/*-
 * ============LICENSE_START=======================================================
 * ONAP-PAP-REST
 * ================================================================================
 * 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.policy.pap.xacml.rest.util;

import java.util.List;

import org.onap.policy.common.logging.flexlogger.FlexLogger;
import org.onap.policy.common.logging.flexlogger.Logger;
import org.onap.policy.rest.XacmlAdminAuthorization;
import org.onap.policy.rest.dao.CommonClassDao;
import org.onap.policy.rest.jpa.GlobalRoleSettings;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class JPAUtils {
    private static final Logger LOGGER = FlexLogger.getLogger(JPAUtils.class);

    private static CommonClassDao commonClassDao;
    private static JPAUtils currentInstance = null;

    @Autowired
    public JPAUtils(CommonClassDao commonClassDao) {
        JPAUtils.commonClassDao = commonClassDao;
    }

    /**
     * Get an instance of a JPAUtils. It creates one if it does not exist. Only one instance is allowed
     * to be created per server.
     *
     * @param emf The EntityFactoryManager to be used for database connections
     * @return The new instance of JPAUtils or throw exception if the given emf is null.
     * @throws IllegalStateException if a JPAUtils has already been constructed. Call
     *         getJPAUtilsInstance() to get this.
     */
    public static JPAUtils getJPAUtilsInstance() {
        if (currentInstance == null) {
            currentInstance = new JPAUtils();
            return currentInstance;
        }
        return currentInstance;
    }

    private JPAUtils() {
        // Default Constructor
    }

    /**
     * Returns the lockdown value, in case of exception it is assumed that lockdown functionality is not
     * supported and returns false.
     *
     *
     * @throws ReadOnlyException
     * @throws ConversionException
     */
    public boolean dbLockdownIgnoreErrors() {
        if (LOGGER.isTraceEnabled())
            LOGGER.trace("ENTER");

        boolean lockdown = false;
        try {
            lockdown = dbLockdown();
        } catch (Exception e) {
            LOGGER.warn("Cannot access DB lockdown value", e);
        }
        return lockdown;
    }

    /**
     * Returns the lockdown value from the database.
     *
     * @throws ReadOnlyException
     * @throws ConversionException
     */
    public boolean dbLockdown() throws IllegalAccessException {
        if (LOGGER.isTraceEnabled())
            LOGGER.trace("ENTER");
        List<Object> data = commonClassDao.getData(GlobalRoleSettings.class);

        GlobalRoleSettings globalRoleSettings = null;

        if (!data.isEmpty()) {
            globalRoleSettings = (GlobalRoleSettings) data.get(0);
        }

        if (globalRoleSettings == null) {
            // this should not happen
            String msg = "NO GlobalSetttings for " + XacmlAdminAuthorization.Role.ROLE_SUPERADMIN.toString();
            if (LOGGER.isErrorEnabled())
                LOGGER.error(msg);
            throw new IllegalAccessException(msg);
        }

        if (!globalRoleSettings.getRole().equals(XacmlAdminAuthorization.Role.ROLE_SUPERADMIN.toString())) {
            String msg = "NOT FOUND db data for " + XacmlAdminAuthorization.Role.ROLE_SUPERADMIN.toString();
            if (LOGGER.isErrorEnabled())
                LOGGER.error(msg);
            throw new IllegalAccessException(msg);
        }

        return globalRoleSettings.isLockdown();
    }
}