local component = require("component")
local computer = require("computer")
local event = require("event")
local fs = require("filesystem")
local ser = require("serialization")
local term = require("term")

local modem = component.modem

local bPort = 20

-- INIT FUNCTION --
function init()
  if not fs.exists("/home/.eConfig.cfg") then
    local file = io.open(".eConfig.cfg", "w")
    file:write("{}")
    file:close()
  end
end

-- READ FUNCTION --
function read()
  local file = io.open(".eConfig.cfg", "r")
  local stream = file:read()
  file:close()
  return ser.unserialize(stream)
end

-- WHO FUNCTION --
function who()
  modem.open(bPort)
  modem.broadcast(bPort, "WHO")
  local doSearch = true
  local routerList = {}
  while doSearch do
    _, _, addr, _, _, flag, alias = event.pull(1, "modem_message")
    if flag == nil then
      doSearch = false
      modem.close(bPort)
      return routerList
    elseif flag == "WHO" then
      routerList[alias] = addr
    end
  end
  modem.close(bPort)
  return routerList
end

-- WRITE FUNCTION --
function write(data)
  local stream = ser.serialize(data)
  local file = io.open(".eConfig.cfg", "w")
  file:write(stream)
  file:close()
end

-- HOSTNAME FUNCTION --
function hostname()
  term.clear()
  print("New hostname:")
  term.write("> ")
  data["hostname"] = io.read()
  write(data)
end

-- ADD RELAY FUNCTION --
function addRelay()
  term.clear()
  print("Searching...")
  local routerList = who()

  if not data["relays"] then
    data["relays"] = {}
    write(data)
  end

  while true do
    term.clear()
    print("Select a relay to add:\n")
    for k, v in pairs(routerList) do
      if not data["relays"][k] then
        print(k, v)
      end
    end
    print("QUIT", "To the main menu")
    term.write("\n> ")
    gatewayAlias = io.read()
    if gatewayAlias == "QUIT" then
      break
    elseif routerList[gatewayAlias] then
      data["relays"][gatewayAlias] = routerList[gatewayAlias]
      write(data)
    else
      print("Wrong selection.")
      os.sleep(0.5)
    end
  end
end

-- REMOVE RELAY FUNCTION --
function removeRelay()
  while true do
    term.clear()
    print("Select a relay to remove:\n")
    if data["relays"] then
      for k, v in pairs(data["relays"]) do
        print(k, v)
      end
    end
    print("QUIT", "To the main menu")
    term.write("\n> ")
    gatewayAlias = io.read()
    if gatewayAlias == "QUIT" then
      break
    elseif data["relays"][gatewayAlias] then
      data["relays"][gatewayAlias] = nil
      write(data)
    else
      print("Wrong selection.")
      os.sleep(0.5)
    end
  end
end

init()
data = read()

while true do
  term.clear()
  if data["hostname"] then
    print("HOSTNAME: "..data["hostname"])
  else
    print("HOSTNAME: <Not defined>")
  end
  if data["relays"] then
    for k, v in pairs(data["relays"]) do
      print("RELAY: "..k, v)
    end
  else
    print("RELAY: <Not defined>")
  end
  print()
  print([[
1. Change hostname
2. Add relay
3. Remove relay
4. Quit
]])
  term.write("> ")
  choice = io.read()

  if choice == "1" then
    hostname()
  elseif choice == "2" then
    addRelay()
  elseif choice == "3" then
    removeRelay()
  elseif choice == "4" then
    break
  end
end