R/auth.R

In MarkEdmondson1234/googleCloudStorageR: Interface with Google Cloud Storage API

#' Authenticate with Google Cloud Storage API 
#'
#' @param json_file Authentication json file you have downloaded from your Google Project
#' @param token An existing authentication token you may have by other means
#' @param email The email to default authenticate through
#' 
#' @details
#'
#' The best way to authenticate is to use an environment argument pointing at your authentication file, making this function unnecessary.
#'
#' Set the file location of your download Google Project JSON file in a \code{GCS_AUTH_FILE} argument
#'
#' Then, when you load the library you should auto-authenticate
#'
#' However, you can authenticate directly using this function pointing at your JSON auth file.  You will still need the two JSON files - the client JSON and the authentication key JSON.  \link{gcs_setup} can help set-up the latter, the client JSON you will need to download from your Google Cloud Project.
#' 
#' If using JSON files from another source, ensure it has either \code{"https://www.googleapis.com/auth/devstorage.full_control" or "https://www.googleapis.com/auth/cloud-platform"} scopes. 
#'
#' @examples
#'
#' \dontrun{
#' # on first run, generate a auth key via gcs_setup()
#' 
#' # the json file for the auth key you are using
#' library(googleCloudStorageR)
#' gcs_auth("location_of_json_file.json")
#' 
#' #' # to use your own Google Cloud Project credentials
#' # go to GCP console and download client credentials JSON 
#' # ideally set this in .Renviron file, not here but just for demonstration
#' Sys.setenv("GAR_CLIENT_JSON" = "location/of/file.json")
#' library(googleCloudStorageR)
#' # should now be able to log in via your own GCP project
#' gcs_auth()
#' 
#' # reauthentication
#' # Once you have authenticated, set email to skip the interactive message
#' gcs_auth(email = "my@email.com")
#' 
#' # or leave unset to bring up menu on which email to auth with
#' gcs_auth()
#' # The googleCLoudStorageR package is requesting access to your Google account. 
#' # Select a pre-authorised account or enter '0' to obtain a new token.
#' # Press Esc/Ctrl + C to abort.
#' #1: my@email.com
#' #2: work@mybusiness.com

#' # you can set authentication for many emails, then switch between them e.g.
#' gcs_auth(email = "my@email.com")
#' gcs_list_buckets("my-project") # lists what buckets you have access to
#' gcs_auth(email = "work@mybusiness.com") 
#' gcs_list_buckets("my-project") # lists second set of buckets
#' 
#' }
#' @importFrom googleAuthR gar_auth_service gar_auth
#' @export
gcs_auth <- function(json_file = NULL,
                     token = NULL, 
                     email = NULL){

  set_scopes()

  if(is.null(json_file)){
    gar_auth(token = token,
             email = email,
             package = "googleCloudStorageR")    
  } else {
    gar_auth_service(json_file = json_file)
  }
}

set_scopes <- function(){
  required_scopes <- c("https://www.googleapis.com/auth/devstorage.full_control",
                       "https://www.googleapis.com/auth/devstorage.read_write",
                       "https://www.googleapis.com/auth/cloud-platform")
  
  op <- getOption("googleAuthR.scopes.selected")
  if(is.null(op)){
    options(googleAuthR.scopes.selected = "https://www.googleapis.com/auth/devstorage.full_control")
  } else if(!any(op %in% required_scopes)){
    myMessage("Adding https://www.googleapis.com/auth/devstorage.full_control to scopes", level = 3)
    options(googleAuthR.scopes.selected = c(op, "https://www.googleapis.com/auth/devstorage.full_control"))
  }
}