#' A selectizeInput customized for data frames with column labels
#'
#' @description
#' Copied and modified from the IDEAFilter package
#' Adds the option to select "none" which is handled later
#'
#' @param inputId passed to \code{\link[shiny]{selectizeInput}}
#' @param label passed to \code{\link[shiny]{selectizeInput}}
#' @param data \code{data.frame} object from which fields should be populated
#' @param selected default selection
#' @param ... passed to \code{\link[shiny]{selectizeInput}}
#' @param col_subset a \code{vector} containing the list of allowable columns to select
#' @param placeholder passed to \code{\link[shiny]{selectizeInput}} options
#' @param onInitialize passed to \code{\link[shiny]{selectizeInput}} options
#' @param none_label label for "none" item
#'
#' @return a \code{\link[shiny]{selectizeInput}} dropdown element
#'
#' @importFrom shiny selectizeInput
#' @keywords internal
#'
columnSelectInput <- function(inputId, label, data, selected = "", ...,
                              col_subset = NULL, placeholder = "", onInitialize, none_label="No variable selected") {
  datar <- if (is.reactive(data)) data else reactive(data)
  col_subsetr <- if (is.reactive(col_subset)) col_subset else reactive(col_subset)

  labels <- Map(function(col) {
    json <- sprintf(
      IDEAFilter:::strip_leading_ws('
    {
      "name": "%s",
      "label": "%s",
      "datatype": "%s"
    }'),
      col,
      attr(datar()[[col]], "label") %||% "",
      IDEAFilter:::get_dataFilter_class(datar()[[col]])
    )
  }, col = names(datar()))

  if (!"none" %in% names(datar())){
    labels <- c("none"=list(sprintf('\n    {\n      \"name\": \"none\",\n      \"label\": \"%s\",\n      \"datatype\": \"\"\n    }',none_label)),labels)
    choices <- setNames(names(labels), labels)
    choices <- choices[match(if (length(col_subsetr()) == 0 || isTRUE(col_subsetr() == "")) names(datar()) else col_subsetr(), choices)]
  } else {
    choices <- setNames(names(datar()), labels)
    choices <- choices[match(if (length(col_subsetr()) == 0 || isTRUE(col_subsetr() == "")) choices else col_subsetr(), choices)]
  }

  shiny::selectizeInput(
    inputId = inputId,
    label = label,
    choices = choices,
    selected = selected,
    ...,
    options = c(
      list(render = I("{
        // format the way that options are rendered
        option: function(item, escape) {
          item.data = JSON.parse(item.label);
          return '<div style=\"padding: 3px 12px\">' +
                   '<div><strong>' +
                      escape(item.data.name) + ' ' +
                      '<span style=\"opacity: 0.3;\"><code style=\"color: black;\"> ' +
                        item.data.datatype +
                      '</code></span>' +
                   '</strong></div>' +
                   (item.data.label != '' ? '<div style=\"line-height: 1em;\"><small>' + escape(item.data.label) + '</small></div>' : '') +
                 '</div>';
        },

        // avoid data vomit splashing on screen when an option is selected
        item: function(item, escape) {
        item.data = JSON.parse(item.label);
        return '<div>' +
                 escape(item.data.name) +
               '</div>';
        }
      }"))
    )
  )
}