package pkger

import (
	"context"
	"errors"
	"fmt"
	"math/rand"
	"sort"
	"strings"
	"sync"
	"time"

	"github.com/influxdata/influxdb"
	ierrors "github.com/influxdata/influxdb/kit/errors"
	"go.uber.org/zap"
)

// APIVersion marks the current APIVersion for influx packages.
const APIVersion = "0.1.0"

// SVC is the packages service interface.
type SVC interface {
	CreatePkg(ctx context.Context, setters ...CreatePkgSetFn) (*Pkg, error)
	DryRun(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg) (Summary, Diff, error)
	Apply(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg) (Summary, error)
}

type serviceOpt struct {
	logger      *zap.Logger
	labelSVC    influxdb.LabelService
	bucketSVC   influxdb.BucketService
	dashSVC     influxdb.DashboardService
	endpointSVC influxdb.NotificationEndpointService
	teleSVC     influxdb.TelegrafConfigStore
	varSVC      influxdb.VariableService

	applyReqLimit int
}

// ServiceSetterFn is a means of setting dependencies on the Service type.
type ServiceSetterFn func(opt *serviceOpt)

// WithLogger sets the logger for the service.
func WithLogger(log *zap.Logger) ServiceSetterFn {
	return func(o *serviceOpt) {
		o.logger = log
	}
}

// WithBucketSVC sets the bucket service.
func WithBucketSVC(bktSVC influxdb.BucketService) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.bucketSVC = bktSVC
	}
}

// WithDashboardSVC sets the dashboard service.
func WithDashboardSVC(dashSVC influxdb.DashboardService) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.dashSVC = dashSVC
	}
}

// WithNoticationEndpointSVC sets the endpoint notification service.
func WithNoticationEndpointSVC(endpointSVC influxdb.NotificationEndpointService) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.endpointSVC = endpointSVC
	}
}

// WithLabelSVC sets the label service.
func WithLabelSVC(labelSVC influxdb.LabelService) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.labelSVC = labelSVC
	}
}

// WithTelegrafSVC sets the telegraf service.
func WithTelegrafSVC(telegrafSVC influxdb.TelegrafConfigStore) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.teleSVC = telegrafSVC
	}
}

// WithVariableSVC sets the variable service.
func WithVariableSVC(varSVC influxdb.VariableService) ServiceSetterFn {
	return func(opt *serviceOpt) {
		opt.varSVC = varSVC
	}
}

// Service provides the pkger business logic including all the dependencies to make
// this resource sausage.
type Service struct {
	log *zap.Logger

	labelSVC    influxdb.LabelService
	bucketSVC   influxdb.BucketService
	dashSVC     influxdb.DashboardService
	endpointSVC influxdb.NotificationEndpointService
	teleSVC     influxdb.TelegrafConfigStore
	varSVC      influxdb.VariableService

	applyReqLimit int
}

var _ SVC = (*Service)(nil)

// NewService is a constructor for a pkger Service.
func NewService(opts ...ServiceSetterFn) *Service {
	opt := &serviceOpt{
		logger:        zap.NewNop(),
		applyReqLimit: 5,
	}
	for _, o := range opts {
		o(opt)
	}

	return &Service{
		log:           opt.logger,
		bucketSVC:     opt.bucketSVC,
		labelSVC:      opt.labelSVC,
		dashSVC:       opt.dashSVC,
		endpointSVC:   opt.endpointSVC,
		teleSVC:       opt.teleSVC,
		varSVC:        opt.varSVC,
		applyReqLimit: opt.applyReqLimit,
	}
}

// CreatePkgSetFn is a functional input for setting the pkg fields.
type CreatePkgSetFn func(opt *CreateOpt) error

// CreateOpt are the options for creating a new package.
type CreateOpt struct {
	Metadata  Metadata
	OrgIDs    map[influxdb.ID]bool
	Resources []ResourceToClone
}

// CreateWithMetadata sets the metadata on the pkg in a CreatePkg call.
func CreateWithMetadata(meta Metadata) CreatePkgSetFn {
	return func(opt *CreateOpt) error {
		opt.Metadata = meta
		return nil
	}
}

// CreateWithExistingResources allows the create method to clone existing resources.
func CreateWithExistingResources(resources ...ResourceToClone) CreatePkgSetFn {
	return func(opt *CreateOpt) error {
		for _, r := range resources {
			if err := r.OK(); err != nil {
				return err
			}
			r.Kind = NewKind(string(r.Kind))
		}
		opt.Resources = append(opt.Resources, resources...)
		return nil
	}
}

// CreateWithAllOrgResources allows the create method to clone all existing resources
// for the given organization.
func CreateWithAllOrgResources(orgID influxdb.ID) CreatePkgSetFn {
	return func(opt *CreateOpt) error {
		if orgID == 0 {
			return errors.New("orgID provided must not be zero")
		}
		if opt.OrgIDs == nil {
			opt.OrgIDs = make(map[influxdb.ID]bool)
		}
		opt.OrgIDs[orgID] = true
		return nil
	}
}

// CreatePkg will produce a pkg from the parameters provided.
func (s *Service) CreatePkg(ctx context.Context, setters ...CreatePkgSetFn) (*Pkg, error) {
	opt := new(CreateOpt)
	for _, setter := range setters {
		if err := setter(opt); err != nil {
			return nil, err
		}
	}

	pkg := &Pkg{
		APIVersion: APIVersion,
		Kind:       KindPackage,
		Metadata:   opt.Metadata,
		Spec: struct {
			Resources []Resource `yaml:"resources" json:"resources"`
		}{
			Resources: make([]Resource, 0, len(opt.Resources)),
		},
	}
	if pkg.Metadata.Name == "" {
		// sudo randomness, this is not an attempt at making charts unique
		// that is a problem for the consumer.
		pkg.Metadata.Name = fmt.Sprintf("new_%7d", rand.Int())
	}
	if pkg.Metadata.Version == "" {
		pkg.Metadata.Version = "v1"
	}

	cloneAssFn := s.resourceCloneAssociationsGen()
	for orgID := range opt.OrgIDs {
		resourcesToClone, err := s.cloneOrgResources(ctx, orgID)
		if err != nil {
			return nil, err
		}
		opt.Resources = append(opt.Resources, resourcesToClone...)
	}

	for _, r := range uniqResourcesToClone(opt.Resources) {
		newResources, err := s.resourceCloneToResource(ctx, r, cloneAssFn)
		if err != nil {
			return nil, err
		}
		pkg.Spec.Resources = append(pkg.Spec.Resources, newResources...)
	}

	pkg.Spec.Resources = uniqResources(pkg.Spec.Resources)

	if err := pkg.Validate(ValidWithoutResources()); err != nil {
		return nil, err
	}

	var kindPriorities = map[Kind]int{
		KindLabel:     1,
		KindBucket:    2,
		KindVariable:  3,
		KindDashboard: 4,
	}

	sort.Slice(pkg.Spec.Resources, func(i, j int) bool {
		iName, jName := pkg.Spec.Resources[i].Name(), pkg.Spec.Resources[j].Name()
		iKind, _ := pkg.Spec.Resources[i].kind()
		jKind, _ := pkg.Spec.Resources[j].kind()

		if iKind.is(jKind) {
			return iName < jName
		}
		return kindPriorities[iKind] < kindPriorities[jKind]
	})

	return pkg, nil
}

func (s *Service) cloneOrgResources(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	resourceTypeGens := []struct {
		resType influxdb.ResourceType
		cloneFn func(context.Context, influxdb.ID) ([]ResourceToClone, error)
	}{
		{
			resType: KindBucket.ResourceType(),
			cloneFn: s.cloneOrgBuckets,
		},
		{
			resType: KindDashboard.ResourceType(),
			cloneFn: s.cloneOrgDashboards,
		},
		{
			resType: KindLabel.ResourceType(),
			cloneFn: s.cloneOrgLabels,
		},
		{
			resType: KindTelegraf.ResourceType(),
			cloneFn: s.cloneTelegrafs,
		},
		{
			resType: KindVariable.ResourceType(),
			cloneFn: s.cloneOrgVariables,
		},
	}

	var resources []ResourceToClone
	for _, resGen := range resourceTypeGens {
		existingResources, err := resGen.cloneFn(ctx, orgID)
		if err != nil {
			return nil, ierrors.Wrap(err, "finding "+string(resGen.resType))
		}
		resources = append(resources, existingResources...)
	}

	return resources, nil
}

func (s *Service) cloneOrgBuckets(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	buckets, _, err := s.bucketSVC.FindBuckets(ctx, influxdb.BucketFilter{
		OrganizationID: &orgID,
	})
	if err != nil {
		return nil, err
	}

	resources := make([]ResourceToClone, 0, len(buckets))
	for _, b := range buckets {
		if b.Type == influxdb.BucketTypeSystem {
			continue
		}
		resources = append(resources, ResourceToClone{
			Kind: KindBucket,
			ID:   b.ID,
		})
	}
	return resources, nil
}

func (s *Service) cloneOrgDashboards(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	dashs, _, err := s.dashSVC.FindDashboards(ctx, influxdb.DashboardFilter{
		OrganizationID: &orgID,
	}, influxdb.FindOptions{Limit: 100})
	if err != nil {
		return nil, err
	}

	resources := make([]ResourceToClone, 0, len(dashs))
	for _, d := range dashs {
		resources = append(resources, ResourceToClone{
			Kind: KindDashboard,
			ID:   d.ID,
		})
	}
	return resources, nil
}

func (s *Service) cloneOrgLabels(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	labels, err := s.labelSVC.FindLabels(ctx, influxdb.LabelFilter{
		OrgID: &orgID,
	}, influxdb.FindOptions{Limit: 10000})
	if err != nil {
		return nil, ierrors.Wrap(err, "finding labels")
	}

	resources := make([]ResourceToClone, 0, len(labels))
	for _, l := range labels {
		resources = append(resources, ResourceToClone{
			Kind: KindLabel,
			ID:   l.ID,
		})
	}
	return resources, nil
}

func (s *Service) cloneTelegrafs(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	teles, _, err := s.teleSVC.FindTelegrafConfigs(ctx, influxdb.TelegrafConfigFilter{OrgID: &orgID})
	if err != nil {
		return nil, err
	}
	resources := make([]ResourceToClone, 0, len(teles))
	for _, t := range teles {
		resources = append(resources, ResourceToClone{
			Kind: KindTelegraf,
			ID:   t.ID,
		})
	}
	return resources, nil
}

func (s *Service) cloneOrgVariables(ctx context.Context, orgID influxdb.ID) ([]ResourceToClone, error) {
	vars, err := s.varSVC.FindVariables(ctx, influxdb.VariableFilter{
		OrganizationID: &orgID,
	}, influxdb.FindOptions{Limit: 10000})
	if err != nil {
		return nil, err
	}

	resources := make([]ResourceToClone, 0, len(vars))
	for _, v := range vars {
		resources = append(resources, ResourceToClone{
			Kind: KindVariable,
			ID:   v.ID,
		})
	}

	return resources, nil
}

func (s *Service) resourceCloneToResource(ctx context.Context, r ResourceToClone, cFn cloneAssociationsFn) (newResources []Resource, e error) {
	defer func() {
		if e != nil {
			e = ierrors.Wrap(e, "cloning resource")
		}
	}()
	var newResource Resource
	switch {
	case r.Kind.is(KindBucket):
		bkt, err := s.bucketSVC.FindBucketByID(ctx, r.ID)
		if err != nil {
			return nil, err
		}
		newResource = bucketToResource(*bkt, r.Name)
	case r.Kind.is(KindDashboard):
		dash, err := s.findDashboardByIDFull(ctx, r.ID)
		if err != nil {
			return nil, err
		}
		newResource = dashboardToResource(*dash, r.Name)
	case r.Kind.is(KindLabel):
		l, err := s.labelSVC.FindLabelByID(ctx, r.ID)
		if err != nil {
			return nil, err
		}
		newResource = labelToResource(*l, r.Name)
	case r.Kind.is(KindTelegraf):
		t, err := s.teleSVC.FindTelegrafConfigByID(ctx, r.ID)
		if err != nil {
			return nil, err
		}
		newResource = telegrafToResource(*t, r.Name)
	case r.Kind.is(KindVariable):
		v, err := s.varSVC.FindVariableByID(ctx, r.ID)
		if err != nil {
			return nil, err
		}
		newResource = variableToResource(*v, r.Name)
	default:
		return nil, errors.New("unsupported kind provided: " + string(r.Kind))
	}

	ass, err := cFn(ctx, r)
	if err != nil {
		return nil, err
	}
	if len(ass.associations) > 0 {
		newResource[fieldAssociations] = ass.associations
	}

	return append([]Resource{newResource}, ass.newLableResources...), nil
}

type (
	associations struct {
		associations      []Resource
		newLableResources []Resource
	}

	cloneAssociationsFn func(context.Context, ResourceToClone) (associations, error)
)

func (s *Service) resourceCloneAssociationsGen() cloneAssociationsFn {
	type key struct {
		id   influxdb.ID
		name string
	}
	// memoize the labels so we dont' create duplicates
	m := make(map[key]bool)
	return func(ctx context.Context, r ResourceToClone) (associations, error) {
		if r.Kind.is(KindUnknown, KindLabel) {
			return associations{}, nil
		}

		labels, err := s.labelSVC.FindResourceLabels(ctx, influxdb.LabelMappingFilter{
			ResourceID:   r.ID,
			ResourceType: r.Kind.ResourceType(),
		})
		if err != nil {
			return associations{}, ierrors.Wrap(err, "finding resource labels")
		}

		var ass associations
		for _, l := range labels {
			ass.associations = append(ass.associations, Resource{
				fieldKind: KindLabel.String(),
				fieldName: l.Name,
			})
			k := key{id: l.ID, name: l.Name}
			if m[k] {
				continue
			}
			m[k] = true
			ass.newLableResources = append(ass.newLableResources, labelToResource(*l, ""))
		}
		return ass, nil
	}
}

// DryRun provides a dry run of the pkg application. The pkg will be marked verified
// for later calls to Apply. This func will be run on an Apply if it has not been run
// already.
func (s *Service) DryRun(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg) (Summary, Diff, error) {
	// so here's the deal, when we have issues with the parsing validation, we
	// continue to do the diff anyhow. any resource that does not have a name
	// will be skipped, and won't bleed into the dry run here. We can now return
	// a error (parseErr) and valid diff/summary.
	var parseErr error
	if !pkg.isParsed {
		err := pkg.Validate()
		if err != nil && !IsParseErr(err) {
			return Summary{}, Diff{}, err
		}
		parseErr = err
	}

	diffBuckets, err := s.dryRunBuckets(ctx, orgID, pkg)
	if err != nil {
		return Summary{}, Diff{}, err
	}

	diffLabels, err := s.dryRunLabels(ctx, orgID, pkg)
	if err != nil {
		return Summary{}, Diff{}, err
	}

	diffEndpoints, err := s.dryRunNotificationEndpoints(ctx, orgID, pkg)
	if err != nil {
		return Summary{}, Diff{}, err
	}

	diffVars, err := s.dryRunVariables(ctx, orgID, pkg)
	if err != nil {
		return Summary{}, Diff{}, err
	}

	diffLabelMappings, err := s.dryRunLabelMappings(ctx, pkg)
	if err != nil {
		return Summary{}, Diff{}, err
	}

	// verify the pkg is verified by a dry run. when calling Service.Apply this
	// is required to have been run. if it is not true, then apply runs
	// the Dry run.
	pkg.isVerified = true

	diff := Diff{
		Buckets:               diffBuckets,
		Dashboards:            s.dryRunDashboards(pkg),
		Labels:                diffLabels,
		LabelMappings:         diffLabelMappings,
		NotificationEndpoints: diffEndpoints,
		Telegrafs:             s.dryRunTelegraf(pkg),
		Variables:             diffVars,
	}
	return pkg.Summary(), diff, parseErr
}

func (s *Service) dryRunBuckets(ctx context.Context, orgID influxdb.ID, pkg *Pkg) ([]DiffBucket, error) {
	mExistingBkts := make(map[string]DiffBucket)
	bkts := pkg.buckets()
	for i := range bkts {
		b := bkts[i]
		existingBkt, err := s.bucketSVC.FindBucketByName(ctx, orgID, b.Name())
		switch err {
		// TODO: case for err not found here and another case handle where
		//  err isn't a not found (some other error)
		case nil:
			b.existing = existingBkt
			mExistingBkts[b.Name()] = newDiffBucket(b, existingBkt)
		default:
			mExistingBkts[b.Name()] = newDiffBucket(b, nil)
		}
	}

	var diffs []DiffBucket
	for _, diff := range mExistingBkts {
		diffs = append(diffs, diff)
	}
	sort.Slice(diffs, func(i, j int) bool {
		return diffs[i].Name < diffs[j].Name
	})

	return diffs, nil
}

func (s *Service) dryRunDashboards(pkg *Pkg) []DiffDashboard {
	var diffs []DiffDashboard
	for _, d := range pkg.dashboards() {
		diffs = append(diffs, newDiffDashboard(d))
	}
	return diffs
}

func (s *Service) dryRunLabels(ctx context.Context, orgID influxdb.ID, pkg *Pkg) ([]DiffLabel, error) {
	mExistingLabels := make(map[string]DiffLabel)
	labels := pkg.labels()
	for i := range labels {
		pkgLabel := labels[i]
		existingLabels, err := s.labelSVC.FindLabels(ctx, influxdb.LabelFilter{
			Name:  pkgLabel.Name(),
			OrgID: &orgID,
		}, influxdb.FindOptions{Limit: 1})
		switch {
		// TODO: case for err not found here and another case handle where
		//  err isn't a not found (some other error)
		case err == nil && len(existingLabels) > 0:
			existingLabel := existingLabels[0]
			pkgLabel.existing = existingLabel
			mExistingLabels[pkgLabel.Name()] = newDiffLabel(pkgLabel, existingLabel)
		default:
			mExistingLabels[pkgLabel.Name()] = newDiffLabel(pkgLabel, nil)
		}
	}

	diffs := make([]DiffLabel, 0, len(mExistingLabels))
	for _, diff := range mExistingLabels {
		diffs = append(diffs, diff)
	}
	sort.Slice(diffs, func(i, j int) bool {
		return diffs[i].Name < diffs[j].Name
	})

	return diffs, nil
}

func (s *Service) dryRunNotificationEndpoints(ctx context.Context, orgID influxdb.ID, pkg *Pkg) ([]DiffNotificationEndpoint, error) {
	existingEndpoints, _, err := s.endpointSVC.FindNotificationEndpoints(ctx, influxdb.NotificationEndpointFilter{
		OrgID: &orgID,
	}) // grab em all
	if err != nil {
		return nil, err
	}

	mExisting := make(map[string]influxdb.NotificationEndpoint)
	for i := range existingEndpoints {
		e := existingEndpoints[i]
		mExisting[e.GetName()] = e
	}

	mExistingToNew := make(map[string]DiffNotificationEndpoint)
	endpoints := pkg.notificationEndpoints()
	for i := range endpoints {
		newEndpoint := endpoints[i]

		var existing influxdb.NotificationEndpoint
		if iExisting, ok := mExisting[newEndpoint.Name()]; ok {
			newEndpoint.existing = iExisting
			existing = iExisting
		}
		mExistingToNew[newEndpoint.Name()] = newDiffNotificationEndpoint(newEndpoint, existing)
	}

	var diffs []DiffNotificationEndpoint
	for _, diff := range mExistingToNew {
		diffs = append(diffs, diff)
	}
	sort.Slice(diffs, func(i, j int) bool {
		return diffs[i].Name < diffs[j].Name
	})

	return diffs, nil
}

func (s *Service) dryRunTelegraf(pkg *Pkg) []DiffTelegraf {
	var diffs []DiffTelegraf
	for _, t := range pkg.telegrafs() {
		diffs = append(diffs, newDiffTelegraf(t))
	}
	return diffs
}

func (s *Service) dryRunVariables(ctx context.Context, orgID influxdb.ID, pkg *Pkg) ([]DiffVariable, error) {
	mExistingLabels := make(map[string]DiffVariable)
	variables := pkg.variables()

VarLoop:
	for i := range variables {
		pkgVar := variables[i]
		existingLabels, err := s.varSVC.FindVariables(ctx, influxdb.VariableFilter{
			OrganizationID: &orgID,
			// TODO: would be ideal to extend find variables to allow for a name matcher
			//  since names are unique for vars within an org, meanwhile, make large limit
			// 	returned vars, should be more than enough for the time being.
		}, influxdb.FindOptions{Limit: 100})
		switch {
		case err == nil && len(existingLabels) > 0:
			for i := range existingLabels {
				existingVar := existingLabels[i]
				if existingVar.Name != pkgVar.Name() {
					continue
				}
				pkgVar.existing = existingVar
				mExistingLabels[pkgVar.Name()] = newDiffVariable(pkgVar, existingVar)
				continue VarLoop
			}
			// fallthrough here for when the variable is not found, it'll fall to the
			// default case and add it as new.
			fallthrough
		default:
			mExistingLabels[pkgVar.Name()] = newDiffVariable(pkgVar, nil)
		}
	}

	diffs := make([]DiffVariable, 0, len(mExistingLabels))
	for _, diff := range mExistingLabels {
		diffs = append(diffs, diff)
	}
	sort.Slice(diffs, func(i, j int) bool {
		return diffs[i].Name < diffs[j].Name
	})

	return diffs, nil
}

type (
	labelMappingDiffFn func(labelID influxdb.ID, labelName string, isNew bool)

	labelMappers interface {
		Association(i int) labelAssociater
		Len() int
	}

	labelAssociater interface {
		ID() influxdb.ID
		Name() string
		Labels() []*label
		ResourceType() influxdb.ResourceType
		Exists() bool
	}
)

func (s *Service) dryRunLabelMappings(ctx context.Context, pkg *Pkg) ([]DiffLabelMapping, error) {
	mappers := []labelMappers{
		mapperBuckets(pkg.buckets()),
		mapperDashboards(pkg.mDashboards),
		mapperNotificationEndpoints(pkg.notificationEndpoints()),
		mapperTelegrafs(pkg.mTelegrafs),
		mapperVariables(pkg.variables()),
	}

	var diffs []DiffLabelMapping
	for _, mapper := range mappers {
		for i := 0; i < mapper.Len(); i++ {
			la := mapper.Association(i)
			err := s.dryRunResourceLabelMapping(ctx, la, func(labelID influxdb.ID, labelName string, isNew bool) {
				pkg.mLabels[labelName].setMapping(la, !isNew)
				diffs = append(diffs, DiffLabelMapping{
					IsNew:     isNew,
					ResType:   la.ResourceType(),
					ResID:     SafeID(la.ID()),
					ResName:   la.Name(),
					LabelID:   SafeID(labelID),
					LabelName: labelName,
				})
			})
			if err != nil {
				return nil, err
			}
		}
	}

	// sort by res type ASC, then res name ASC, then label name ASC
	sort.Slice(diffs, func(i, j int) bool {
		n, m := diffs[i], diffs[j]
		if n.ResType < m.ResType {
			return true
		}
		if n.ResType > m.ResType {
			return false
		}
		if n.ResName < m.ResName {
			return true
		}
		if n.ResName > m.ResName {
			return false
		}
		return n.LabelName < m.LabelName
	})

	return diffs, nil
}

func (s *Service) dryRunResourceLabelMapping(ctx context.Context, la labelAssociater, mappingFn labelMappingDiffFn) error {
	if !la.Exists() {
		for _, l := range la.Labels() {
			mappingFn(l.ID(), l.Name(), true)
		}
		return nil
	}

	// loop through and hit api for all labels associated with a bkt
	// lookup labels in pkg, add it to the label mapping, if exists in
	// the results from API, mark it exists
	existingLabels, err := s.labelSVC.FindResourceLabels(ctx, influxdb.LabelMappingFilter{
		ResourceID:   la.ID(),
		ResourceType: la.ResourceType(),
	})
	if err != nil {
		// TODO: inspect err, if its a not found error, do nothing, if any other error
		//  handle it better
		return err
	}

	pkgLabels := labelSlcToMap(la.Labels())
	for _, l := range existingLabels {
		// should ignore any labels that are not specified in pkg
		mappingFn(l.ID, l.Name, false)
		delete(pkgLabels, l.Name)
	}

	// now we add labels that were not apart of the existing labels
	for _, l := range pkgLabels {
		mappingFn(l.ID(), l.Name(), true)
	}
	return nil
}

// Apply will apply all the resources identified in the provided pkg. The entire pkg will be applied
// in its entirety. If a failure happens midway then the entire pkg will be rolled back to the state
// from before the pkg were applied.
func (s *Service) Apply(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg) (sum Summary, e error) {
	if !pkg.isParsed {
		if err := pkg.Validate(); err != nil {
			return Summary{}, err
		}
	}

	if !pkg.isVerified {
		_, _, err := s.DryRun(ctx, orgID, userID, pkg)
		if err != nil {
			return Summary{}, err
		}
	}

	coordinator := &rollbackCoordinator{sem: make(chan struct{}, s.applyReqLimit)}
	defer coordinator.rollback(s.log, &e)

	// each grouping here runs for its entirety, then returns an error that
	// is indicative of running all appliers provided. For instance, the labels
	// may have 1 variable fail and one of the buckets fails. The errors aggregate so
	// the caller will be informed of both the failed label variable the failed bucket.
	// the groupings here allow for steps to occur before exiting. The first step is
	// adding the dependencies, resources that are associated by other resources. Then the
	// primary resources. Here we get all the errors associated with them.
	// If those are all good, then we run the secondary(dependent) resources which
	// rely on the primary resources having been created.
	appliers := [][]applier{
		// want to make all dependencies for belwo donezo before moving on to resources
		// that have dependencies on lables
		{
			// deps for primary resources
			s.applyLabels(pkg.labels()),
		},
		{
			// primary resources
			s.applyVariables(pkg.variables()),
			s.applyBuckets(pkg.buckets()),
			s.applyDashboards(pkg.dashboards()),
			s.applyNotificationEndpoints(pkg.notificationEndpoints()),
			s.applyTelegrafs(pkg.telegrafs()),
		},
	}

	for _, group := range appliers {
		if err := coordinator.runTilEnd(ctx, orgID, userID, group...); err != nil {
			return Summary{}, err
		}
	}

	// secondary resources
	// this last grouping relies on the above 2 steps having completely successfully
	secondary := []applier{s.applyLabelMappings(pkg.labelMappings())}
	if err := coordinator.runTilEnd(ctx, orgID, userID, secondary...); err != nil {
		return Summary{}, err
	}

	return pkg.Summary(), nil
}

func (s *Service) applyBuckets(buckets []*bucket) applier {
	const resource = "bucket"

	mutex := new(doMutex)
	rollbackBuckets := make([]*bucket, 0, len(buckets))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var b bucket
		mutex.Do(func() {
			buckets[i].OrgID = orgID
			b = *buckets[i]
		})
		if !b.shouldApply() {
			return nil
		}

		influxBucket, err := s.applyBucket(ctx, b)
		if err != nil {
			return &applyErrBody{
				name: b.Name(),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			buckets[i].id = influxBucket.ID
			rollbackBuckets = append(rollbackBuckets, buckets[i])
		})

		return nil
	}

	return applier{
		creater: creater{
			entries: len(buckets),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn:       func() error { return s.rollbackBuckets(rollbackBuckets) },
		},
	}
}

func (s *Service) rollbackBuckets(buckets []*bucket) error {
	var errs []string
	for _, b := range buckets {
		if b.existing == nil {
			err := s.bucketSVC.DeleteBucket(context.Background(), b.ID())
			if err != nil {
				errs = append(errs, b.ID().String())
			}
			continue
		}

		rp := b.RetentionRules.RP()
		_, err := s.bucketSVC.UpdateBucket(context.Background(), b.ID(), influxdb.BucketUpdate{
			Description:     &b.Description,
			RetentionPeriod: &rp,
		})
		if err != nil {
			errs = append(errs, b.ID().String())
		}
	}

	if len(errs) > 0 {
		// TODO: fixup error
		return fmt.Errorf(`bucket_ids=[%s] err="unable to delete bucket"`, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) applyBucket(ctx context.Context, b bucket) (influxdb.Bucket, error) {
	rp := b.RetentionRules.RP()
	if b.existing != nil {
		influxBucket, err := s.bucketSVC.UpdateBucket(ctx, b.ID(), influxdb.BucketUpdate{
			Description:     &b.Description,
			RetentionPeriod: &rp,
		})
		if err != nil {
			return influxdb.Bucket{}, err
		}
		return *influxBucket, nil
	}

	influxBucket := influxdb.Bucket{
		OrgID:           b.OrgID,
		Description:     b.Description,
		Name:            b.Name(),
		RetentionPeriod: rp,
	}
	err := s.bucketSVC.CreateBucket(ctx, &influxBucket)
	if err != nil {
		return influxdb.Bucket{}, err
	}

	return influxBucket, nil
}

func (s *Service) applyDashboards(dashboards []*dashboard) applier {
	const resource = "dashboard"

	mutex := new(doMutex)
	rollbackDashboards := make([]*dashboard, 0, len(dashboards))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var d dashboard
		mutex.Do(func() {
			dashboards[i].OrgID = orgID
			d = *dashboards[i]
		})

		influxBucket, err := s.applyDashboard(ctx, d)
		if err != nil {
			return &applyErrBody{
				name: d.Name(),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			dashboards[i].id = influxBucket.ID
			rollbackDashboards = append(rollbackDashboards, dashboards[i])
		})
		return nil
	}

	return applier{
		creater: creater{
			entries: len(dashboards),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn: func() error {
				return s.deleteByIDs("dashboard", len(rollbackDashboards), s.dashSVC.DeleteDashboard, func(i int) influxdb.ID {
					return rollbackDashboards[i].ID()
				})
			},
		},
	}
}

func (s *Service) applyDashboard(ctx context.Context, d dashboard) (influxdb.Dashboard, error) {
	cells := convertChartsToCells(d.Charts)
	influxDashboard := influxdb.Dashboard{
		OrganizationID: d.OrgID,
		Description:    d.Description,
		Name:           d.Name(),
		Cells:          cells,
	}
	err := s.dashSVC.CreateDashboard(ctx, &influxDashboard)
	if err != nil {
		return influxdb.Dashboard{}, err
	}

	return influxDashboard, nil
}

func convertChartsToCells(ch []chart) []*influxdb.Cell {
	icells := make([]*influxdb.Cell, 0, len(ch))
	for _, c := range ch {
		icell := &influxdb.Cell{
			CellProperty: influxdb.CellProperty{
				X: int32(c.XPos),
				Y: int32(c.YPos),
				H: int32(c.Height),
				W: int32(c.Width),
			},
			View: &influxdb.View{
				ViewContents: influxdb.ViewContents{Name: c.Name},
				Properties:   c.properties(),
			},
		}
		icells = append(icells, icell)
	}
	return icells
}

func (s *Service) applyLabels(labels []*label) applier {
	const resource = "label"

	mutex := new(doMutex)
	rollBackLabels := make([]*label, 0, len(labels))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var l label
		mutex.Do(func() {
			labels[i].OrgID = orgID
			l = *labels[i]
		})
		if !l.shouldApply() {
			return nil
		}

		influxLabel, err := s.applyLabel(ctx, l)
		if err != nil {
			return &applyErrBody{
				name: l.Name(),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			labels[i].id = influxLabel.ID
			rollBackLabels = append(rollBackLabels, labels[i])
		})

		return nil
	}

	return applier{
		creater: creater{
			entries: len(labels),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn:       func() error { return s.rollbackLabels(rollBackLabels) },
		},
	}
}

func (s *Service) rollbackLabels(labels []*label) error {
	var errs []string
	for _, l := range labels {
		if l.existing == nil {
			err := s.labelSVC.DeleteLabel(context.Background(), l.ID())
			if err != nil {
				errs = append(errs, l.ID().String())
			}
			continue
		}

		_, err := s.labelSVC.UpdateLabel(context.Background(), l.ID(), influxdb.LabelUpdate{
			Properties: l.existing.Properties,
		})
		if err != nil {
			errs = append(errs, l.ID().String())
		}
	}

	if len(errs) > 0 {
		return fmt.Errorf(`label_ids=[%s] err="unable to delete label"`, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) applyLabel(ctx context.Context, l label) (influxdb.Label, error) {
	if l.existing != nil {
		updatedlabel, err := s.labelSVC.UpdateLabel(ctx, l.ID(), influxdb.LabelUpdate{
			Properties: l.properties(),
		})
		if err != nil {
			return influxdb.Label{}, err
		}
		return *updatedlabel, nil
	}

	influxLabel := l.toInfluxLabel()
	err := s.labelSVC.CreateLabel(ctx, &influxLabel)
	if err != nil {
		return influxdb.Label{}, err
	}

	return influxLabel, nil
}

func (s *Service) applyNotificationEndpoints(endpoints []*notificationEndpoint) applier {
	const resource = "notification_endpoints"

	mutex := new(doMutex)
	rollbackEndpoints := make([]*notificationEndpoint, 0, len(endpoints))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var endpoint notificationEndpoint
		mutex.Do(func() {
			endpoints[i].OrgID = orgID
			endpoint = *endpoints[i]
		})

		influxEndpoint, err := s.applyNotificationEndpoint(ctx, endpoint, userID)
		if err != nil {
			return &applyErrBody{
				name: endpoint.Name(),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			endpoints[i].id = influxEndpoint.GetID()
			rollbackEndpoints = append(rollbackEndpoints, endpoints[i])
		})

		return nil
	}

	return applier{
		creater: creater{
			entries: len(endpoints),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn: func() error {
				return s.rollbackNotificationEndpoints(rollbackEndpoints)
			},
		},
	}
}

func (s *Service) applyNotificationEndpoint(ctx context.Context, e notificationEndpoint, userID influxdb.ID) (influxdb.NotificationEndpoint, error) {
	if e.existing != nil {
		// stub out userID since we're always using hte http client which will fill it in for us with the token
		// feels a bit broken that is required.
		// TODO: look into this userID requirement
		updatedEndpoint, err := s.endpointSVC.UpdateNotificationEndpoint(ctx, e.ID(), e.existing, 0)
		if err != nil {
			return nil, err
		}
		return updatedEndpoint, nil
	}

	actual := e.summarize().NotificationEndpoint
	err := s.endpointSVC.CreateNotificationEndpoint(ctx, actual, userID)
	if err != nil {
		return nil, err
	}

	return actual, nil
}

func (s *Service) rollbackNotificationEndpoints(endpoints []*notificationEndpoint) error {
	var errs []string
	for _, e := range endpoints {
		if e.existing == nil {
			_, _, err := s.endpointSVC.DeleteNotificationEndpoint(context.Background(), e.ID())
			if err != nil {
				errs = append(errs, e.ID().String())
			}
			continue
		}

		_, err := s.endpointSVC.UpdateNotificationEndpoint(context.Background(), e.ID(), e.existing, 0)
		if err != nil {
			errs = append(errs, e.ID().String())
		}
	}

	if len(errs) > 0 {
		return fmt.Errorf(`notication_endpoint_ids=[%s] err="unable to delete"`, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) applyTelegrafs(teles []*telegraf) applier {
	const resource = "telegrafs"

	mutex := new(doMutex)
	rollbackTelegrafs := make([]*telegraf, 0, len(teles))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var cfg influxdb.TelegrafConfig
		mutex.Do(func() {
			teles[i].config.OrgID = orgID
			cfg = teles[i].config
		})

		err := s.teleSVC.CreateTelegrafConfig(ctx, &cfg, userID)
		if err != nil {
			return &applyErrBody{
				name: cfg.Name,
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			teles[i].config = cfg
			rollbackTelegrafs = append(rollbackTelegrafs, teles[i])
		})

		return nil
	}

	return applier{
		creater: creater{
			entries: len(teles),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn: func() error {
				return s.deleteByIDs("telegraf", len(rollbackTelegrafs), s.teleSVC.DeleteTelegrafConfig, func(i int) influxdb.ID {
					return rollbackTelegrafs[i].ID()
				})
			},
		},
	}
}

func (s *Service) applyVariables(vars []*variable) applier {
	const resource = "variable"

	mutex := new(doMutex)
	rollBackVars := make([]*variable, 0, len(vars))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var v variable
		mutex.Do(func() {
			vars[i].OrgID = orgID
			v = *vars[i]
		})
		if !v.shouldApply() {
			return nil
		}
		influxVar, err := s.applyVariable(ctx, v)
		if err != nil {
			return &applyErrBody{
				name: v.Name(),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			vars[i].id = influxVar.ID
			rollBackVars = append(rollBackVars, vars[i])
		})
		return nil
	}

	return applier{
		creater: creater{
			entries: len(vars),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn:       func() error { return s.rollbackVariables(rollBackVars) },
		},
	}
}

func (s *Service) rollbackVariables(variables []*variable) error {
	var errs []string
	for _, v := range variables {
		if v.existing == nil {
			err := s.varSVC.DeleteVariable(context.Background(), v.ID())
			if err != nil {
				errs = append(errs, v.ID().String())
			}
			continue
		}

		_, err := s.varSVC.UpdateVariable(context.Background(), v.ID(), &influxdb.VariableUpdate{
			Description: v.existing.Description,
			Arguments:   v.existing.Arguments,
		})
		if err != nil {
			errs = append(errs, v.ID().String())
		}
	}

	if len(errs) > 0 {
		return fmt.Errorf(`variable_ids=[%s] err="unable to delete variable"`, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) applyVariable(ctx context.Context, v variable) (influxdb.Variable, error) {
	if v.existing != nil {
		updatedVar, err := s.varSVC.UpdateVariable(ctx, v.ID(), &influxdb.VariableUpdate{
			Description: v.Description,
			Arguments:   v.influxVarArgs(),
		})
		if err != nil {
			return influxdb.Variable{}, err
		}
		return *updatedVar, nil
	}

	influxVar := influxdb.Variable{
		OrganizationID: v.OrgID,
		Name:           v.Name(),
		Description:    v.Description,
		Arguments:      v.influxVarArgs(),
	}
	err := s.varSVC.CreateVariable(ctx, &influxVar)
	if err != nil {
		return influxdb.Variable{}, err
	}

	return influxVar, nil
}

func (s *Service) applyLabelMappings(labelMappings []SummaryLabelMapping) applier {
	const resource = "label_mapping"

	mutex := new(doMutex)
	rollbackMappings := make([]influxdb.LabelMapping, 0, len(labelMappings))

	createFn := func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody {
		var mapping SummaryLabelMapping
		mutex.Do(func() {
			mapping = labelMappings[i]
		})
		if mapping.exists {
			// this block here does 2 things, it does not write a
			// mapping when one exists. it also avoids having to worry
			// about deleting an existing mapping since it will not be
			// passed to the delete function below b/c it is never added
			// to the list of mappings that is referenced in the delete
			// call.
			return nil
		}

		m := influxdb.LabelMapping{
			LabelID:      influxdb.ID(mapping.LabelID),
			ResourceID:   influxdb.ID(mapping.ResourceID),
			ResourceType: mapping.ResourceType,
		}
		err := s.labelSVC.CreateLabelMapping(ctx, &m)
		if err != nil {
			return &applyErrBody{
				name: fmt.Sprintf("%s:%s:%s", mapping.ResourceType, mapping.ResourceID, mapping.LabelID),
				msg:  err.Error(),
			}
		}

		mutex.Do(func() {
			rollbackMappings = append(rollbackMappings, m)
		})

		return nil
	}

	return applier{
		creater: creater{
			entries: len(labelMappings),
			fn:      createFn,
		},
		rollbacker: rollbacker{
			resource: resource,
			fn:       func() error { return s.rollbackLabelMappings(rollbackMappings) },
		},
	}
}

func (s *Service) rollbackLabelMappings(mappings []influxdb.LabelMapping) error {
	var errs []string
	for i := range mappings {
		l := mappings[i]
		err := s.labelSVC.DeleteLabelMapping(context.Background(), &l)
		if err != nil {
			errs = append(errs, fmt.Sprintf("%s:%s", l.LabelID.String(), l.ResourceID.String()))
		}
	}

	if len(errs) > 0 {
		return fmt.Errorf(`label_resource_id_pairs=[%s] err="unable to delete label"`, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) deleteByIDs(resource string, numIDs int, deleteFn func(context.Context, influxdb.ID) error, iterFn func(int) influxdb.ID) error {
	var errs []string
	for i := range make([]struct{}, numIDs) {
		id := iterFn(i)
		err := deleteFn(context.Background(), id)
		if err != nil {
			errs = append(errs, id.String())
		}
	}

	if len(errs) > 0 {
		return fmt.Errorf(`%s_ids=[%s] err="unable to delete"`, resource, strings.Join(errs, ", "))
	}

	return nil
}

func (s *Service) findDashboardByIDFull(ctx context.Context, id influxdb.ID) (*influxdb.Dashboard, error) {
	dash, err := s.dashSVC.FindDashboardByID(ctx, id)
	if err != nil {
		return nil, err
	}
	for _, cell := range dash.Cells {
		v, err := s.dashSVC.GetDashboardCellView(ctx, id, cell.ID)
		if err != nil {
			return nil, err
		}
		cell.View = v
	}
	return dash, nil
}

type doMutex struct {
	sync.Mutex
}

func (m *doMutex) Do(fn func()) {
	m.Lock()
	defer m.Unlock()
	fn()
}

type (
	applier struct {
		creater    creater
		rollbacker rollbacker
	}

	rollbacker struct {
		resource string
		fn       func() error
	}

	creater struct {
		entries int
		fn      func(ctx context.Context, i int, orgID, userID influxdb.ID) *applyErrBody
	}
)

type rollbackCoordinator struct {
	rollbacks []rollbacker

	sem chan struct{}
}

func (r *rollbackCoordinator) runTilEnd(ctx context.Context, orgID, userID influxdb.ID, appliers ...applier) error {
	errStr := newErrStream(ctx)

	wg := new(sync.WaitGroup)
	for i := range appliers {
		// cannot reuse the shared variable from for loop since we're using concurrency b/c
		// that temp var gets recycled between iterations
		app := appliers[i]
		r.rollbacks = append(r.rollbacks, app.rollbacker)
		for idx := range make([]struct{}, app.creater.entries) {
			r.sem <- struct{}{}
			wg.Add(1)

			go func(i int, resource string) {
				defer func() {
					wg.Done()
					<-r.sem
				}()

				ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
				defer cancel()

				if err := app.creater.fn(ctx, i, orgID, userID); err != nil {
					errStr.add(errMsg{resource: resource, err: *err})
				}
			}(idx, app.rollbacker.resource)
		}
	}
	wg.Wait()

	return errStr.close()
}

func (r *rollbackCoordinator) rollback(l *zap.Logger, err *error) {
	if *err == nil {
		return
	}

	for _, r := range r.rollbacks {
		if err := r.fn(); err != nil {
			l.Error("failed to delete "+r.resource, zap.Error(err))
		}
	}
}

type errMsg struct {
	resource string
	err      applyErrBody
}

type errStream struct {
	msgStream chan errMsg
	err       chan error
	done      <-chan struct{}
}

func newErrStream(ctx context.Context) *errStream {
	e := &errStream{
		msgStream: make(chan errMsg),
		err:       make(chan error),
		done:      ctx.Done(),
	}
	e.do()
	return e
}

func (e *errStream) do() {
	go func() {
		mErrs := func() map[string]applyErrs {
			mErrs := make(map[string]applyErrs)
			for {
				select {
				case <-e.done:
					return nil
				case msg, ok := <-e.msgStream:
					if !ok {
						return mErrs
					}
					mErrs[msg.resource] = append(mErrs[msg.resource], &msg.err)
				}
			}
		}()

		if len(mErrs) == 0 {
			e.err <- nil
			return
		}

		var errs []string
		for resource, err := range mErrs {
			errs = append(errs, err.toError(resource, "failed to create").Error())
		}
		e.err <- errors.New(strings.Join(errs, "\n"))
	}()
}

func (e *errStream) close() error {
	close(e.msgStream)
	return <-e.err
}

func (e *errStream) add(msg errMsg) {
	select {
	case <-e.done:
	case e.msgStream <- msg:
	}
}

// TODO: clean up apply errors to inform the user in an actionable way
type applyErrBody struct {
	name string
	msg  string
}

type applyErrs []*applyErrBody

func (a applyErrs) toError(resType, msg string) error {
	if len(a) == 0 {
		return nil
	}
	errMsg := fmt.Sprintf(`resource_type=%q err=%q`, resType, msg)
	for _, e := range a {
		errMsg += fmt.Sprintf("\n\tname=%q err_msg=%q", e.name, e.msg)
	}
	return errors.New(errMsg)
}

func labelSlcToMap(labels []*label) map[string]*label {
	m := make(map[string]*label)
	for i := range labels {
		m[labels[i].Name()] = labels[i]
	}
	return m
}