/*-
 * ============LICENSE_START=======================================================
 * VID
 * ================================================================================
 * Copyright (C) 2017 - 2019 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.vid.utils;

import static java.util.Objects.isNull;
import static org.onap.vid.utils.KotlinUtilsKt.JACKSON_OBJECT_MAPPER;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;
import javax.persistence.AttributeConverter;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.onap.portalsdk.core.domain.FusionObject;
import org.onap.vid.exceptions.GenericUncheckedException;

public class DaoUtils {

    //all credit for this wonderful method go to is9613
    public static<T> T tryWithSessionAndTransaction(SessionFactory sessionFactory, Function<Session, T> update) {
        // opens a session and transactions, executes the input query.
        // gracefully close session and transaction once error occurres.
        Session session = null;
        Transaction tx = null;
        try {
            session = sessionFactory.openSession();
            tx = session.beginTransaction();

            T res = update.apply(session);

            tx.commit();

            return res;
        } catch (RuntimeException e) {
            try {
                if (tx != null) {
                    tx.rollback();
                }
            } catch (RuntimeException e2) {
                // e2 is ingnored; we would like to know the
                // original failure reason, not only the reason
                // for rollback's failure
                throw new GenericUncheckedException("Failed rolling back transaction", e);
            }
            throw new GenericUncheckedException("Rolled back transaction", e);
        } finally {
            if (session != null) {
                session.close();
            }
        }
    }

    public static HashMap<String, Object> getPropsMap() {
        HashMap<String, Object> props = new HashMap<>();
        props.put(FusionObject.Parameters.PARAM_USERID, 0);
        return props;
    }

    public static class StringToLongMapAttributeConverter extends JsonAttributeConverter<Map<String, Long>> {

        private final TypeReference<Map<String, Long>> typeReference =
            new TypeReference<Map<String, Long>>() {};

        @Override
        public TypeReference<Map<String, Long>> getTypeReference() {
            return typeReference;
        }
    }

    private static abstract class JsonAttributeConverter<T> implements AttributeConverter<T, String> {

        abstract public TypeReference<T> getTypeReference();

        @Override
        public String convertToDatabaseColumn(T attribute) {
            try {
                return isNull(attribute) ? null
                    : JACKSON_OBJECT_MAPPER.writeValueAsString(attribute);
            } catch (JsonProcessingException e) {
                return ExceptionUtils.rethrow(e);
            }
        }

        @Override
        public T convertToEntityAttribute(String dbData) {
            try {
                return isNull(dbData) ? null
                    : JACKSON_OBJECT_MAPPER.readValue(dbData, getTypeReference());
            } catch (JsonProcessingException e) {
                return ExceptionUtils.rethrow(e);
            }
        }
    }
}