/*
 * Copyright (c) 2010-2015 Evolveum
 *
 * 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.evolveum.midpoint.repo.sql.query2.definition;

import com.evolveum.midpoint.prism.ItemDefinition;
import com.evolveum.midpoint.prism.PrismContext;
import com.evolveum.midpoint.prism.Visitor;
import com.evolveum.midpoint.prism.path.ItemPath;
import com.evolveum.midpoint.repo.sql.query.QueryException;
import com.evolveum.midpoint.repo.sql.query2.resolution.DataSearchResult;

/**
 * Special placeholder to allow for cross-references: entity definition that points to another entity.
 * Currently, the process of resolving allows to point to root entity definitions here only.
 * As a hack, we implement self pointers (e.g. RAssignment.metadata->RAssignment) also for non-root
 * entities, provided they are resolved on creation. (The reason of using JpaEntityPointerDefinition
 * there is just to break navigation cycles e.g. when using a visitor.)
 *
 * @author mederly
 */
public class JpaEntityPointerDefinition extends JpaDataNodeDefinition {

    private JpaEntityDefinition resolvedEntityDefinition;           // lazily evaluated

    public JpaEntityPointerDefinition(Class jpaClass) {
        super(jpaClass, null);
    }

    public JpaEntityPointerDefinition(JpaEntityDefinition alreadyResolved) {
        super(alreadyResolved.getJpaClass(), alreadyResolved.getJaxbClass());
        this.resolvedEntityDefinition = alreadyResolved;
    }

    public JpaEntityDefinition getResolvedEntityDefinition() {
        return resolvedEntityDefinition;
    }

    public void setResolvedEntityDefinition(JpaEntityDefinition resolvedEntityDefinition) {
        this.resolvedEntityDefinition = resolvedEntityDefinition;
    }

    @Override
    public DataSearchResult<?> nextLinkDefinition(ItemPath path, ItemDefinition itemDefinition,
            PrismContext prismContext) throws QueryException {
        return resolvedEntityDefinition.nextLinkDefinition(path, itemDefinition, prismContext);
    }

    @Override
    protected String getDebugDumpClassName() {
        return "EntPtr";
    }

    @Override
    public String debugDump(int indent) {
        if (resolvedEntityDefinition == null) {
            return getShortInfo();
        } else {
            return getDebugDumpClassName() + ":" + resolvedEntityDefinition.getShortInfo();
        }
    }

    @Override
    public void accept(Visitor visitor) {
        visitor.visit(this);
    }

    public boolean isResolved() {
        return resolvedEntityDefinition != null;
    }
}