firestore_client.go

// 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 firestore

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

	firestorepb "cloud.google.com/go/firestore/apiv1/firestorepb"
	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"
	"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 newClientHook clientHook

// CallOptions contains the retry settings for each method of Client.
type CallOptions struct {
	GetDocument         []gax.CallOption
	ListDocuments       []gax.CallOption
	UpdateDocument      []gax.CallOption
	DeleteDocument      []gax.CallOption
	BatchGetDocuments   []gax.CallOption
	BeginTransaction    []gax.CallOption
	Commit              []gax.CallOption
	Rollback            []gax.CallOption
	RunQuery            []gax.CallOption
	RunAggregationQuery []gax.CallOption
	PartitionQuery      []gax.CallOption
	Write               []gax.CallOption
	Listen              []gax.CallOption
	ListCollectionIds   []gax.CallOption
	BatchWrite          []gax.CallOption
	CreateDocument      []gax.CallOption
	CancelOperation     []gax.CallOption
	DeleteOperation     []gax.CallOption
	GetOperation        []gax.CallOption
	ListOperations      []gax.CallOption
}

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

func defaultCallOptions() *CallOptions {
	return &CallOptions{
		GetDocument: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		ListDocuments: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		UpdateDocument: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		DeleteDocument: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		BatchGetDocuments: []gax.CallOption{
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		BeginTransaction: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		Commit: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		Rollback: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		RunQuery: []gax.CallOption{
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		RunAggregationQuery: []gax.CallOption{
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		PartitionQuery: []gax.CallOption{
			gax.WithTimeout(300000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		Write: []gax.CallOption{},
		Listen: []gax.CallOption{
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		ListCollectionIds: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Internal,
					codes.DeadlineExceeded,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		BatchWrite: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
					codes.Aborted,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		CreateDocument: []gax.CallOption{
			gax.WithTimeout(60000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnCodes([]codes.Code{
					codes.ResourceExhausted,
					codes.Unavailable,
				}, gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				})
			}),
		},
		CancelOperation: []gax.CallOption{},
		DeleteOperation: []gax.CallOption{},
		GetOperation:    []gax.CallOption{},
		ListOperations:  []gax.CallOption{},
	}
}

func defaultRESTCallOptions() *CallOptions {
	return &CallOptions{
		GetDocument: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		ListDocuments: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		UpdateDocument: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable)
			}),
		},
		DeleteDocument: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		BatchGetDocuments: []gax.CallOption{
			gax.WithTimeout(300000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		BeginTransaction: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		Commit: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable)
			}),
		},
		Rollback: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		RunQuery: []gax.CallOption{
			gax.WithTimeout(300000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		RunAggregationQuery: []gax.CallOption{
			gax.WithTimeout(300000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		PartitionQuery: []gax.CallOption{
			gax.WithTimeout(300000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		Write: []gax.CallOption{
			gax.WithTimeout(86400000 * time.Millisecond),
		},
		Listen: []gax.CallOption{
			gax.WithTimeout(86400000 * time.Millisecond),
			gax.WithRetry(func() gax.Retryer {
				return gax.OnHTTPCodes(gax.Backoff{
					Initial:    100 * time.Millisecond,
					Max:        60000 * time.Millisecond,
					Multiplier: 1.30,
				},
					http.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		ListCollectionIds: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusInternalServerError,
					http.StatusGatewayTimeout)
			}),
		},
		BatchWrite: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable,
					http.StatusConflict)
			}),
		},
		CreateDocument: []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.StatusTooManyRequests,
					http.StatusServiceUnavailable)
			}),
		},
		CancelOperation: []gax.CallOption{},
		DeleteOperation: []gax.CallOption{},
		GetOperation:    []gax.CallOption{},
		ListOperations:  []gax.CallOption{},
	}
}

// internalClient is an interface that defines the methods available from Cloud Firestore API.
type internalClient interface {
	Close() error
	setGoogleClientInfo(...string)
	Connection() *grpc.ClientConn
	GetDocument(context.Context, *firestorepb.GetDocumentRequest, ...gax.CallOption) (*firestorepb.Document, error)
	ListDocuments(context.Context, *firestorepb.ListDocumentsRequest, ...gax.CallOption) *DocumentIterator
	UpdateDocument(context.Context, *firestorepb.UpdateDocumentRequest, ...gax.CallOption) (*firestorepb.Document, error)
	DeleteDocument(context.Context, *firestorepb.DeleteDocumentRequest, ...gax.CallOption) error
	BatchGetDocuments(context.Context, *firestorepb.BatchGetDocumentsRequest, ...gax.CallOption) (firestorepb.Firestore_BatchGetDocumentsClient, error)
	BeginTransaction(context.Context, *firestorepb.BeginTransactionRequest, ...gax.CallOption) (*firestorepb.BeginTransactionResponse, error)
	Commit(context.Context, *firestorepb.CommitRequest, ...gax.CallOption) (*firestorepb.CommitResponse, error)
	Rollback(context.Context, *firestorepb.RollbackRequest, ...gax.CallOption) error
	RunQuery(context.Context, *firestorepb.RunQueryRequest, ...gax.CallOption) (firestorepb.Firestore_RunQueryClient, error)
	RunAggregationQuery(context.Context, *firestorepb.RunAggregationQueryRequest, ...gax.CallOption) (firestorepb.Firestore_RunAggregationQueryClient, error)
	PartitionQuery(context.Context, *firestorepb.PartitionQueryRequest, ...gax.CallOption) *CursorIterator
	Write(context.Context, ...gax.CallOption) (firestorepb.Firestore_WriteClient, error)
	Listen(context.Context, ...gax.CallOption) (firestorepb.Firestore_ListenClient, error)
	ListCollectionIds(context.Context, *firestorepb.ListCollectionIdsRequest, ...gax.CallOption) *StringIterator
	BatchWrite(context.Context, *firestorepb.BatchWriteRequest, ...gax.CallOption) (*firestorepb.BatchWriteResponse, error)
	CreateDocument(context.Context, *firestorepb.CreateDocumentRequest, ...gax.CallOption) (*firestorepb.Document, error)
	CancelOperation(context.Context, *longrunningpb.CancelOperationRequest, ...gax.CallOption) error
	DeleteOperation(context.Context, *longrunningpb.DeleteOperationRequest, ...gax.CallOption) error
	GetOperation(context.Context, *longrunningpb.GetOperationRequest, ...gax.CallOption) (*longrunningpb.Operation, error)
	ListOperations(context.Context, *longrunningpb.ListOperationsRequest, ...gax.CallOption) *OperationIterator
}

// Client is a client for interacting with Cloud Firestore API.
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
//
// The Cloud Firestore service.
//
// Cloud Firestore is a fast, fully managed, serverless, cloud-native NoSQL
// document database that simplifies storing, syncing, and querying data for
// your mobile, web, and IoT apps at global scale. Its client libraries provide
// live synchronization and offline support, while its security features and
// integrations with Firebase and Google Cloud Platform accelerate building
// truly serverless apps.
type Client struct {
	// The internal transport-dependent client.
	internalClient internalClient

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

// 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: Connections are now pooled so this method does not always
// return the same resource.
func (c *Client) Connection() *grpc.ClientConn {
	return c.internalClient.Connection()
}

// GetDocument gets a single document.
func (c *Client) GetDocument(ctx context.Context, req *firestorepb.GetDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	return c.internalClient.GetDocument(ctx, req, opts...)
}

// ListDocuments lists documents.
func (c *Client) ListDocuments(ctx context.Context, req *firestorepb.ListDocumentsRequest, opts ...gax.CallOption) *DocumentIterator {
	return c.internalClient.ListDocuments(ctx, req, opts...)
}

// UpdateDocument updates or inserts a document.
func (c *Client) UpdateDocument(ctx context.Context, req *firestorepb.UpdateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	return c.internalClient.UpdateDocument(ctx, req, opts...)
}

// DeleteDocument deletes a document.
func (c *Client) DeleteDocument(ctx context.Context, req *firestorepb.DeleteDocumentRequest, opts ...gax.CallOption) error {
	return c.internalClient.DeleteDocument(ctx, req, opts...)
}

// BatchGetDocuments gets multiple documents.
//
// Documents returned by this method are not guaranteed to be returned in the
// same order that they were requested.
func (c *Client) BatchGetDocuments(ctx context.Context, req *firestorepb.BatchGetDocumentsRequest, opts ...gax.CallOption) (firestorepb.Firestore_BatchGetDocumentsClient, error) {
	return c.internalClient.BatchGetDocuments(ctx, req, opts...)
}

// BeginTransaction starts a new transaction.
func (c *Client) BeginTransaction(ctx context.Context, req *firestorepb.BeginTransactionRequest, opts ...gax.CallOption) (*firestorepb.BeginTransactionResponse, error) {
	return c.internalClient.BeginTransaction(ctx, req, opts...)
}

// Commit commits a transaction, while optionally updating documents.
func (c *Client) Commit(ctx context.Context, req *firestorepb.CommitRequest, opts ...gax.CallOption) (*firestorepb.CommitResponse, error) {
	return c.internalClient.Commit(ctx, req, opts...)
}

// Rollback rolls back a transaction.
func (c *Client) Rollback(ctx context.Context, req *firestorepb.RollbackRequest, opts ...gax.CallOption) error {
	return c.internalClient.Rollback(ctx, req, opts...)
}

// RunQuery runs a query.
func (c *Client) RunQuery(ctx context.Context, req *firestorepb.RunQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunQueryClient, error) {
	return c.internalClient.RunQuery(ctx, req, opts...)
}

// RunAggregationQuery runs an aggregation query.
//
// Rather than producing Document results like
// Firestore.RunQuery, this API
// allows running an aggregation to produce a series of
// AggregationResult server-side.
//
// High-Level Example:
func (c *Client) RunAggregationQuery(ctx context.Context, req *firestorepb.RunAggregationQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunAggregationQueryClient, error) {
	return c.internalClient.RunAggregationQuery(ctx, req, opts...)
}

// PartitionQuery partitions a query by returning partition cursors that can be used to run
// the query in parallel. The returned partition cursors are split points that
// can be used by RunQuery as starting/end points for the query results.
func (c *Client) PartitionQuery(ctx context.Context, req *firestorepb.PartitionQueryRequest, opts ...gax.CallOption) *CursorIterator {
	return c.internalClient.PartitionQuery(ctx, req, opts...)
}

// Write streams batches of document updates and deletes, in order. This method is
// only available via gRPC or WebChannel (not REST).
//
// This method is not supported for the REST transport.
func (c *Client) Write(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_WriteClient, error) {
	return c.internalClient.Write(ctx, opts...)
}

// Listen listens to changes. This method is only available via gRPC or WebChannel
// (not REST).
//
// This method is not supported for the REST transport.
func (c *Client) Listen(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_ListenClient, error) {
	return c.internalClient.Listen(ctx, opts...)
}

// ListCollectionIds lists all the collection IDs underneath a document.
func (c *Client) ListCollectionIds(ctx context.Context, req *firestorepb.ListCollectionIdsRequest, opts ...gax.CallOption) *StringIterator {
	return c.internalClient.ListCollectionIds(ctx, req, opts...)
}

// BatchWrite applies a batch of write operations.
//
// The BatchWrite method does not apply the write operations atomically
// and can apply them out of order. Method does not allow more than one write
// per document. Each write succeeds or fails independently. See the
// BatchWriteResponse for the
// success status of each write.
//
// If you require an atomically applied set of writes, use
// Commit instead.
func (c *Client) BatchWrite(ctx context.Context, req *firestorepb.BatchWriteRequest, opts ...gax.CallOption) (*firestorepb.BatchWriteResponse, error) {
	return c.internalClient.BatchWrite(ctx, req, opts...)
}

// CreateDocument creates a new document.
func (c *Client) CreateDocument(ctx context.Context, req *firestorepb.CreateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	return c.internalClient.CreateDocument(ctx, req, opts...)
}

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

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

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

// gRPCClient is a client for interacting with Cloud Firestore 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

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

	// The gRPC API client.
	client firestorepb.FirestoreClient

	operationsClient longrunningpb.OperationsClient

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

	logger *slog.Logger
}

// NewClient creates a new firestore client based on gRPC.
// The returned client must be Closed when it is done being used to clean up its underlying connections.
//
// The Cloud Firestore service.
//
// Cloud Firestore is a fast, fully managed, serverless, cloud-native NoSQL
// document database that simplifies storing, syncing, and querying data for
// your mobile, web, and IoT apps at global scale. Its client libraries provide
// live synchronization and offline support, while its security features and
// integrations with Firebase and Google Cloud Platform accelerate building
// truly serverless apps.
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...)
	}

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

	c := &gRPCClient{
		connPool:         connPool,
		client:           firestorepb.NewFirestoreClient(connPool),
		CallOptions:      &client.CallOptions,
		logger:           internaloption.GetLogger(opts),
		operationsClient: longrunningpb.NewOperationsClient(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 *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", 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 *gRPCClient) Close() error {
	return c.connPool.Close()
}

// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
type restClient 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 Client
	CallOptions **CallOptions

	logger *slog.Logger
}

// NewRESTClient creates a new firestore rest client.
//
// The Cloud Firestore service.
//
// Cloud Firestore is a fast, fully managed, serverless, cloud-native NoSQL
// document database that simplifies storing, syncing, and querying data for
// your mobile, web, and IoT apps at global scale. Its client libraries provide
// live synchronization and offline support, while its security features and
// integrations with Firebase and Google Cloud Platform accelerate building
// truly serverless apps.
func NewRESTClient(ctx context.Context, opts ...option.ClientOption) (*Client, error) {
	clientOpts := append(defaultRESTClientOptions(), opts...)
	httpClient, endpoint, err := httptransport.NewClient(ctx, clientOpts...)
	if err != nil {
		return nil, err
	}

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

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

func defaultRESTClientOptions() []option.ClientOption {
	return []option.ClientOption{
		internaloption.WithDefaultEndpoint("https://firestore.googleapis.com"),
		internaloption.WithDefaultEndpointTemplate("https://firestore.UNIVERSE_DOMAIN"),
		internaloption.WithDefaultMTLSEndpoint("https://firestore.mtls.googleapis.com"),
		internaloption.WithDefaultUniverseDomain("googleapis.com"),
		internaloption.WithDefaultAudience("https://firestore.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 *restClient) 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 *restClient) 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 *restClient) Connection() *grpc.ClientConn {
	return nil
}
func (c *gRPCClient) GetDocument(ctx context.Context, req *firestorepb.GetDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, 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).GetDocument[0:len((*c.CallOptions).GetDocument):len((*c.CallOptions).GetDocument)], opts...)
	var resp *firestorepb.Document
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		resp, err = executeRPC(ctx, c.client.GetDocument, req, settings.GRPC, c.logger, "GetDocument")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) ListDocuments(ctx context.Context, req *firestorepb.ListDocumentsRequest, opts ...gax.CallOption) *DocumentIterator {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v&%s=%v", "parent", url.QueryEscape(req.GetParent()), "collection_id", url.QueryEscape(req.GetCollectionId()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).ListDocuments[0:len((*c.CallOptions).ListDocuments):len((*c.CallOptions).ListDocuments)], opts...)
	it := &DocumentIterator{}
	req = proto.Clone(req).(*firestorepb.ListDocumentsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*firestorepb.Document, string, error) {
		resp := &firestorepb.ListDocumentsResponse{}
		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.client.ListDocuments, req, settings.GRPC, c.logger, "ListDocuments")
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetDocuments(), 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) UpdateDocument(ctx context.Context, req *firestorepb.UpdateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "document.name", url.QueryEscape(req.GetDocument().GetName()))}

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

func (c *gRPCClient) DeleteDocument(ctx context.Context, req *firestorepb.DeleteDocumentRequest, 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).DeleteDocument[0:len((*c.CallOptions).DeleteDocument):len((*c.CallOptions).DeleteDocument)], opts...)
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		_, err = executeRPC(ctx, c.client.DeleteDocument, req, settings.GRPC, c.logger, "DeleteDocument")
		return err
	}, opts...)
	return err
}

func (c *gRPCClient) BatchGetDocuments(ctx context.Context, req *firestorepb.BatchGetDocumentsRequest, opts ...gax.CallOption) (firestorepb.Firestore_BatchGetDocumentsClient, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "database", url.QueryEscape(req.GetDatabase()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).BatchGetDocuments[0:len((*c.CallOptions).BatchGetDocuments):len((*c.CallOptions).BatchGetDocuments)], opts...)
	var resp firestorepb.Firestore_BatchGetDocumentsClient
	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", "BatchGetDocuments")
		resp, err = c.client.BatchGetDocuments(ctx, req, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "BatchGetDocuments")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) BeginTransaction(ctx context.Context, req *firestorepb.BeginTransactionRequest, opts ...gax.CallOption) (*firestorepb.BeginTransactionResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "database", url.QueryEscape(req.GetDatabase()))}

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

func (c *gRPCClient) Commit(ctx context.Context, req *firestorepb.CommitRequest, opts ...gax.CallOption) (*firestorepb.CommitResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "database", url.QueryEscape(req.GetDatabase()))}

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

func (c *gRPCClient) Rollback(ctx context.Context, req *firestorepb.RollbackRequest, opts ...gax.CallOption) error {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "database", url.QueryEscape(req.GetDatabase()))}

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

func (c *gRPCClient) RunQuery(ctx context.Context, req *firestorepb.RunQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunQueryClient, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).RunQuery[0:len((*c.CallOptions).RunQuery):len((*c.CallOptions).RunQuery)], opts...)
	var resp firestorepb.Firestore_RunQueryClient
	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", "RunQuery")
		resp, err = c.client.RunQuery(ctx, req, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "RunQuery")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) RunAggregationQuery(ctx context.Context, req *firestorepb.RunAggregationQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunAggregationQueryClient, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).RunAggregationQuery[0:len((*c.CallOptions).RunAggregationQuery):len((*c.CallOptions).RunAggregationQuery)], opts...)
	var resp firestorepb.Firestore_RunAggregationQueryClient
	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", "RunAggregationQuery")
		resp, err = c.client.RunAggregationQuery(ctx, req, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "RunAggregationQuery")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) PartitionQuery(ctx context.Context, req *firestorepb.PartitionQueryRequest, opts ...gax.CallOption) *CursorIterator {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).PartitionQuery[0:len((*c.CallOptions).PartitionQuery):len((*c.CallOptions).PartitionQuery)], opts...)
	it := &CursorIterator{}
	req = proto.Clone(req).(*firestorepb.PartitionQueryRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*firestorepb.Cursor, string, error) {
		resp := &firestorepb.PartitionQueryResponse{}
		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.client.PartitionQuery, req, settings.GRPC, c.logger, "PartitionQuery")
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetPartitions(), 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) Write(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_WriteClient, error) {
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, c.xGoogHeaders...)
	var resp firestorepb.Firestore_WriteClient
	opts = append((*c.CallOptions).Write[0:len((*c.CallOptions).Write):len((*c.CallOptions).Write)], 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", "Write")
		resp, err = c.client.Write(ctx, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "Write")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) Listen(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_ListenClient, error) {
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, c.xGoogHeaders...)
	var resp firestorepb.Firestore_ListenClient
	opts = append((*c.CallOptions).Listen[0:len((*c.CallOptions).Listen):len((*c.CallOptions).Listen)], 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", "Listen")
		resp, err = c.client.Listen(ctx, settings.GRPC...)
		c.logger.DebugContext(ctx, "api streaming client response", "serviceName", serviceName, "rpcName", "Listen")
		return err
	}, opts...)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *gRPCClient) ListCollectionIds(ctx context.Context, req *firestorepb.ListCollectionIdsRequest, opts ...gax.CallOption) *StringIterator {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	ctx = gax.InsertMetadataIntoOutgoingContext(ctx, hds...)
	opts = append((*c.CallOptions).ListCollectionIds[0:len((*c.CallOptions).ListCollectionIds):len((*c.CallOptions).ListCollectionIds)], opts...)
	it := &StringIterator{}
	req = proto.Clone(req).(*firestorepb.ListCollectionIdsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]string, string, error) {
		resp := &firestorepb.ListCollectionIdsResponse{}
		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.client.ListCollectionIds, req, settings.GRPC, c.logger, "ListCollectionIds")
			return err
		}, opts...)
		if err != nil {
			return nil, "", err
		}

		it.Response = resp
		return resp.GetCollectionIds(), 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) BatchWrite(ctx context.Context, req *firestorepb.BatchWriteRequest, opts ...gax.CallOption) (*firestorepb.BatchWriteResponse, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v", "database", url.QueryEscape(req.GetDatabase()))}

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

func (c *gRPCClient) CreateDocument(ctx context.Context, req *firestorepb.CreateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	hds := []string{"x-goog-request-params", fmt.Sprintf("%s=%v&%s=%v", "parent", url.QueryEscape(req.GetParent()), "collection_id", url.QueryEscape(req.GetCollectionId()))}

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

func (c *gRPCClient) 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 *gRPCClient) DeleteOperation(ctx context.Context, req *longrunningpb.DeleteOperationRequest, 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).DeleteOperation[0:len((*c.CallOptions).DeleteOperation):len((*c.CallOptions).DeleteOperation)], opts...)
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		var err error
		_, err = executeRPC(ctx, c.operationsClient.DeleteOperation, req, settings.GRPC, c.logger, "DeleteOperation")
		return err
	}, opts...)
	return err
}

func (c *gRPCClient) 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 *gRPCClient) 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
}

// GetDocument gets a single document.
func (c *restClient) GetDocument(ctx context.Context, req *firestorepb.GetDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%v", req.GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")
	if items := req.GetMask().GetFieldPaths(); len(items) > 0 {
		for _, item := range items {
			params.Add("mask.fieldPaths", fmt.Sprintf("%v", item))
		}
	}
	if req.GetReadTime() != nil {
		field, err := protojson.Marshal(req.GetReadTime())
		if err != nil {
			return nil, err
		}
		params.Add("readTime", string(field[1:len(field)-1]))
	}
	if req.GetTransaction() != nil {
		params.Add("transaction", fmt.Sprintf("%v", req.GetTransaction()))
	}

	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).GetDocument[0:len((*c.CallOptions).GetDocument):len((*c.CallOptions).GetDocument)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &firestorepb.Document{}
	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, "GetDocument")
		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
}

// ListDocuments lists documents.
func (c *restClient) ListDocuments(ctx context.Context, req *firestorepb.ListDocumentsRequest, opts ...gax.CallOption) *DocumentIterator {
	it := &DocumentIterator{}
	req = proto.Clone(req).(*firestorepb.ListDocumentsRequest)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]*firestorepb.Document, string, error) {
		resp := &firestorepb.ListDocumentsResponse{}
		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("/v1/%v/%v", req.GetParent(), req.GetCollectionId())

		params := url.Values{}
		params.Add("$alt", "json;enum-encoding=int")
		if items := req.GetMask().GetFieldPaths(); len(items) > 0 {
			for _, item := range items {
				params.Add("mask.fieldPaths", fmt.Sprintf("%v", item))
			}
		}
		if req.GetOrderBy() != "" {
			params.Add("orderBy", fmt.Sprintf("%v", req.GetOrderBy()))
		}
		if req.GetPageSize() != 0 {
			params.Add("pageSize", fmt.Sprintf("%v", req.GetPageSize()))
		}
		if req.GetPageToken() != "" {
			params.Add("pageToken", fmt.Sprintf("%v", req.GetPageToken()))
		}
		if req.GetReadTime() != nil {
			field, err := protojson.Marshal(req.GetReadTime())
			if err != nil {
				return nil, "", err
			}
			params.Add("readTime", string(field[1:len(field)-1]))
		}
		if req.GetShowMissing() {
			params.Add("showMissing", fmt.Sprintf("%v", req.GetShowMissing()))
		}
		if req.GetTransaction() != nil {
			params.Add("transaction", fmt.Sprintf("%v", req.GetTransaction()))
		}

		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, "ListDocuments")
			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.GetDocuments(), 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
}

// UpdateDocument updates or inserts a document.
func (c *restClient) UpdateDocument(ctx context.Context, req *firestorepb.UpdateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	body := req.GetDocument()
	jsonReq, err := m.Marshal(body)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%v", req.GetDocument().GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")
	if req.GetCurrentDocument().GetExists() {
		params.Add("currentDocument.exists", fmt.Sprintf("%v", req.GetCurrentDocument().GetExists()))
	}
	if req.GetCurrentDocument().GetUpdateTime() != nil {
		field, err := protojson.Marshal(req.GetCurrentDocument().GetUpdateTime())
		if err != nil {
			return nil, err
		}
		params.Add("currentDocument.updateTime", string(field[1:len(field)-1]))
	}
	if items := req.GetMask().GetFieldPaths(); len(items) > 0 {
		for _, item := range items {
			params.Add("mask.fieldPaths", fmt.Sprintf("%v", item))
		}
	}
	if items := req.GetUpdateMask().GetFieldPaths(); len(items) > 0 {
		for _, item := range items {
			params.Add("updateMask.fieldPaths", fmt.Sprintf("%v", item))
		}
	}

	baseUrl.RawQuery = params.Encode()

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

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

// DeleteDocument deletes a document.
func (c *restClient) DeleteDocument(ctx context.Context, req *firestorepb.DeleteDocumentRequest, opts ...gax.CallOption) error {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%v", req.GetName())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")
	if req.GetCurrentDocument().GetExists() {
		params.Add("currentDocument.exists", fmt.Sprintf("%v", req.GetCurrentDocument().GetExists()))
	}
	if req.GetCurrentDocument().GetUpdateTime() != nil {
		field, err := protojson.Marshal(req.GetCurrentDocument().GetUpdateTime())
		if err != nil {
			return err
		}
		params.Add("currentDocument.updateTime", string(field[1:len(field)-1]))
	}

	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("DELETE", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

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

// BatchGetDocuments gets multiple documents.
//
// Documents returned by this method are not guaranteed to be returned in the
// same order that they were requested.
func (c *restClient) BatchGetDocuments(ctx context.Context, req *firestorepb.BatchGetDocumentsRequest, opts ...gax.CallOption) (firestorepb.Firestore_BatchGetDocumentsClient, 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("/v1/%v/documents:batchGet", req.GetDatabase())

	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", "database", url.QueryEscape(req.GetDatabase()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	var streamClient *batchGetDocumentsRESTClient
	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, "BatchGetDocuments")
		if err != nil {
			return err
		}

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

	return streamClient, e
}

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

func (c *batchGetDocumentsRESTClient) Recv() (*firestorepb.BatchGetDocumentsResponse, 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.(*firestorepb.BatchGetDocumentsResponse)
	return res, nil
}

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

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

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

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

// BeginTransaction starts a new transaction.
func (c *restClient) BeginTransaction(ctx context.Context, req *firestorepb.BeginTransactionRequest, opts ...gax.CallOption) (*firestorepb.BeginTransactionResponse, 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("/v1/%v/documents:beginTransaction", req.GetDatabase())

	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", "database", url.QueryEscape(req.GetDatabase()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).BeginTransaction[0:len((*c.CallOptions).BeginTransaction):len((*c.CallOptions).BeginTransaction)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &firestorepb.BeginTransactionResponse{}
	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, "BeginTransaction")
		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
}

// Commit commits a transaction, while optionally updating documents.
func (c *restClient) Commit(ctx context.Context, req *firestorepb.CommitRequest, opts ...gax.CallOption) (*firestorepb.CommitResponse, 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("/v1/%v/documents:commit", req.GetDatabase())

	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", "database", url.QueryEscape(req.GetDatabase()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).Commit[0:len((*c.CallOptions).Commit):len((*c.CallOptions).Commit)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &firestorepb.CommitResponse{}
	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, "Commit")
		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
}

// Rollback rolls back a transaction.
func (c *restClient) Rollback(ctx context.Context, req *firestorepb.RollbackRequest, opts ...gax.CallOption) error {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%v/documents:rollback", req.GetDatabase())

	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", "database", url.QueryEscape(req.GetDatabase()))}

	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(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

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

// RunQuery runs a query.
func (c *restClient) RunQuery(ctx context.Context, req *firestorepb.RunQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunQueryClient, 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("/v1/%v:runQuery", req.GetParent())

	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", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	var streamClient *runQueryRESTClient
	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, "RunQuery")
		if err != nil {
			return err
		}

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

	return streamClient, e
}

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

func (c *runQueryRESTClient) Recv() (*firestorepb.RunQueryResponse, 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.(*firestorepb.RunQueryResponse)
	return res, nil
}

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

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

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

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

// RunAggregationQuery runs an aggregation query.
//
// Rather than producing Document results like
// Firestore.RunQuery, this API
// allows running an aggregation to produce a series of
// AggregationResult server-side.
//
// High-Level Example:
func (c *restClient) RunAggregationQuery(ctx context.Context, req *firestorepb.RunAggregationQueryRequest, opts ...gax.CallOption) (firestorepb.Firestore_RunAggregationQueryClient, 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("/v1/%v:runAggregationQuery", req.GetParent())

	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", "parent", url.QueryEscape(req.GetParent()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	var streamClient *runAggregationQueryRESTClient
	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, "RunAggregationQuery")
		if err != nil {
			return err
		}

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

	return streamClient, e
}

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

func (c *runAggregationQueryRESTClient) Recv() (*firestorepb.RunAggregationQueryResponse, 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.(*firestorepb.RunAggregationQueryResponse)
	return res, nil
}

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

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

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

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

// PartitionQuery partitions a query by returning partition cursors that can be used to run
// the query in parallel. The returned partition cursors are split points that
// can be used by RunQuery as starting/end points for the query results.
func (c *restClient) PartitionQuery(ctx context.Context, req *firestorepb.PartitionQueryRequest, opts ...gax.CallOption) *CursorIterator {
	it := &CursorIterator{}
	req = proto.Clone(req).(*firestorepb.PartitionQueryRequest)
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]*firestorepb.Cursor, string, error) {
		resp := &firestorepb.PartitionQueryResponse{}
		if pageToken != "" {
			req.PageToken = pageToken
		}
		if pageSize > math.MaxInt32 {
			req.PageSize = math.MaxInt32
		} else if pageSize != 0 {
			req.PageSize = int32(pageSize)
		}
		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("/v1/%v:partitionQuery", req.GetParent())

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

		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("POST", baseUrl.String(), bytes.NewReader(jsonReq))
			if err != nil {
				return err
			}
			httpReq.Header = headers

			buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "PartitionQuery")
			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.GetPartitions(), 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
}

// Write streams batches of document updates and deletes, in order. This method is
// only available via gRPC or WebChannel (not REST).
//
// This method is not supported for the REST transport.
func (c *restClient) Write(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_WriteClient, error) {
	return nil, errors.New("Write not yet supported for REST clients")
}

// Listen listens to changes. This method is only available via gRPC or WebChannel
// (not REST).
//
// This method is not supported for the REST transport.
func (c *restClient) Listen(ctx context.Context, opts ...gax.CallOption) (firestorepb.Firestore_ListenClient, error) {
	return nil, errors.New("Listen not yet supported for REST clients")
}

// ListCollectionIds lists all the collection IDs underneath a document.
func (c *restClient) ListCollectionIds(ctx context.Context, req *firestorepb.ListCollectionIdsRequest, opts ...gax.CallOption) *StringIterator {
	it := &StringIterator{}
	req = proto.Clone(req).(*firestorepb.ListCollectionIdsRequest)
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]string, string, error) {
		resp := &firestorepb.ListCollectionIdsResponse{}
		if pageToken != "" {
			req.PageToken = pageToken
		}
		if pageSize > math.MaxInt32 {
			req.PageSize = math.MaxInt32
		} else if pageSize != 0 {
			req.PageSize = int32(pageSize)
		}
		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("/v1/%v:listCollectionIds", req.GetParent())

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

		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("POST", baseUrl.String(), bytes.NewReader(jsonReq))
			if err != nil {
				return err
			}
			httpReq.Header = headers

			buf, err := executeHTTPRequest(ctx, c.httpClient, httpReq, c.logger, jsonReq, "ListCollectionIds")
			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.GetCollectionIds(), 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
}

// BatchWrite applies a batch of write operations.
//
// The BatchWrite method does not apply the write operations atomically
// and can apply them out of order. Method does not allow more than one write
// per document. Each write succeeds or fails independently. See the
// BatchWriteResponse for the
// success status of each write.
//
// If you require an atomically applied set of writes, use
// Commit instead.
func (c *restClient) BatchWrite(ctx context.Context, req *firestorepb.BatchWriteRequest, opts ...gax.CallOption) (*firestorepb.BatchWriteResponse, 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("/v1/%v/documents:batchWrite", req.GetDatabase())

	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", "database", url.QueryEscape(req.GetDatabase()))}

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).BatchWrite[0:len((*c.CallOptions).BatchWrite):len((*c.CallOptions).BatchWrite)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &firestorepb.BatchWriteResponse{}
	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, "BatchWrite")
		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
}

// CreateDocument creates a new document.
func (c *restClient) CreateDocument(ctx context.Context, req *firestorepb.CreateDocumentRequest, opts ...gax.CallOption) (*firestorepb.Document, error) {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	body := req.GetDocument()
	jsonReq, err := m.Marshal(body)
	if err != nil {
		return nil, err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return nil, err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%v/%v", req.GetParent(), req.GetCollectionId())

	params := url.Values{}
	params.Add("$alt", "json;enum-encoding=int")
	if req.GetDocumentId() != "" {
		params.Add("documentId", fmt.Sprintf("%v", req.GetDocumentId()))
	}
	if items := req.GetMask().GetFieldPaths(); len(items) > 0 {
		for _, item := range items {
			params.Add("mask.fieldPaths", fmt.Sprintf("%v", item))
		}
	}

	baseUrl.RawQuery = params.Encode()

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

	hds = append(c.xGoogHeaders, hds...)
	hds = append(hds, "Content-Type", "application/json")
	headers := gax.BuildHeaders(ctx, hds...)
	opts = append((*c.CallOptions).CreateDocument[0:len((*c.CallOptions).CreateDocument):len((*c.CallOptions).CreateDocument)], opts...)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &firestorepb.Document{}
	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, "CreateDocument")
		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
}

// CancelOperation is a utility method from google.longrunning.Operations.
func (c *restClient) CancelOperation(ctx context.Context, req *longrunningpb.CancelOperationRequest, opts ...gax.CallOption) error {
	m := protojson.MarshalOptions{AllowPartial: true, UseEnumNumbers: true}
	jsonReq, err := m.Marshal(req)
	if err != nil {
		return err
	}

	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%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(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

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

// DeleteOperation is a utility method from google.longrunning.Operations.
func (c *restClient) DeleteOperation(ctx context.Context, req *longrunningpb.DeleteOperationRequest, opts ...gax.CallOption) error {
	baseUrl, err := url.Parse(c.endpoint)
	if err != nil {
		return err
	}
	baseUrl.Path += fmt.Sprintf("/v1/%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...)
	return gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		if settings.Path != "" {
			baseUrl.Path = settings.Path
		}
		httpReq, err := http.NewRequest("DELETE", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

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

// GetOperation is a utility method from google.longrunning.Operations.
func (c *restClient) 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("/v1/%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 *restClient) 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("/v1/%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
}