// Copyright 2019 NetApp, Inc. All Rights Reserved.
package ontap

import (
	"errors"
	"fmt"
	"math"
	"strconv"
	"strings"

	"github.com/RoaringBitmap/roaring"
	log "github.com/sirupsen/logrus"

	tridentconfig "github.com/netapp/trident/config"
	"github.com/netapp/trident/storage"
	sa "github.com/netapp/trident/storage_attribute"
	drivers "github.com/netapp/trident/storage_drivers"
	"github.com/netapp/trident/storage_drivers/ontap/api"
	"github.com/netapp/trident/storage_drivers/ontap/api/azgo"
	"github.com/netapp/trident/utils"
)

// NASFlexGroupStorageDriver is for NFS FlexGroup storage provisioning
type NASFlexGroupStorageDriver struct {
	initialized bool
	Config      drivers.OntapStorageDriverConfig
	API         *api.Client
	Telemetry   *Telemetry
}

func (d *NASFlexGroupStorageDriver) GetConfig() *drivers.OntapStorageDriverConfig {
	return &d.Config
}

func (d *NASFlexGroupStorageDriver) GetAPI() *api.Client {
	return d.API
}

func (d *NASFlexGroupStorageDriver) GetTelemetry() *Telemetry {
	d.Telemetry.Telemetry = tridentconfig.OrchestratorTelemetry
	return d.Telemetry
}

// Name is for returning the name of this driver
func (d *NASFlexGroupStorageDriver) Name() string {
	return drivers.OntapNASFlexGroupStorageDriverName
}

// Initialize from the provided config
func (d *NASFlexGroupStorageDriver) Initialize(
	context tridentconfig.DriverContext, configJSON string, commonConfig *drivers.CommonStorageDriverConfig,
) error {

	if commonConfig.DebugTraceFlags["method"] {
		fields := log.Fields{"Method": "Initialize", "Type": "NASFlexGroupStorageDriver"}
		log.WithFields(fields).Debug(">>>> Initialize")
		defer log.WithFields(fields).Debug("<<<< Initialize")
	}

	// Parse the config
	config, err := InitializeOntapConfig(context, configJSON, commonConfig)
	if err != nil {
		return fmt.Errorf("error initializing %s driver: %v", d.Name(), err)
	}
	d.Config = *config

	d.API, err = InitializeOntapDriver(config)
	if err != nil {
		return fmt.Errorf("error initializing %s driver: %v", d.Name(), err)
	}
	d.Config = *config

	err = d.validate()
	if err != nil {
		return fmt.Errorf("error validating %s driver: %v", d.Name(), err)
	}

	// Set up the autosupport heartbeat
	d.Telemetry = NewOntapTelemetry(d)
	d.Telemetry.Start()

	d.initialized = true
	return nil
}

func (d *NASFlexGroupStorageDriver) Initialized() bool {
	return d.initialized
}

func (d *NASFlexGroupStorageDriver) Terminate() {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{"Method": "Terminate", "Type": "NASFlexGroupStorageDriver"}
		log.WithFields(fields).Debug(">>>> Terminate")
		defer log.WithFields(fields).Debug("<<<< Terminate")
	}
	if d.Telemetry != nil {
		d.Telemetry.Stop()
	}
	d.initialized = false
}

// Validate the driver configuration and execution environment
func (d *NASFlexGroupStorageDriver) validate() error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{"Method": "validate", "Type": "NASFlexGroupStorageDriver"}
		log.WithFields(fields).Debug(">>>> validate")
		defer log.WithFields(fields).Debug("<<<< validate")
	}

	if !d.API.SupportsFeature(api.NetAppFlexGroups) {
		return fmt.Errorf("ONTAP version does not support FlexGroups")
	}

	err := ValidateNASDriver(d.API, &d.Config)
	if err != nil {
		return fmt.Errorf("driver validation failed: %v", err)
	}

	return nil
}

// Create a volume with the specified options
func (d *NASFlexGroupStorageDriver) Create(
	volConfig *storage.VolumeConfig, storagePool *storage.Pool, volAttributes map[string]sa.Request,
) error {

	name := volConfig.InternalName

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method": "Create",
			"Type":   "NASFlexGroupStorageDriver",
			"name":   name,
			"attrs":  volAttributes,
		}
		log.WithFields(fields).Debug(">>>> Create")
		defer log.WithFields(fields).Debug("<<<< Create")
	}

	// If the volume already exists, bail out
	volExists, err := d.API.FlexGroupExists(name)
	if err != nil {
		return fmt.Errorf("error checking for existing FlexGroup: %v", err)
	}
	if volExists {
		return drivers.NewVolumeExistsError(name)
	}

	// Determine volume size in bytes
	requestedSize, err := utils.ConvertSizeToBytes(volConfig.Size)
	if err != nil {
		return fmt.Errorf("could not convert volume size %s: %v", volConfig.Size, err)
	}
	sizeBytes, err := strconv.ParseUint(requestedSize, 10, 64)
	if err != nil {
		return fmt.Errorf("%v is an invalid volume size: %v", volConfig.Size, err)
	}
	sizeBytes, err = GetVolumeSize(sizeBytes, d.Config)
	if err != nil {
		return err
	}
	if sizeBytes > math.MaxInt64 {
		return errors.New("invalid size requested")
	}
	size := int(sizeBytes)

	// Get the aggregates assigned to the SVM.  There must be at least one!
	vserverAggrs, err := d.API.VserverGetAggregateNames()
	if err != nil {
		return err
	}

	if len(vserverAggrs) == 0 {
		err = fmt.Errorf("no assigned aggregates found")
		return err
	}

	vserverAggrNames := make([]azgo.AggrNameType, 0)
	for _, aggrName := range vserverAggrs {
		vserverAggrNames = append(vserverAggrNames, azgo.AggrNameType(aggrName))
	}

	log.WithFields(log.Fields{
		"aggregates": vserverAggrs,
	}).Debug("Read aggregates assigned to SVM.")

	// Get options
	opts, err := d.GetVolumeOpts(volConfig, storagePool, volAttributes)
	if err != nil {
		return err
	}

	// get options with default fallback values
	// see also: ontap_common.go#PopulateConfigurationDefaults
	spaceReserve := utils.GetV(opts, "spaceReserve", d.Config.SpaceReserve)
	snapshotPolicy := utils.GetV(opts, "snapshotPolicy", d.Config.SnapshotPolicy)
	snapshotReserve := utils.GetV(opts, "snapshotReserve", d.Config.SnapshotReserve)
	unixPermissions := utils.GetV(opts, "unixPermissions", d.Config.UnixPermissions)
	snapshotDir := utils.GetV(opts, "snapshotDir", d.Config.SnapshotDir)
	exportPolicy := utils.GetV(opts, "exportPolicy", d.Config.ExportPolicy)
	securityStyle := utils.GetV(opts, "securityStyle", d.Config.SecurityStyle)
	encryption := utils.GetV(opts, "encryption", d.Config.Encryption)

	// limits checks are not currently applicable to the Flexgroups driver, ommited here on purpose

	enableSnapshotDir, err := strconv.ParseBool(snapshotDir)
	if err != nil {
		return fmt.Errorf("invalid boolean value for snapshotDir: %v", err)
	}

	enableEncryption, err := strconv.ParseBool(encryption)
	if err != nil {
		return fmt.Errorf("invalid boolean value for encryption: %v", err)
	}

	snapshotReserveInt, err := GetSnapshotReserve(snapshotPolicy, snapshotReserve)
	if err != nil {
		return fmt.Errorf("invalid value for snapshotReserve: %v", err)
	}

	log.WithFields(log.Fields{
		"name":            name,
		"size":            size,
		"spaceReserve":    spaceReserve,
		"snapshotPolicy":  snapshotPolicy,
		"snapshotReserve": snapshotReserveInt,
		"unixPermissions": unixPermissions,
		"snapshotDir":     enableSnapshotDir,
		"exportPolicy":    exportPolicy,
		"aggregates":      vserverAggrNames,
		"securityStyle":   securityStyle,
		"encryption":      enableEncryption,
	}).Debug("Creating FlexGroup.")

	// Create the FlexGroup
	_, err = d.API.FlexGroupCreate(
		name, size, vserverAggrNames, spaceReserve, snapshotPolicy, unixPermissions,
		exportPolicy, securityStyle, enableEncryption, snapshotReserveInt)

	if err != nil {
		return fmt.Errorf("error creating FlexGroup %v: %v", name, err)
	}

	// Disable '.snapshot' to allow official mysql container's chmod-in-init to work
	if !enableSnapshotDir {
		_, err := d.API.FlexGroupVolumeDisableSnapshotDirectoryAccess(name)
		if err != nil {
			return fmt.Errorf("error disabling snapshot directory access: %v", err)
		}
	}

	// Mount the volume at the specified junction
	mountResponse, err := d.API.VolumeMount(name, "/"+name)
	if err = api.GetError(mountResponse, err); err != nil {
		return fmt.Errorf("error mounting volume to junction: %v", err)
	}

	return nil
}

// CreateClone creates a volume clone
func (d *NASFlexGroupStorageDriver) CreateClone(volConfig *storage.VolumeConfig) error {
	return errors.New("clones are not supported for FlexGroups")
}

// Import brings an existing volume under trident's control
func (d *NASFlexGroupStorageDriver) Import(volConfig *storage.VolumeConfig, originalName string) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":       "Import",
			"Type":         "NASFlexGroupStorageDriver",
			"originalName": originalName,
			"notManaged":   volConfig.ImportNotManaged,
		}
		log.WithFields(fields).Debug(">>>> Import")
		defer log.WithFields(fields).Debug("<<<< Import")
	}

	// Ensure the volume exists
	flexgroup, err := d.API.FlexGroupGet(originalName)
	if err != nil {
		return err
	} else if flexgroup == nil {
		return fmt.Errorf("could not import volume %s, volume not found", originalName)
	}

	// Validate the volume is what it should be
	if flexgroup.VolumeIdAttributesPtr != nil {
		volumeIdAttrs := flexgroup.VolumeIdAttributes()
		if volumeIdAttrs.TypePtr != nil && volumeIdAttrs.Type() != "rw" {
			log.WithField("originalName", originalName).Error("Could not import volume, type is not rw.")
			return fmt.Errorf("could not import volume %s, type is %s, not rw", originalName, volumeIdAttrs.Type())
		}
	}

	// Get the volume size
	if flexgroup.VolumeSpaceAttributesPtr == nil || flexgroup.VolumeSpaceAttributesPtr.SizePtr == nil {
		log.WithField("originalName", originalName).Errorf("Could not import volume, size not available")
		return fmt.Errorf("could not import volume %s, size not available", originalName)
	}
	volConfig.Size = strconv.FormatInt(int64(flexgroup.VolumeSpaceAttributesPtr.Size()), 10)

	// We cannot rename flexgroups, so internal name should match the imported originalName
	volConfig.InternalName = originalName

	// Make sure we're not importing a volume without a junction path when not managed
	if volConfig.ImportNotManaged {
		if flexgroup.VolumeIdAttributesPtr == nil {
			return fmt.Errorf("unable to read volume id attributes of volume %s", originalName)
		} else if flexgroup.VolumeIdAttributesPtr.JunctionPathPtr == nil || flexgroup.VolumeIdAttributesPtr.
			JunctionPath() == "" {
			return fmt.Errorf("junction path is not set for volume %s", originalName)
		}
	}

	return nil
}

// Rename changes the name of a volume
func (d *NASFlexGroupStorageDriver) Rename(name string, newName string) error {
	// Flexgroups cannot be renamed
	return nil
}

// Destroy the volume
func (d *NASFlexGroupStorageDriver) Destroy(name string) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method": "Destroy",
			"Type":   "NASFlexGroupStorageDriver",
			"name":   name,
		}
		log.WithFields(fields).Debug(">>>> Destroy")
		defer log.WithFields(fields).Debug("<<<< Destroy")
	}

	// Needed once FlexGroups support clones
	// TODO: If this is the parent of one or more clones, those clones have to split from this
	// volume before it can be deleted, which means separate copies of those volumes.
	// If there are a lot of clones on this volume, that could seriously balloon the amount of
	// utilized space. Is that what we want? Or should we just deny the delete, and force the
	// user to keep the volume around until all of the clones are gone? If we do that, need a
	// way to list the clones. Maybe volume inspect.

	_, err := d.API.FlexGroupDestroy(name, true)
	if err != nil {
		return fmt.Errorf("error destroying FlexGroup %v: %v", name, err)
	}

	return nil
}

// Publish the volume to the host specified in publishInfo.  This method may or may not be running on the host
// where the volume will be mounted, so it should limit itself to updating access rules, initiator groups, etc.
// that require some host identity (but not locality) as well as storage controller API access.
func (d *NASFlexGroupStorageDriver) Publish(name string, publishInfo *utils.VolumePublishInfo) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method": "Publish",
			"Type":   "NASFlexGroupStorageDriver",
			"name":   name,
		}
		log.WithFields(fields).Debug(">>>> Publish")
		defer log.WithFields(fields).Debug("<<<< Publish")
	}

	// Add fields needed by Attach
	publishInfo.NfsPath = fmt.Sprintf("/%s", name)
	publishInfo.NfsServerIP = d.Config.DataLIF
	publishInfo.FilesystemType = "nfs"
	publishInfo.MountOptions = d.Config.NfsMountOptions

	return nil
}

// GetSnapshot gets a snapshot.  To distinguish between an API error reading the snapshot
// and a non-existent snapshot, this method may return (nil, nil).
func (d *NASFlexGroupStorageDriver) GetSnapshot(snapConfig *storage.SnapshotConfig) (*storage.Snapshot, error) {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":       "GetSnapshot",
			"Type":         "NASFlexGroupStorageDriver",
			"snapshotName": snapConfig.InternalName,
			"volumeName":   snapConfig.VolumeInternalName,
		}
		log.WithFields(fields).Debug(">>>> GetSnapshot")
		defer log.WithFields(fields).Debug("<<<< GetSnapshot")
	}

	//return GetSnapshot(snapConfig, &d.Config, d.API, d.API.FlexGroupSize)
	return nil, drivers.NewSnapshotsNotSupportedError(d.Name())
}

// Return the list of snapshots associated with the specified volume
func (d *NASFlexGroupStorageDriver) GetSnapshots(volConfig *storage.VolumeConfig) ([]*storage.Snapshot, error) {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":     "GetSnapshots",
			"Type":       "NASFlexGroupStorageDriver",
			"volumeName": volConfig.InternalName,
		}
		log.WithFields(fields).Debug(">>>> GetSnapshots")
		defer log.WithFields(fields).Debug("<<<< GetSnapshots")
	}

	//return GetSnapshots(volConfig, &d.Config, d.API, d.API.FlexGroupSize)
	return make([]*storage.Snapshot, 0), nil
}

// CreateSnapshot creates a snapshot for the given volume
func (d *NASFlexGroupStorageDriver) CreateSnapshot(snapConfig *storage.SnapshotConfig) (*storage.Snapshot, error) {

	internalSnapName := snapConfig.InternalName
	internalVolName := snapConfig.VolumeInternalName

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":       "CreateSnapshot",
			"Type":         "NASFlexGroupStorageDriver",
			"snapshotName": internalSnapName,
			"sourceVolume": internalVolName,
		}
		log.WithFields(fields).Debug(">>>> CreateSnapshot")
		defer log.WithFields(fields).Debug("<<<< CreateSnapshot")
	}

	//return CreateSnapshot(snapConfig, &d.Config, d.API, d.API.FlexGroupSize)
	return nil, drivers.NewSnapshotsNotSupportedError(d.Name())
}

// RestoreSnapshot restores a volume (in place) from a snapshot.
func (d *NASFlexGroupStorageDriver) RestoreSnapshot(snapConfig *storage.SnapshotConfig) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":       "RestoreSnapshot",
			"Type":         "NASFlexGroupStorageDriver",
			"snapshotName": snapConfig.InternalName,
			"volumeName":   snapConfig.VolumeInternalName,
		}
		log.WithFields(fields).Debug(">>>> RestoreSnapshot")
		defer log.WithFields(fields).Debug("<<<< RestoreSnapshot")
	}

	//return RestoreSnapshot(snapConfig, &d.Config, d.API)
	return drivers.NewSnapshotsNotSupportedError(d.Name())
}

// DeleteSnapshot creates a snapshot of a volume.
func (d *NASFlexGroupStorageDriver) DeleteSnapshot(snapConfig *storage.SnapshotConfig) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":       "DeleteSnapshot",
			"Type":         "NASFlexGroupStorageDriver",
			"snapshotName": snapConfig.InternalName,
			"volumeName":   snapConfig.VolumeInternalName,
		}
		log.WithFields(fields).Debug(">>>> DeleteSnapshot")
		defer log.WithFields(fields).Debug("<<<< DeleteSnapshot")
	}

	//return DeleteSnapshot(snapConfig, &d.Config, d.API)
	return drivers.NewSnapshotsNotSupportedError(d.Name())
}

// Tests the existence of a FlexGroup. Returns nil if the FlexGroup
// exists and an error otherwise.
func (d *NASFlexGroupStorageDriver) Get(name string) error {

	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{"Method": "Get", "Type": "NASFlexGroupStorageDriver"}
		log.WithFields(fields).Debug(">>>> Get")
		defer log.WithFields(fields).Debug("<<<< Get")
	}

	volExists, err := d.API.FlexGroupExists(name)
	if err != nil {
		return fmt.Errorf("error checking for existing volume: %v", err)
	}
	if !volExists {
		log.WithField("FlexGroup", name).Debug("FlexGroup not found.")
		return fmt.Errorf("volume %s does not exist", name)
	}

	return nil
}

// Retrieve storage backend capabilities
func (d *NASFlexGroupStorageDriver) GetStorageBackendSpecs(backend *storage.Backend) error {
	if d.Config.BackendName == "" {
		// Use the old naming scheme if no name is specified
		backend.Name = "ontapnasfg_" + d.Config.DataLIF
	} else {
		backend.Name = d.Config.BackendName
	}
	poolAttrs := d.getStoragePoolAttributes()
	return d.getStorageBackendSpecs(backend, poolAttrs)
}

// getStorageBackendSpecsCommon discovers the aggregates assigned to the configured SVM. The aggregates assigned to
// a SVM represent a single StoragePool for a FlexGroup. The default attributes for a FlexGroup are assigned to the pool.
func (d *NASFlexGroupStorageDriver) getStorageBackendSpecs(
	backend *storage.Backend, poolAttributes map[string]sa.Offer) (err error) {

	config := d.GetConfig()
	vserverAggrs, err := d.vserverAggregates(config.SVM)
	if err != nil {
		return err
	}

	log.WithFields(log.Fields{
		"svm":        config.SVM,
		"aggregates": vserverAggrs,
	}).Debug("Read aggregates assigned to SVM.")

	// For a FlexGroup all aggregates that belong to the SVM represent the storage pool.
	pool := storage.NewStoragePool(backend, config.SVM)
	for attrName, offer := range poolAttributes {
		pool.Attributes[attrName] = offer
	}
	backend.AddStoragePool(pool)

	return
}

func (d *NASFlexGroupStorageDriver) vserverAggregates(svmName string) ([]string, error) {
	var err error
	// Get the aggregates assigned to the SVM.  There must be at least one!
	vserverAggrs, err := d.API.VserverGetAggregateNames()
	if err != nil {
		return nil, err
	}
	if len(vserverAggrs) == 0 {
		err = fmt.Errorf("SVM %s has no assigned aggregates", svmName)
		return nil, err
	}

	return vserverAggrs, nil
}

func (d *NASFlexGroupStorageDriver) getStoragePoolAttributes() map[string]sa.Offer {

	return map[string]sa.Offer{
		sa.BackendType:      sa.NewStringOffer(d.Name()),
		sa.Snapshots:        sa.NewBoolOffer(true),
		sa.Encryption:       sa.NewBoolOffer(true),
		sa.Clones:           sa.NewBoolOffer(false),
		sa.ProvisioningType: sa.NewStringOffer("thick", "thin"),
	}
}

func (d *NASFlexGroupStorageDriver) GetVolumeOpts(
	volConfig *storage.VolumeConfig,
	pool *storage.Pool,
	requests map[string]sa.Request,
) (map[string]string, error) {
	return getVolumeOptsCommon(volConfig, pool, requests), nil
}

func (d *NASFlexGroupStorageDriver) GetInternalVolumeName(name string) string {
	return getInternalVolumeNameCommon(d.Config.CommonStorageDriverConfig, name)
}

func (d *NASFlexGroupStorageDriver) CreatePrepare(volConfig *storage.VolumeConfig) error {
	return createPrepareCommon(d, volConfig)
}

func (d *NASFlexGroupStorageDriver) CreateFollowup(volConfig *storage.VolumeConfig) error {

	volConfig.AccessInfo.NfsServerIP = d.Config.DataLIF
	volConfig.AccessInfo.MountOptions = strings.TrimPrefix(d.Config.NfsMountOptions, "-o ")
	volConfig.FileSystem = ""

	// Set correct junction path
	flexgroup, err := d.API.FlexGroupGet(volConfig.InternalName)
	if err != nil {
		return err
	} else if flexgroup == nil {
		return fmt.Errorf("could not create volume %s, volume not found", volConfig.InternalName)
	}

	if flexgroup.VolumeIdAttributesPtr == nil {
		return errors.New("error reading volume id attributes")
	}
	if flexgroup.VolumeIdAttributesPtr.JunctionPathPtr == nil || flexgroup.VolumeIdAttributesPtr.JunctionPath() == "" {
		// Flexgroup is not mounted, we need to mount it
		volConfig.AccessInfo.NfsPath = "/" + volConfig.InternalName
		mountResponse, err := d.API.VolumeMount(volConfig.InternalName, volConfig.AccessInfo.NfsPath)
		if err = api.GetError(mountResponse, err); err != nil {
			return fmt.Errorf("error mounting volume to junction %s; %v", volConfig.AccessInfo.NfsPath, err)
		}
	} else {
		volConfig.AccessInfo.NfsPath = flexgroup.VolumeIdAttributesPtr.JunctionPath()
	}

	return nil
}

func (d *NASFlexGroupStorageDriver) GetProtocol() tridentconfig.Protocol {
	return tridentconfig.File
}

func (d *NASFlexGroupStorageDriver) StoreConfig(
	b *storage.PersistentStorageBackendConfig,
) {
	drivers.SanitizeCommonStorageDriverConfig(d.Config.CommonStorageDriverConfig)
	b.OntapConfig = &d.Config
}

func (d *NASFlexGroupStorageDriver) GetExternalConfig() interface{} {
	return getExternalConfig(d.Config)
}

// GetVolumeExternal queries the storage backend for all relevant info about
// a single container volume managed by this driver and returns a VolumeExternal
// representation of the volume.
func (d *NASFlexGroupStorageDriver) GetVolumeExternal(name string) (*storage.VolumeExternal, error) {

	volumeAttributes, err := d.API.FlexGroupGet(name)
	if err != nil {
		return nil, err
	}

	return d.getVolumeExternal(volumeAttributes), nil
}

// GetVolumeExternalWrappers queries the storage backend for all relevant info about
// container volumes managed by this driver.  It then writes a VolumeExternal
// representation of each volume to the supplied channel, closing the channel
// when finished.
func (d *NASFlexGroupStorageDriver) GetVolumeExternalWrappers(
	channel chan *storage.VolumeExternalWrapper) {

	// Let the caller know we're done by closing the channel
	defer close(channel)

	// Get all volumes matching the storage prefix
	volumesResponse, err := d.API.FlexGroupGetAll(*d.Config.StoragePrefix)
	if err = api.GetError(volumesResponse, err); err != nil {
		channel <- &storage.VolumeExternalWrapper{Volume: nil, Error: err}
		return
	}

	// Convert all volumes to VolumeExternal and write them to the channel
	if volumesResponse.Result.AttributesListPtr != nil {
		for _, volume := range volumesResponse.Result.AttributesListPtr.VolumeAttributesPtr {
			channel <- &storage.VolumeExternalWrapper{Volume: d.getVolumeExternal(&volume), Error: nil}
		}
	}
}

// getVolumeExternal is a private method that accepts info about a volume
// as returned by the storage backend and formats it as a VolumeExternal
// object.
func (d *NASFlexGroupStorageDriver) getVolumeExternal(
	volumeAttrs *azgo.VolumeAttributesType) *storage.VolumeExternal {

	volumeExportAttrs := volumeAttrs.VolumeExportAttributesPtr
	volumeIDAttrs := volumeAttrs.VolumeIdAttributesPtr
	volumeSecurityAttrs := volumeAttrs.VolumeSecurityAttributesPtr
	volumeSecurityUnixAttrs := volumeSecurityAttrs.VolumeSecurityUnixAttributesPtr
	volumeSpaceAttrs := volumeAttrs.VolumeSpaceAttributesPtr
	volumeSnapshotAttrs := volumeAttrs.VolumeSnapshotAttributesPtr

	internalName := string(volumeIDAttrs.Name())
	name := internalName
	if strings.HasPrefix(internalName, *d.Config.StoragePrefix) {
		name = internalName[len(*d.Config.StoragePrefix):]
	}

	volumeConfig := &storage.VolumeConfig{
		Version:         tridentconfig.OrchestratorAPIVersion,
		Name:            name,
		InternalName:    internalName,
		Size:            strconv.FormatInt(int64(volumeSpaceAttrs.Size()), 10),
		Protocol:        tridentconfig.File,
		SnapshotPolicy:  volumeSnapshotAttrs.SnapshotPolicy(),
		ExportPolicy:    volumeExportAttrs.Policy(),
		SnapshotDir:     strconv.FormatBool(volumeSnapshotAttrs.SnapdirAccessEnabled()),
		UnixPermissions: volumeSecurityUnixAttrs.Permissions(),
		StorageClass:    "",
		AccessMode:      tridentconfig.ReadWriteMany,
		AccessInfo:      utils.VolumeAccessInfo{},
		BlockSize:       "",
		FileSystem:      "",
	}

	return &storage.VolumeExternal{
		Config: volumeConfig,
		Pool:   volumeIDAttrs.OwningVserverName(),
	}
}

// GetUpdateType returns a bitmap populated with updates to the driver
func (d *NASFlexGroupStorageDriver) GetUpdateType(driverOrig storage.Driver) *roaring.Bitmap {
	bitmap := roaring.New()
	dOrig, ok := driverOrig.(*NASFlexGroupStorageDriver)
	if !ok {
		bitmap.Add(storage.InvalidUpdate)
		return bitmap
	}

	if d.Config.DataLIF != dOrig.Config.DataLIF {
		bitmap.Add(storage.VolumeAccessInfoChange)
	}

	if d.Config.Password != dOrig.Config.Password {
		bitmap.Add(storage.PasswordChange)
	}

	if d.Config.Username != dOrig.Config.Username {
		bitmap.Add(storage.UsernameChange)
	}

	return bitmap
}

// Resize expands the FlexGroup size.
func (d *NASFlexGroupStorageDriver) Resize(volConfig *storage.VolumeConfig, sizeBytes uint64) error {

	name := volConfig.InternalName
	if d.Config.DebugTraceFlags["method"] {
		fields := log.Fields{
			"Method":    "Resize",
			"Type":      "NASFlexGroupStorageDriver",
			"name":      name,
			"sizeBytes": sizeBytes,
		}
		log.WithFields(fields).Debug(">>>> Resize")
		defer log.WithFields(fields).Debug("<<<< Resize")
	}

	flexvolSize, err := resizeValidation(name, sizeBytes, d.API.FlexGroupExists, d.API.FlexGroupSize)
	if err != nil {
		return err
	}

	if flexvolSize == sizeBytes {
		return nil
	}

	_, err = d.API.FlexGroupSetSize(name, strconv.FormatUint(sizeBytes, 10))
	if err != nil {
		log.WithField("error", err).Error("FlexGroup resize failed.")
		return fmt.Errorf("flexgroup resize failed")
	}

	volConfig.Size = strconv.FormatUint(sizeBytes, 10)
	return nil
}