text: // Copyright 2018 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.
  
  // AUTO-GENERATED CODE. DO NOT EDIT.
  
  package speech
  
  import (
  	"time"
  
  	"cloud.google.com/go/internal/version"
  	"cloud.google.com/go/longrunning"
  	lroauto "cloud.google.com/go/longrunning/autogen"
  	gax "github.com/googleapis/gax-go"
  	"golang.org/x/net/context"
  	"google.golang.org/api/option"
  	"google.golang.org/api/transport"
  	speechpb "google.golang.org/genproto/googleapis/cloud/speech/v1"
  	longrunningpb "google.golang.org/genproto/googleapis/longrunning"
  	"google.golang.org/grpc"
  	"google.golang.org/grpc/codes"
  	"google.golang.org/grpc/metadata"
  )
  
  // CallOptions contains the retry settings for each method of Client.
  type CallOptions struct {
  	Recognize            []gax.CallOption
  	LongRunningRecognize []gax.CallOption
  	StreamingRecognize   []gax.CallOption
  }
  
  func defaultClientOptions() []option.ClientOption {
  	return []option.ClientOption{
  		option.WithEndpoint("speech.googleapis.com:443"),
  		option.WithScopes(DefaultAuthScopes()...),
  	}
  }
  
  func defaultCallOptions() *CallOptions {
  	retry := map[[2]string][]gax.CallOption{
  		{"default", "idempotent"}: {
  			gax.WithRetry(func() gax.Retryer {
  				return gax.OnCodes([]codes.Code{
  					codes.DeadlineExceeded,
  					codes.Unavailable,
  				}, gax.Backoff{
  					Initial:    100 * time.Millisecond,
  					Max:        60000 * time.Millisecond,
  					Multiplier: 1.3,
  				})
  			}),
  		},
  	}
  	return &CallOptions{
  		Recognize:            retry[[2]string{"default", "idempotent"}],
  		LongRunningRecognize: retry[[2]string{"default", "non_idempotent"}],
  		StreamingRecognize:   retry[[2]string{"default", "idempotent"}],
  	}
  }
  
  // Client is a client for interacting with Google Cloud Speech API.
  type Client struct {
  	// The connection to the service.
  	conn *grpc.ClientConn
  
  	// The gRPC API client.
  	client speechpb.SpeechClient
  
  	// LROClient is used internally to handle longrunning operations.
  	// It is exposed so that its CallOptions can be modified if required.
  	// Users should not Close this client.
  	LROClient *lroauto.OperationsClient
  
  	// The call options for this service.
  	CallOptions *CallOptions
  
  	// The x-goog-* metadata to be sent with each request.
  	xGoogMetadata metadata.MD
  }
  
  // NewClient creates a new speech client.
  //
  // Service that implements Google Cloud Speech API.
  func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error) {
  	conn, err := transport.DialGRPC(ctx, append(defaultClientOptions(), opts...)...)
  	if err != nil {
  		return nil, err
  	}
  	c := &Client{
  		conn:        conn,
  		CallOptions: defaultCallOptions(),
  
  		client: speechpb.NewSpeechClient(conn),
  	}
  	c.setGoogleClientInfo()
  
  	c.LROClient, err = lroauto.NewOperationsClient(ctx, option.WithGRPCConn(conn))
  	if err != nil {
  		// This error "should not happen", since we are just reusing old connection
  		// and never actually need to dial.
  		// If this does happen, we could leak conn. However, we cannot close conn:
  		// If the user invoked the function with option.WithGRPCConn,
  		// we would close a connection that's still in use.
  		// TODO(pongad): investigate error conditions.
  		return nil, err
  	}
  	return c, nil
  }
  
  // Connection returns the client's connection to the API service.
  func (c *Client) Connection() *grpc.ClientConn {
  	return c.conn
  }
  
  // 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.conn.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) {
  	kv := append([]string{"gl-go", version.Go()}, keyval...)
  	kv = append(kv, "gapic", version.Repo, "gax", gax.Version, "grpc", grpc.Version)
  	c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
  }
  
  // Recognize performs synchronous speech recognition: receive results after all audio
  // has been sent and processed.
  func (c *Client) Recognize(ctx context.Context, req *speechpb.RecognizeRequest, opts ...gax.CallOption) (*speechpb.RecognizeResponse, error) {
  	ctx = insertMetadata(ctx, c.xGoogMetadata)
  	opts = append(c.CallOptions.Recognize[0:len(c.CallOptions.Recognize):len(c.CallOptions.Recognize)], opts...)
  	var resp *speechpb.RecognizeResponse
  	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
  		var err error
  		resp, err = c.client.Recognize(ctx, req, settings.GRPC...)
  		return err
  	}, opts...)
  	if err != nil {
  		return nil, err
  	}
  	return resp, nil
  }
  
  // LongRunningRecognize performs asynchronous speech recognition: receive results via the
  // google.longrunning.Operations interface. Returns either an
  // Operation.error or an Operation.response which contains
  // a LongRunningRecognizeResponse message.
  func (c *Client) LongRunningRecognize(ctx context.Context, req *speechpb.LongRunningRecognizeRequest, opts ...gax.CallOption) (*LongRunningRecognizeOperation, error) {
  	ctx = insertMetadata(ctx, c.xGoogMetadata)
  	opts = append(c.CallOptions.LongRunningRecognize[0:len(c.CallOptions.LongRunningRecognize):len(c.CallOptions.LongRunningRecognize)], opts...)
  	var resp *longrunningpb.Operation
  	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
  		var err error
  		resp, err = c.client.LongRunningRecognize(ctx, req, settings.GRPC...)
  		return err
  	}, opts...)
  	if err != nil {
  		return nil, err
  	}
  	return &LongRunningRecognizeOperation{
  		lro: longrunning.InternalNewOperation(c.LROClient, resp),
  	}, nil
  }
  
  // StreamingRecognize performs bidirectional streaming speech recognition: receive results while
  // sending audio. This method is only available via the gRPC API (not REST).
  func (c *Client) StreamingRecognize(ctx context.Context, opts ...gax.CallOption) (speechpb.Speech_StreamingRecognizeClient, error) {
  	ctx = insertMetadata(ctx, c.xGoogMetadata)
  	opts = append(c.CallOptions.StreamingRecognize[0:len(c.CallOptions.StreamingRecognize):len(c.CallOptions.StreamingRecognize)], opts...)
  	var resp speechpb.Speech_StreamingRecognizeClient
  	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
  		var err error
  		resp, err = c.client.StreamingRecognize(ctx, settings.GRPC...)
  		return err
  	}, opts...)
  	if err != nil {
  		return nil, err
  	}
  	return resp, nil
  }
  
  // LongRunningRecognizeOperation manages a long-running operation from LongRunningRecognize.
  type LongRunningRecognizeOperation struct {
  	lro *longrunning.Operation
  }
  
  // LongRunningRecognizeOperation returns a new LongRunningRecognizeOperation from a given name.
  // The name must be that of a previously created LongRunningRecognizeOperation, possibly from a different process.
  func (c *Client) LongRunningRecognizeOperation(name string) *LongRunningRecognizeOperation {
  	return &LongRunningRecognizeOperation{
  		lro: longrunning.InternalNewOperation(c.LROClient, &longrunningpb.Operation{Name: name}),
  	}
  }
  
  // Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
  //
  // See documentation of Poll for error-handling information.
  func (op *LongRunningRecognizeOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*speechpb.LongRunningRecognizeResponse, error) {
  	var resp speechpb.LongRunningRecognizeResponse
  	if err := op.lro.WaitWithInterval(ctx, &resp, 45000*time.Millisecond, opts...); err != nil {
  		return nil, err
  	}
  	return &resp, nil
  }
  
  // Poll fetches the latest state of the long-running operation.
  //
  // Poll also fetches the latest metadata, which can be retrieved by Metadata.
  //
  // If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
  // the operation has completed with failure, the error is returned and op.Done will return true.
  // If Poll succeeds and the operation has completed successfully,
  // op.Done will return true, and the response of the operation is returned.
  // If Poll succeeds and the operation has not completed, the returned response and error are both nil.
  func (op *LongRunningRecognizeOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*speechpb.LongRunningRecognizeResponse, error) {
  	var resp speechpb.LongRunningRecognizeResponse
  	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
  		return nil, err
  	}
  	if !op.Done() {
  		return nil, nil
  	}
  	return &resp, nil
  }
  
  // Metadata returns metadata associated with the long-running operation.
  // Metadata itself does not contact the server, but Poll does.
  // To get the latest metadata, call this method after a successful call to Poll.
  // If the metadata is not available, the returned metadata and error are both nil.
  func (op *LongRunningRecognizeOperation) Metadata() (*speechpb.LongRunningRecognizeMetadata, error) {
  	var meta speechpb.LongRunningRecognizeMetadata
  	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
  		return nil, nil
  	} else if err != nil {
  		return nil, err
  	}
  	return &meta, nil
  }
  
  // Done reports whether the long-running operation has completed.
  func (op *LongRunningRecognizeOperation) Done() bool {
  	return op.lro.Done()
  }
  
  // Name returns the name of the long-running operation.
  // The name is assigned by the server and is unique within the service from which the operation is created.
  func (op *LongRunningRecognizeOperation) Name() string {
  	return op.lro.Name()
  }
  