parallelize render_game

[seth127]

each player/map could be done in parallel, probably pretty easily

[seth127]

Tried this tonight. Didn't quite work. It hung forever on parallel = TRUE and came back immediately on parallel = FALSE

#' Render the Rmd files for a game
#'
#' Takes an `.Rmd` template and a `.json` as input and renders
#' the markdown(s).
#' **This is basically how you "play" the game.**
#' @importFrom purrr walk
#' @importFrom furrr future_walk
#' @importFrom digest digest
#' @importFrom readr read_file
#' @export
render_game <- function(game_path, players = FALSE, html = FALSE, parallel = FALSE) {
  game_name <- basename(game_path)
  rmd_template <- file.path(game_path, paste0(game_name, ".Rmd"))
  json_input <- file.path(game_path, paste0(game_name, ".json"))
  checkmate::assert_file_exists(rmd_template)
  checkmate::assert_file_exists(json_input)

  write_lines(glue('
!{game_name}.Rmd
!{game_name}.json
*.Rmd
*.html'),
    file.path(game_path, ".gitignore")
  )

  template_string <- readr::read_lines(rmd_template)
  .md5 <- digest::digest(template_string)

  to_render <- if (isTRUE(players)) {
    .pj <- jsonlite::fromJSON(json_input, simplifyVector = FALSE)$players
    c("GLOBAL", purrr::map_chr(.pj, ~ sanitize_name(.x[["name"]])))
  } else {
    "GLOBAL"
  }
  if (isTRUE(parallel)) {
    if (requireNamespace("furrr", quietly = TRUE)) {
      future::plan(future::multisession)
      furrr::future_walk(
        to_render,
        render_func,
        furrr_options(seed = 1271984)
      )
    } else {
      walk(to_render, ~ render_func)
    }
  } else {
    # is there a better way to do this ^ ?
    walk(to_render, ~ render_func)
  }

  message("All done rendering.")
}

#' Copy game HTML files to a new dir (for publishing and hosting)
#' @export
publish_game_html <- function(game_dir, dest_dir, overwrite = FALSE) {
  html_files <- fs::dir_ls(game_dir, glob = "*.html")
  dest_dir <- file.path(dest_dir, basename(game_dir))
  if (isTRUE(overwrite) && fs::dir_exists(dest_dir)) fs::dir_delete(dest_dir)
  if (!fs::dir_exists(dest_dir)) fs::dir_create(dest_dir)

  fs::file_copy(html_files, dest_dir)
}

#' @keywords internal
render_func <- function(.x) {
  data <- list(
    PLAYER = .x,
    RMD_MD5 = .md5
  )

  player_hash <- digest::digest(paste(game_name, .x), algo = "md5")
  message(glue("{paste(game_name, .x)} -- {player_hash}"))

  # build Rmd string
  text <- template_string

  if (.x == "GLOBAL") {
    # turn on code rendering for GLOBAL only
    text <- text %>%
      str_replace(stringr::fixed("echo = FALSE"), "echo = TRUE")
  } else {
    # add in the player's moves for printing only (because real code is echo = FALSE)
    moves <- text %>%
      str_detect("^### moves") %>%
      which() %>%
      c(length(text))

    for (.i in 1:(length(moves)-1)) {
      this_move <- text[moves[.i]:moves[.i+1]] %>%
        str_subset(paste0("(kill|modify)_unit.+", .x)) %>%
        str_replace_all(" ?\\%\\>\\% ?", "") %>%
        paste(collapse = "\n")

      text[moves[.i]] <- paste0("### moves\n\n```{r, eval = FALSE, echo = TRUE}\n", this_move, "\n```\n\n")
    }
  }

  text <- whisker::whisker.render(text, data)

  write_lines(text, file.path(game_path, paste0(player_hash, ".Rmd")))

  if (isTRUE(html)) {
    rmd_file <- file.path(game_path, paste0(player_hash, ".Rmd"))
    message(glue("  Rendering html from {rmd_file}..."))
    rmarkdown::render(
      rmd_file,
      output_format = "html_document",
      output_dir = game_path,
      quiet = TRUE
    )
  }
}