OC-IRC: An IRC Client 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 = {
  {name = "Libera.Chat", address = "irc.libera.chat", port = 6667},
  {name = "OFTC", address = "irc.oftc.net", port = 6667},
  {name = "EFnet", address = "irc.efnet.org", port = 6667},
}

local selectedServerIndex = 1
local username = "User"
local socket = nil
local currentChannel = nil
local messageBuffer = {}
local maxBufferSize = 49
local currentBufferIndex = 1
local userList = {}

local function saveServers()
  local file = io.open("/home/oc_irc_servers.txt", "w")
  if file then
    for _, server in ipairs(servers) do
      file:write(string.format("%s,%s,%d\n", server.name, server.address, server.port))
    end
    file:close()
  end
end

local function loadServers()
  local file = io.open("/home/oc_irc_servers.txt", "r")
  if file then
    servers = {}
    for line in file:lines() do
      local name, address, port = line:match("([^,]+),([^,]+),(%d+)")
      if name and address and port then
        table.insert(servers, {name = name, address = address, port = tonumber(port)})
      end
    end
    file:close()
  end
end

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

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

loadServers()
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 (%s:%d)", i, server.name, server.address, server.port))
      else
        gpu.setForeground(0x00FF00)
        gpu.set(1, i, string.format("%d. %s (%s:%d)", i, server.name, server.address, server.port))
        gpu.setForeground(0xFFFFFF)
      end
    else
      gpu.set(1, i, string.format("%d. %s (%s:%d)", i, server.name, 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, "Press A to add a custom server, R to remove a server")
  gpu.set(1, #servers + 4, "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():gsub("\n", "")
  if socket then socket.write("NICK " .. newNick .. "\r\n") end
  username = newNick
  saveUsername()
  return newNick
end

local function addCustomServer()
  term.clear()
  print("Adding a custom server:")
  term.write("Enter server name: ")
  local name = term.read():gsub("\n", "")
  term.write("Enter server address: ")
  local address = term.read():gsub("\n", "")
  term.write("Enter server port: ")
  local portInput = term.read():gsub("\n", "")
  local port = tonumber(portInput)
  if not port or port < 1 or port > 65535 then
    print("Invalid port number. Please enter a number between 1 and 65535.")
    os.sleep(2)
    return
  end

  if name and address and port then
    table.insert(servers, {name = name, address = address, port = port})
    saveServers()
    print("Custom server added successfully!")
  else
    print("Invalid input. Server not added.")
  end
  os.sleep(2)
end

local function removeServer()
  term.clear()
  print("Removing a server:")
  for i, server in ipairs(servers) do
    print(string.format("%d. %s (%s:%d)", i, server.name, server.address, server.port))
  end
  term.write("Enter the number of the server to remove: ")
  local input = term.read():gsub("\n", "")
  local index = tonumber(input)
  if index and servers[index] then
    table.remove(servers, index)
    saveServers()
    print("Server removed successfully!")
  else
    print("Invalid input. No server removed.")
  end
  os.sleep(2)
end

local function readWithTimeout(socket, timeout)
  local buffer = ""
  local endTime = computer.uptime() + timeout
  while computer.uptime() < endTime do
    local chunk = socket.read(1024)
    if chunk then
      buffer = buffer .. chunk
      if buffer:find("\n") then return buffer end
    end
    os.sleep(0.05)
  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 updateUserList(channel, users)
  if not userList[channel] then userList[channel] = {} end
  userList[channel] = {}
  for user in users:gmatch("%S+") do table.insert(userList[channel], user) end
end

local function drawModernUI()
  local width, height = gpu.getResolution()
  local userListWidth = 20
  local messageWidth = width - userListWidth - 1
  local inputHeight = 3
  local messageHeight = height - inputHeight - 1

  gpu.setBackground(0x000000)
  gpu.fill(1, 1, width, height, " ")

  gpu.setBackground(0x1E1E1E)
  gpu.fill(messageWidth + 2, 1, userListWidth, height, " ")
  gpu.setForeground(0xFFFFFF)
  gpu.set(messageWidth + 2, 1, "Users")
  if currentChannel and userList[currentChannel] then
    for i, user in ipairs(userList[currentChannel]) do
      if i <= height - 2 then
        gpu.set(messageWidth + 2, i + 1, user:sub(1, userListWidth - 1))
      else break end
    end
  end

  gpu.setBackground(0x000000)
  gpu.fill(1, 1, messageWidth, messageHeight, " ")

  gpu.setBackground(0x2D2D2D)
  gpu.fill(1, height - inputHeight + 1, width, inputHeight, " ")
  gpu.setForeground(0xFFFFFF)
  gpu.set(1, height - inputHeight + 1, "Input:")

  gpu.setBackground(0x4A4A4A)
  gpu.fill(1, messageHeight + 1, width, 1, "─")
  gpu.fill(messageWidth + 1, 1, 1, height, "│")
  gpu.set(messageWidth + 1, messageHeight + 1, "┴")

  gpu.setBackground(0x000000)
  gpu.setForeground(0xFFFFFF)
end

local function wrapText(text, width)
  local lines = {}
  local line = ""
  for word in text:gmatch("%S+") do
    if #line + #word + 1 > width then
      table.insert(lines, line)
      line = word
    else
      if #line > 0 then line = line .. " " .. word
      else line = word end
    end
  end
  if #line > 0 then table.insert(lines, line) end
  return lines
end

local function displayBuffer()
  local width, height = gpu.getResolution()
  if getGPUTier() == 3 then
    local userListWidth = 20
    local messageWidth = width - userListWidth - 1
    local inputHeight = 3
    local messageHeight = height - inputHeight - 1

    gpu.setBackground(0x000000)
    gpu.fill(1, 1, messageWidth, messageHeight, " ")

    local startIndex = math.max(1, #messageBuffer - messageHeight + 1)
    for i = 1, messageHeight do
      local message = messageBuffer[startIndex + i - 1]
      if message then
        gpu.set(1, i, message:sub(1, messageWidth))
      end
    end
  else
    term.clear()
    local startIndex = math.max(1, currentBufferIndex - maxBufferSize + 1)
    for i = startIndex, currentBufferIndex do print(messageBuffer[i] or "") end
  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 start = computer.uptime()
  socket.write("PING :ocping\r\n")
  local timeout = computer.uptime() + 5
  while computer.uptime() < timeout do
    local response = readWithTimeout(socket, 0.1)
    if response and response:find("PONG :ocping") then
      local pingTime = (computer.uptime() - start) * 1000
      addMessage(string.format("Server ping: %.2f ms", pingTime))
      return
    end
  end
  addMessage("Ping timed out.")
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 getTextInput(prompt, y)
  local width, _ = gpu.getResolution()
  local input = ""
  local cursorPos = 1

  local function redrawInput()
    gpu.fill(1, y, width, 1, " ")
    gpu.set(1, y, prompt .. input)
    gpu.set(#prompt + cursorPos, y, "_")
  end

  redrawInput()

  while true do
    local _, _, char, code = event.pull("key_down")
    if code == 28 then return input
    elseif code == 14 then
      if cursorPos > 1 then
        input = input:sub(1, cursorPos - 2) .. input:sub(cursorPos)
        cursorPos = cursorPos - 1
      end
    elseif code == 203 then cursorPos = math.max(1, cursorPos - 1)
    elseif code == 205 then cursorPos = math.min(#input + 1, cursorPos + 1)
    elseif char >= 32 and char <= 126 then
      input = input:sub(1, cursorPos - 1) .. string.char(char) .. input:sub(cursorPos)
      cursorPos = cursorPos + 1
    end
    redrawInput()
  end
end

local function handleUserInput(isCommand)
  local prefix = isCommand and "Command" or "Chat"
  local input
  if getGPUTier() == 3 then
    local width, height = gpu.getResolution()
    input = getTextInput(prefix .. "> ", height - 1)
  else
    term.write("\n" .. prefix .. "> ")
    input = term.read():gsub("\n", "")
  end

  if input then
    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()
  if getGPUTier() == 3 then drawModernUI() end
  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()

  local buffer = ""
  while true do
    local chunk = socket.read(1024)
    if chunk then
      buffer = buffer .. chunk
      local lines = {}
      buffer = buffer:gsub("(.-)\r\n", function(line)
        table.insert(lines, line)
        return ""
      end)

      for _, line in ipairs(lines) 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")
        elseif line:match("^:.+ 353 .+ = #%S+ :.*$") then
          local channel, users = line:match("^:.+ 353 .+ = (#%S+) :(.*)$")
          updateUserList(channel, users)
          if getGPUTier() == 3 then drawModernUI() end
        else
          addMessage(line)
        end
      end
      displayBuffer()
    end

    local eventName, _, char, code = event.pull(0.05)
    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 updateMaxBufferSize()
  local _, height = gpu.getResolution()
  if getGPUTier() == 3 then
    maxBufferSize = height - 4
  else
    maxBufferSize = 49
  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 OC-IRC...")
      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 char == 97 or char == 65 then
      addCustomServer()
    elseif char == 114 or char == 82 then
      removeServer()
    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
        updateMaxBufferSize()
        handleServerCommunication()
      end
    end
  end
end

main()