R/wcGetZip.R

In jmlondon/wcUtils: Utilities to Access the Wildlife Computers Data Portal API

#' Retrieve a single zip file from Wildlife Computers Data Portal
#' 
#' \code{wcGetZip} will return a path to a downloaded zip file
#' 
#' The Wildlife Computers Data Portal will return deployment data in the form of a zipped file with 
#' various comma-separated files and other accessory files. 
#' 
#' @param wc.key public access key (default retrieves from option value set in .Renviron)
#' @param wc.secret secret access key (default retrieves from option value set in .Renviron)
#' @param keyfile path to a json formatted keyfile with WCACCESSKEY and wcSecretKey

#' @return a path to the zip file
#' 
#' @export
wcGetZip <- function(id,wc.key = Sys.getenv("WCACCESSKEY"),
                     wc.secret = Sys.getenv("WCACCESSKEY"),
                     keyfile=NULL) {
  download_params <- paste("action=download_deployment&id=",id,sep = "")
  if (!is.null(keyfile)) {
    keys <- jsonlite::fromJSON(keyfile)
    wc.key <- keys$WCACCESSKEY
    wc.secret <- keys$wcSecretKey
  }
  
  if (is.null(wc.key) | is.null(wc.secret)) {
    stop("Wildlife Computers keys not found. Either use .Renviron (see help) or a keyfile.json")
  }
  
  x.hash <- digest::hmac(wc.secret,download_params,algo = "sha256")
  
  zip_file <- fs::path(tempdir(),id,ext = "zip")
  r <- httr::POST("http://my.wildlifecomputers.com/services/",
                  body = download_params,
                  httr::add_headers("X-Access" = wc.key,"X-Hash" = x.hash),
                  httr::write_disk(zip_file, overwrite = TRUE))
  unzip.fail <- tryCatch(
    unzip(zip_file, exdir=tempdir()),
    warning = function(cnd) {
      message(paste("error unzipping: ", zip_file))
      return(cnd)
    })
  while(inherits(unzip.fail, "simpleWarning")){
     message(paste("error unzipping: ",id))
     message("will try to download again")
     unlink(zip_file)
     r <- httr::POST("http://my.wildlifecomputers.com/services/",
                     body = download_params,
                     httr::add_headers("X-Access" = wc.key,"X-Hash" = x.hash),
                     httr::write_disk(zip_file, overwrite = TRUE))
     unzip.fail <- tryCatch(
       unzip(zip_file, exdir=tempdir()),
       warning = function(cnd) {
         message(paste("error unzipping: ", zip_file))
       })
  }
  return(zip_file)
}