"Script to generate /src/fennel-ls/docs/lua54.fnl and friends automatically"

(fn sh [...]
  "run a shell command."
  (let [command (table.concat
                  (icollect [_ arg (ipairs [...])]
                      (if
                        ;; table skips escaping
                        (= (type arg) :table)
                        (. arg 1)
                        ;; simple string skips escaping
                        (arg:find "^[a-zA-Z0-9/_-]+$")
                        arg
                        ;; full escaping
                        (.. "'"
                            (string.gsub arg "'" "\\'")
                            "'")))
                  " ")]
    (print (.. "tools/gen-docs: " command))
    (os.execute command)))

(fn mkdir-p [dirname]
  (sh "mkdir" "-p" dirname))

(fn curl-cached [url]
  (let [filename (.. "build/" (url:gsub "[/:]" "_"))
        file (io.open filename :r)]
    (if file
        file
        (do
          (sh "curl" url [">"] filename)
          (io.open filename :r)))))

(fn derive-docs-from-url [url out-filename convert]
  (let [result
        (convert
          (with-open [file (curl-cached url)]
            (file:read "*a")))]
    (with-open [file (io.open (.. "src/fennel-ls/docs/" out-filename) :w)]
      (file:write ";; auto-generated by `make docs` from fennel-ls. Contents come from " url "\n"
                  result "\n"))))

(fn main []
  (mkdir-p "build/")
  (let [{:convert lua-manual} (require :tools.gen-docs.lua-manual)
        {:convert tic-manual} (require :tools.gen-docs.tic80)]
    (derive-docs-from-url "https://www.lua.org/manual/5.1/manual.html" "lua51.fnl" lua-manual)
    (derive-docs-from-url "https://www.lua.org/manual/5.2/manual.html" "lua52.fnl" lua-manual)
    (derive-docs-from-url "https://www.lua.org/manual/5.3/manual.html" "lua53.fnl" lua-manual)
    (derive-docs-from-url "https://www.lua.org/manual/5.4/manual.html" "lua54.fnl" lua-manual)
    (derive-docs-from-url "https://tic80.com/learn"                    "tic80.fnl" tic-manual)))

(main)