longtable scale widths

[Liripo]

kbl2 <- function(x,
                 align="c",booktabs = T,longtable=T,caption="",
                 format="latex",...){
  res <- kbl(x,align = align,booktabs = booktabs,longtable = longtable,
      caption = caption,format = format,...) %>% 
    kable_styling(font_size = 8,
                  latex_options = c("striped", "HOLD_position"))
  attr(res,"max_width") <- get_table_max_widths(x)
  res
}
#‘自定义width
str_max_length <- function(x){
  list <- str_split(x,"\n")
  purrr::map_int(list,~max(nchar(.x)))
}

get_table_max_widths <- function(x){
  max_widths <- purrr::map2_int(x,names(x),function(x,y){
    max(str_max_length(c(x,y)))
  })
  if(tibble::has_rownames(x)){
    maxwidth <- max(str_max_length(rownames(x)))
    max_widths <- c(maxwidth,max_widths)
  }
  max_widths
}

#'自动调整表格大小
#' 还有很多要完善的
scale_widths <- function(kable_input2,widths = NULL,unit="\\\\textwidth",scale=0.027) {
  table_info <- magic_mirror(kable_input2)
  align_collapse <- ifelse(table_info$booktabs | !is.null(table_info$xtable), "", "\\|")
  kable_align_old <- paste(table_info$align_vector, collapse = align_collapse)
  if(is.null(widths) & unit == "\\\\textwidth"){
    scale <- 1-(table_info$ncol-1)*scale
    widths <- attr(kable_input2,"max_width")
    widths <- widths/sum(widths)*scale
  }
  table_info$align_vector <- purrr::map2_chr(table_info$align_vector_origin,widths,function(x,width){
    extra_align <- switch(x, 
      l = "\\\\raggedright\\\\arraybackslash", 
      c = "\\\\centering\\\\arraybackslash", 
      r = "\\\\raggedleft\\\\arraybackslash")
  x <- paste0("p", "\\{", width,unit,"\\}")
  latex_array_options <- paste0("\\>\\{", extra_align, "\\}")
  x <- paste0(latex_array_options, x)
  })
  kable_align_new <- paste(table_info$align_vector, collapse = align_collapse)
  out <- sub(paste0("\\{", kable_align_old, "\\}"), paste0("\\{",kable_align_new, "\\}"), kableExtra:::solve_enc(kable_input2), perl = T)
  out <- structure(out, format = "latex", class = "knitr_kable")
  out
}

I am trying to automatically adjust the table in the longtable, I wrote the above code, but it feels terrible