        String logicalOperator = getLogicalOperator().toString();
052        
053        String joinExpression = this.stream()
054            .filter(Objects::nonNull)
055            .map(Expression::build)
056            .filter(StringUtils::isNotBlank)
057            .collect(Collectors.joining(logicalOperator));
058
059        if (joinExpression.contains(logicalOperator))
060        {
061            joinExpression = "(" + joinExpression + ")";
062        }
063        
064        return joinExpression;
065    }
066    
067    /**
068     * Get the logicial operator to apply between operations, can contains spaces to separate the operator from the expressions.
069     * @return the operator to apply between each expressions
070     */
071    protected abstract LogicalOperator getLogicalOperator();
072}