/*
 * Copyright 2014 - 2017 Blazebit.
 *
 * 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.blazebit.persistence.impl.transform;

import com.blazebit.persistence.impl.AbstractManager;
import com.blazebit.persistence.impl.ClauseType;
import com.blazebit.persistence.impl.GroupByManager;
import com.blazebit.persistence.impl.JoinManager;
import com.blazebit.persistence.impl.JoinNode;
import com.blazebit.persistence.impl.OrderByManager;
import com.blazebit.persistence.impl.SelectInfo;
import com.blazebit.persistence.impl.SelectManager;
import com.blazebit.persistence.impl.expression.PathExpression;
import com.blazebit.persistence.impl.expression.PathReference;
import com.blazebit.persistence.impl.expression.SimplePathReference;
import com.blazebit.persistence.impl.expression.modifier.ExpressionModifier;

import java.util.*;

/**
 *
 * @author Christian Beikov
 * @author Moritz Becker
 * @since 1.2.0
 */
public class SizeTransformerGroup implements ExpressionTransformerGroup<ExpressionModifier> {

    private final SizeTransformationVisitor sizeTransformationVisitor;
    private final SelectManager<?> selectManager;
    private final JoinManager joinManager;
    private final GroupByManager groupByManager;
    private final SizeExpressionTransformer sizeExpressionTransformer;
    private final SizeSelectInfoTransformer sizeSelectExpressionTransformer;

    public SizeTransformerGroup(SizeTransformationVisitor sizeTransformationVisitor, OrderByManager orderByManager, SelectManager<?> selectManager, JoinManager joinManager, GroupByManager groupByManager) {
        this.sizeTransformationVisitor = sizeTransformationVisitor;
        this.selectManager = selectManager;
        this.joinManager = joinManager;
        this.groupByManager = groupByManager;
        this.sizeExpressionTransformer = new SizeExpressionTransformer(sizeTransformationVisitor);
        this.sizeSelectExpressionTransformer = new SizeSelectInfoTransformer(sizeTransformationVisitor, orderByManager);
    }

    @Override
    public void applyExpressionTransformer(AbstractManager<? extends ExpressionModifier> manager) {
        if (manager.getClauseType() != ClauseType.SELECT || selectManager.containsSizeSelect()) {
            switch (manager.getClauseType()) {
                case WHERE:
                case JOIN:
                case GROUP_BY:
                case HAVING:
                case ORDER_BY:
                    manager.apply(sizeExpressionTransformer);
                    break;
                case SELECT:
                    ((AbstractManager<SelectInfo>) manager).apply(sizeSelectExpressionTransformer);
                    break;
                default:
                    // Ignore
            }
        }
    }

    @Override
    public void afterGlobalTransformation() {
        // finally add the required joins for the transformations that were carried out
        for (SizeTransformationVisitor.LateJoinEntry lateJoinEntry : sizeTransformationVisitor.getLateJoins().values()) {
            PathExpression requiredJoinExpression = lateJoinEntry.getPathsToJoin().get(0);
            joinManager.implicitJoin(requiredJoinExpression, true, null, null, false, false, true, false);
            PathReference generatedJoin = requiredJoinExpression.getPathReference();
            ((JoinNode) generatedJoin.getBaseNode()).getClauseDependencies().addAll(lateJoinEntry.getClauseDependencies());
            for (int i = 1; i < lateJoinEntry.getPathsToJoin().size(); i++) {
                lateJoinEntry.getPathsToJoin().get(i).setPathReference(new SimplePathReference(generatedJoin.getBaseNode(), generatedJoin.getField(), generatedJoin.getType()));
            }
        }
    }

    @Override
    public Set<String> getRequiredGroupByClauses() {
        return sizeTransformationVisitor.getRequiredGroupBys();
    }

    @Override
    public Set<String> getOptionalGroupByClauses() {
        return sizeTransformationVisitor.getSubqueryGroupBys();
    }
}