#' Style a data.frame prior to converting to geojson.
#'
#' @export
#' @param input A data.frame
#' @param var A single variable to map colors, symbols, and/or sizes to.
#' @param var_col The variable to map colors to.
#' @param var_sym The variable to map symbols to.
#' @param var_size The variable to map size to.
#' @param color Valid RGB hex color
#' @param symbol An icon ID from the Maki project
#' <http://www.mapbox.com/maki/> or a single alphanumeric character
#' (a-z or 0-9).
#' @param size One of 'small', 'medium', or 'large'
style_geojson <- function(input, var = NULL, var_col = NULL, var_sym = NULL,
    var_size = NULL, color = NULL, symbol = NULL, size = NULL) {
    if (!inherits(input, "data.frame"))
        stop("Your input object needs to be a data.frame")
    if (nrow(input) == 0)
        stop("Your data.frame has no rows...")
    if (is.null(var_col) & is.null(var_sym) & is.null(var_size))
        var_col <- var_sym <- var_size <- var
    if (!is.null(color)) {
        if (length(color) == 1) {
            color_vec <- rep(color, nrow(input))
        } else {
            mapping <- data.frame(var = unique(input[[var_col]]), col2 = color)
            stuff <- input[[var_col]]
            color_vec <- with(mapping, col2[match(stuff, var)])
        }
    } else {
        color_vec <- NULL
    }
    if (!is.null(symbol)) {
        if (length(symbol) == 1) {
            symbol_vec <- rep(symbol, nrow(input))
        } else {
            mapping <- data.frame(var = unique(input[[var_sym]]), symb = symbol)
            stuff <- input[[var_sym]]
            symbol_vec <- with(mapping, symb[match(stuff, var)])
        }
    } else {
        symbol_vec <- NULL
    }
    if (!is.null(size)) {
        if (length(size) == 1) {
            size_vec <- rep(size, nrow(input))
        } else {
            mapping <- data.frame(var = unique(input[[var_size]]), sz = size)
            stuff <- input[[var_size]]
            size_vec <- with(mapping, sz[match(stuff, var)])
        }
    } else {
        size_vec <- NULL
    }
    output <- do.call(cbind, sc(list(input, `marker-color` = color_vec,
                                     `marker-symbol` = symbol_vec,
        `marker-size` = size_vec)))
    return(output)
}

# param - input The file being uploaded, path to the file on your machine.
togeojson2 <- function(x) {
  ff <- list(type = "FeatureCollection", features = Map(function(z) {
    list(
      type = "Feature",
      properties = as.list(z),
      geometry = list(
        type = "Point",
        coordinates = c(as.numeric(z$longitude), as.numeric(z$latitude))
      )
    )
  }, unname(apply(x, 1, as.list))))
  ffj <- jsonlite::toJSON(ff, auto_unbox = TRUE)
  geofile <- tempfile(fileext = ".geojson")
  geofileConn <- file(geofile)
  writeLines(ffj, geofileConn)
  return(geofile)
}