/*
 * ============LICENSE_START=======================================================
 * Copyright (C) 2023 Nordix Foundation
 * ================================================================================
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 * ============LICENSE_END=========================================================
 */

package org.onap.cps.ncmp.api.impl.events.avcsubscription;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Named;
import org.onap.cps.ncmp.events.avcsubscription1_0_0.dmi_to_ncmp.SubscriptionEventResponse;
import org.onap.cps.ncmp.events.avcsubscription1_0_0.dmi_to_ncmp.SubscriptionStatus;
import org.onap.cps.ncmp.events.avcsubscription1_0_0.ncmp_to_client.AdditionalInfo;
import org.onap.cps.ncmp.events.avcsubscription1_0_0.ncmp_to_client.AdditionalInfoDetail;
import org.onap.cps.ncmp.events.avcsubscription1_0_0.ncmp_to_client.SubscriptionEventOutcome;
import org.onap.cps.spi.exceptions.DataValidationException;

@Mapper(componentModel = "spring")
public interface SubscriptionOutcomeMapper {

    @Mapping(source = "data.subscriptionStatus", target = "data.additionalInfo",
            qualifiedByName = "mapListOfSubscriptionStatusToAdditionalInfo")
    SubscriptionEventOutcome toSubscriptionEventOutcome(SubscriptionEventResponse subscriptionEventResponse);

    /**
     * Maps list of SubscriptionStatus to an AdditionalInfo.
     *
     * @param subscriptionStatusList containing details
     * @return an AdditionalInfo
     */
    @Named("mapListOfSubscriptionStatusToAdditionalInfo")
    default AdditionalInfo mapListOfSubscriptionStatusToAdditionalInfo(
            final List<SubscriptionStatus> subscriptionStatusList) {
        if (subscriptionStatusList == null || subscriptionStatusList.isEmpty()) {
            throw new DataValidationException("Invalid subscriptionStatusList",
                    "SubscriptionStatus list cannot be null or empty");
        }

        final Map<String, List<SubscriptionStatus>> rejectedSubscriptionsPerDetails = getSubscriptionsPerDetails(
                subscriptionStatusList, SubscriptionStatus.Status.REJECTED);
        final Map<String, List<String>> rejectedCmHandlesPerDetails =
                getCmHandlesPerDetails(rejectedSubscriptionsPerDetails);
        final List<AdditionalInfoDetail> rejectedCmHandles = getAdditionalInfoDetailList(rejectedCmHandlesPerDetails);


        final Map<String, List<SubscriptionStatus>> pendingSubscriptionsPerDetails = getSubscriptionsPerDetails(
                subscriptionStatusList, SubscriptionStatus.Status.PENDING);
        final Map<String, List<String>> pendingCmHandlesPerDetails =
                getCmHandlesPerDetails(pendingSubscriptionsPerDetails);
        final List<AdditionalInfoDetail> pendingCmHandles = getAdditionalInfoDetailList(pendingCmHandlesPerDetails);

        final AdditionalInfo additionalInfo = new AdditionalInfo();
        additionalInfo.setRejected(rejectedCmHandles);
        additionalInfo.setPending(pendingCmHandles);

        return additionalInfo;
    }

    private static Map<String, List<SubscriptionStatus>> getSubscriptionsPerDetails(
            final List<SubscriptionStatus> subscriptionStatusList, final SubscriptionStatus.Status status) {
        return subscriptionStatusList.stream()
                .filter(subscriptionStatus -> subscriptionStatus.getStatus() == status)
                .collect(Collectors.groupingBy(SubscriptionStatus::getDetails));
    }

    private static Map<String, List<String>> getCmHandlesPerDetails(
            final Map<String, List<SubscriptionStatus>> subscriptionsPerDetails) {
        return subscriptionsPerDetails.entrySet().stream()
                .collect(Collectors.toMap(
                        Map.Entry::getKey,
                        entry -> entry.getValue().stream()
                                .map(SubscriptionStatus::getId)
                                .collect(Collectors.toList())
                ));
    }

    private static List<AdditionalInfoDetail> getAdditionalInfoDetailList(
            final Map<String, List<String>> cmHandlesPerDetails) {
        return cmHandlesPerDetails.entrySet().stream()
                .map(entry -> {
                    final AdditionalInfoDetail detail = new AdditionalInfoDetail();
                    detail.setDetails(entry.getKey());
                    detail.setTargets(entry.getValue());
                    return detail;
                }).collect(Collectors.toList());
    }
}