OC-DALNET: DALNET For OpenComputers

local component = require("component")
local term = require("term")
local event = require("event")
local keyboard = require("keyboard")
local gpu = component.gpu
local internet = component.internet
local filesystem = require("filesystem")
local computer = require("computer")

local function getGPUTier()
  local w, h = gpu.maxResolution()
  if w == 50 and h == 16 then
    return 1
  elseif w == 80 and h == 25 then
    return 2
  else
    return 3
  end
end

local isColorSupported = false
if gpu and gpu.maxDepth then
    isColorSupported = gpu.maxDepth() > 1
end

local servers = {
  {address = "atw.hu.eu.dal.net", port = 6667},
  {address = "bifrost.ca.us.dal.net", port = 6667},
  {address = "bitcoin.uk.eu.dal.net", port = 6667},
  {address = "choopa.nj.us.dal.net", port = 6667},
  {address = "halcyon.il.us.dal.net", port = 6667},
  {address = "istana.il.us.dal.net", port = 6667},
  {address = "lair.nl.eu.dal.net", port = 6667},
  {address = "lion.tx.us.dal.net", port = 6667},
  {address = "punch.wa.us.dal.net", port = 6667},
  {address = "sakura.jp.as.dal.net", port = 6667},
  {address = "serenity.fl.us.dal.net", port = 6667},
  {address = "nonstop.ix.me.dal.net", port = 6667},
}

local selectedServerIndex = 1
local username = "User"
local socket = nil
local currentChannel = nil

local messageBuffer = {}
local maxBufferSize = 49
local currentBufferIndex = 1

local function saveUsername()
  local file = io.open("/home/dalnet_username.txt", "w")
  if file then
    file:write(username)
    file:close()
  end
end

local function loadUsername()
  local file = io.open("/home/dalnet_username.txt", "r")
  if file then
    username = file:read("*all")
    file:close()
  end
end

loadUsername()

local function drawLogo()
  if getGPUTier() == 1 then
    return
  end

  local logo = {
    " ________  ________          ________  ________  ___       ________   _______  _________   ",
    "|\\   __  \\|\\   ____\\        |\\   ___ \\|\\   __  \\|\\  \\     |\\   ___  \\|\\  ___ \\|\\___   ___\\ ",
    "\\ \\  \\|\\  \\ \\  \\___|        \\ \\  \\_|\\ \\ \\  \\|\\  \\ \\  \\    \\ \\  \\\\ \\  \\ \\   __/\\|___ \\  \\_| ",
    " \\ \\  \\\\\\  \\ \\  \\            \\ \\  \\ \\\\ \\ \\   __  \\ \\  \\    \\ \\  \\\\ \\  \\ \\  \\_|/__  \\ \\  \\  ",
    "  \\ \\  \\\\\\  \\ \\  \\____        \\ \\  \\_\\\\ \\ \\  \\ \\  \\ \\  \\____\\ \\  \\\\ \\  \\ \\  \\_|\\ \\  \\ \\  \\ ",
    "   \\ \\_______\\ \\_______\\       \\ \\_______\\ \\__\\ \\__\\ \\_______\\ \\__\\\\ \\__\\ \\_______\\  \\ \\__\\",
    "    \\|_______|\\|_______|        \\|_______|\\|__|\\|__|\\|_______|\\|__| \\|__|\\|_______|   \\|__|"
  }

  local width, height = gpu.getResolution()
  local startY = height - #logo - 1

  for i, line in ipairs(logo) do
    gpu.set(1, startY + i, line)
  end
end

local function drawServerList()
  local oldForeground = gpu.getForeground()
  local oldBackground = gpu.getBackground()

  gpu.setBackground(0x000000)
  term.clear()

  for i, server in ipairs(servers) do
    if i == selectedServerIndex then
      if getGPUTier() == 1 then
        gpu.set(1, i, "-> " .. string.format("%d. %s:%d", i, server.address, server.port))
      else
        gpu.setForeground(0x00FF00)
        gpu.set(1, i, string.format("%d. %s:%d", i, server.address, server.port))
        gpu.setForeground(0xFFFFFF)
      end
    else
      gpu.set(1, i, string.format("%d. %s:%d", i, server.address, server.port))
    end
  end

  gpu.setForeground(0xFFFFFF)
  gpu.set(1, #servers + 2, "Press N to change username. Current username: " .. username)
  gpu.set(1, #servers + 3, "Use arrow keys to navigate, Enter to connect, X to exit")

  drawLogo()

  gpu.setForeground(oldForeground)
  gpu.setBackground(oldBackground)
end

local function changeNickname()
  term.write("\nEnter new nickname: ")
  local newNick = term.read()
  newNick = newNick:gsub("\n", "")
  if socket then
    socket.write("NICK " .. newNick .. "\r\n")
  end
  username = newNick
  saveUsername()
  return newNick
end

local function readWithTimeout(socket, timeout)
  local start = computer.uptime()
  local buffer = ""
  while computer.uptime() - start < timeout do
    local chunk = socket.read(1024)
    if chunk then
      buffer = buffer .. chunk
      if buffer:find("\n") then
        return buffer
      end
    end
    os.sleep(0.1)
  end
  return buffer ~= "" and buffer or nil
end

local function addMessage(message)
  table.insert(messageBuffer, message)
  if #messageBuffer > maxBufferSize then
    table.remove(messageBuffer, 1)
  end
  currentBufferIndex = #messageBuffer
end

local function displayBuffer()
  term.clear()
  local startIndex = math.max(1, currentBufferIndex - maxBufferSize + 1)
  for i = startIndex, currentBufferIndex do
    print(messageBuffer[i] or "")
  end
end

local function connectToServer(server)
  term.clear()
  addMessage("Connecting to " .. server.address .. " as " .. username)
  displayBuffer()

  socket = internet.connect(server.address, server.port)
  if not socket then
    addMessage("Failed to connect to " .. server.address)
    displayBuffer()
    return nil
  end

  local timeout = 10
  local start = computer.uptime()
  while not socket.finishConnect() do
    if computer.uptime() - start > timeout then
      addMessage("Connection timed out")
      displayBuffer()
      return nil
    end
    os.sleep(0.1)
  end

  socket.write("NICK " .. username .. "\r\n")
  socket.write("USER " .. username .. " 0 * :" .. username .. "\r\n")

  local connected = false
  local timeout = 30
  local start = computer.uptime()

  while computer.uptime() - start < timeout do
    local response = readWithTimeout(socket, 1)
    if response then
      for line in response:gmatch("[^\r\n]+") do
        addMessage(line)
        if line:find("433") then
          addMessage("Nickname is already in use. Please choose a different nickname.")
          displayBuffer()
          username = changeNickname()
          socket.write("NICK " .. username .. "\r\n")
        elseif line:find("001") then
          addMessage("Successfully connected to " .. server.address .. " as " .. username)
          connected = true
          break
        end
      end
      displayBuffer()
    end
    if connected then break end
  end

  if not connected then
    addMessage("Connection timed out or failed")
    displayBuffer()
    socket.close()
    return nil
  end

  return socket
end

local function disconnectFromServer()
  if socket then
    socket.write("QUIT :Disconnecting\r\n")
    socket.close()
    socket = nil
    currentChannel = nil
    addMessage("Disconnected from server.")
    displayBuffer()
    return true
  end
  return false
end

local function exitChannel()
  if currentChannel then
    socket.write("PART " .. currentChannel .. " :Leaving\r\n")
    addMessage("Left channel: " .. currentChannel)
    currentChannel = nil
    displayBuffer()
    return true
  end
  return false
end

local function ping()
  if not socket then
    addMessage("Not connected to a server.")
    return
  end

  local serverStart = computer.uptime()
  socket.write("PING :serverping\r\n")

  local serverPingReceived = false
  local timeout = computer.uptime() + 5

  while computer.uptime() < timeout do
    local response = readWithTimeout(socket, 0.1)
    if response then
      for line in response:gmatch("[^\r\n]+") do
        if line:find("PONG :serverping") then
          local serverEnd = computer.uptime()
          local serverPing = (serverEnd - serverStart) * 1000
          addMessage(string.format("Server ping: %.2f ms", serverPing))
          serverPingReceived = true
          break
        end
      end
    end
    if serverPingReceived then break end
  end

  if not serverPingReceived then
    addMessage("Server ping timed out.")
  end

  if currentChannel then
    local channelStart = computer.uptime()
    socket.write("PRIVMSG " .. currentChannel .. " :\001PING " .. channelStart .. "\001\r\n")

    local channelPingReceived = false
    timeout = computer.uptime() + 5

    while computer.uptime() < timeout do
      local response = readWithTimeout(socket, 0.1)
      if response then
        for line in response:gmatch("[^\r\n]+") do
          if line:find("NOTICE .* :\001PING (.+)\001") then
            local channelEnd = computer.uptime()
            local pingTime = line:match("NOTICE .* :\001PING (.+)\001")
            local channelPing = (channelEnd - tonumber(pingTime)) * 1000
            addMessage(string.format("Channel ping: %.2f ms", channelPing))
            channelPingReceived = true
            break
          end
        end
      end
      if channelPingReceived then break end
    end

    if not channelPingReceived then
      addMessage("Channel ping timed out.")
    end
  else
    addMessage("Not connected to a channel.")
  end

  displayBuffer()
end

local function showHelp()
  addMessage("Available commands:")
  addMessage(":helpoc - Show this help message")
  addMessage("connect #channel - Join a channel")
  addMessage("exit - Leave the current channel")
  addMessage("disconnect - Disconnect from the server")
  addMessage("ping - Ping the server and current channel")
  displayBuffer()
end

local function handleUserInput(isCommand)
  local prefix = isCommand and "Command" or "Chat"
  term.write("\n" .. prefix .. "> ")
  local input = term.read()
  if input then
    input = input:gsub("\n", "")
    if isCommand then
      if input:match("^connect #") then
        currentChannel = input:match("^connect (.+)$")
        socket.write("JOIN " .. currentChannel .. "\r\n")
      elseif input == "disconnect" then
        return disconnectFromServer()
      elseif input == "exit" then
        return exitChannel()
      elseif input == ":helpoc" then
        showHelp()
      elseif input == "ping" then
        ping()
      else
        socket.write(input .. "\r\n")
      end
    else
      if currentChannel then
        socket.write("PRIVMSG " .. currentChannel .. " :" .. input .. "\r\n")
        addMessage("<" .. username .. "> " .. input)
      else
        addMessage("Not connected to a channel. Use 'connect #channel' to join one.")
      end
    end
    displayBuffer()
  end
  return false
end

local function handleServerCommunication()
  addMessage("Connected to server. Press Ctrl for chat, Alt for commands.")
  addMessage("Use 'connect #channel' to join a channel, 'exit' to leave a channel, and 'disconnect' to disconnect from the server.")
  addMessage("Use 'ping' to ping the server and current channel.")
  addMessage("Use Up/Down arrows or PageUp/PageDown to scroll through messages.")
  displayBuffer()

  while true do
    local data = readWithTimeout(socket, 0.1)
    if data then
      for line in data:gmatch("[^\r\n]+") do
        if line:find("PING") then
          local pingId = line:match("PING :(.+)")
          socket.write("PONG :" .. pingId .. "\r\n")
        elseif line:match("PRIVMSG .* :\001PING ") then
          local user = line:match("^:([^!]+)")
          local pingTime = line:match("PRIVMSG .* :\001PING (.+)\001")
          socket.write("NOTICE " .. user .. " :\001PING " .. pingTime .. "\001\r\n")
        else
          addMessage(line)
        end
      end
      displayBuffer()
    end

    local eventName, _, char, code = event.pull(0.1)
    if eventName == "key_down" then
      if code == 29 then
        if handleUserInput(false) then return end
      elseif code == 56 then
        if handleUserInput(true) then return end
      elseif code == 200 then
        currentBufferIndex = math.max(1, currentBufferIndex - 1)
        displayBuffer()
      elseif code == 208 then
        currentBufferIndex = math.min(#messageBuffer, currentBufferIndex + 1)
        displayBuffer()
      elseif code == 201 then
        currentBufferIndex = math.max(1, currentBufferIndex - maxBufferSize)
        displayBuffer()
      elseif code == 209 then
        currentBufferIndex = math.min(#messageBuffer, currentBufferIndex + maxBufferSize)
        displayBuffer()
      end
    end
  end
end

local function main()
  while true do
    drawServerList()
    local eventName, _, char, code = event.pull("key_down")

    if char == 120 or char == 88 then
      print("Exiting program...")
      os.exit()
    elseif code == 200 then
      selectedServerIndex = math.max(1, selectedServerIndex - 1)
    elseif code == 208 then
      selectedServerIndex = math.min(#servers, selectedServerIndex + 1)
    elseif code == 203 then
      selectedServerIndex = math.max(1, selectedServerIndex - 1)
    elseif code == 205 then
      selectedServerIndex = math.min(#servers, selectedServerIndex + 1)
    elseif char == 110 or char == 78 then
      username = changeNickname()
    elseif code == 28 then
      term.clear()
      socket = connectToServer(servers[selectedServerIndex])
      if not socket then
        addMessage("Connection failed. Press any key to return to server list.")
        displayBuffer()
        event.pull("key_down")
      else
        if isColorSupported then
          gpu.setResolution(gpu.maxResolution())
          gpu.setBackground(0x000000)
          gpu.setForeground(0xFFFFFF)
        end
        handleServerCommunication()
      end
    end
  end
end

main()