// Copyright 2021 Google LLC
//
// 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
//
//     https://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.

// Code generated by protoc-gen-go_gapic. DO NOT EDIT.

package domains

import (
	"context"
	"fmt"
	"math"
	"net/url"
	"time"

	"cloud.google.com/go/longrunning"
	lroauto "cloud.google.com/go/longrunning/autogen"
	gax "github.com/googleapis/gax-go/v2"
	"google.golang.org/api/iterator"
	"google.golang.org/api/option"
	"google.golang.org/api/option/internaloption"
	gtransport "google.golang.org/api/transport/grpc"
	domainspb "google.golang.org/genproto/googleapis/cloud/domains/v1beta1"
	longrunningpb "google.golang.org/genproto/googleapis/longrunning"
	"google.golang.org/grpc"
	"google.golang.org/grpc/metadata"
	"google.golang.org/protobuf/proto"
)

var newClientHook clientHook

// CallOptions contains the retry settings for each method of Client.
type CallOptions struct {
	SearchDomains               []gax.CallOption
	RetrieveRegisterParameters  []gax.CallOption
	RegisterDomain              []gax.CallOption
	RetrieveTransferParameters  []gax.CallOption
	TransferDomain              []gax.CallOption
	ListRegistrations           []gax.CallOption
	GetRegistration             []gax.CallOption
	UpdateRegistration          []gax.CallOption
	ConfigureManagementSettings []gax.CallOption
	ConfigureDnsSettings        []gax.CallOption
	ConfigureContactSettings    []gax.CallOption
	ExportRegistration          []gax.CallOption
	DeleteRegistration          []gax.CallOption
	RetrieveAuthorizationCode   []gax.CallOption
	ResetAuthorizationCode      []gax.CallOption
}

func defaultGRPCClientOptions() []option.ClientOption {
	return []option.ClientOption{
		internaloption.WithDefaultEndpoint("domains.googleapis.com:443"),
		internaloption.WithDefaultMTLSEndpoint("domains.mtls.googleapis.com:443"),
		internaloption.WithDefaultAudience("https://domains.googleapis.com/"),
		internaloption.WithDefaultScopes(DefaultAuthScopes()...),
		internaloption.EnableJwtWithScope(),
		option.WithGRPCDialOption(grpc.WithDisableServiceConfig()),
		option.WithGRPCDialOption(grpc.WithDefaultCallOptions(
			grpc.MaxCallRecvMsgSize(math.MaxInt32))),
	}
}

func defaultCallOptions() *CallOptions {
	return &CallOptions{
		SearchDomains:               []gax.CallOption{},
		RetrieveRegisterParameters:  []gax.CallOption{},
		RegisterDomain:              []gax.CallOption{},
		RetrieveTransferParameters:  []gax.CallOption{},
		TransferDomain:              []gax.CallOption{},
		ListRegistrations:           []gax.CallOption{},
		GetRegistration:             []gax.CallOption{},
		UpdateRegistration:          []gax.CallOption{},
		ConfigureManagementSettings: []gax.CallOption{},
		ConfigureDnsSettings:        []gax.CallOption{},
		ConfigureContactSettings:    []gax.CallOption{},
		ExportRegistration:          []gax.CallOption{},
		DeleteRegistration:          []gax.CallOption{},
		RetrieveAuthorizationCode:   []gax.CallOption{},
		ResetAuthorizationCode:      []gax.CallOption{},
	}
}

// internalClient is an interface that defines the methods availaible from Cloud Domains API.
type internalClient interface {
	Close() error
	setGoogleClientInfo(...string)
	Connection() *grpc.ClientConn
	SearchDomains(context.Context, *domainspb.SearchDomainsRequest, ...gax.CallOption) (*domainspb.SearchDomainsResponse, error)
	RetrieveRegisterParameters(context.Context, *domainspb.RetrieveRegisterParametersRequest, ...gax.CallOption) (*domainspb.RetrieveRegisterParametersResponse, error)
	RegisterDomain(context.Context, *domainspb.RegisterDomainRequest, ...gax.CallOption) (*RegisterDomainOperation, error)
	RegisterDomainOperation(name string) *RegisterDomainOperation
	RetrieveTransferParameters(context.Context, *domainspb.RetrieveTransferParametersRequest, ...gax.CallOption) (*domainspb.RetrieveTransferParametersResponse, error)
	TransferDomain(context.Context, *domainspb.TransferDomainRequest, ...gax.CallOption) (*TransferDomainOperation, error)
	TransferDomainOperation(name string) *TransferDomainOperation
	ListRegistrations(context.Context, *domainspb.ListRegistrationsRequest, ...gax.CallOption) *RegistrationIterator
	GetRegistration(context.Context, *domainspb.GetRegistrationRequest, ...gax.CallOption) (*domainspb.Registration, error)
	UpdateRegistration(context.Context, *domainspb.UpdateRegistrationRequest, ...gax.CallOption) (*UpdateRegistrationOperation, error)
	UpdateRegistrationOperation(name string) *UpdateRegistrationOperation
	ConfigureManagementSettings(context.Context, *domainspb.ConfigureManagementSettingsRequest, ...gax.CallOption) (*ConfigureManagementSettingsOperation, error)
	ConfigureManagementSettingsOperation(name string) *ConfigureManagementSettingsOperation
	ConfigureDnsSettings(context.Context, *domainspb.ConfigureDnsSettingsRequest, ...gax.CallOption) (*ConfigureDnsSettingsOperation, error)
	ConfigureDnsSettingsOperation(name string) *ConfigureDnsSettingsOperation
	ConfigureContactSettings(context.Context, *domainspb.ConfigureContactSettingsRequest, ...gax.CallOption) (*ConfigureContactSettingsOperation, error)
	ConfigureContactSettingsOperation(name string) *ConfigureContactSettingsOperation
	ExportRegistration(context.Context, *domainspb.ExportRegistrationRequest, ...gax.CallOption) (*ExportRegistrationOperation, error)
	ExportRegistrationOperation(name string) *ExportRegistrationOperation
	DeleteRegistration(context.Context, *domainspb.DeleteRegistrationRequest, ...gax.CallOption) (*DeleteRegistrationOperation, error)
	DeleteRegistrationOperation(name string) *DeleteRegistrationOperation
	RetrieveAuthorizationCode(context.Context, *domainspb.RetrieveAuthorizationCodeRequest, ...gax.CallOption) (*domainspb.AuthorizationCode, error)
	ResetAuthorizationCode(context.Context, *domainspb.ResetAuthorizationCodeRequest, ...gax.CallOption) (*domainspb.AuthorizationCode, error)
}

// Client is a client for interacting with Cloud Domains API.
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
//
// The Cloud Domains API enables management and configuration of domain names.
type Client struct {
	// The internal transport-dependent client.
	internalClient internalClient

	// The call options for this service.
	CallOptions *CallOptions

	// LROClient is used internally to handle long-running operations.
	// It is exposed so that its CallOptions can be modified if required.
	// Users should not Close this client.
	LROClient *lroauto.OperationsClient
}

// Wrapper methods routed to the internal client.

// Close closes the connection to the API service. The user should invoke this when
// the client is no longer required.
func (c *Client) Close() error {
	return c.internalClient.Close()
}

// setGoogleClientInfo sets the name and version of the application in
// the `x-goog-api-client` header passed on each request. Intended for
// use by Google-written clients.
func (c *Client) setGoogleClientInfo(keyval ...string) {
	c.internalClient.setGoogleClientInfo(keyval...)
}

// Connection returns a connection to the API service.
//
// Deprecated.
func (c *Client) Connection() *grpc.ClientConn {
	return c.internalClient.Connection()
}

// SearchDomains searches for available domain names similar to the provided query.
//
// Availability results from this method are approximate; call
// RetrieveRegisterParameters on a domain before registering to confirm
// availability.
func (c *Client) SearchDomains(ctx context.Context, req *domainspb.SearchDomainsRequest, opts ...gax.CallOption) (*domainspb.SearchDomainsResponse, error) {
	return c.internalClient.SearchDomains(ctx, req, opts...)
}

// RetrieveRegisterParameters gets parameters needed to register a new domain name, including price and
// up-to-date availability. Use the returned values to call RegisterDomain.
func (c *Client) RetrieveRegisterParameters(ctx context.Context, req *domainspb.RetrieveRegisterParametersRequest, opts ...gax.CallOption) (*domainspb.RetrieveRegisterParametersResponse, error) {
	return c.internalClient.RetrieveRegisterParameters(ctx, req, opts...)
}

// RegisterDomain registers a new domain name and creates a corresponding Registration
// resource.
//
// Call RetrieveRegisterParameters first to check availability of the domain
// name and determine parameters like price that are needed to build a call to
// this method.
//
// A successful call creates a Registration resource in state
// REGISTRATION_PENDING, which resolves to ACTIVE within 1-2
// minutes, indicating that the domain was successfully registered. If the
// resource ends up in state REGISTRATION_FAILED, it indicates that the
// domain was not registered successfully, and you can safely delete the
// resource and retry registration.
func (c *Client) RegisterDomain(ctx context.Context, req *domainspb.RegisterDomainRequest, opts ...gax.CallOption) (*RegisterDomainOperation, error) {
	return c.internalClient.RegisterDomain(ctx, req, opts...)
}

// RegisterDomainOperation returns a new RegisterDomainOperation from a given name.
// The name must be that of a previously created RegisterDomainOperation, possibly from a different process.
func (c *Client) RegisterDomainOperation(name string) *RegisterDomainOperation {
	return c.internalClient.RegisterDomainOperation(name)
}

// RetrieveTransferParameters gets parameters needed to transfer a domain name from another registrar to
// Cloud Domains. For domains managed by Google Domains, transferring to Cloud
// Domains is not supported.
//
// Use the returned values to call TransferDomain.
func (c *Client) RetrieveTransferParameters(ctx context.Context, req *domainspb.RetrieveTransferParametersRequest, opts ...gax.CallOption) (*domainspb.RetrieveTransferParametersResponse, error) {
	return c.internalClient.RetrieveTransferParameters(ctx, req, opts...)
}

// TransferDomain transfers a domain name from another registrar to Cloud Domains.  For
// domains managed by Google Domains, transferring to Cloud Domains is not
// supported.
//
// Before calling this method, go to the domain’s current registrar to unlock
// the domain for transfer and retrieve the domain’s transfer authorization
// code. Then call RetrieveTransferParameters to confirm that the domain is
// unlocked and to get values needed to build a call to this method.
//
// A successful call creates a Registration resource in state
// TRANSFER_PENDING. It can take several days to complete the transfer
// process. The registrant can often speed up this process by approving the
// transfer through the current registrar, either by clicking a link in an
// email from the registrar or by visiting the registrar’s website.
//
// A few minutes after transfer approval, the resource transitions to state
// ACTIVE, indicating that the transfer was successful. If the transfer is
// rejected or the request expires without being approved, the resource can
// end up in state TRANSFER_FAILED. If transfer fails, you can safely delete
// the resource and retry the transfer.
func (c *Client) TransferDomain(ctx context.Context, req *domainspb.TransferDomainRequest, opts ...gax.CallOption) (*TransferDomainOperation, error) {
	return c.internalClient.TransferDomain(ctx, req, opts...)
}

// TransferDomainOperation returns a new TransferDomainOperation from a given name.
// The name must be that of a previously created TransferDomainOperation, possibly from a different process.
func (c *Client) TransferDomainOperation(name string) *TransferDomainOperation {
	return c.internalClient.TransferDomainOperation(name)
}

// ListRegistrations lists the Registration resources in a project.
func (c *Client) ListRegistrations(ctx context.Context, req *domainspb.ListRegistrationsRequest, opts ...gax.CallOption) *RegistrationIterator {
	return c.internalClient.ListRegistrations(ctx, req, opts...)
}

// GetRegistration gets the details of a Registration resource.
func (c *Client) GetRegistration(ctx context.Context, req *domainspb.GetRegistrationRequest, opts ...gax.CallOption) (*domainspb.Registration, error) {
	return c.internalClient.GetRegistration(ctx, req, opts...)
}

// UpdateRegistration updates select fields of a Registration resource, notably labels. To
// update other fields, use the appropriate custom update method:
//
//   To update management settings, see ConfigureManagementSettings
//
//   To update DNS configuration, see ConfigureDnsSettings
//
//   To update contact information, see ConfigureContactSettings
func (c *Client) UpdateRegistration(ctx context.Context, req *domainspb.UpdateRegistrationRequest, opts ...gax.CallOption) (*UpdateRegistrationOperation, error) {
	return c.internalClient.UpdateRegistration(ctx, req, opts...)
}

// UpdateRegistrationOperation returns a new UpdateRegistrationOperation from a given name.
// The name must be that of a previously created UpdateRegistrationOperation, possibly from a different process.
func (c *Client) UpdateRegistrationOperation(name string) *UpdateRegistrationOperation {
	return c.internalClient.UpdateRegistrationOperation(name)
}

// ConfigureManagementSettings updates a Registration's management settings.
func (c *Client) ConfigureManagementSettings(ctx context.Context, req *domainspb.ConfigureManagementSettingsRequest, opts ...gax.CallOption) (*ConfigureManagementSettingsOperation, error) {
	return c.internalClient.ConfigureManagementSettings(ctx, req, opts...)
}

// ConfigureManagementSettingsOperation returns a new ConfigureManagementSettingsOperation from a given name.
// The name must be that of a previously created ConfigureManagementSettingsOperation, possibly from a different process.
func (c *Client) ConfigureManagementSettingsOperation(name string) *ConfigureManagementSettingsOperation {
	return c.internalClient.ConfigureManagementSettingsOperation(name)
}

// ConfigureDnsSettings updates a Registration's DNS settings.
func (c *Client) ConfigureDnsSettings(ctx context.Context, req *domainspb.ConfigureDnsSettingsRequest, opts ...gax.CallOption) (*ConfigureDnsSettingsOperation, error) {
	return c.internalClient.ConfigureDnsSettings(ctx, req, opts...)
}

// ConfigureDnsSettingsOperation returns a new ConfigureDnsSettingsOperation from a given name.
// The name must be that of a previously created ConfigureDnsSettingsOperation, possibly from a different process.
func (c *Client) ConfigureDnsSettingsOperation(name string) *ConfigureDnsSettingsOperation {
	return c.internalClient.ConfigureDnsSettingsOperation(name)
}

// ConfigureContactSettings updates a Registration's contact settings. Some changes require
// confirmation by the domain’s registrant contact .
func (c *Client) ConfigureContactSettings(ctx context.Context, req *domainspb.ConfigureContactSettingsRequest, opts ...gax.CallOption) (*ConfigureContactSettingsOperation, error) {
	return c.internalClient.ConfigureContactSettings(ctx, req, opts...)
}

// ConfigureContactSettingsOperation returns a new ConfigureContactSettingsOperation from a given name.
// The name must be that of a previously created ConfigureContactSettingsOperation, possibly from a different process.
func (c *Client) ConfigureContactSettingsOperation(name string) *ConfigureContactSettingsOperation {
	return c.internalClient.ConfigureContactSettingsOperation(name)
}

// ExportRegistration exports a Registration resource, such that it is no longer managed by
// Cloud Domains.
//
// When an active domain is successfully exported, you can continue to use the
// domain in Google Domains (at https://domains.google/) until it expires. The
// calling user becomes the domain’s sole owner in Google Domains, and
// permissions for the domain are subsequently managed there. The domain does
// not renew automatically unless the new owner sets up billing in Google
// Domains.
func (c *Client) ExportRegistration(ctx context.Context, req *domainspb.ExportRegistrationRequest, opts ...gax.CallOption) (*ExportRegistrationOperation, error) {
	return c.internalClient.ExportRegistration(ctx, req, opts...)
}

// ExportRegistrationOperation returns a new ExportRegistrationOperation from a given name.
// The name must be that of a previously created ExportRegistrationOperation, possibly from a different process.
func (c *Client) ExportRegistrationOperation(name string) *ExportRegistrationOperation {
	return c.internalClient.ExportRegistrationOperation(name)
}

// DeleteRegistration deletes a Registration resource.
//
// This method works on any Registration resource using Subscription or
// Commitment billing (at /domains/pricing#billing-models), provided that the
// resource was created at least 1 day in the past.
//
// For Registration resources using
// Monthly billing (at /domains/pricing#billing-models), this method works if:
//
//   state is EXPORTED with expire_time in the past
//
//   state is REGISTRATION_FAILED
//
//   state is TRANSFER_FAILED
//
// When an active registration is successfully deleted, you can continue to
// use the domain in Google Domains (at https://domains.google/) until it
// expires. The calling user becomes the domain’s sole owner in Google
// Domains, and permissions for the domain are subsequently managed there. The
// domain does not renew automatically unless the new owner sets up billing in
// Google Domains.
func (c *Client) DeleteRegistration(ctx context.Context, req *domainspb.DeleteRegistrationRequest, opts ...gax.CallOption) (*DeleteRegistrationOperation, error) {
	return c.internalClient.DeleteRegistration(ctx, req, opts...)
}

// DeleteRegistrationOperation returns a new DeleteRegistrationOperation from a given name.
// The name must be that of a previously created DeleteRegistrationOperation, possibly from a different process.
func (c *Client) DeleteRegistrationOperation(name string) *DeleteRegistrationOperation {
	return c.internalClient.DeleteRegistrationOperation(name)
}

// RetrieveAuthorizationCode gets the authorization code of the Registration for the purpose of
// transferring the domain to another registrar.
//
// You can call this method only after 60 days have elapsed since the initial
// domain registration.
func (c *Client) RetrieveAuthorizationCode(ctx context.Context, req *domainspb.RetrieveAuthorizationCodeRequest, opts ...gax.CallOption) (*domainspb.AuthorizationCode, error) {
	return c.internalClient.RetrieveAuthorizationCode(ctx, req, opts...)
}

// ResetAuthorizationCode resets the authorization code of the Registration to a new random string.
//
// You can call this method only after 60 days have elapsed since the initial
// domain registration.
func (c *Client) ResetAuthorizationCode(ctx context.Context, req *domainspb.ResetAuthorizationCodeRequest, opts ...gax.CallOption) (*domainspb.AuthorizationCode, error) {
	return c.internalClient.ResetAuthorizationCode(ctx, req, opts...)
}

// gRPCClient is a client for interacting with Cloud Domains API over gRPC transport.
//
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
type gRPCClient struct {
	// Connection pool of gRPC connections to the service.
	connPool gtransport.ConnPool

	// flag to opt out of default deadlines via GOOGLE_API_GO_EXPERIMENTAL_DISABLE_DEFAULT_DEADLINE
	disableDeadlines bool

	// Points back to the CallOptions field of the containing Client
	CallOptions **CallOptions

	// The gRPC API client.
	client domainspb.DomainsClient

	// LROClient is used internally to handle long-running operations.
	// It is exposed so that its CallOptions can be modified if required.
	// Users should not Close this client.
	LROClient **lroauto.OperationsClient

	// The x-goog-* metadata to be sent with each request.
	xGoogMetadata metadata.MD
}

// NewClient creates a new domains client based on gRPC.
// The returned client must be Closed when it is done being used to clean up its underlying connections.
//
// The Cloud Domains API enables management and configuration of domain names.
func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error) {
	clientOpts := defaultGRPCClientOptions()
	if newClientHook != nil {
		hookOpts, err := newClientHook(ctx, clientHookParams{})
		if err != nil {
			return nil, err
		}
		clientOpts = append(clientOpts, hookOpts...)
	}

	disableDeadlines, err := checkDisableDeadlines()
	if err != nil {
		return nil, err
	}

	connPool, err := gtransport.DialPool(ctx, append(clientOpts, opts...)...)
	if err != nil {
		return nil, err
	}
	client := Client{CallOptions: defaultCallOptions()}

	c := &gRPCClient{
		connPool:         connPool,
		disableDeadlines: disableDeadlines,
		client:           domainspb.NewDomainsClient(connPool),
		CallOptions:      &client.CallOptions,
	}
	c.setGoogleClientInfo()

	client.internalClient = c

	client.LROClient, err = lroauto.NewOperationsClient(ctx, gtransport.WithConnPool(connPool))
	if err != nil {
		// This error "should not happen", since we are just reusing old connection pool
		// and never actually need to dial.
		// If this does happen, we could leak connp. However, we cannot close conn:
		// If the user invoked the constructor with option.WithGRPCConn,
		// we would close a connection that's still in use.
		// TODO: investigate error conditions.
		return nil, err
	}
	c.LROClient = &client.LROClient
	return &client, nil
}

// Connection returns a connection to the API service.
//
// Deprecated.
func (c *gRPCClient) Connection() *grpc.ClientConn {
	return c.connPool.Conn()
}

// setGoogleClientInfo sets the name and version of the application in
// the `x-goog-api-client` header passed on each request. Intended for
// use by Google-written clients.
func (c *gRPCClient) setGoogleClientInfo(keyval ...string) {
	kv := append([]string{"gl-go", versionGo()}, keyval...)
	kv = append(kv, "gapic", versionClient, "gax", gax.Version, "grpc", grpc.Version)
	c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
}

// Close closes the connection to the API service. The user should invoke this when
// the client is no longer required.
func (c *gRPCClient) Close() error {
	return c.connPool.Close()
}

func (c *gRPCClient) SearchDomains(ctx context.Context, req *domainspb.SearchDomainsRequest, opts ...gax.CallOption) (*domainspb.SearchDomainsResponse, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "location", url.QueryEscape(req.GetLocation())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).SearchDomains[0:len((*c.CallOptions).SearchDomains):len((*c.CallOptions).SearchDomains)], opts...)
	var resp *domainspb.SearchDomainsResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.SearchDomains(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) RetrieveRegisterParameters(ctx context.Context, req *domainspb.RetrieveRegisterParametersRequest, opts ...gax.CallOption) (*domainspb.RetrieveRegisterParametersResponse, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "location", url.QueryEscape(req.GetLocation())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).RetrieveRegisterParameters[0:len((*c.CallOptions).RetrieveRegisterParameters):len((*c.CallOptions).RetrieveRegisterParameters)], opts...)
	var resp *domainspb.RetrieveRegisterParametersResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.RetrieveRegisterParameters(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) RegisterDomain(ctx context.Context, req *domainspb.RegisterDomainRequest, opts ...gax.CallOption) (*RegisterDomainOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).RegisterDomain[0:len((*c.CallOptions).RegisterDomain):len((*c.CallOptions).RegisterDomain)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.RegisterDomain(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &RegisterDomainOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) RetrieveTransferParameters(ctx context.Context, req *domainspb.RetrieveTransferParametersRequest, opts ...gax.CallOption) (*domainspb.RetrieveTransferParametersResponse, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "location", url.QueryEscape(req.GetLocation())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).RetrieveTransferParameters[0:len((*c.CallOptions).RetrieveTransferParameters):len((*c.CallOptions).RetrieveTransferParameters)], opts...)
	var resp *domainspb.RetrieveTransferParametersResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.RetrieveTransferParameters(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) TransferDomain(ctx context.Context, req *domainspb.TransferDomainRequest, opts ...gax.CallOption) (*TransferDomainOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).TransferDomain[0:len((*c.CallOptions).TransferDomain):len((*c.CallOptions).TransferDomain)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.TransferDomain(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &TransferDomainOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) ListRegistrations(ctx context.Context, req *domainspb.ListRegistrationsRequest, opts ...gax.CallOption) *RegistrationIterator {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ListRegistrations[0:len((*c.CallOptions).ListRegistrations):len((*c.CallOptions).ListRegistrations)], opts...)
	it := &RegistrationIterator{}
	req = proto.Clone(req).(*domainspb.ListRegistrationsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*domainspb.Registration, string, error) {
		resp := &domainspb.ListRegistrationsResponse{}
		if pageToken != "" {
			req.PageToken = pageToken
		}
		if pageSize > math.MaxInt32 {
			req.PageSize = math.MaxInt32
		} else if pageSize != 0 {
			req.PageSize = int32(pageSize)
		}
		err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
			var err error
			resp, err = c.client.ListRegistrations(ctx, req, settings.GRPC...)
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetRegistrations(), resp.GetNextPageToken(), nil
	}
	fetch := func(pageSize int, pageToken string) (string, error) {
		items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
		if err != nil {
			return "", err
		}
		it.items = append(it.items, items...)
		return nextPageToken, nil
	}

	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
	it.pageInfo.MaxSize = int(req.GetPageSize())
	it.pageInfo.Token = req.GetPageToken()

	return it
}

func (c *gRPCClient) GetRegistration(ctx context.Context, req *domainspb.GetRegistrationRequest, opts ...gax.CallOption) (*domainspb.Registration, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).GetRegistration[0:len((*c.CallOptions).GetRegistration):len((*c.CallOptions).GetRegistration)], opts...)
	var resp *domainspb.Registration
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.GetRegistration(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) UpdateRegistration(ctx context.Context, req *domainspb.UpdateRegistrationRequest, opts ...gax.CallOption) (*UpdateRegistrationOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration.name", url.QueryEscape(req.GetRegistration().GetName())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).UpdateRegistration[0:len((*c.CallOptions).UpdateRegistration):len((*c.CallOptions).UpdateRegistration)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.UpdateRegistration(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &UpdateRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) ConfigureManagementSettings(ctx context.Context, req *domainspb.ConfigureManagementSettingsRequest, opts ...gax.CallOption) (*ConfigureManagementSettingsOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration", url.QueryEscape(req.GetRegistration())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ConfigureManagementSettings[0:len((*c.CallOptions).ConfigureManagementSettings):len((*c.CallOptions).ConfigureManagementSettings)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.ConfigureManagementSettings(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &ConfigureManagementSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) ConfigureDnsSettings(ctx context.Context, req *domainspb.ConfigureDnsSettingsRequest, opts ...gax.CallOption) (*ConfigureDnsSettingsOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration", url.QueryEscape(req.GetRegistration())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ConfigureDnsSettings[0:len((*c.CallOptions).ConfigureDnsSettings):len((*c.CallOptions).ConfigureDnsSettings)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.ConfigureDnsSettings(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &ConfigureDnsSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) ConfigureContactSettings(ctx context.Context, req *domainspb.ConfigureContactSettingsRequest, opts ...gax.CallOption) (*ConfigureContactSettingsOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration", url.QueryEscape(req.GetRegistration())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ConfigureContactSettings[0:len((*c.CallOptions).ConfigureContactSettings):len((*c.CallOptions).ConfigureContactSettings)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.ConfigureContactSettings(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &ConfigureContactSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) ExportRegistration(ctx context.Context, req *domainspb.ExportRegistrationRequest, opts ...gax.CallOption) (*ExportRegistrationOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ExportRegistration[0:len((*c.CallOptions).ExportRegistration):len((*c.CallOptions).ExportRegistration)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.ExportRegistration(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &ExportRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) DeleteRegistration(ctx context.Context, req *domainspb.DeleteRegistrationRequest, opts ...gax.CallOption) (*DeleteRegistrationOperation, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).DeleteRegistration[0:len((*c.CallOptions).DeleteRegistration):len((*c.CallOptions).DeleteRegistration)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.DeleteRegistration(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return &DeleteRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, resp),
	}, nil
}

func (c *gRPCClient) RetrieveAuthorizationCode(ctx context.Context, req *domainspb.RetrieveAuthorizationCodeRequest, opts ...gax.CallOption) (*domainspb.AuthorizationCode, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration", url.QueryEscape(req.GetRegistration())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).RetrieveAuthorizationCode[0:len((*c.CallOptions).RetrieveAuthorizationCode):len((*c.CallOptions).RetrieveAuthorizationCode)], opts...)
	var resp *domainspb.AuthorizationCode
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.RetrieveAuthorizationCode(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) ResetAuthorizationCode(ctx context.Context, req *domainspb.ResetAuthorizationCodeRequest, opts ...gax.CallOption) (*domainspb.AuthorizationCode, error) {
	md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "registration", url.QueryEscape(req.GetRegistration())))
	ctx = insertMetadata(ctx, c.xGoogMetadata, md)
	opts = append((*c.CallOptions).ResetAuthorizationCode[0:len((*c.CallOptions).ResetAuthorizationCode):len((*c.CallOptions).ResetAuthorizationCode)], opts...)
	var resp *domainspb.AuthorizationCode
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = c.client.ResetAuthorizationCode(ctx, req, settings.GRPC...)
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

// ConfigureContactSettingsOperation manages a long-running operation from ConfigureContactSettings.
type ConfigureContactSettingsOperation struct {
	lro *longrunning.Operation
}

// ConfigureContactSettingsOperation returns a new ConfigureContactSettingsOperation from a given name.
// The name must be that of a previously created ConfigureContactSettingsOperation, possibly from a different process.
func (c *gRPCClient) ConfigureContactSettingsOperation(name string) *ConfigureContactSettingsOperation {
	return &ConfigureContactSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *ConfigureContactSettingsOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *ConfigureContactSettingsOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *ConfigureContactSettingsOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *ConfigureContactSettingsOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *ConfigureContactSettingsOperation) Name() string {
	return op.lro.Name()
}

// ConfigureDnsSettingsOperation manages a long-running operation from ConfigureDnsSettings.
type ConfigureDnsSettingsOperation struct {
	lro *longrunning.Operation
}

// ConfigureDnsSettingsOperation returns a new ConfigureDnsSettingsOperation from a given name.
// The name must be that of a previously created ConfigureDnsSettingsOperation, possibly from a different process.
func (c *gRPCClient) ConfigureDnsSettingsOperation(name string) *ConfigureDnsSettingsOperation {
	return &ConfigureDnsSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *ConfigureDnsSettingsOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *ConfigureDnsSettingsOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *ConfigureDnsSettingsOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *ConfigureDnsSettingsOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *ConfigureDnsSettingsOperation) Name() string {
	return op.lro.Name()
}

// ConfigureManagementSettingsOperation manages a long-running operation from ConfigureManagementSettings.
type ConfigureManagementSettingsOperation struct {
	lro *longrunning.Operation
}

// ConfigureManagementSettingsOperation returns a new ConfigureManagementSettingsOperation from a given name.
// The name must be that of a previously created ConfigureManagementSettingsOperation, possibly from a different process.
func (c *gRPCClient) ConfigureManagementSettingsOperation(name string) *ConfigureManagementSettingsOperation {
	return &ConfigureManagementSettingsOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *ConfigureManagementSettingsOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *ConfigureManagementSettingsOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *ConfigureManagementSettingsOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *ConfigureManagementSettingsOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *ConfigureManagementSettingsOperation) Name() string {
	return op.lro.Name()
}

// DeleteRegistrationOperation manages a long-running operation from DeleteRegistration.
type DeleteRegistrationOperation struct {
	lro *longrunning.Operation
}

// DeleteRegistrationOperation returns a new DeleteRegistrationOperation from a given name.
// The name must be that of a previously created DeleteRegistrationOperation, possibly from a different process.
func (c *gRPCClient) DeleteRegistrationOperation(name string) *DeleteRegistrationOperation {
	return &DeleteRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *DeleteRegistrationOperation) Wait(ctx context.Context, opts ...gax.CallOption) error {
	return op.lro.WaitWithInterval(ctx, nil, time.Minute, opts...)
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *DeleteRegistrationOperation) Poll(ctx context.Context, opts ...gax.CallOption) error {
	return op.lro.Poll(ctx, nil, opts...)
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *DeleteRegistrationOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *DeleteRegistrationOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *DeleteRegistrationOperation) Name() string {
	return op.lro.Name()
}

// ExportRegistrationOperation manages a long-running operation from ExportRegistration.
type ExportRegistrationOperation struct {
	lro *longrunning.Operation
}

// ExportRegistrationOperation returns a new ExportRegistrationOperation from a given name.
// The name must be that of a previously created ExportRegistrationOperation, possibly from a different process.
func (c *gRPCClient) ExportRegistrationOperation(name string) *ExportRegistrationOperation {
	return &ExportRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *ExportRegistrationOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *ExportRegistrationOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *ExportRegistrationOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *ExportRegistrationOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *ExportRegistrationOperation) Name() string {
	return op.lro.Name()
}

// RegisterDomainOperation manages a long-running operation from RegisterDomain.
type RegisterDomainOperation struct {
	lro *longrunning.Operation
}

// RegisterDomainOperation returns a new RegisterDomainOperation from a given name.
// The name must be that of a previously created RegisterDomainOperation, possibly from a different process.
func (c *gRPCClient) RegisterDomainOperation(name string) *RegisterDomainOperation {
	return &RegisterDomainOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *RegisterDomainOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *RegisterDomainOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *RegisterDomainOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *RegisterDomainOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *RegisterDomainOperation) Name() string {
	return op.lro.Name()
}

// TransferDomainOperation manages a long-running operation from TransferDomain.
type TransferDomainOperation struct {
	lro *longrunning.Operation
}

// TransferDomainOperation returns a new TransferDomainOperation from a given name.
// The name must be that of a previously created TransferDomainOperation, possibly from a different process.
func (c *gRPCClient) TransferDomainOperation(name string) *TransferDomainOperation {
	return &TransferDomainOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *TransferDomainOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *TransferDomainOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *TransferDomainOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *TransferDomainOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *TransferDomainOperation) Name() string {
	return op.lro.Name()
}

// UpdateRegistrationOperation manages a long-running operation from UpdateRegistration.
type UpdateRegistrationOperation struct {
	lro *longrunning.Operation
}

// UpdateRegistrationOperation returns a new UpdateRegistrationOperation from a given name.
// The name must be that of a previously created UpdateRegistrationOperation, possibly from a different process.
func (c *gRPCClient) UpdateRegistrationOperation(name string) *UpdateRegistrationOperation {
	return &UpdateRegistrationOperation{
		lro: longrunning.InternalNewOperation(*c.LROClient, &longrunningpb.Operation{Name: name}),
	}
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *UpdateRegistrationOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *UpdateRegistrationOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*domainspb.Registration, error) {
	var resp domainspb.Registration
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *UpdateRegistrationOperation) Metadata() (*domainspb.OperationMetadata, error) {
	var meta domainspb.OperationMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *UpdateRegistrationOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *UpdateRegistrationOperation) Name() string {
	return op.lro.Name()
}

// RegistrationIterator manages a stream of *domainspb.Registration.
type RegistrationIterator struct {
	items    []*domainspb.Registration
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*domainspb.Registration, nextPageToken string, err error)
}

// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
func (it *RegistrationIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *RegistrationIterator) Next() (*domainspb.Registration, error) {
	var item *domainspb.Registration
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *RegistrationIterator) bufLen() int {
	return len(it.items)
}

func (it *RegistrationIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}