/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */

//$Id$

package org.hibernate.test.subquery;

import org.hibernate.QueryException;
import org.hibernate.Session;
import org.hibernate.dialect.H2Dialect;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;

import org.hibernate.testing.RequiresDialect;
import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
import org.hibernate.type.Type;
import org.junit.Test;

import javax.persistence.Query;
import java.util.List;
import java.util.function.Consumer;

/**
 * Test some subquery scenarios.
 *
 * @author Christian Beikov
 */
@RequiresDialect(H2Dialect.class)
public class SubqueryTest extends BaseCoreFunctionalTestCase {

    private static final SQLFunction LIMIT_FUNCTION = new SQLFunction() {
        public boolean hasArguments() {
            return true;
        }

        public boolean hasParenthesesIfNoArguments() {
            return true;
        }

        public Type getReturnType(Type type, Mapping mpng) throws QueryException {
            return type;
        }

        public String render(Type type, List list, SessionFactoryImplementor sfi) throws QueryException {
            String subquery = list.get(0).toString();
            return subquery.substring(0, subquery.length() - 1) + " limit " + list.get(1) + ")";
        }
    };

    @Override
    protected Class<?>[] getAnnotatedClasses() {
        return new Class[]{
                EntityA.class
        };
    }

    @Test
    public void testNestedOrderBySubqueryInFunction() {
        withLimit(s -> {
            Query q = s.createQuery(
                    "SELECT a.id FROM EntityA a " +
                    "ORDER BY CASE WHEN (" +
                        "SELECT 1 FROM EntityA s1 " +
                        "WHERE s1.id IN(" +
                            "LIMIT(" +
                                "(" +
                                    "SELECT 1 FROM EntityA sub " +
                                    "ORDER BY " +
                                    "CASE WHEN sub.name IS NULL THEN 1 ELSE 0 END, " +
                                    "sub.name DESC, " +
                                    "CASE WHEN sub.id IS NULL THEN 1 ELSE 0 END, " +
                                    "sub.id DESC" +
                                ")," +
                            "1)" +
                        ")" +
                    ") = 1 THEN 1 ELSE 0 END"
            );
            q.getResultList();
        });
    }

    private void withLimit(Consumer<Session> consumer) {
        rebuildSessionFactory( c -> c.addSqlFunction( "limit", LIMIT_FUNCTION ) );

        try {
            Session s = openSession();
            consumer.accept( s );
        } finally {
            // Rebuild to remove the function
            rebuildSessionFactory();
        }
    }

}