/*
 *  ============LICENSE_START=======================================================
 *  Copyright (C) 2022-2024 Nordix Foundation
 *  Modifications Copyright (C) 2022 Bell Canada
 *  Modifications Copyright (C) 2023 TechMahindra Ltd.
 *  ================================================================================
 *  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;

import static org.onap.cps.ncmp.api.NcmpResponseStatus.CM_HANDLES_NOT_FOUND;
import static org.onap.cps.ncmp.api.NcmpResponseStatus.CM_HANDLE_INVALID_ID;
import static org.onap.cps.ncmp.api.impl.NetworkCmProxyDataServicePropertyHandler.PropertyType.DMI_PROPERTY;
import static org.onap.cps.ncmp.api.impl.NetworkCmProxyDataServicePropertyHandler.PropertyType.PUBLIC_PROPERTY;
import static org.onap.cps.ncmp.api.impl.ncmppersistence.NcmpPersistence.NCMP_DATASPACE_NAME;
import static org.onap.cps.ncmp.api.impl.ncmppersistence.NcmpPersistence.NCMP_DMI_REGISTRY_ANCHOR;
import static org.onap.cps.ncmp.api.impl.ncmppersistence.NcmpPersistence.NCMP_DMI_REGISTRY_PARENT;

import com.google.common.collect.ImmutableMap;
import java.time.OffsetDateTime;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.onap.cps.api.CpsDataService;
import org.onap.cps.ncmp.api.impl.inventory.InventoryPersistence;
import org.onap.cps.ncmp.api.impl.utils.CmHandleIdMapper;
import org.onap.cps.ncmp.api.impl.utils.YangDataConverter;
import org.onap.cps.ncmp.api.impl.yangmodels.YangModelCmHandle;
import org.onap.cps.ncmp.api.models.CmHandleRegistrationResponse;
import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
import org.onap.cps.spi.exceptions.DataNodeNotFoundException;
import org.onap.cps.spi.exceptions.DataValidationException;
import org.onap.cps.spi.model.DataNode;
import org.onap.cps.spi.model.DataNodeBuilder;
import org.onap.cps.utils.JsonObjectMapper;
import org.springframework.stereotype.Service;

@Slf4j
@Service
@RequiredArgsConstructor
//Accepting the security hotspot as the string checked is generated from inside code and not user input.
@SuppressWarnings("squid:S5852")
public class NetworkCmProxyDataServicePropertyHandler {

    private final InventoryPersistence inventoryPersistence;
    private final CpsDataService cpsDataService;
    private final JsonObjectMapper jsonObjectMapper;
    private final CmHandleIdMapper cmHandleIdMapper;

    /**
     * Iterates over incoming ncmpServiceCmHandles and update the dataNodes based on the updated attributes.
     * The attributes which are not passed will remain as is.
     *
     * @param ncmpServiceCmHandles collection of ncmpServiceCmHandles
     */
    public List<CmHandleRegistrationResponse> updateCmHandleProperties(
        final Collection<NcmpServiceCmHandle> ncmpServiceCmHandles) {
        final List<CmHandleRegistrationResponse> cmHandleRegistrationResponses = new ArrayList<>();
        for (final NcmpServiceCmHandle ncmpServiceCmHandle : ncmpServiceCmHandles) {
            final String cmHandleId = ncmpServiceCmHandle.getCmHandleId();
            try {
                final DataNode existingCmHandleDataNode = inventoryPersistence.getCmHandleDataNode(cmHandleId)
                        .iterator().next();
                updateAlternateId(existingCmHandleDataNode, ncmpServiceCmHandle);
                processUpdates(existingCmHandleDataNode, ncmpServiceCmHandle);
                cmHandleRegistrationResponses.add(CmHandleRegistrationResponse.createSuccessResponse(cmHandleId));
            } catch (final DataNodeNotFoundException e) {
                log.error("Unable to find dataNode for cmHandleId : {} , caused by : {}", cmHandleId, e.getMessage());
                cmHandleRegistrationResponses.add(
                    CmHandleRegistrationResponse.createFailureResponse(cmHandleId, CM_HANDLES_NOT_FOUND));
            } catch (final DataValidationException e) {
                log.error("Unable to update cm handle : {}, caused by : {}", cmHandleId, e.getMessage());
                cmHandleRegistrationResponses.add(
                    CmHandleRegistrationResponse.createFailureResponse(cmHandleId, CM_HANDLE_INVALID_ID));
            } catch (final Exception exception) {
                log.error("Unable to update cmHandle : {} , caused by : {}", cmHandleId, exception.getMessage());
                cmHandleRegistrationResponses.add(
                    CmHandleRegistrationResponse.createFailureResponse(cmHandleId, exception));
            }
        }
        return cmHandleRegistrationResponses;
    }

    private void updateAlternateId(final DataNode existingCmHandleDataNode,
                                   final NcmpServiceCmHandle ncmpServiceCmHandle) {
        final String newAlternateId = ncmpServiceCmHandle.getAlternateId();
        if (cmHandleIdMapper.addMapping(ncmpServiceCmHandle.getCmHandleId(), newAlternateId)) {
            try {
                final YangModelCmHandle yangModelCmHandle =
                        YangDataConverter.convertCmHandleToYangModel(existingCmHandleDataNode,
                                ncmpServiceCmHandle.getCmHandleId());
                setAndUpdateAlternateId(yangModelCmHandle, newAlternateId);
            } catch (final Exception e) {
                cmHandleIdMapper.removeMapping(ncmpServiceCmHandle.getCmHandleId());
                throw e;
            }
        }
    }

    private void processUpdates(final DataNode existingCmHandleDataNode, final NcmpServiceCmHandle incomingCmHandle) {
        if (!incomingCmHandle.getPublicProperties().isEmpty()) {
            updateProperties(existingCmHandleDataNode, PUBLIC_PROPERTY, incomingCmHandle.getPublicProperties());
        }
        if (!incomingCmHandle.getDmiProperties().isEmpty()) {
            updateProperties(existingCmHandleDataNode, DMI_PROPERTY, incomingCmHandle.getDmiProperties());
        }
    }

    private void updateProperties(final DataNode existingCmHandleDataNode, final PropertyType propertyType,
            final Map<String, String> incomingProperties) {
        final Collection<DataNode> replacementPropertyDataNodes =
                getReplacementDataNodes(existingCmHandleDataNode, propertyType, incomingProperties);
        replacementPropertyDataNodes.addAll(
                getUnchangedPropertyDataNodes(existingCmHandleDataNode, propertyType, incomingProperties));
        if (replacementPropertyDataNodes.isEmpty()) {
            removeAllProperties(existingCmHandleDataNode, propertyType);
        } else {
            inventoryPersistence.replaceListContent(existingCmHandleDataNode.getXpath(), replacementPropertyDataNodes);
        }
    }

    private void removeAllProperties(final DataNode existingCmHandleDataNode, final PropertyType propertyType) {
        existingCmHandleDataNode.getChildDataNodes().forEach(dataNode -> {
            final Matcher matcher = propertyType.propertyXpathPattern.matcher(dataNode.getXpath());
            if (matcher.find()) {
                log.info("Deleting dataNode with xpath : [{}]", dataNode.getXpath());
                inventoryPersistence.deleteDataNode(dataNode.getXpath());
            }
        });
    }

    private Collection<DataNode> getUnchangedPropertyDataNodes(final DataNode existingCmHandleDataNode,
            final PropertyType propertyType, final Map<String, String> incomingProperties) {
        final Collection<DataNode> unchangedPropertyDataNodes = new HashSet<>();
        for (final DataNode existingPropertyDataNode : existingCmHandleDataNode.getChildDataNodes()) {
            final Matcher matcher = propertyType.propertyXpathPattern.matcher(existingPropertyDataNode.getXpath());
            if (matcher.find()) {
                final String keyName = matcher.group(2);
                if (!incomingProperties.containsKey(keyName)) {
                    unchangedPropertyDataNodes.add(existingPropertyDataNode);
                }
            }
        }
        return unchangedPropertyDataNodes;
    }

    private Collection<DataNode> getReplacementDataNodes(final DataNode existingCmHandleDataNode,
            final PropertyType propertyType, final Map<String, String> incomingProperties) {
        final Collection<DataNode> replacementPropertyDataNodes = new HashSet<>();
        incomingProperties.forEach((updatedAttributeKey, updatedAttributeValue) -> {
            final String propertyXpath = getAttributeXpath(existingCmHandleDataNode, propertyType, updatedAttributeKey);
            if (updatedAttributeValue != null) {
                log.info("Creating a new DataNode with xpath {} , key : {} and value : {}", propertyXpath,
                        updatedAttributeKey, updatedAttributeValue);
                replacementPropertyDataNodes.add(
                        buildDataNode(propertyXpath, updatedAttributeKey, updatedAttributeValue));
            }
        });
        return replacementPropertyDataNodes;
    }

    private String getAttributeXpath(final DataNode cmHandle, final PropertyType propertyType,
            final String attributeKey) {
        return cmHandle.getXpath() + "/" + propertyType.xpathPrefix + String.format("[@name='%s']", attributeKey);
    }

    private DataNode buildDataNode(final String xpath, final String attributeKey, final String attributeValue) {
        final Map<String, String> updatedLeaves = new LinkedHashMap<>(1);
        updatedLeaves.put("name", attributeKey);
        updatedLeaves.put("value", attributeValue);
        log.debug("Building a new node with xpath {} with leaves (name : {} , value : {})", xpath, attributeKey,
                attributeValue);
        return new DataNodeBuilder().withXpath(xpath).withLeaves(ImmutableMap.copyOf(updatedLeaves)).build();
    }

    private void setAndUpdateAlternateId(final YangModelCmHandle upgradedCmHandle, final String alternateId) {
        final Map<String, Map<String, String>> dmiRegistryProperties = new HashMap<>(1);
        final Map<String, String> cmHandleProperties = new HashMap<>(2);
        cmHandleProperties.put("id", upgradedCmHandle.getId());
        cmHandleProperties.put("alternate-id", alternateId);
        dmiRegistryProperties.put("cm-handles", cmHandleProperties);
        cpsDataService.updateNodeLeaves(NCMP_DATASPACE_NAME, NCMP_DMI_REGISTRY_ANCHOR, NCMP_DMI_REGISTRY_PARENT,
                jsonObjectMapper.asJsonString(dmiRegistryProperties), OffsetDateTime.now());
        log.info("Updating alternateId for cmHandle {} with value : {})", upgradedCmHandle.getId(), alternateId);
    }

    enum PropertyType {
        DMI_PROPERTY("additional-properties"), PUBLIC_PROPERTY("public-properties");

        private static final String LIST_INDEX_PATTERN = "\\[@(\\w+)[^\\/]'([^']+)']";

        final String xpathPrefix;
        final Pattern propertyXpathPattern;

        PropertyType(final String xpathPrefix) {
            this.xpathPrefix = xpathPrefix;
            this.propertyXpathPattern = Pattern.compile(xpathPrefix + LIST_INDEX_PATTERN);
        }
    }
}