func downloadProfiles()

in profiler/export/main.go [48:125]
60 lines of code
13 McCabe index (conditional complexity)

func downloadProfiles(ctx context.Context, w io.Writer, project, pageToken string, pageSize, maxProfiles int) error {
	client, err := cloudprofiler.NewExportClient(ctx)
	if err != nil {
		return err
	}
	defer client.Close()
	log.Printf("Attempting to fetch %v profiles with a pageSize of %v for %v\n", maxProfiles, pageSize, project)

	// Initial request for the ListProfiles API
	request := &pb.ListProfilesRequest{
		Parent:    fmt.Sprintf("projects/%s", project),
		PageSize:  int32(pageSize),
		PageToken: pageToken,
	}

	// create a folder for storing profiles & metadata
	profilesDirName := fmt.Sprintf("profiles_%v", time.Now().Unix())
	if err := os.Mkdir(profilesDirName, 0750); err != nil {
		log.Fatal(err)
	}
	// create a file for storing profile metadata
	metadata, err := os.Create(fmt.Sprintf("%s/metadata.csv", profilesDirName))
	if err != nil {
		return err
	}
	defer metadata.Close()

	writer := csv.NewWriter(metadata)
	defer writer.Flush()

	writer.Write([]string{"File", "Name", "ProfileType", "Target", "Duration", "Labels"})

	profileCount := 0
	// Keep calling ListProfiles API till all profile pages are fetched or max pages reached
	profilesIterator := client.ListProfiles(ctx, request)
	for {
		// Read individual profile - the client will automatically make API calls to fetch next pages
		profile, err := profilesIterator.Next()

		if err == iterator.Done {
			log.Println("Read all available profiles")
			break
		}
		if err != nil {
			return fmt.Errorf("error reading profile from response: %w", err)
		}
		profileCount++

		filename := fmt.Sprintf("%s/profile%06d.pb.gz", profilesDirName, profileCount)
		err = os.WriteFile(filename, profile.ProfileBytes, 0640)

		if err != nil {
			return fmt.Errorf("unable to write file %s: %w", filename, err)
		}
		fmt.Fprintf(w, "deployment target: %v\n", profile.Deployment.Labels)

		labelBytes, err := json.Marshal(profile.Labels)
		if err != nil {
			return err
		}

		err = writer.Write([]string{filename, profile.Name, profile.Deployment.Target, profile.Duration.String(), string(labelBytes)})
		if err != nil {
			return err
		}

		if maxProfiles > 0 && profileCount >= maxProfiles {
			fmt.Fprintf(w, "result: %v", ProfilesDownloadedSuccessfully)
			break
		}

		if profilesIterator.PageInfo().Remaining() == 0 {
			// This signifies that the client will make a new API call internally
			log.Printf("next page token: %v\n", profilesIterator.PageInfo().Token)
		}
	}
	return nil
}