// Copyright 2025 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 cx

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"log/slog"
	"math"
	"net/http"
	"net/url"
	"time"

	cxpb "cloud.google.com/go/dialogflow/cx/apiv3beta1/cxpb"
	longrunningpb "cloud.google.com/go/longrunning/autogen/longrunningpb"
	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"
	httptransport "google.golang.org/api/transport/http"
	locationpb "google.golang.org/genproto/googleapis/cloud/location"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/metadata"
	"google.golang.org/protobuf/encoding/protojson"
	"google.golang.org/protobuf/proto"
)

var newSessionsClientHook clientHook

// SessionsCallOptions contains the retry settings for each method of SessionsClient.
type SessionsCallOptions struct {
	DetectIntent                []gax.CallOption
	ServerStreamingDetectIntent []gax.CallOption
	StreamingDetectIntent       []gax.CallOption
	MatchIntent                 []gax.CallOption
	FulfillIntent               []gax.CallOption
	SubmitAnswerFeedback        []gax.CallOption
	GetLocation                 []gax.CallOption
	ListLocations               []gax.CallOption
	CancelOperation             []gax.CallOption
	GetOperation                []gax.CallOption
	ListOperations              []gax.CallOption
}

func defaultSessionsGRPCClientOptions() []option.ClientOption {
	return []option.ClientOption{
		internaloption.WithDefaultEndpoint("dialogflow.googleapis.com:443"),
		internaloption.WithDefaultEndpointTemplate("dialogflow.UNIVERSE_DOMAIN:443"),
		internaloption.WithDefaultMTLSEndpoint("dialogflow.mtls.googleapis.com:443"),
		internaloption.WithDefaultUniverseDomain("googleapis.com"),
		internaloption.WithDefaultAudience("https://dialogflow.googleapis.com/"),
		internaloption.WithDefaultScopes(DefaultAuthScopes()...),
		internaloption.EnableJwtWithScope(),
		internaloption.EnableNewAuthLibrary(),
		option.WithGRPCDialOption(grpc.WithDefaultCallOptions(
			grpc.MaxCallRecvMsgSize(math.MaxInt32))),
	}
}

func defaultSessionsCallOptions() *SessionsCallOptions {
	return &SessionsCallOptions{
		DetectIntent: []gax.CallOption{
			gax.WithTimeout(220000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		ServerStreamingDetectIntent: []gax.CallOption{},
		StreamingDetectIntent:       []gax.CallOption{},
		MatchIntent: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		FulfillIntent: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		SubmitAnswerFeedback: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		GetLocation:     []gax.CallOption{},
		ListLocations:   []gax.CallOption{},
		CancelOperation: []gax.CallOption{},
		GetOperation:    []gax.CallOption{},
		ListOperations:  []gax.CallOption{},
	}
}

func defaultSessionsRESTCallOptions() *SessionsCallOptions {
	return &SessionsCallOptions{
		DetectIntent: []gax.CallOption{
			gax.WithTimeout(220000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusServiceUnavailable)
			}),
		},
		ServerStreamingDetectIntent: []gax.CallOption{
			gax.WithTimeout(220000 * time.Millisecond),
		},
		StreamingDetectIntent: []gax.CallOption{
			gax.WithTimeout(220000 * time.Millisecond),
		},
		MatchIntent: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusServiceUnavailable)
			}),
		},
		FulfillIntent: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusServiceUnavailable)
			}),
		},
		SubmitAnswerFeedback: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusServiceUnavailable)
			}),
		},
		GetLocation:     []gax.CallOption{},
		ListLocations:   []gax.CallOption{},
		CancelOperation: []gax.CallOption{},
		GetOperation:    []gax.CallOption{},
		ListOperations:  []gax.CallOption{},
	}
}

// internalSessionsClient is an interface that defines the methods available from Dialogflow API.
type internalSessionsClient interface {
	Close() error
	setGoogleClientInfo(...string)
	Connection() *grpc.ClientConn
	DetectIntent(context.Context, *cxpb.DetectIntentRequest, ...gax.CallOption) (*cxpb.DetectIntentResponse, error)
	ServerStreamingDetectIntent(context.Context, *cxpb.DetectIntentRequest, ...gax.CallOption) (cxpb.Sessions_ServerStreamingDetectIntentClient, error)
	StreamingDetectIntent(context.Context, ...gax.CallOption) (cxpb.Sessions_StreamingDetectIntentClient, error)
	MatchIntent(context.Context, *cxpb.MatchIntentRequest, ...gax.CallOption) (*cxpb.MatchIntentResponse, error)
	FulfillIntent(context.Context, *cxpb.FulfillIntentRequest, ...gax.CallOption) (*cxpb.FulfillIntentResponse, error)
	SubmitAnswerFeedback(context.Context, *cxpb.SubmitAnswerFeedbackRequest, ...gax.CallOption) (*cxpb.AnswerFeedback, error)
	GetLocation(context.Context, *locationpb.GetLocationRequest, ...gax.CallOption) (*locationpb.Location, error)
	ListLocations(context.Context, *locationpb.ListLocationsRequest, ...gax.CallOption) *LocationIterator
	CancelOperation(context.Context, *longrunningpb.CancelOperationRequest, ...gax.CallOption) error
	GetOperation(context.Context, *longrunningpb.GetOperationRequest, ...gax.CallOption) (*longrunningpb.Operation, error)
	ListOperations(context.Context, *longrunningpb.ListOperationsRequest, ...gax.CallOption) *OperationIterator
}

// SessionsClient is a client for interacting with Dialogflow API.
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
//
// A session represents an interaction with a user. You retrieve user input
// and pass it to the
// DetectIntent
// method to determine user intent and respond.
type SessionsClient struct {
	// The internal transport-dependent client.
	internalClient internalSessionsClient

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

// 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 *SessionsClient) 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 *SessionsClient) setGoogleClientInfo(keyval ...string) {
	c.internalClient.setGoogleClientInfo(keyval...)
}

// Connection returns a connection to the API service.
//
// Deprecated: Connections are now pooled so this method does not always
// return the same resource.
func (c *SessionsClient) Connection() *grpc.ClientConn {
	return c.internalClient.Connection()
}

// DetectIntent processes a natural language query and returns structured, actionable data
// as a result. This method is not idempotent, because it may cause session
// entity types to be updated, which in turn might affect results of future
// queries.
//
// Note: Always use agent versions for production traffic.
// See Versions and
// environments (at https://cloud.google.com/dialogflow/cx/docs/concept/version).
func (c *SessionsClient) DetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (*cxpb.DetectIntentResponse, error) {
	return c.internalClient.DetectIntent(ctx, req, opts...)
}

// ServerStreamingDetectIntent processes a natural language query and returns structured, actionable data
// as a result through server-side streaming. Server-side streaming allows
// Dialogflow to send partial
// responses (at https://cloud.google.com/dialogflow/cx/docs/concept/fulfillment#partial-response)
// earlier in a single request.
func (c *SessionsClient) ServerStreamingDetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (cxpb.Sessions_ServerStreamingDetectIntentClient, error) {
	return c.internalClient.ServerStreamingDetectIntent(ctx, req, opts...)
}

// StreamingDetectIntent processes a natural language query in audio format in a streaming fashion
// and returns structured, actionable data as a result. This method is only
// available via the gRPC API (not REST).
//
// Note: Always use agent versions for production traffic.
// See Versions and
// environments (at https://cloud.google.com/dialogflow/cx/docs/concept/version).
//
// This method is not supported for the REST transport.
func (c *SessionsClient) StreamingDetectIntent(ctx context.Context, opts ...gax.CallOption) (cxpb.Sessions_StreamingDetectIntentClient, error) {
	return c.internalClient.StreamingDetectIntent(ctx, opts...)
}

// MatchIntent returns preliminary intent match results, doesn’t change the session
// status.
func (c *SessionsClient) MatchIntent(ctx context.Context, req *cxpb.MatchIntentRequest, opts ...gax.CallOption) (*cxpb.MatchIntentResponse, error) {
	return c.internalClient.MatchIntent(ctx, req, opts...)
}

// FulfillIntent fulfills a matched intent returned by
// MatchIntent.
// Must be called after
// MatchIntent,
// with input from
// MatchIntentResponse.
// Otherwise, the behavior is undefined.
func (c *SessionsClient) FulfillIntent(ctx context.Context, req *cxpb.FulfillIntentRequest, opts ...gax.CallOption) (*cxpb.FulfillIntentResponse, error) {
	return c.internalClient.FulfillIntent(ctx, req, opts...)
}

// SubmitAnswerFeedback updates the feedback received from the user for a single turn of the bot
// response.
func (c *SessionsClient) SubmitAnswerFeedback(ctx context.Context, req *cxpb.SubmitAnswerFeedbackRequest, opts ...gax.CallOption) (*cxpb.AnswerFeedback, error) {
	return c.internalClient.SubmitAnswerFeedback(ctx, req, opts...)
}

// GetLocation gets information about a location.
func (c *SessionsClient) GetLocation(ctx context.Context, req *locationpb.GetLocationRequest, opts ...gax.CallOption) (*locationpb.Location, error) {
	return c.internalClient.GetLocation(ctx, req, opts...)
}

// ListLocations lists information about the supported locations for this service.
func (c *SessionsClient) ListLocations(ctx context.Context, req *locationpb.ListLocationsRequest, opts ...gax.CallOption) *LocationIterator {
	return c.internalClient.ListLocations(ctx, req, opts...)
}

// CancelOperation is a utility method from google.longrunning.Operations.
func (c *SessionsClient) CancelOperation(ctx context.Context, req *longrunningpb.CancelOperationRequest, opts ...gax.CallOption) error {
	return c.internalClient.CancelOperation(ctx, req, opts...)
}

// GetOperation is a utility method from google.longrunning.Operations.
func (c *SessionsClient) GetOperation(ctx context.Context, req *longrunningpb.GetOperationRequest, opts ...gax.CallOption) (*longrunningpb.Operation, error) {
	return c.internalClient.GetOperation(ctx, req, opts...)
}

// ListOperations is a utility method from google.longrunning.Operations.
func (c *SessionsClient) ListOperations(ctx context.Context, req *longrunningpb.ListOperationsRequest, opts ...gax.CallOption) *OperationIterator {
	return c.internalClient.ListOperations(ctx, req, opts...)
}

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

	// Points back to the CallOptions field of the containing SessionsClient
	CallOptions **SessionsCallOptions

	// The gRPC API client.
	sessionsClient cxpb.SessionsClient

	operationsClient longrunningpb.OperationsClient

	locationsClient locationpb.LocationsClient

	// The x-goog-* metadata to be sent with each request.
	xGoogHeaders []string

	logger *slog.Logger
}

// NewSessionsClient creates a new sessions client based on gRPC.
// The returned client must be Closed when it is done being used to clean up its underlying connections.
//
// A session represents an interaction with a user. You retrieve user input
// and pass it to the
// DetectIntent
// method to determine user intent and respond.
func NewSessionsClient(ctx context.Context, opts ...option.ClientOption) (*SessionsClient, error) {
	clientOpts := defaultSessionsGRPCClientOptions()
	if newSessionsClientHook != nil {
		hookOpts, err := newSessionsClientHook(ctx, clientHookParams{})
		if err != nil {
			return nil, err
		}
		clientOpts = append(clientOpts, hookOpts...)
	}

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

	c := &sessionsGRPCClient{
		connPool:         connPool,
		sessionsClient:   cxpb.NewSessionsClient(connPool),
		CallOptions:      &client.CallOptions,
		logger:           internaloption.GetLogger(opts),
		operationsClient: longrunningpb.NewOperationsClient(connPool),
		locationsClient:  locationpb.NewLocationsClient(connPool),
	}
	c.setGoogleClientInfo()

	client.internalClient = c

	return &client, nil
}

// Connection returns a connection to the API service.
//
// Deprecated: Connections are now pooled so this method does not always
// return the same resource.
func (c *sessionsGRPCClient) 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 *sessionsGRPCClient) setGoogleClientInfo(keyval ...string) {
	kv := append([]string{"gl-go", gax.GoVersion}, keyval...)
	kv = append(kv, "gapic", getVersionClient(), "gax", gax.Version, "grpc", grpc.Version)
	c.xGoogHeaders = []string{
		"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 *sessionsGRPCClient) Close() error {
	return c.connPool.Close()
}

// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
type sessionsRESTClient struct {
	// The http endpoint to connect to.
	endpoint string

	// The http client.
	httpClient *http.Client

	// The x-goog-* headers to be sent with each request.
	xGoogHeaders []string

	// Points back to the CallOptions field of the containing SessionsClient
	CallOptions **SessionsCallOptions

	logger *slog.Logger
}

// NewSessionsRESTClient creates a new sessions rest client.
//
// A session represents an interaction with a user. You retrieve user input
// and pass it to the
// DetectIntent
// method to determine user intent and respond.
func NewSessionsRESTClient(ctx context.Context, opts ...option.ClientOption) (*SessionsClient, error) {
	clientOpts := append(defaultSessionsRESTClientOptions(), opts...)
	httpClient, endpoint, err := httptransport.NewClient(ctx, clientOpts...)
	if err != nil {
		return nil, err
	}

	callOpts := defaultSessionsRESTCallOptions()
	c := &sessionsRESTClient{
		endpoint:    endpoint,
		httpClient:  httpClient,
		CallOptions: &callOpts,
		logger:      internaloption.GetLogger(opts),
	}
	c.setGoogleClientInfo()

	return &SessionsClient{internalClient: c, CallOptions: callOpts}, nil
}

func defaultSessionsRESTClientOptions() []option.ClientOption {
	return []option.ClientOption{
		internaloption.WithDefaultEndpoint("https://dialogflow.googleapis.com"),
		internaloption.WithDefaultEndpointTemplate("https://dialogflow.UNIVERSE_DOMAIN"),
		internaloption.WithDefaultMTLSEndpoint("https://dialogflow.mtls.googleapis.com"),
		internaloption.WithDefaultUniverseDomain("googleapis.com"),
		internaloption.WithDefaultAudience("https://dialogflow.googleapis.com/"),
		internaloption.WithDefaultScopes(DefaultAuthScopes()...),
		internaloption.EnableNewAuthLibrary(),
	}
}

// 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 *sessionsRESTClient) setGoogleClientInfo(keyval ...string) {
	kv := append([]string{"gl-go", gax.GoVersion}, keyval...)
	kv = append(kv, "gapic", getVersionClient(), "gax", gax.Version, "rest", "UNKNOWN")
	c.xGoogHeaders = []string{
		"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 *sessionsRESTClient) Close() error {
	// Replace httpClient with nil to force cleanup.
	c.httpClient = nil
	return nil
}

// Connection returns a connection to the API service.
//
// Deprecated: This method always returns nil.
func (c *sessionsRESTClient) Connection() *grpc.ClientConn {
	return nil
}
func (c *sessionsGRPCClient) DetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (*cxpb.DetectIntentResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).DetectIntent[0:len((*c.CallOptions).DetectIntent):len((*c.CallOptions).DetectIntent)], opts...)
	var resp *cxpb.DetectIntentResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.sessionsClient.DetectIntent, req, settings.GRPC, c.logger, "DetectIntent")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) ServerStreamingDetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (cxpb.Sessions_ServerStreamingDetectIntentClient, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).ServerStreamingDetectIntent[0:len((*c.CallOptions).ServerStreamingDetectIntent):len((*c.CallOptions).ServerStreamingDetectIntent)], opts...)
	var resp cxpb.Sessions_ServerStreamingDetectIntentClient
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		c.logger.DebugContext(ctx, "api streaming client request", "serviceName", serviceName, "rpcName", "ServerStreamingDetectIntent")
		resp, err = c.sessionsClient.ServerStreamingDetectIntent(ctx, req, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "ServerStreamingDetectIntent")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) StreamingDetectIntent(ctx context.Context, opts ...gax.CallOption) (cxpb.Sessions_StreamingDetectIntentClient, error) {
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, c.xGoogHeaders...)
	var resp cxpb.Sessions_StreamingDetectIntentClient
	opts = append((*c.CallOptions).StreamingDetectIntent[0:len((*c.CallOptions).StreamingDetectIntent):len((*c.CallOptions).StreamingDetectIntent)], opts...)
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		c.logger.DebugContext(ctx, "api streaming client request", "serviceName", serviceName, "rpcName", "StreamingDetectIntent")
		resp, err = c.sessionsClient.StreamingDetectIntent(ctx, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "StreamingDetectIntent")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) MatchIntent(ctx context.Context, req *cxpb.MatchIntentRequest, opts ...gax.CallOption) (*cxpb.MatchIntentResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).MatchIntent[0:len((*c.CallOptions).MatchIntent):len((*c.CallOptions).MatchIntent)], opts...)
	var resp *cxpb.MatchIntentResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.sessionsClient.MatchIntent, req, settings.GRPC, c.logger, "MatchIntent")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) FulfillIntent(ctx context.Context, req *cxpb.FulfillIntentRequest, opts ...gax.CallOption) (*cxpb.FulfillIntentResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "match_intent_request.session", url.QueryEscape(req.GetMatchIntentRequest().GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).FulfillIntent[0:len((*c.CallOptions).FulfillIntent):len((*c.CallOptions).FulfillIntent)], opts...)
	var resp *cxpb.FulfillIntentResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.sessionsClient.FulfillIntent, req, settings.GRPC, c.logger, "FulfillIntent")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) SubmitAnswerFeedback(ctx context.Context, req *cxpb.SubmitAnswerFeedbackRequest, opts ...gax.CallOption) (*cxpb.AnswerFeedback, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).SubmitAnswerFeedback[0:len((*c.CallOptions).SubmitAnswerFeedback):len((*c.CallOptions).SubmitAnswerFeedback)], opts...)
	var resp *cxpb.AnswerFeedback
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.sessionsClient.SubmitAnswerFeedback, req, settings.GRPC, c.logger, "SubmitAnswerFeedback")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) GetLocation(ctx context.Context, req *locationpb.GetLocationRequest, opts ...gax.CallOption) (*locationpb.Location, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).GetLocation[0:len((*c.CallOptions).GetLocation):len((*c.CallOptions).GetLocation)], opts...)
	var resp *locationpb.Location
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.locationsClient.GetLocation, req, settings.GRPC, c.logger, "GetLocation")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) ListLocations(ctx context.Context, req *locationpb.ListLocationsRequest, opts ...gax.CallOption) *LocationIterator {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).ListLocations[0:len((*c.CallOptions).ListLocations):len((*c.CallOptions).ListLocations)], opts...)
	it := &LocationIterator{}
	req = proto.Clone(req).(*locationpb.ListLocationsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*locationpb.Location, string, error) {
		resp := &locationpb.ListLocationsResponse{}
		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 = executeRPC(ctx, c.locationsClient.ListLocations, req, settings.GRPC, c.logger, "ListLocations")
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetLocations(), 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 *sessionsGRPCClient) CancelOperation(ctx context.Context, req *longrunningpb.CancelOperationRequest, opts ...gax.CallOption) error {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).CancelOperation[0:len((*c.CallOptions).CancelOperation):len((*c.CallOptions).CancelOperation)], opts...)
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		_, err = executeRPC(ctx, c.operationsClient.CancelOperation, req, settings.GRPC, c.logger, "CancelOperation")
		return err
	}, opts...)
	return err
}

func (c *sessionsGRPCClient) GetOperation(ctx context.Context, req *longrunningpb.GetOperationRequest, opts ...gax.CallOption) (*longrunningpb.Operation, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).GetOperation[0:len((*c.CallOptions).GetOperation):len((*c.CallOptions).GetOperation)], opts...)
	var resp *longrunningpb.Operation
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.operationsClient.GetOperation, req, settings.GRPC, c.logger, "GetOperation")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *sessionsGRPCClient) ListOperations(ctx context.Context, req *longrunningpb.ListOperationsRequest, opts ...gax.CallOption) *OperationIterator {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).ListOperations[0:len((*c.CallOptions).ListOperations):len((*c.CallOptions).ListOperations)], opts...)
	it := &OperationIterator{}
	req = proto.Clone(req).(*longrunningpb.ListOperationsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*longrunningpb.Operation, string, error) {
		resp := &longrunningpb.ListOperationsResponse{}
		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 = executeRPC(ctx, c.operationsClient.ListOperations, req, settings.GRPC, c.logger, "ListOperations")
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetOperations(), 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
}

// DetectIntent processes a natural language query and returns structured, actionable data
// as a result. This method is not idempotent, because it may cause session
// entity types to be updated, which in turn might affect results of future
// queries.
//
// Note: Always use agent versions for production traffic.
// See Versions and
// environments (at https://cloud.google.com/dialogflow/cx/docs/concept/version).
func (c *sessionsRESTClient) DetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (*cxpb.DetectIntentResponse, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:detectIntent", req.GetSession())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).DetectIntent[0:len((*c.CallOptions).DetectIntent):len((*c.CallOptions).DetectIntent)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &cxpb.DetectIntentResponse{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "DetectIntent")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// ServerStreamingDetectIntent processes a natural language query and returns structured, actionable data
// as a result through server-side streaming. Server-side streaming allows
// Dialogflow to send partial
// responses (at https://cloud.google.com/dialogflow/cx/docs/concept/fulfillment#partial-response)
// earlier in a single request.
func (c *sessionsRESTClient) ServerStreamingDetectIntent(ctx context.Context, req *cxpb.DetectIntentRequest, opts ...gax.CallOption) (cxpb.Sessions_ServerStreamingDetectIntentClient, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:serverStreamingDetectIntent", req.GetSession())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	var streamClient *serverStreamingDetectIntentRESTClient
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		httpRsp, err := executeStreamingHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "ServerStreamingDetectIntent")
		if err != nil {
			return err
		}

		streamClient = &serverStreamingDetectIntentRESTClient{
			ctx:    ctx,
			md:     metadata.MD(httpRsp.Header),
			stream: gax.NewProtoJSONStreamReader(httpRsp.Body, (&cxpb.DetectIntentResponse{}).ProtoReflect().Type()),
		}
		return nil
	}, opts...)

	return streamClient, e
}

// serverStreamingDetectIntentRESTClient is the stream client used to consume the server stream created by
// the REST implementation of ServerStreamingDetectIntent.
type serverStreamingDetectIntentRESTClient struct {
	ctx    context.Context
	md     metadata.MD
	stream *gax.ProtoJSONStream
}

func (c *serverStreamingDetectIntentRESTClient) Recv() (*cxpb.DetectIntentResponse, error) {
	if err := c.ctx.Err(); err != nil {
		defer c.stream.Close()
		return nil, err
	}
	msg, err := c.stream.Recv()
	if err != nil {
		defer c.stream.Close()
		return nil, err
	}
	res := msg.(*cxpb.DetectIntentResponse)
	return res, nil
}

func (c *serverStreamingDetectIntentRESTClient) Header() (metadata.MD, error) {
	return c.md, nil
}

func (c *serverStreamingDetectIntentRESTClient) Trailer() metadata.MD {
	return c.md
}

func (c *serverStreamingDetectIntentRESTClient) CloseSend() error {
	// This is a no-op to fulfill the interface.
	return errors.New("this method is not implemented for a server-stream")
}

func (c *serverStreamingDetectIntentRESTClient) Context() context.Context {
	return c.ctx
}

func (c *serverStreamingDetectIntentRESTClient) SendMsg(m interface{}) error {
	// This is a no-op to fulfill the interface.
	return errors.New("this method is not implemented for a server-stream")
}

func (c *serverStreamingDetectIntentRESTClient) RecvMsg(m interface{}) error {
	// This is a no-op to fulfill the interface.
	return errors.New("this method is not implemented, use Recv")
}

// StreamingDetectIntent processes a natural language query in audio format in a streaming fashion
// and returns structured, actionable data as a result. This method is only
// available via the gRPC API (not REST).
//
// Note: Always use agent versions for production traffic.
// See Versions and
// environments (at https://cloud.google.com/dialogflow/cx/docs/concept/version).
//
// This method is not supported for the REST transport.
func (c *sessionsRESTClient) StreamingDetectIntent(ctx context.Context, opts ...gax.CallOption) (cxpb.Sessions_StreamingDetectIntentClient, error) {
	return nil, errors.New("StreamingDetectIntent not yet supported for REST clients")
}

// MatchIntent returns preliminary intent match results, doesn’t change the session
// status.
func (c *sessionsRESTClient) MatchIntent(ctx context.Context, req *cxpb.MatchIntentRequest, opts ...gax.CallOption) (*cxpb.MatchIntentResponse, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:matchIntent", req.GetSession())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).MatchIntent[0:len((*c.CallOptions).MatchIntent):len((*c.CallOptions).MatchIntent)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &cxpb.MatchIntentResponse{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "MatchIntent")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// FulfillIntent fulfills a matched intent returned by
// MatchIntent.
// Must be called after
// MatchIntent,
// with input from
// MatchIntentResponse.
// Otherwise, the behavior is undefined.
func (c *sessionsRESTClient) FulfillIntent(ctx context.Context, req *cxpb.FulfillIntentRequest, opts ...gax.CallOption) (*cxpb.FulfillIntentResponse, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:fulfillIntent", req.GetMatchIntentRequest().GetSession())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "match_intent_request.session", url.QueryEscape(req.GetMatchIntentRequest().GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).FulfillIntent[0:len((*c.CallOptions).FulfillIntent):len((*c.CallOptions).FulfillIntent)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &cxpb.FulfillIntentResponse{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "FulfillIntent")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// SubmitAnswerFeedback updates the feedback received from the user for a single turn of the bot
// response.
func (c *sessionsRESTClient) SubmitAnswerFeedback(ctx context.Context, req *cxpb.SubmitAnswerFeedbackRequest, opts ...gax.CallOption) (*cxpb.AnswerFeedback, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:submitAnswerFeedback", req.GetSession())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "session", url.QueryEscape(req.GetSession()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).SubmitAnswerFeedback[0:len((*c.CallOptions).SubmitAnswerFeedback):len((*c.CallOptions).SubmitAnswerFeedback)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &cxpb.AnswerFeedback{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "SubmitAnswerFeedback")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// GetLocation gets information about a location.
func (c *sessionsRESTClient) GetLocation(ctx context.Context, req *locationpb.GetLocationRequest, opts ...gax.CallOption) (*locationpb.Location, error) {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v", req.GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).GetLocation[0:len((*c.CallOptions).GetLocation):len((*c.CallOptions).GetLocation)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &locationpb.Location{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, nil, "GetLocation")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// ListLocations lists information about the supported locations for this service.
func (c *sessionsRESTClient) ListLocations(ctx context.Context, req *locationpb.ListLocationsRequest, opts ...gax.CallOption) *LocationIterator {
	it := &LocationIterator{}
	req = proto.Clone(req).(*locationpb.ListLocationsRequest)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]*locationpb.Location, string, error) {
		resp := &locationpb.ListLocationsResponse{}
		if pageToken != "" {
			req.PageToken = pageToken
		}
		if pageSize > math.MaxInt32 {
			req.PageSize = math.MaxInt32
		} else if pageSize != 0 {
			req.PageSize = int32(pageSize)
		}
		baseUrl, err := url.Parse(c.endpoint)
		if err != nil {
			return nil, "", err
		}
		baseUrl.Path += fmt.Sprintf("/v3beta1/%v/locations", req.GetName())

		params := url.Values{}
		params.Add("$alt", "json;enum-encoding=int")
		if req.GetFilter() != "" {
			params.Add("filter", fmt.Sprintf("%v", req.GetFilter()))
		}
		if req.GetPageSize() != 0 {
			params.Add("pageSize", fmt.Sprintf("%v", req.GetPageSize()))
		}
		if req.GetPageToken() != "" {
			params.Add("pageToken", fmt.Sprintf("%v", req.GetPageToken()))
		}

		baseUrl.RawQuery = params.Encode()

		// Build HTTP headers from client and context metadata.
		hds := append(c.xGoogHeaders, "Content-Type", "application/json")
		headers := gax.BuildHeaders(ctx, hds...)
		e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
			if settings.Path != "" {
				baseUrl.Path = settings.Path
			}
			httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
			if err != nil {
				return err
			}
			httpReq.Header = headers

			buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, nil, "ListLocations")
			if err != nil {
				return err
			}
			if err := unm.Unmarshal(buf, resp); err != nil {
				return err
			}

			return nil
		}, opts...)
		if e != nil {
			return nil, "", e
		}
		it.Response = resp
		return resp.GetLocations(), 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
}

// CancelOperation is a utility method from google.longrunning.Operations.
func (c *sessionsRESTClient) CancelOperation(ctx context.Context, req *longrunningpb.CancelOperationRequest, opts ...gax.CallOption) error {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v:cancel", req.GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	return gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("POST", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		_, err = executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, nil, "CancelOperation")
		return err
	}, opts...)
}

// GetOperation is a utility method from google.longrunning.Operations.
func (c *sessionsRESTClient) GetOperation(ctx context.Context, req *longrunningpb.GetOperationRequest, opts ...gax.CallOption) (*longrunningpb.Operation, error) {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v3beta1/%v", req.GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "name", url.QueryEscape(req.GetName()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).GetOperation[0:len((*c.CallOptions).GetOperation):len((*c.CallOptions).GetOperation)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &longrunningpb.Operation{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, nil, "GetOperation")
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return err
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// ListOperations is a utility method from google.longrunning.Operations.
func (c *sessionsRESTClient) ListOperations(ctx context.Context, req *longrunningpb.ListOperationsRequest, opts ...gax.CallOption) *OperationIterator {
	it := &OperationIterator{}
	req = proto.Clone(req).(*longrunningpb.ListOperationsRequest)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]*longrunningpb.Operation, string, error) {
		resp := &longrunningpb.ListOperationsResponse{}
		if pageToken != "" {
			req.PageToken = pageToken
		}
		if pageSize > math.MaxInt32 {
			req.PageSize = math.MaxInt32
		} else if pageSize != 0 {
			req.PageSize = int32(pageSize)
		}
		baseUrl, err := url.Parse(c.endpoint)
		if err != nil {
			return nil, "", err
		}
		baseUrl.Path += fmt.Sprintf("/v3beta1/%v/operations", req.GetName())

		params := url.Values{}
		params.Add("$alt", "json;enum-encoding=int")
		if req.GetFilter() != "" {
			params.Add("filter", fmt.Sprintf("%v", req.GetFilter()))
		}
		if req.GetPageSize() != 0 {
			params.Add("pageSize", fmt.Sprintf("%v", req.GetPageSize()))
		}
		if req.GetPageToken() != "" {
			params.Add("pageToken", fmt.Sprintf("%v", req.GetPageToken()))
		}

		baseUrl.RawQuery = params.Encode()

		// Build HTTP headers from client and context metadata.
		hds := append(c.xGoogHeaders, "Content-Type", "application/json")
		headers := gax.BuildHeaders(ctx, hds...)
		e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
			if settings.Path != "" {
				baseUrl.Path = settings.Path
			}
			httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
			if err != nil {
				return err
			}
			httpReq.Header = headers

			buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, nil, "ListOperations")
			if err != nil {
				return err
			}
			if err := unm.Unmarshal(buf, resp); err != nil {
				return err
			}

			return nil
		}, opts...)
		if e != nil {
			return nil, "", e
		}
		it.Response = resp
		return resp.GetOperations(), 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
}
