R/utils.R

In r5r: Rapid Realistic Routing with 'R5'

#' Get most recent JAR file url from metadata
#'
#' Returns the most recent JAR file url from metadata, depending on the version.
#'
#' @param version A string, the version of R5's to get the filename of.
#'
#' @return The a url a string.
#'
#' @family support functions
#'
#' @keywords internal
fileurl_from_metadata <- function(version) {

  checkmate::assert_string(version)

  metadata <- system.file("extdata/metadata_r5r.csv", package = "r5r")
  metadata <- data.table::fread(metadata)

  # check for invalid 'version' input

  if (!(version %in% metadata$version)) {
    stop(
      "Error: Invalid value to argument 'version'. ",
      "Please use one of the following: ",
      paste(unique(metadata$version), collapse = "; ")
    )
  }

  # check which jar file to download based on the 'version' parameter

  env <- environment()
  metadata <- metadata[version == get("version", envir = env)]
  metadata <- metadata[release_date == max(release_date)]
  url <- metadata$download_path
  return(url)

}


#' Check internet connection with Ipea server
#'
#' @description
#' Checks if there is internet connection to Ipea server to download r5r data.
#'
#' @param file_url A string with the file_url address of an geobr dataset
#'
#' @return Logical. `TRUE` if url is working, `FALSE` if not.
#' @family support functions
#'
#' @keywords internal
check_connection <- function(file_url = 'https://www.ipea.gov.br/geobr/metadata/metadata_gpkg.csv'){

  # file_url <- 'http://google.com/'               # ok
  # file_url <- 'http://www.google.com:81/'   # timeout
  # file_url <- 'http://httpbin.org/status/300' # error

  # check if user has internet connection
  if (!curl::has_internet()) { message("\nNo internet connection.")
    return(FALSE)
  }

  # message
  msg <- "Problem connecting to data server. Please try it again in a few minutes."

  # test server connection
  x <- try(silent = TRUE,
           httr::GET(file_url, # timeout(5),
                     config = httr::config(ssl_verifypeer = FALSE)))
  # link offline
  if (class(x)[1]=="try-error") {
    message( msg )
    return(FALSE)
  }

  # link working fine
  else if ( identical(httr::status_code(x), 200L)) {
    return(TRUE)
  }

  # link not working or timeout
  else if (! identical(httr::status_code(x), 200L)) {
    message(msg )
    return(FALSE)

  } else if (httr::http_error(x) == TRUE) {
    message(msg)
    return(FALSE)
  }

}