osem_remote_error = function (response) {
  suppressWarnings({
    hasCode = !is.null(response$code)
  })

  if (hasCode) stop(response$message)
  invisible(response)
}

parse_dateparams = function (from, to) {
  from = utc_date(from)
  to = utc_date(to)
  if (from - to > 0)
    stop('"from" must be earlier than "to"')

  c(date_as_isostring(from), date_as_isostring(to))
}

# NOTE: cannot handle mixed vectors of POSIXlt and POSIXct
utc_date = function (date) {
  time = as.POSIXct(date)
  attr(time, 'tzone') = 'UTC'
  time
}

# NOTE: cannot handle mixed vectors of POSIXlt and POSIXct
date_as_isostring = function (date) format(date, format = '%FT%TZ')

osem_as_sf = function (x, ...) {
  sf::st_as_sf(x, ..., coords = c('lon', 'lat'), crs = 4326)
}