/*-
 * ============LICENSE_START=======================================================
 * VID
 * ================================================================================
 * Copyright (C) 2017 - 2020 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.services;

import static java.util.Collections.emptyMap;
import static java.util.stream.Collectors.toSet;
import static org.apache.commons.lang3.StringUtils.isAllEmpty;
import static org.onap.vid.utils.KotlinUtilsKt.JACKSON_OBJECT_MAPPER;

import com.fasterxml.jackson.databind.JsonNode;
import com.google.common.collect.ImmutableList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Predicate;
import javax.inject.Inject;
import javax.ws.rs.core.Response;
import org.onap.portalsdk.core.logging.logic.EELFLoggerDelegate;
import org.onap.vid.aai.AaiClientInterface;
import org.onap.vid.aai.model.ModelVer;
import org.onap.vid.asdc.parser.ServiceModelInflator;
import org.onap.vid.asdc.parser.ServiceModelInflator.Names;
import org.onap.vid.model.ServiceModel;
import org.onap.vid.model.aaiTree.AAITreeNode;
import org.onap.vid.model.aaiTree.NodeType;
import org.onap.vid.properties.Features;
import org.springframework.stereotype.Component;
import org.togglz.core.manager.FeatureManager;

@Component
public class AAITreeNodesEnricher {

    private final AaiClientInterface aaiClient;

    private final VidService sdcService;

    private final ServiceModelInflator serviceModelInflator;

    private final FeatureManager featureManager;

    private static final EELFLoggerDelegate LOGGER = EELFLoggerDelegate.getLogger(AAITreeNodesEnricher.class);

    @Inject
    public AAITreeNodesEnricher(
        AaiClientInterface aaiClient,
        VidService sdcService,
        FeatureManager featureManager,
        ServiceModelInflator serviceModelInflator
    ) {
        this.aaiClient = aaiClient;
        this.sdcService = sdcService;
        this.featureManager = featureManager;
        this.serviceModelInflator = serviceModelInflator;
    }

    void enrichNodesWithModelCustomizationName(Collection<AAITreeNode> nodes, ServiceModel serviceModel) {
        final Map<String, Names> customizationNameByVersionId = serviceModelInflator.toNamesByVersionId(serviceModel);

        nodes.forEach(node -> {
            final Names names = customizationNameByVersionId.get(node.getModelVersionId());
            if (names != null) {
                node.setKeyInModel(names.getModelKey());
                node.setModelCustomizationName(names.getModelCustomizationName());
            }
        });
    }

    void enrichVfModulesWithModelCustomizationNameFromOtherVersions(Collection<AAITreeNode> nodes, String modelInvariantId) {
        if (!featureManager.isActive(Features.FLAG_EXP_TOPOLOGY_TREE_VFMODULE_NAMES_FROM_OTHER_TOSCA_VERSIONS)) {
            return;
        }

        if (nodes.stream().noneMatch(vfModuleWithMissingData())) {
            return;
        }

        final List<ModelVer> allModelVersions = aaiClient.getSortedVersionsByInvariantId(modelInvariantId);

        final ListIterator<ModelVer> modelVersionsIterator = allModelVersions.listIterator();
        final Map<String, Names> namesByCustomizationId = new HashMap<>();

        nodes.stream().filter(vfModuleWithMissingData()).forEach(node -> {
            String modelCustomizationId = node.getModelCustomizationId();

            fetchCustomizationIdsFromToscaModelsWhileNeeded(namesByCustomizationId, modelVersionsIterator, modelCustomizationId);

            final Names names = namesByCustomizationId.get(modelCustomizationId);
            if (names != null) {
                node.setKeyInModel(names.getModelKey());
                node.setModelCustomizationName(names.getModelCustomizationName());
            }
        });
    }

    private Predicate<AAITreeNode> vfModuleWithMissingData() {
        final Predicate<AAITreeNode> isVfModule = node -> node.getType() == NodeType.VF_MODULE;

        final Predicate<AAITreeNode> nodeWithMissingData =
            node -> isAllEmpty(node.getKeyInModel(), node.getModelCustomizationName());

        return isVfModule.and(nodeWithMissingData);
    }

    /**
     * Loads inOutMutableNamesByCustomizationId with all customization IDs from the list of modelVersions. Will seize loading
     * if yieldCustomizationId presents in inOutMutableNamesByCustomizationId.
     * @param inOutMutableNamesByCustomizationId Mutable Map to fill-up
     * @param modelVersions Iterable of model-version-ids to load
     * @param yieldCustomizationId The key to stop loading on
     */
    void fetchCustomizationIdsFromToscaModelsWhileNeeded(
        Map<String, Names> inOutMutableNamesByCustomizationId,
        ListIterator<ModelVer> modelVersions,
        String yieldCustomizationId
    ) {
        while (modelVersions.hasNext() && !inOutMutableNamesByCustomizationId.containsKey(yieldCustomizationId)) {
            inOutMutableNamesByCustomizationId.putAll(
                fetchAllCustomizationIds(modelVersions.next().getModelVersionId())
            );
        }
    }

    private Map<String, Names> fetchAllCustomizationIds(String modelVersionId) {
        try {
            ServiceModel serviceModel = sdcService.getServiceModelOrThrow(modelVersionId);
            return serviceModelInflator.toNamesByCustomizationId(serviceModel);
        } catch (Exception e) {
            // Ignore the failure: SDC may lack the historic model, but this is NOT a reason to fail the whole enrichment
            LOGGER.debug(EELFLoggerDelegate.debugLogger,
                "Could not get model customization ids from SCD where modelVersionId={}", modelVersionId, e);
            return emptyMap();
        }
    }

    public void enrichNodesWithModelVersionAndModelName(Collection<AAITreeNode> nodes) {

        Collection<String> invariantIDs = getModelInvariantIds(nodes);

        Map<String, String> modelVersionByModelVersionId = new HashMap<>();
        Map<String, String> modelNameByModelVersionId = new HashMap<>();

        JsonNode models = getModels(aaiClient, invariantIDs);
        if (models!=null) {
            for (JsonNode model : models) {
                JsonNode modelVersions = model.get("model-vers").get("model-ver");
                for (JsonNode modelVersion : modelVersions) {
                    final String modelVersionId = modelVersion.get("model-version-id").asText();
                    modelVersionByModelVersionId.put(modelVersionId, modelVersion.get("model-version").asText());
                    modelNameByModelVersionId.put(modelVersionId, modelVersion.get("model-name").asText());
                }
            }
        }

        nodes.forEach(node -> {
            node.setModelVersion(modelVersionByModelVersionId.get(node.getModelVersionId()));
            node.setModelName(modelNameByModelVersionId.get(node.getModelVersionId()));
        });

    }

    private JsonNode getModels(AaiClientInterface aaiClient, Collection<String> invariantIDs) {
        Response response = aaiClient.getVersionByInvariantId(ImmutableList.copyOf(invariantIDs));
        try {
            JsonNode responseJson = JACKSON_OBJECT_MAPPER.readTree(response.readEntity(String.class));
            return responseJson.get("model");
        } catch (Exception e) {
            LOGGER.error(EELFLoggerDelegate.errorLogger, "Failed to getVersionByInvariantId from A&AI", e);
        }
        return JACKSON_OBJECT_MAPPER.createObjectNode();
    }

    private Set<String> getModelInvariantIds(Collection<AAITreeNode> nodes) {
        return nodes.stream()
                .map(AAITreeNode::getModelInvariantId)
                .filter(Objects::nonNull)
                .collect(toSet());
    }

}