library(tidyverse)

extract_files <- function(repo, ext) {
  repo_name <- as.character(repo$name)
  path <- glue::glue("CRAN/{repo_name}.zip")

  files <- try(zip::zip_list(path), silent = TRUE)
  if (inherits(files, "try-error")) return(files)

  files$package <- repo_name
  files$content <- NA_character_

  files <- files[tolower(fs::path_ext(files$filename)) == ext,]
  files <- files[files$uncompressed_size > 0, ]

  if (nrow(files) == 0) return(files)

  temp <- tempfile()
  on.exit(unlink(temp), add = TRUE)

  zip::unzip(path, files = files$filename, exdir = temp)

  content <- map_chr(
    files$filename,
    \(fname) read_file(fs::path(temp, fname))
  )

  files$content <- content
  files
}

# this contains the packages that we include in the dataset as they
# have permissive licenses.
packages <- arrow::read_parquet("packages.parquet")
opt_out <- readr::read_lines("optout.txt")

repos <- jsonlite::read_json("repos.json") %>%
  discard(\(repo) as.character(repo$name) %in% opt_out)

library(future)
plan(multisession, workers = 8)

make_data <- function(repos, ext) {
  files <- furrr::future_map(
    repos,
    \(repo) extract_files(repo, ext),
    .progress = TRUE
  )
  files <- files |>
    purrr::discard(\(x) inherits(x, "try-error")) |>
    dplyr::bind_rows()

  files <- files %>%
    select(package, path = filename, content, size = uncompressed_size) %>%
    left_join(packages %>% select(package, license = license_gh), by = "package")

  arrow::write_dataset(
    files,
    path = fs::path("data", ext),
    format = "parquet",
    basename_template = "data-{i}.parquet"
  )
}

# R Files
make_data(repos, "r")
make_data(repos, "rmd")
make_data(repos, "rd")