// Simple CLI helpers for Fun scripts.
//
// argv(): returns an array of the raw arguments passed to the script
//         (not including the script path). Requires the interpreter to
//         export FUN_ARGC and FUN_ARGV_i environment variables.
// parse_args(args): parses flags and positionals from argv() like:
//   -f  -> flags["f"] = 1
//   --force -> flags["force"] = 1
//   --force=42 -> flags["force"] = "42"
//   -abc -> flags["a"]=1, flags["b"]=1, flags["c"]=1

fun argv()
  n = to_number(env("FUN_ARGC"))
  a = []
  i = 0
  while (i < n)
    key = join(["FUN_ARGV_", to_string(i)], "")
    push(a, env(key))
    i = i + 1
  return a

// Returns: { "flags": map, "positionals": array }
fun parse_args(args)
  flags = {}
  pos = []
  i = 0
  n = len(args)
  while (i < n)
    s = args[i]
    if (len(s) >= 2 && substr(s, 0, 2) == "--")
      eq = find(s, "=")
      if (eq >= 0)
        key = substr(s, 2, eq - 2)           // between -- and =
        val = substr(s, eq + 1, len(s) - (eq + 1))
        flags[key] = val
      else
        key = substr(s, 2, len(s) - 2)
        flags[key] = 1
    else if (len(s) == 2 && substr(s, 0, 1) == "-")
      // short -f boolean
      key = substr(s, 1, 1)
      flags[key] = 1
    else if (len(s) > 2 && substr(s, 0, 1) == "-")
      // compact short flags like -abc -> a=1, b=1, c=1
      j = 1
      while (j < len(s))
        k = substr(s, j, 1)
        flags[k] = 1
        j = j + 1
    else
      push(pos, s)
    i = i + 1
  return { "flags": flags, "positionals": pos }