#!/usr/bin/env moon

-- concatenate a collection of lua modules into one

lfs = require "lfs"
alt_getopt = require "alt_getopt"

import insert, concat from table
import dump, split from require "moonscript.util"

opts, ind = alt_getopt.get_opts arg, "l:", {
  load: "l"
}

if not arg[ind]
  print "usage: splat [-l module_names] directory [directories...]"
  os.exit!

dirs = [a for a in *arg[ind,]]

normalize = (path) ->
  path\match("(.-)/*$").."/"

scan_directory = (root, patt, collected={}) ->
  root = normalize root
  for fname in lfs.dir root
    if not fname\match "^%."
      full_path = root..fname

      if lfs.attributes(full_path, "mode") == "directory"
        scan_directory full_path, patt, collected
      else
        if full_path\match patt
          insert collected, full_path

  collected

path_to_module_name = (path) ->
  (path\match("(.-)%.lua")\gsub("/", "."))

each_line = (text) ->
  import yield from coroutine
  coroutine.wrap ->
    start = 1
    while true
      pos, after = text\find "\n", start, true
      break if not pos
      yield text\sub start, pos - 1
      start = after + 1
    yield text\sub start, #text
    nil

write_module = (name, text) ->
  print "package.preload['"..name.."'] = function()"
  for line in each_line text
    print "  "..line
  print "end"

modules = {}
for dir in *dirs
  files = scan_directory dir, "%.lua$"
  chunks = for path in *files
    module_name = path_to_module_name path
    content = io.open(path)\read"*a"
    modules[module_name] = true
    {module_name, content}

  for chunk in *chunks
    name, content = unpack chunk
    base = name\match"(.-)%.init"
    if base and not modules[base] then
      modules[base] = true
      name = base
    write_module name, content

if opts.l
  for module_name in *split opts.l, ","
    if modules[module_name]
      print ([[package.preload["%s"]()]])\format module_name