R/scihub_login.R

In pobsteta/theia2r: An R toolbox to find, download and preprocess Sentinel-2 data

#' @title Import / export SciHub username and password
#' @description Read the SciHub login information or save new username and
#'  password. Login information is stored in a file `apihub.txt` inside the
#'  directory of `s2download`. This functions allow to read or write this
#'  file, and to edit them from inside the GUI.
#'  Remember that, in case login information is not provided, default `user` 
#'  username and `user` password are used, but this can cause timeouts, since
#'  [a limit of two parallel downloads per user exists](https://scihub.copernicus.eu/twiki/do/view/SciHubWebPortal/APIHubDescription).
#' @param apihub_path Path of the file in which login information is saved.
#'  If NA (default) it is automatically read from `s2download` path.
#' @param username SciHub username.
#' @param password SciHub password.
#' @return NULL
#' @author Luigi Ranghetti, phD (2017) \email{ranghetti.l@@irea.cnr.it}
#' @note License: GPL 3.0
#' @importFrom reticulate py_to_r
#' @importFrom shiny a actionButton icon modalButton modalDialog passwordInput tagList textInput
#' @importFrom shinyFiles shinyFileSave

#' @name read_scihub_login
#' @rdname scihub_login
#' @export

read_scihub_login <- function(apihub_path = NA) {
    
    # if apihub_path is not specified, retrieve from the current s2download installation
    if (is.na(apihub_path)) {
        # import s2download
        s2download <- import_s2download(convert = FALSE)
        apihub_path <- file.path(py_to_r(s2download$inst_path), "apihub.txt")
    }
    
    # return user and password
    if (file.exists(apihub_path)) {
        readLines(apihub_path)[1] %>% strsplit(" ") %>% unlist()
    } else {
        # if apihub does not exists, return default credentials
        c("user", "user")
    }
    
}


#' @name write_scihub_login
#' @rdname scihub_login
#' @export

write_scihub_login <- function(username, password, apihub_path = NA) {
    
    # if apihub_path is not specified, retrieve from the current s2download installation
    if (is.na(apihub_path)) {
        # import s2download
        s2download <- import_s2download(convert = FALSE)
        apihub_path <- file.path(py_to_r(s2download$inst_path), "apihub.txt")
    }
    
    # write credentials
    writeLines(paste(username, password), apihub_path)
    
}

#' @name scihub_modal
#' @rdname scihub_login

# write dialog content
scihub_modal <- function(username = NA, password = NA) {
    # read scihub user/password
    if (anyNA(c(username, password))) {
        apihub <- read_scihub_login()
        username <- apihub[1]
        password <- apihub[2]
    }
    modalDialog(title = "Set SciHub username and password", size = "s", textInput("scihub_username", "Username", username), passwordInput("scihub_password", "Password", 
        password), a("Register new account", href = "https://scihub.copernicus.eu/dhus/#/self-registration", target = "_blank"), " — ", a("Forgot password?", href = "https://scihub.copernicus.eu/dhus/#/forgot-password", 
        target = "_blank"), checkboxInput("apihub_default", label = span("Store inside the package ", actionLink("help_apihub", icon("question-circle"))), value = TRUE), 
        easyClose = FALSE, footer = tagList(div(style = "display:inline-block;vertical-align:top;", conditionalPanel(condition = "output.switch_save_apihub == 'custom'", 
            shinySaveButton("apihub_path_sel", "Save as...", "Specify path for apihub text file", filetype = list(plain = "txt"), class = "scihub_savebutton"))), div(style = "display:inline-block;vertical-align:top;", 
            conditionalPanel(condition = "output.switch_save_apihub == 'default'", actionButton("save_apihub", " Save", icon = icon("save"), class = "scihub_savebutton"))), 
            div(style = "display:inline-block;vertical-align:top;", modalButton(" Cancel", icon = icon("ban")))))
}