#' File Upload Control
#'
#' Creates more accessible shiny file upload input.
#'
#' @inheritParams shiny::fileInput
#'
#' @seealso [shiny::fileInput()]
#'
#' @export
a11yFileInput <- function(
  inputId, label, multiple = FALSE, accept = NULL, width = NULL,
  buttonLabel = "Browse...", placeholder = "No file selected",
  capture = NULL
) {
  restoredValue <- shiny::restoreInput(id = inputId, default = NULL)
  if (!is.null(restoredValue) && !is.data.frame(restoredValue)) {
    warning("Restored value for ", inputId, " has incorrect format.")
    restoredValue <- NULL
  }
  if (!is.null(restoredValue)) {
    restoredValue <- jsonlite::toJSON(restoredValue, strict_atomic = FALSE)
  }

  inputTag <- htmltools::tags$input(
    id = inputId,
    class = "shiny-input-file",
    name = inputId,
    type = "file",
    style = "position: absolute !important; top: -99999px !important; \
      left: -99999px !important;",
    `data-restore` = restoredValue
  )
  if (multiple) {
    inputTag$attribs$multiple <- "multiple"
  }
  if (length(accept) > 0) {
    inputTag$attribs$accept <- paste(accept, collapse = ",")
  }
  if (!is.null(capture)) {
    inputTag$attribs$capture <- capture
  }
  htmltools::tags$div(
    class = "form-group shiny-input-container",
    style = htmltools::css(width = htmltools::validateCssUnit(width)),
    htmltools::tags$label(
      label,
      class = "control-label",
      class = if (is.null(label)) "shiny-label-null",
      id = paste0(inputId, "-label"),
      `for` = inputId
    ),
    htmltools::tags$div(
      class = "input-group",
      htmltools::tags$div(
        class = "input-group-btn input-group-prepend",
        htmltools::tags$span(
          class = "btn btn-default btn-file", buttonLabel
        ),
        inputTag
      ),
      htmltools::tags$input(
        type = "text",
        class = "form-control",
        placeholder = placeholder,
        readonly = "readonly",
        `aria-label` = "Uploaded file name"
      )
    ),
    htmltools::tags$div(
      id = paste(inputId, "_progress", sep = ""),
      class = "progress active shiny-file-input-progress",
      htmltools::tags$div(class = "progress-bar")
    )
  )
}