basic_functions = require("lib.basic-functions")
hash = require("lib.hash")
--aes = require("lib.aes") --aes does not yet work with require
os.loadAPI("bos/lib/aes.lua")

function create_keyfile()
  basic_functions.clear_display()
  write("Please enter shared secret for networking: ")
  local pw_hash = hash.digestStr(read("*") .. "salty salt")
  basic_functions.write_to_file("bos/files/networking-key.txt", pw_hash)
  basic_functions.clear_display()
end

local function get_keyfile()
  local pw_hash = basic_functions.read_file_oneline("bos/files/networking-key.txt")
  return pw_hash
end

local function setup()
  own_label = os.computerLabel()
  peripheral.find("modem", rednet.open)
  if not fs.exists "bos/files/networking-key.txt" then
    create_keyfile()
  end
end

--[[
String target ist label des Computers. zb "computer1", "miner1", "farmer1", etc
String message ist einfach der Text der Übertragen werden soll
]]
function send_message(to, what, payload)
  setup()
  local keyfile = get_keyfile()
  local msg_table = {}
  msg_table[0] = own_label
  msg_table[1] = to
  msg_table[2] = what
  msg_table[3] = payload

  local enc_msg = aes.encrypt(keyfile, textutils.serialize(msg_table))
  rednet.broadcast(enc_msg)
end

function send_file(to, origin_path, target_path)
  setup()
  local keyfile = get_keyfile()
  local payload_table = {}

  print("sending " .. origin_path .. " to " .. to)

  local file_content = basic_functions.read_file_all(origin_path)
  payload_table[0] = target_path
  payload_table[1] = file_content

  send_message(to, "file_transfer", payload_table)
  sleep(0.5)
end

function receive_message()
  setup()
  local keyfile = get_keyfile()
  local id, rec_msg, prot = rednet.receive()
  local pcall_success, decr_msg = pcall(aes.decrypt, keyfile, rec_msg)

  if pcall_success and decr_msg ~= nil then
    local rec_table = textutils.unserialize(decr_msg)

    local from = rec_table[0]
    local to = rec_table[1]
    local what = rec_table[2]
    local payload = rec_table[3]

    if to == own_label or to == "all" then
      if what == "file_transfer" then
        basic_functions.write_to_file(payload[0], payload[1])
        return "event: file transfer received"
      elseif what == "execute_script" then
        shell.run(payload)
        return
      elseif what == "script_command" then
        return rec_table[3]
      end

      return rec_table
    end
  else
    return "event: unencrypted message"
  end
end

return {
  send_message = send_message,
  send_file = send_file,
  receive_message = receive_message,
}