R/import_theia_download.R

In pobsteta/shiny-cnes: Package to download space image from CNES server (theia, peps...)

#' @title Import theia_download python module
#' @description [theia_download](https://github.com/pobsteta/theia_download) is
#'  a collection of python scripts used to download
#'  and correct Sentinel-2 images, and it is required by this package.
#'  This internal function check if their dependences (python, wget and aria2)
#'  are installed, and imports the module.
#' @param with_aria2 (optional) Logical: if TRUE (default), the presence of
#'  aria2 is checked; if FALSE, only Wget and python are checked.
#' @param ... Optional parameters of \code{\link[reticulate]{import}}
#' @return `theia_download` python module
#'
#' @author Pascal Obstetar (20178 \email{pascal.obstetar@@gmail.com}
#' @note License: GPL 3.0
#' @importFrom reticulate import_from_path import_builtins py_to_r use_python
import_theia_download <- function(with_aria2 = TRUE, ...) {

  # define the required binary dependencies
  mandeps <- c("python", "wget")
  optdeps <- if (with_aria2 == TRUE) {
    c("aria2c")
  } else {
    character()
  }
  dependencies <- c(mandeps, optdeps)

  # define theia_download path
  theia_download_path <- system.file("theia_download", package = "shinycnes")

  # check that git, python2 and wget are installed
  binpaths <- load_binpaths(dependencies)

  missing_dep <- dependencies[binpaths[dependencies] == ""]
  if (length(missing_dep) > 0) {
    if (Sys.info()["sysname"] != "Windows") {
      # On Linux, send an error / a warning if something is missing
      print_message(type = if (length(mandeps[binpaths[mandeps] == ""]) > 0) {
        "error"
      } else {
        "warning"
      }, "Some dependencies (", paste(missing_dep, collapse = ", "), ") were not found in your system; ", "please install them or update your system PATH. ")
    } else {
      # On Windows, download and install (them) or inform how to install them) Download wget and aria2
      suppressMessages(install_wget())
      if (with_aria2 == TRUE) {
        suppressMessages(install_aria2())
      }
      # If other ones are missing:
      if (length(missing_dep[!missing_dep %in% c("wget", "aria2c")]) > 0) {
        print_message(
          type = if (length(mandeps[binpaths[mandeps] == ""]) > 0) {
            "error"
          } else {
            "warning"
          }, "Some dependencies (", paste(missing_dep, collapse = ", "), ") were not found in your system; ", "please install them or update your system PATH.",
          if ("python" %in% missing_dep) {
            paste0("\nTo install python, we suggest to use the OSGeo4W installer ", "(http://download.osgeo.org/osgeo4w/osgeo4w-setup-x86", if (Sys.info()["machine"] ==
              "x86-64") {
              "_64"
            }, ".exe), ", "to choose the \"Advanced install\" and to check ", "the package \"gdal-python\".")
          }
        )
      }
    }
  } # TODO pip2 not working to install gitPython

  # checks the python version and import modules
  py <- init_python()
  # load theia_download
  theia_download <- tryCatch(reticulate::import_from_path("theia_download", theia_download_path, ...), error = print)
  # if (is(theia_download, "error")) {
  #      theia_download <- reticulate::import_from_path("theia_download", paste0(normalize_path(theia_download_path), "/"), ...)
  # }
  theia_download$inst_path <- theia_download_path
  return(theia_download)
}