/*
 *  ============LICENSE_START=======================================================
 *  Copyright (C) 2021-2024 Nordix Foundation
 *  Modifications Copyright (C) 2020-2022 Bell Canada.
 *  Modifications Copyright (C) 2021 Pantheon.tech
 *  Modifications Copyright (C) 2022-2024 TechMahindra Ltd.
 *  Modifications Copyright (C) 2022 Deutsche Telekom AG
 *  ================================================================================
 *  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.api.impl;

import io.micrometer.core.annotation.Timed;
import java.io.Serializable;
import java.time.OffsetDateTime;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.onap.cps.api.CpsAnchorService;
import org.onap.cps.api.CpsDataService;
import org.onap.cps.api.CpsDeltaService;
import org.onap.cps.cpspath.parser.CpsPathUtil;
import org.onap.cps.events.CpsDataUpdateEventsService;
import org.onap.cps.events.model.Data.Operation;
import org.onap.cps.spi.CpsDataPersistenceService;
import org.onap.cps.spi.FetchDescendantsOption;
import org.onap.cps.spi.exceptions.DataValidationException;
import org.onap.cps.spi.model.Anchor;
import org.onap.cps.spi.model.DataNode;
import org.onap.cps.spi.model.DataNodeBuilder;
import org.onap.cps.spi.model.DeltaReport;
import org.onap.cps.spi.utils.CpsValidator;
import org.onap.cps.utils.ContentType;
import org.onap.cps.utils.YangParser;
import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
import org.springframework.stereotype.Service;

@Service
@Slf4j
@RequiredArgsConstructor
public class CpsDataServiceImpl implements CpsDataService {

    private static final String ROOT_NODE_XPATH = "/";
    private static final long DEFAULT_LOCK_TIMEOUT_IN_MILLISECONDS = 300L;

    private final CpsDataPersistenceService cpsDataPersistenceService;
    private final CpsDataUpdateEventsService cpsDataUpdateEventsService;
    private final CpsAnchorService cpsAnchorService;

    private final CpsValidator cpsValidator;
    private final YangParser yangParser;
    private final CpsDeltaService cpsDeltaService;

    @Override
    public void saveData(final String dataspaceName, final String anchorName, final String nodeData,
        final OffsetDateTime observedTimestamp) {
        saveData(dataspaceName, anchorName, nodeData, observedTimestamp, ContentType.JSON);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.root.save",
        description = "Time taken to save a root data node")
    public void saveData(final String dataspaceName, final String anchorName, final String nodeData,
                         final OffsetDateTime observedTimestamp, final ContentType contentType) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodes = buildDataNodes(anchor, ROOT_NODE_XPATH, nodeData, contentType);
        cpsDataPersistenceService.storeDataNodes(dataspaceName, anchorName, dataNodes);
        sendDataUpdatedEvent(anchor, ROOT_NODE_XPATH, Operation.CREATE, observedTimestamp);
    }

    @Override
    public void saveData(final String dataspaceName, final String anchorName, final String parentNodeXpath,
                         final String nodeData, final OffsetDateTime observedTimestamp) {
        saveData(dataspaceName, anchorName, parentNodeXpath, nodeData, observedTimestamp, ContentType.JSON);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.child.save",
        description = "Time taken to save a child data node")
    public void saveData(final String dataspaceName, final String anchorName, final String parentNodeXpath,
                         final String nodeData, final OffsetDateTime observedTimestamp,
                         final ContentType contentType) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodes = buildDataNodes(anchor, parentNodeXpath, nodeData, contentType);
        cpsDataPersistenceService.addChildDataNodes(dataspaceName, anchorName, parentNodeXpath, dataNodes);
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.CREATE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.list.element.save",
        description = "Time taken to save list elements")
    public void saveListElements(final String dataspaceName, final String anchorName, final String parentNodeXpath,
                                 final String jsonData, final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> listElementDataNodeCollection =
            buildDataNodes(anchor, parentNodeXpath, jsonData, ContentType.JSON);
        if (isRootNodeXpath(parentNodeXpath)) {
            cpsDataPersistenceService.storeDataNodes(dataspaceName, anchorName, listElementDataNodeCollection);
        } else {
            cpsDataPersistenceService.addListElements(dataspaceName, anchorName, parentNodeXpath,
                                                      listElementDataNodeCollection);
        }
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.UPDATE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.get",
            description = "Time taken to get data nodes for an xpath")
    public Collection<DataNode> getDataNodes(final String dataspaceName, final String anchorName,
                                             final String xpath,
                                             final FetchDescendantsOption fetchDescendantsOption) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        return cpsDataPersistenceService.getDataNodes(dataspaceName, anchorName, xpath, fetchDescendantsOption);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.batch.get",
        description = "Time taken to get a batch of data nodes")
    public Collection<DataNode> getDataNodesForMultipleXpaths(final String dataspaceName, final String anchorName,
                                                              final Collection<String> xpaths,
                                                              final FetchDescendantsOption fetchDescendantsOption) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        return cpsDataPersistenceService.getDataNodesForMultipleXpaths(dataspaceName, anchorName, xpaths,
                fetchDescendantsOption);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.leaves.update",
        description = "Time taken to update a batch of leaf data nodes")
    public void updateNodeLeaves(final String dataspaceName, final String anchorName, final String parentNodeXpath,
        final String jsonData, final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodesInPatch = buildDataNodes(anchor, parentNodeXpath, jsonData,
                ContentType.JSON);
        final Map<String, Map<String, Serializable>> xpathToUpdatedLeaves = dataNodesInPatch.stream()
                .collect(Collectors.toMap(DataNode::getXpath, DataNode::getLeaves));
        cpsDataPersistenceService.batchUpdateDataLeaves(dataspaceName, anchorName, xpathToUpdatedLeaves);
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.UPDATE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.leaves.descendants.leaves.update",
        description = "Time taken to update data node leaves and existing descendants leaves")
    public void updateNodeLeavesAndExistingDescendantLeaves(final String dataspaceName, final String anchorName,
        final String parentNodeXpath,
        final String dataNodeUpdatesAsJson,
        final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodeUpdates =
            buildDataNodes(anchor, parentNodeXpath, dataNodeUpdatesAsJson, ContentType.JSON);
        for (final DataNode dataNodeUpdate : dataNodeUpdates) {
            processDataNodeUpdate(anchor, dataNodeUpdate);
        }
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.UPDATE, observedTimestamp);
    }

    @Override
    public String startSession() {
        return cpsDataPersistenceService.startSession();
    }

    @Override
    public void closeSession(final String sessionId) {
        cpsDataPersistenceService.closeSession(sessionId);
    }

    @Override
    public void lockAnchor(final String sessionID, final String dataspaceName, final String anchorName) {
        lockAnchor(sessionID, dataspaceName, anchorName, DEFAULT_LOCK_TIMEOUT_IN_MILLISECONDS);
    }

    @Override
    public void lockAnchor(final String sessionID, final String dataspaceName,
                           final String anchorName, final Long timeoutInMilliseconds) {
        cpsDataPersistenceService.lockAnchor(sessionID, dataspaceName, anchorName, timeoutInMilliseconds);
    }

    @Override
    @Timed(value = "cps.data.service.get.delta",
            description = "Time taken to get delta between anchors")
    public List<DeltaReport> getDeltaByDataspaceAndAnchors(final String dataspaceName,
                                                           final String sourceAnchorName,
                                                           final String targetAnchorName, final String xpath,
                                                           final FetchDescendantsOption fetchDescendantsOption) {

        final Collection<DataNode> sourceDataNodes = getDataNodesForMultipleXpaths(dataspaceName,
                sourceAnchorName, Collections.singletonList(xpath), fetchDescendantsOption);
        final Collection<DataNode> targetDataNodes = getDataNodesForMultipleXpaths(dataspaceName,
                targetAnchorName, Collections.singletonList(xpath), fetchDescendantsOption);

        return cpsDeltaService.getDeltaReports(sourceDataNodes, targetDataNodes);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.descendants.update",
        description = "Time taken to update a data node and descendants")
    public void updateDataNodeAndDescendants(final String dataspaceName, final String anchorName,
                                             final String parentNodeXpath, final String jsonData,
                                             final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodes = buildDataNodes(anchor, parentNodeXpath, jsonData, ContentType.JSON);
        cpsDataPersistenceService.updateDataNodesAndDescendants(dataspaceName, anchorName, dataNodes);
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.UPDATE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.descendants.batch.update",
        description = "Time taken to update a batch of data nodes and descendants")
    public void updateDataNodesAndDescendants(final String dataspaceName, final String anchorName,
                                              final Map<String, String> nodesJsonData,
                                              final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> dataNodes = buildDataNodes(anchor, nodesJsonData);
        cpsDataPersistenceService.updateDataNodesAndDescendants(dataspaceName, anchorName, dataNodes);
        nodesJsonData.keySet().forEach(nodeXpath ->
                sendDataUpdatedEvent(anchor, nodeXpath, Operation.UPDATE, observedTimestamp));
    }

    @Override
    @Timed(value = "cps.data.service.list.update",
        description = "Time taken to update a list")
    public void replaceListContent(final String dataspaceName, final String anchorName, final String parentNodeXpath,
            final String jsonData, final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        final Collection<DataNode> newListElements =
            buildDataNodes(anchor, parentNodeXpath, jsonData, ContentType.JSON);
        replaceListContent(dataspaceName, anchorName, parentNodeXpath, newListElements, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.list.batch.update",
        description = "Time taken to update a batch of lists")
    public void replaceListContent(final String dataspaceName, final String anchorName, final String parentNodeXpath,
            final Collection<DataNode> dataNodes, final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        cpsDataPersistenceService.replaceListContent(dataspaceName, anchorName, parentNodeXpath, dataNodes);
        sendDataUpdatedEvent(anchor, parentNodeXpath, Operation.UPDATE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.delete",
        description = "Time taken to delete a datanode")
    public void deleteDataNode(final String dataspaceName, final String anchorName, final String dataNodeXpath,
                               final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        cpsDataPersistenceService.deleteDataNode(dataspaceName, anchorName, dataNodeXpath);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        sendDataUpdatedEvent(anchor, dataNodeXpath, Operation.DELETE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.batch.delete",
        description = "Time taken to delete a batch of datanodes")
    public void deleteDataNodes(final String dataspaceName, final String anchorName,
                                final Collection<String> dataNodeXpaths, final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        cpsDataPersistenceService.deleteDataNodes(dataspaceName, anchorName, dataNodeXpaths);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        dataNodeXpaths.forEach(dataNodeXpath ->
                sendDataUpdatedEvent(anchor, dataNodeXpath, Operation.DELETE, observedTimestamp));
    }


    @Override
    @Timed(value = "cps.data.service.datanode.delete.anchor",
        description = "Time taken to delete all datanodes for an anchor")
    public void deleteDataNodes(final String dataspaceName, final String anchorName,
                                final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        cpsDataPersistenceService.deleteDataNodes(dataspaceName, anchorName);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        sendDataUpdatedEvent(anchor, ROOT_NODE_XPATH, Operation.DELETE, observedTimestamp);
    }

    @Override
    @Timed(value = "cps.data.service.datanode.delete.anchor.batch",
        description = "Time taken to delete all datanodes for multiple anchors")
    public void deleteDataNodes(final String dataspaceName, final Collection<String> anchorNames,
                                final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName);
        cpsValidator.validateNameCharacters(anchorNames);
        cpsDataPersistenceService.deleteDataNodes(dataspaceName, anchorNames);
        for (final Anchor anchor : cpsAnchorService.getAnchors(dataspaceName, anchorNames)) {
            sendDataUpdatedEvent(anchor, ROOT_NODE_XPATH, Operation.DELETE, observedTimestamp);
        }
    }

    @Override
    @Timed(value = "cps.data.service.list.delete",
        description = "Time taken to delete a list or list element")
    public void deleteListOrListElement(final String dataspaceName, final String anchorName, final String listNodeXpath,
        final OffsetDateTime observedTimestamp) {
        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
        cpsDataPersistenceService.deleteListDataNode(dataspaceName, anchorName, listNodeXpath);
        final Anchor anchor = cpsAnchorService.getAnchor(dataspaceName, anchorName);
        sendDataUpdatedEvent(anchor, listNodeXpath, Operation.DELETE, observedTimestamp);
    }

    private Collection<DataNode> buildDataNodes(final Anchor anchor, final Map<String, String> nodesJsonData) {
        final Collection<DataNode> dataNodes = new ArrayList<>();
        for (final Map.Entry<String, String> nodeJsonData : nodesJsonData.entrySet()) {
            dataNodes.addAll(buildDataNodes(anchor, nodeJsonData.getKey(), nodeJsonData.getValue(), ContentType.JSON));
        }
        return dataNodes;
    }

    private Collection<DataNode> buildDataNodes(final Anchor anchor, final String parentNodeXpath,
                                                final String nodeData, final ContentType contentType) {

        if (ROOT_NODE_XPATH.equals(parentNodeXpath)) {
            final ContainerNode containerNode = yangParser.parseData(contentType, nodeData, anchor, "");
            final Collection<DataNode> dataNodes = new DataNodeBuilder()
                    .withContainerNode(containerNode)
                    .buildCollection();
            if (dataNodes.isEmpty()) {
                throw new DataValidationException("No data nodes.", "No data nodes provided");
            }
            return dataNodes;
        }
        final String normalizedParentNodeXpath = CpsPathUtil.getNormalizedXpath(parentNodeXpath);
        final ContainerNode containerNode =
            yangParser.parseData(contentType, nodeData, anchor, normalizedParentNodeXpath);
        final Collection<DataNode> dataNodes = new DataNodeBuilder()
            .withParentNodeXpath(normalizedParentNodeXpath)
            .withContainerNode(containerNode)
            .buildCollection();
        if (dataNodes.isEmpty()) {
            throw new DataValidationException("No data nodes.", "No data nodes provided");
        }
        return dataNodes;
    }


    private static boolean isRootNodeXpath(final String xpath) {
        return ROOT_NODE_XPATH.equals(xpath);
    }

    private void processDataNodeUpdate(final Anchor anchor, final DataNode dataNodeUpdate) {
        cpsDataPersistenceService.batchUpdateDataLeaves(anchor.getDataspaceName(), anchor.getName(),
                Collections.singletonMap(dataNodeUpdate.getXpath(), dataNodeUpdate.getLeaves()));
        final Collection<DataNode> childDataNodeUpdates = dataNodeUpdate.getChildDataNodes();
        for (final DataNode childDataNodeUpdate : childDataNodeUpdates) {
            processDataNodeUpdate(anchor, childDataNodeUpdate);
        }
    }

    private void sendDataUpdatedEvent(final Anchor anchor, final String xpath,
                                      final Operation operation, final OffsetDateTime observedTimestamp) {
        try {
            cpsDataUpdateEventsService.publishCpsDataUpdateEvent(anchor, xpath, operation, observedTimestamp);
        } catch (final Exception exception) {
            log.error("Failed to send message to notification service", exception);
        }
    }
}