# shitty vfs implementation
# proc and /bin arent on disk, theyre completely virtual

const TASK_STATES = { "free", "ready", "dead", "blocked" }

global vfs_owns = fn(path) -> bool do
  if (path == "/proc" or path:starts_with?("/proc/"))
    return :true
  return :false
end

global parse_pid = fn(text) -> num do
  if (text:len() == 0)
    return -1

  let number = 0
  for index in 0..text:len() do
    const code = text[index]:ascii()
    if (code < 48 or code > 57)
      return -1
    number = number * 10 + (code - 48)
  end

  return number
end

global vfs_ls = fn(path) do
  if path == "/proc" do
    puts("  uptime\n  meminfo\n")

    for pid in 0..task_max() do
      if (task_state(pid) != 0)
        puts("  #{pid}\n")
    end
  end else do
    puts("ls: #{path}: no such directory\n")
  end
end

global vfs_cat = fn(path) do
  if path == "/proc/uptime" do
    puts("#{math.floor(uptime() / 100)}s\n")
    return :nil
  end

  if path == "/proc/meminfo" do
    puts("#{(mem_free() shr 20)} MiB free / #{(mem_total() shr 20)} MiB total\n")
    return :nil
  end

  if path:starts_with?("/proc/") do
    const pid = parse_pid(path[6..])
    if pid >= 0 and pid < task_max() and task_state(pid) != 0 do
      puts("pid #{pid}: #{TASK_STATES[task_state(pid)]}\n")
      return :nil
    end
    puts("cat: #{path}: no such file\n")
    return :nil
  end

  puts("cat: #{path}: no such file\n")
end