/*
 * Copyright © 2017 AT&T and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.transportpce.olm.util;

import com.google.common.base.Strings;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
import org.opendaylight.transportpce.common.Timeouts;
import org.opendaylight.transportpce.common.device.DeviceTransactionManager;
import org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.GetPmInput;
import org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.GetPmOutputBuilder;
import org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.get.pm.output.MeasurementsBuilder;
import org.opendaylight.yang.gen.v1.http.org.openroadm.pm.rev161014.CurrentPmlist;
import org.opendaylight.yang.gen.v1.http.org.openroadm.pm.rev161014.current.pm.Measurements;
import org.opendaylight.yang.gen.v1.http.org.openroadm.pm.rev161014.currentpmlist.CurrentPm;
import org.opendaylight.yang.gen.v1.http.org.openroadm.pm.types.rev161014.PmGranularity;
import org.opendaylight.yang.gen.v1.http.org.openroadm.pm.types.rev161014.PmNamesEnum;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.Resource;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.CircuitPack;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Connection;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Degree;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Interface;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.InternalLink;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.PhysicalLink;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Port;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Service;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Shelf;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.rev161014.resource.resource.resource.Srg;
import org.opendaylight.yang.gen.v1.http.org.openroadm.resource.types.rev161014.ResourceTypeEnum;
import org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.olm.get.pm.input.ResourceIdentifier;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

final class OlmUtils121 {

    private static final Logger LOG = LoggerFactory.getLogger(OlmUtils121.class);

    /**
     * This method retrieves list of current PMs for given nodeId,
     * resourceType, resourceName and Granularity.Currently vendorExtentions
     * are excluded but can be added back based on requirement
     *
     * <p>
     * 1. pmFetch This operation traverse through current PM list and gets PM for
     * given NodeId and Resource name
     *
     * @param input
     *            Input parameter from the olm yang model get-pm rpc
     * @param deviceTransactionManager
     *            Device tx manager
     *
     * @return Result of the request list of PM readings
     */
    public static GetPmOutputBuilder pmFetch(GetPmInput input, DeviceTransactionManager deviceTransactionManager) {
        LOG.info("Getting PM Data for 1.2.1 NodeId: {} ResourceType: {} ResourceName: {}", input.getNodeId(),
                input.getResourceType(), input.getResourceIdentifier());
        GetPmOutputBuilder pmOutputBuilder = new GetPmOutputBuilder();
        InstanceIdentifier<CurrentPmlist> currentPmsIID = InstanceIdentifier.create(CurrentPmlist.class);
        Optional<CurrentPmlist> currentPmList;
        currentPmList = deviceTransactionManager
                .getDataFromDevice(input.getNodeId(), LogicalDatastoreType.OPERATIONAL, currentPmsIID,
                        Timeouts.DEVICE_READ_TIMEOUT, Timeouts.DEVICE_READ_TIMEOUT_UNIT);
        if (currentPmList.isPresent()) {
            String pmExtension = null;
            org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Location location = null;
            org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Direction direction = null;
            if (input.getPmExtension() != null) {
                pmExtension = input.getPmExtension();
            }
            if (input.getLocation() != null) {
                location = input.getLocation();
            }
            if (input.getDirection() != null) {
                direction = input.getDirection();
            }
            //PmNamesEnum pmName = null;
            List<org.opendaylight.yang.gen.v1.http
                    .org.opendaylight.transportpce.olm.rev210618.get.pm.output.Measurements> measurements =
                extractWantedMeasurements(currentPmList.orElseThrow(),
                    ResourceTypeEnum.forValue(input.getResourceType().getIntValue()),
                    input.getResourceIdentifier(),
                    PmGranularity.forValue(input.getGranularity().getIntValue()),
                    //pmName
                    null,
                    pmExtension,
                    location,
                    direction);
            if (measurements.isEmpty()) {
                LOG.error("No Matching PM data found for node: {}, resource type: {}, resource name: {}",
                        input.getNodeId(), input.getResourceType(),
                        getResourceIdentifierAsString(input.getResourceIdentifier()));
            } else {
                pmOutputBuilder.setNodeId(input.getNodeId()).setResourceType(input.getResourceType())
                        .setResourceIdentifier(input.getResourceIdentifier()).setGranularity(input.getGranularity())
                        .setMeasurements(measurements);
                LOG.info("PM Data found successfully for node: {}, resource type: {}, resource name {}",
                        input.getNodeId(), input.getResourceType(),
                        getResourceIdentifierAsString(input.getResourceIdentifier()));
            }

        } else {
            LOG.info("Device PM Data for node: {} is not available", input.getNodeId());
        }

        return pmOutputBuilder;
    }

    private static String getResourceIdentifierAsString(ResourceIdentifier resourceIdentifier) {
        if (Strings.isNullOrEmpty(resourceIdentifier.getCircuitPackName())) {
            return resourceIdentifier.getResourceName();
        } else {
            return resourceIdentifier.getResourceName() + ", circuit pack name: "
                    + resourceIdentifier.getCircuitPackName();
        }
    }

    private static
        List<org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.get.pm.output.Measurements>
            extractWantedMeasurements(CurrentPmlist currentPmList, ResourceTypeEnum resourceTypeEnum,
            ResourceIdentifier wantedResourceIdentifier,PmGranularity pmGranularity, PmNamesEnum pmNamesEnum,
            String extension, org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Location
            location, org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Direction direction) {
        List<org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.get.pm.output.Measurements>
            measurements = new ArrayList<>();
        for (CurrentPm pm : currentPmList.nonnullCurrentPm().values()) {
            ResourceTypeEnum currentResourceType = pm.getResource().getResourceType().getType();
            if (currentResourceType.equals(resourceTypeEnum)) {
                Resource currentResource = pm.getResource().getResource().getResource();
                PmGranularity currentGranularity = pm.getGranularity();
                boolean isWantedPowerMeasure = isWantedPowerMeasure(currentResource, currentGranularity,
                        resourceTypeEnum, wantedResourceIdentifier, pmGranularity);
                if (isWantedPowerMeasure) {
                    measurements.addAll(extractMeasurements(pm.getMeasurements(),pmNamesEnum,
                            extension,location,direction));
                }
            }
        }
        return measurements;
    }

    private static
         List<org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.get.pm.output.Measurements>
            extractMeasurements(List<Measurements> measurementsFromDevice, PmNamesEnum pmNamesEnum, String extension,
            org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Location location,
            org.opendaylight.yang.gen.v1.http.org.transportpce.common.types.rev220926.Direction direction) {
        List<org.opendaylight.yang.gen.v1.http.org.opendaylight.transportpce.olm.rev210618.get.pm.output.Measurements>
            extractedMeasurements = new ArrayList<>();
        List<Measurements> pmMeasurements = measurementsFromDevice;
        Stream<Measurements> measurementStream = pmMeasurements.stream();
        if (pmNamesEnum != null) {
            LOG.info("pm name is not null {} {} {}",pmNamesEnum,pmNamesEnum.getName(),pmMeasurements.get(0)
                .getMeasurement().getPmParameterName().getType());
            measurementStream = measurementStream.filter(measure -> measure.getMeasurement().getPmParameterName()
                .getType().getName().equals(pmNamesEnum.getName()));
        }
        if (extension != null) {
            LOG.info("extension is not null {}",extension);
            measurementStream = measurementStream.filter(measure -> measure.getMeasurement()
                    .getPmParameterName().getType().toString().equals("vendorExtension")
                    && measure.getMeasurement().getPmParameterName().getExtension().equals(extension));
        }
        if (location != null) {
            LOG.info("location is not null {}",location);
            measurementStream = measurementStream.filter(measure -> measure.getMeasurement().getLocation().getName()
                .equals(location.getName()));
        }
        if (direction != null) {
            LOG.info("direction is not null {}",direction);
            measurementStream = measurementStream.filter(measure -> measure.getMeasurement().getDirection().getName()
                .equals(direction.getName()));
        }
        List<Measurements> filteredMeasurements = measurementStream.collect(Collectors.toList());
        for (Measurements measure : filteredMeasurements) {
            MeasurementsBuilder measurement = new MeasurementsBuilder();
            measurement.setPmparameterName(measure.getMeasurement().getPmParameterName().getType().toString());
            if (measure.getMeasurement().getPmParameterValue().getDecimal64() != null) {
                measurement.setPmparameterValue(measure.getMeasurement().getPmParameterValue().getDecimal64()
                    .toString());
            } else if (measure.getMeasurement().getPmParameterValue().getUint64() != null) {
                measurement.setPmparameterValue(measure.getMeasurement().getPmParameterValue().getUint64().toString());
            }
            extractedMeasurements.add(measurement.build());
        }
        return extractedMeasurements;
    }

    private static boolean isWantedPowerMeasure(Resource resource, PmGranularity granularity,
            ResourceTypeEnum resourceTypeEnum, ResourceIdentifier wantedResourceIdentifier,
            PmGranularity pmGranularity) {
        boolean identifiersAreEqual = compareResourceIdentifiers(resource, resourceTypeEnum,
                wantedResourceIdentifier);
        return identifiersAreEqual && granularity != null && granularity.equals(pmGranularity);
    }

    private static boolean compareResourceIdentifiers(Resource resource, ResourceTypeEnum resourceTypeEnum,
            ResourceIdentifier wantedResourceIdentifier) {
        switch (resourceTypeEnum) {
            case CircuitPack:
                Optional<CircuitPack> circuitPackOptional = tryCastToParticularResource(CircuitPack.class, resource);
                return circuitPackOptional.flatMap(
                    circuitPack -> Optional.ofNullable(circuitPack.getCircuitPackName()))
                        .map(circuitPackName -> circuitPackName.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case Connection:
                Optional<Connection> connectionOptional = tryCastToParticularResource(Connection.class, resource);
                return connectionOptional.flatMap(
                    connection -> Optional.ofNullable(connection.getConnectionNumber()))
                        .map(connectionNumber -> connectionNumber.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case Degree:
                Optional<Degree> degreeOptional = tryCastToParticularResource(Degree.class, resource);
                return degreeOptional.flatMap(
                    degree -> Optional.ofNullable(degree.getDegreeNumber()))
                        .flatMap(degreeInteger -> Optional.of(degreeInteger.toString()))
                        .map(degreeNumberAsString ->
                                degreeNumberAsString.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case Interface:
                Optional<Interface> interfaceOptional = tryCastToParticularResource(Interface.class, resource);
                return interfaceOptional.flatMap(
                    interfaceResource -> Optional.ofNullable(interfaceResource.getInterfaceName()))
                        .map(interfaceName -> interfaceName.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case InternalLink:
                Optional<InternalLink> internalLinkOptional = tryCastToParticularResource(InternalLink.class, resource);
                return internalLinkOptional.flatMap(
                    internalLink -> Optional.ofNullable(internalLink.getInternalLinkName()))
                        .map(internalLinkName -> internalLinkName.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case PhysicalLink:
                Optional<PhysicalLink> physicalLinkOptional = tryCastToParticularResource(PhysicalLink.class, resource);
                return physicalLinkOptional.flatMap(
                    physicalLink -> Optional.ofNullable(physicalLink.getPhysicalLinkName()))
                        .map(physicalLinkName -> physicalLinkName.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case Service:
                Optional<Service> serviceOptional = tryCastToParticularResource(Service.class, resource);
                return serviceOptional.flatMap(
                    service -> Optional.ofNullable(service.getServiceName()))
                        .map(serviceName -> serviceName.equals(wantedResourceIdentifier.getResourceName()))
                    .orElse(false);
            case Shelf:
                Optional<Shelf> shelfOptional = tryCastToParticularResource(Shelf.class, resource);
                return shelfOptional.flatMap(
                    shelf -> Optional.ofNullable(shelf.getShelfName()))
                        .map(shelfName -> shelfName.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case SharedRiskGroup:
                Optional<Srg> sharedRiskGroupOptional = tryCastToParticularResource(Srg.class, resource);
                return sharedRiskGroupOptional.flatMap(
                    sharedRiskGroup -> Optional.ofNullable(sharedRiskGroup.getSrgNumber()))
                        .flatMap(sharedRiskGroupNumberInteger -> Optional.of(sharedRiskGroupNumberInteger.toString()))
                        .map(srgNumberAsString -> srgNumberAsString.equals(wantedResourceIdentifier.getResourceName()))
                        .orElse(false);
            case Port:
                Optional<Port> portContainerOptional = tryCastToParticularResource(Port.class, resource);
                return portContainerOptional.flatMap(
                    portContainer -> Optional.ofNullable(portContainer.getPort()))
                        .map(port -> {
                            String portName = port.getPortName();
                            String circuitPackName = port.getCircuitPackName();
                            return portName != null && circuitPackName != null
                                    && portName.equals(wantedResourceIdentifier.getResourceName())
                                    && circuitPackName.equals(wantedResourceIdentifier.getCircuitPackName());
                        })
                        .orElse(false);
            default:
                LOG.warn("Unknown resource type {}", resourceTypeEnum);
                return false;
        }
    }

    @SuppressWarnings("unchecked")
    public static <T extends Resource> Optional<T> tryCastToParticularResource(Class<T> resourceClass,
            Resource resource) {
        if (resource == null) {
            LOG.warn("Resource is null.");
        } else if (! resourceClass.isInstance(resource)) {
            LOG.warn("Resource implement different type than expected. Expected {}, actual {}.",
                    resourceClass.getSimpleName(), resource.getClass().getSimpleName());
        } else {
            return Optional.of((T) resource);
        }
        return Optional.empty();
    }

    private OlmUtils121() {
    }

}