OC-TELNET 2 : A Better Telnet Client For OpenComputers

local component = require("component")
local event = require("event")
local term = require("term")
local unicode = require("unicode")
local serialization = require("serialization")
local shell = require("shell")
local fs = require("filesystem")
local gpu = component.gpu
local keyboard = require("keyboard")

local internet = component.list("internet")()
local inet = component.proxy(internet)

if not inet then
  error("Internet Card not found. Please install an Internet Card.")
end

local IAC, DONT, DO, WONT, WILL = string.char(255), string.char(254), string.char(253), string.char(252), string.char(251)
local SB, SE = string.char(250), string.char(240)
local NOP, DM, BRK, IP, AO, AYT, EC, EL, GA = string.char(241), string.char(242), string.char(243), string.char(244), string.char(245), string.char(246), string.char(247), string.char(248), string.char(249)

local ECHO, SUPPRESS_GO_AHEAD, STATUS, TIMING_MARK = string.char(1), string.char(3), string.char(5), string.char(6)
local TERMINAL_TYPE, WINDOW_SIZE, TERMINAL_SPEED = string.char(24), string.char(31), string.char(32)
local REMOTE_FLOW_CONTROL, LINEMODE, ENVIRONMENT = string.char(33), string.char(34), string.char(36)

local config = {
  default_host = "localhost",
  default_port = 23,
  log_file = "/home/telnet.log",
  color_enabled = true
}

local function load_config()
  local config_path = "/home/telnet_config.lua"
  if fs.exists(config_path) then
    local file = io.open(config_path, "r")
    local content = file:read("*all")
    file:close()
    local loaded_config = serialization.unserialize(content)
    for k, v in pairs(loaded_config) do
      config[k] = v
    end
  end
end

local function save_config()
  local config_path = "/home/telnet_config.lua"
  local file = io.open(config_path, "w")
  file:write(serialization.serialize(config))
  file:close()
end

local function log(message)
  local file = io.open(config.log_file, "a")
  file:write(os.date("[%Y-%m-%d %H:%M:%S] ") .. message .. "\n")
  file:close()
end

local function send_command(connection, cmd, option)
  connection.write(IAC .. cmd .. option)
end

local function handle_option(connection, cmd, option)
  if cmd == DO then
    if option == TERMINAL_TYPE then
      send_command(connection, WILL, TERMINAL_TYPE)
      connection.write(IAC .. SB .. TERMINAL_TYPE .. string.char(0) .. "ANSI" .. IAC .. SE)
    elseif option == WINDOW_SIZE then
      send_command(connection, WILL, WINDOW_SIZE)
      local width, height = term.getViewport()
      connection.write(IAC .. SB .. WINDOW_SIZE .. string.char(0) .. string.char(width) .. string.char(0) .. string.char(height) .. IAC .. SE)
    else
      send_command(connection, WONT, option)
    end
  elseif cmd == WILL then
    if option == ECHO or option == SUPPRESS_GO_AHEAD then
      send_command(connection, DO, option)
    else
      send_command(connection, DONT, option)
    end
  end
end

local function handleANSI(str)
    local i = 1
    while i <= #str do
        local c = str:sub(i, i)
        if c == "\27" then
            local seq, cmd = str:match("\27%[([%d;]*)([A-Za-z])", i)
            if seq and cmd then
                local params = {}
                for param in seq:gmatch("%d+") do
                    table.insert(params, tonumber(param))
                end

                if #params == 0 then
                    params = {1}
                end

                if cmd == "H" or cmd == "f" then
                    local x, y = params[2] or 1, params[1] or 1
                    term.setCursor(x, y)
                elseif cmd == "J" then
                    if params[1] == 2 then
                        term.clear()
                    elseif params[1] == 0 then
                        term.clearLine()
                    end
                elseif cmd == "K" then
                    term.clearLine()
                elseif cmd == "A" then
                    local x, y = term.getCursor()
                    term.setCursor(x, y - (params[1] or 1))
                elseif cmd == "B" then
                    local x, y = term.getCursor()
                    term.setCursor(x, y + (params[1] or 1))
                elseif cmd == "C" then
                    local x, y = term.getCursor()
                    term.setCursor(x + (params[1] or 1), y)
                elseif cmd == "D" then
                    local x, y = term.getCursor()
                    term.setCursor(x - (params[1] or 1), y)
                elseif cmd == "m" then
                    for _, param in ipairs(params) do
                        if param == 0 then
                            gpu.setForeground(0xFFFFFF)
                            gpu.setBackground(0x000000)
                        elseif param == 1 then
                        elseif param >= 30 and param <= 37 then
                            local colors = {
                                0x000000, 0xFF0000, 0x00FF00, 0xFFFF00,
                                0x0000FF, 0xFF00FF, 0x00FFFF, 0xFFFFFF
                            }
                            gpu.setForeground(colors[param - 29])
                        elseif param >= 40 and param <= 47 then
                            local colors = {
                                0x000000, 0xFF0000, 0x00FF00, 0xFFFF00,
                                0x0000FF, 0xFF00FF, 0x00FFFF, 0xFFFFFF
                            }
                            gpu.setBackground(colors[param - 39])
                        end
                    end
                end
                i = i + #seq + 3
            else
                io.write(c)
                i = i + 1
            end
        else
            io.write(c)
            i = i + 1
        end
    end
end

local function telnet(host, port)
  local connection = inet.connect(host, port)

  if not connection then
    error("Failed to connect to " .. host .. ":" .. port)
  end

  print("Connected to " .. host .. ":" .. port)
  log("Connected to " .. host .. ":" .. port)

  local buffer = ""
  local in_iac = false
  local cmd, option

  while true do
    local data = connection.read(1024)
    if data then
      for i = 1, #data do
        local char = data:sub(i, i)
        if in_iac then
          if not cmd then
            cmd = char
          elseif not option then
            option = char
            handle_option(connection, cmd, option)
            in_iac, cmd, option = false, nil, nil
          end
        elseif char == IAC then
          in_iac = true
        else
          buffer = buffer .. char
        end
      end

      if #buffer > 0 then
        if config.color_enabled then
          handleANSI(buffer)
        else
          io.write(buffer)
        end
        log(buffer)
        buffer = ""
      end
    end

    local _, _, char, code = event.pull(0.05, "key_down")
    if char then
      local utf8char = unicode.char(char)
      connection.write(utf8char)
      if not connection.finishConnect() then
        print("\nConnection closed")
        log("Connection closed")
        break
      end
    end
  end

  connection.close()
end

local function config_menu()
  print("Configuration Menu")
  io.write("Enter default host (current: " .. config.default_host .. "): ")
  local new_host = io.read()
  if new_host ~= "" then config.default_host = new_host end

  io.write("Enter default port (current: " .. config.default_port .. "): ")
  local new_port = tonumber(io.read())
  if new_port then config.default_port = new_port end

  io.write("Enable color? (y/n, current: " .. (config.color_enabled and "yes" or "no") .. "): ")
  local color_choice = io.read():lower()
  if color_choice == "y" or color_choice == "n" then
    config.color_enabled = (color_choice == "y")
  end

  save_config()
  print("Configuration saved")
end

local function connect_to_server()
  io.write("Enter host (or press Enter for default): ")
  local host = io.read()
  host = host ~= "" and host or config.default_host

  io.write("Enter port (or press Enter for default): ")
  local port_input = io.read()
  local port = tonumber(port_input) or config.default_port

  telnet(host, port)
end

local function display_logo()
  print([[
   U  ___ u   ____        _____  U _____ u  _      _   _   U _____ u  _____
    \/"_ \/U /"___|      |_ " _| \| ___"|/ |"|    | \ |"|  \| ___"|/ |_ " _|
    | | | |\| | u  U  u    | |    |  _|" U | | u <|  \| |>  |  _|"     | |
.-,_| |_| | | |/__ /___\  /| |\   | |___  \| |/__U| |\  |u  | |___    /| |\
 \_)-\___/   \____|__"__|u |_|U   |_____|  |_____||_| \_|   |_____|  u |_|U
      \\    _// \\       _// \\_  <<   >>  //  \\ ||   \\,-.<<   >>  _// \\_
     (__)  (__)(__)     (__) (__)(__) (__)(_")("_)(_")  (_/(__) (__)(__) (__)
  ____
 |___"\
 U __) |
 \/ __/ \
 |_____|u
 <<  //
(__)(__)
]])
end

local function main_menu()
  while true do
    print("\nOC-TELNET 2 Coded by nonogamer9!")
    print("1. Connect to server")
    print("2. Configure settings")
    print("3. Exit")
    io.write("Choose an option: ")
    local choice = io.read()

    if choice == "1" then
      connect_to_server()
    elseif choice == "2" then
      config_menu()
    elseif choice == "3" then
      break
    else
      print("Invalid option. Please try again.")
    end
  end
end

display_logo()
load_config()
main_menu()